giovedì 30 gennaio 2020

Il Merkava (in ebraico מרכבה, "carro") ed il sistema Trophy (מעיל רוח, "Windbreaker")


Il Merkava (in ebraico מרכבה, "carro") è un carro armato progettato e prodotto in Israele in dotazione al corpo corazzato israeliano.
Il nome di questo veicolo scelto per l'evocativo riferimento biblico relativo al Carro di fuoco descritto nella visione biblica avuta dal profeta Ezechiele e fa allo stesso tempo anche un riferimento al fatto che il blocco motore di questo carro armato si trova nella parte anteriore.




Tecnica

Il Merkava ha come caratteristica peculiare quella di avere il blocco motore (cioè il gruppo motore-cambio-trasmissione) nella parte anteriore dello scafo. Questo permette di offrire maggiore protezione all'equipaggio e di utilizzare il vano libero nella parte posteriore per lo stoccaggio di munizioni in contenitori pallettizzati anti-fiamma o, rinunciando a parte delle munizioni per il cannone, per trasportare personale aggiuntivo. Tale vano è accessibile mediante un portello simile a quelli usati per molti APC o per veicoli IFV.
Sin dall'inizio questo carro fu concepito con lo scopo di garantire elevate probabilità di sopravvivenza all'equipaggio e di offrire un livello di protezione ampiamente superiore a quello all'epoca disponibile su altri veicoli. In particolare, tale obiettivo fu raggiunto attraverso vari accorgimenti quali una pesante corazzatura (che però nelle prime versioni ha talvolta influito negativamente sulla velocità del mezzo), la collocazione dei sistemi principali del carro nella parte anteriore dello scafo, l'aggiunta di un portellone posteriore per facilitare l'evacuazione in caso di necessità, l'alloggiamento dei bunker per il munizionamento nello scafo e un'elevata autonomia di fuoco, grazie ad un cospicuo numero di munizioni stivate a bordo. Nella versione con cannone calibro 105, il Merkava può infatti trasportare fino a 90 colpi, più del doppio del suo principale avversario, il T-72
Inoltre il carro è stato ottimizzato fin dall'inizio per operare anche in un contesto di operazioni a bassa intensità ma alta frizione, che comportano ripetuti scontri con fanteria in ambiente sfavorevole a un veicolo blindato pesante, come un centro cittadino. A tal fine sono stati adottati una serie di sistemi volti a rendere più efficace il veicolo, sia dal punto di vista dell'armamento, che della protezione. Alcuni di questi sono abbastanza unici nel contesto degli MBT moderni. 




Tra essi vanno citati:
  • l'adozione di un mortaio da 60 mm (nella prima versione fissato al lato destro della torretta in corrispondenza della postazione del capocarro e successivamente nelle versioni 2, 3 & 4 spostato all'interno, sul lato sinistro della torretta, in modo da essere azionabile dal servente) per appoggiare la fanteria;
  • l'adozione di una linea di catene terminanti con una palla d'acciaio che pendono da sotto il cesto della torre e arrivano quasi a filo con lo scafo per fare detonare eventuali granate a razzo (RPG) o proiettili HEAT prima che colpiscano l'anello posteriore della torretta;
  • l'aggiunta delle corazze modulari, che in caso di danneggiamento è possibile sostituire agevolmente.


Versioni del Merkava

Attualmente ne esistono quattro versioni:
  • Merkava 1 (con pezzo principale da 105 mm)
  • Merkava 2 (con pezzo principale da 105 mm)
  • Merkava 3 (con pezzo principale da 120 mm)
  • Merkava 4 (con pezzo principale da 120 mm, tuttora in produzione)

Tutte le versioni hanno quattro uomini di equipaggio (capocarro, conduttore, puntatore e servente al pezzo).




Merkava Mk. I

Prima versione introdotta a partire dal 1979 fu disegnata per operare sul difficile terreno delle alture del Golan e del nord di Israele, venne armata con un cannone da 105 mm derivato dall'L7 inglese e con un mortaio da 60mm, montato esternamente.
Spinta da un motore della potenza di 750 Hp, invero non molto potente, grazie ad un'ottima trasmissione e a innovative sospensioni riuscì comunque ad assicurare un buon livello di mobilità al carro, certamente superiore a quella dell'M-60 (Magach) e del Centurion (Sho't), che all'epoca erano i carri in dotazione alle forze armate israeliane.
Questa fu inoltre la prima versione ad essere dispiegata durante un conflitto nel 1982, durante l'Operazione Pace in Galilea in seguito all'occupazione del Libano meridionale da parte di Israele.
Complessivamente i vertici militari israeliani rimasero soddisfatti del nuovo mezzo, che si dimostrò a loro avviso superiore ai T-72 dell'esercito siriano. Tuttavia, come spesso avviene nelle prime versioni, ebbe alcuni problemi, principalmente all'impianto frenante e al sistema di puntamento del cannone, che risultò piuttosto impreciso.



Merkava Mk. II

Entrato in servizio nel 1983 e dotato di un motore dalla potenza di 900 Cv, dispone di un sistema migliorato del controllo del tiro nettamente più preciso, a cui è stato aggiunto anche un sensore FLIR.
L'esperienza operativa in Libano suggerì inoltre una serie di migliorie (in seguito estese agli esemplari della serie Mk. I), destinate a incrementare la sopravvivenza del veicolo in ambiente urbano. A partire da questa versione il mortaio da 60 mm venne posto in posizione interna, e compare la serie di catene montate sulla parte posteriore del cesto della torretta.
Il motore venne inoltre dotato di una trasmissione irrobustita, consentendo al carro di muoversi agilmente anche su terreni difficili, quali quelli delle alture del Golan e di affrontare pendenze fino al 70% (contrariamente a quanto riescono a fare la maggior parte dei veicoli corazzati capaci di superare pendii con una pendenza non superiore al 60%).
Inoltre in un contesto operativo caratterizzato da terreno aspro, risultò particolarmente utile una delle caratteristiche distintive del Merkava, ovvero il fatto che il cannone può essere deflesso (inclinato verso il basso) molto più che sugli altri MBT, in modo da poter colpire postazioni sottostanti.

Merkava Mk. III

Introdotto nel 1990 dispone di un nuovo cannone a canna liscia da 120 mm prodotto su licenza Rheinmetall, compatibile con il munizionamento standard NATO usato da questo sistema d'arma. Inoltre questa versione dispone di un nuovo motore da 1200 Cv e nuove sospensioni e trasmissioni.
La trasmissione consente di portare alle ruote motrici circa 1000 dei 1200 cv disponibili, garantendo al carro una mobilità su terreno vario analoga a quella dell'M1A1.

Merkava Mk. III B e "Baz"

Aggiornamento di "mezzavita" e introdotto a partire dal 1995, annovera un sistema di condotta di tiro migliorato e sistema NBC integrato fin dalla fase progettuale (nelle altre versioni è stato integrato a seguito di aggiornamento della dotazione di bordo).
Il sistema permette di avere anche l'aria condizionata per l'equipaggio.
Sul fronte della protezione passiva, è stata invece adottata una nuova corazza aggiuntiva modulare Kasag, la cui composizione coperta da segreto, anche se pare plausibile che sia un materiale composito acciaio-ceramico. La corazzatura è montata leggermente spaziata rispetto alla corazzatura principale. L'analisi di almeno un MK III perso in seguito a un attacco con un AT-4 che ha colpito il cielo della torre, ha suggerito di rinforzare particolarmente la parte superiore del carro, piuttosto che l'arco frontale, già ampiamente protetto.
A proteggere lo scafo e i suoi occupanti concorre anche la riserva di combustibile, strategicamente disposta e il fatto che da questa versione in poi si siano eliminati i fluidi ad alta pressione dall'ambiente interno di combattimento, asservendo i movimenti della torretta e della canna a motori elettrici.
Inoltre questa versione è la prima tra gli MBT non di origine sovietica a poter impiegare il proprio cannone per abbattere elicotteri d'attacco grazie ad un missile, lo IAI LAHAT, sparato attraverso la canna del cannone (che viene usato come rampa di lancio). Con una portata di oltre 6 chilometri, tale sistema ha una probabilità dichiarata di colpire un elicottero superiore al 65%.
I carri dal secondo blocco di produzione della versione III B sono stati inoltre dotati di periscopio a immagine termica indipendente per il capocarro (CITV), che migliora di molto le capacità di rilevare e ingaggiare rapidamente bersagli sul campo. La versione così modificata è stata denominata "Baz" (falco). Il CITV, data la sua provata efficacia, è stato adottato anche su tutte le versioni successive del carro.
I vertici militari israeliani sperano che l'introduzione di tale dispositivo possa limitare la cattiva abitudine dei capocarro di combattere con la botola aperta e la testa fuori, cosa che se da un lato consente un'ottima percezione da parte del capocarro della situazione, dall'altro rende il capocarro molto vulnerabile ai cecchini, specialmente in ambiente urbano.

Merkava III LIC

Evoluzione "sul campo" del MK III Baz. Prevede ulteriori equipaggiamenti per operare in conflitti a bassa intensità. I principali sono la sostituzione della mitragliatrice coassiale da 7,62 mm con una da 12,7 mm, reti di protezione per ottiche e ventole e una telecamera posteriore.

Generazione D

L'analisi delle prestazioni sul campo dei veicoli impiegati nelle operazioni in cui Israele è stato coinvolto ha contribuito alla messa in luce di potenziali problemi da correggere, per massimizzare le possibilità di sopravvivenza dei suoi mezzi corazzati in un conflitto.
In particolare è emerso che gli avversari di Israele non sono più armati solo di RPG e ATGM di prima generazione, ma dispongono oggi di ATGM avanzati, in grado di costituire una seria minaccia anche per carri armati che nei due decenni passati sarebbero stati considerati pressoché invulnerabili.
È stato quindi progettato un pacchetto di protezioni attive e passive, destinate a migliorare le capacità di sopravvivenza dei veicoli.
Il pacchetto è stato sperimentato inizialmente sugli M-60. L'efficacia è stata dimostrata quando un M-60 è stato colpito da una salva di una ventina di missili. Solo due hanno perforato la corazzatura. Con le vecchie corazzature reattive, che ai tempi dell'operazione "Pace in Galilea" garantivano la quasi totale invulnerabilità, è stato stimato che sarebbero stati necessari sette colpi per perforare la corazza.
L'aggiornamento, esteso anche ai Merkava e culminato con la progettazione di un carro sostanzialmente nuovo, ha preso il nome di "Dor Dalet", che in ebraico significa "generazione D".




Merkava Mk. III Dor Dalet

Annovera una torretta completamente ridisegnata, per garantire migliore protezione. La nuova torretta, ulteriormente raffinata, è stata adottata anche dal MK IV conservando l'armamento originario, da alcuni Mk II. Inoltre ha cingoli di disegno più efficace.
Le ruote sono completamente in acciaio, senza cerchi gommati. Questo accorgimento permette di ridurre l'usura. L'armamento principale dispone da questa versione di un caricatore semiautomatico a tamburo, contenente cinque colpi di pronto impiego, destinato a rendere più agevole e veloce il compito del soldato addetto al caricamento del pezzo.




Merkava Mk. IV Dor Dalet

In servizio dal 2004 il Merkava Mk. IV Dor Dalet si distingue dalle versioni precedenti per via della sua torretta e del suo scafo di nuova concezione, che non presentano più le evidenti asimmetrie delle versioni precedenti.
La caratteristica più peculiare della nuova torre è l'eliminazione del portello del servente. La sua presenza rende, secondo gli ingegneri militari israeliani, più vulnerabile la torre agli attacchi dall'alto.
Il servente può agevolmente abbandonare il carro, in caso di emergenza, dal portello posteriore (come del resto tutto l'equipaggio). Come tutte le versioni precedenti anche il Merkava Mk. IV sfrutta le componenti meccaniche del carro per fornire ulteriore protezione.
Tale protezione, classicamente in un MBT risulta essere massima nell'arco frontale, mentre nella versione Mk. IV è stata pensata per fornire protezione a 360º, compresi attacchi dall'alto.
Il cannone da 120 mm è di nuova concezione, progettato in Israele, può reggere pressioni interne più elevate, permettendo di sparare proiettili ad energia cinetica KE (Kinetic Energy) a velocità maggiore, mentre il caricatore semiautomatico è stato dotato di sufficiente spazio per ospitare fino a 10 colpi.
La mitragliatrice coassiale da 7,62 mm è stata sostituita con una da 12,7 mm.
Sono stati anche rivisti gli organi di movimento: un nuovo motore da 1500 Cv è accoppiato a una nuova trasmissione e a nuove sospensioni tipo "Caterpillar"(sistema denominato "Mazkom", sistema cingoli-molle-ruote). La velocità massima di questa versione è di circa 60 km/h.
La visibilità su 360º è assicurata da un sistema video costituito da quattro telecamere installate in parti rinforzate dello scafo. Il carro monta anche un sistema di raccolta e visualizzazione dati di battaglia digitale, simile a quello statunitense IVIS, progettato dalla Elbit System. L'adozione di questa nuova versione del Merkava ha portato alla totale radiazione dei vecchi Centurion di produzione britannica e dei Magach dai reparti della riserva.
È da notare che la produzione di tale carro sta incontrando forti riserve in ambito governativo, a causa del suo alto costo (4-5 milioni di dollari per carro).




Altre versioni

Merkava ambulanza corazzata

Alcuni carri sono stati attrezzati per poter accogliere un paio di feriti o un ferito e un paramedico, comprese le attrezzature sanitarie di base. La modifica permette di disporre di un'ambulanza corazzata in grado di evacuare soldati feriti sotto pesante fuoco nemico, rispondendo contemporaneamente al fuoco.
Veicolo da recupero corazzato Merkava ARV
Chiamato Nam'mer (tigre), può trainare carri danneggiati e dispone di un generatore di emergenza.

Sholef

Obice semovente in calibro 155mm. Ne furono realizzati due prototipi dalla Soltam tra il 1984 e l'86, ma non entrò mai in produzione.

Namer

Sviluppato sempre sfruttando lo scafo del Merkava il Namer è un veicolo per il trasporto truppe con un elevato livello di protezione.

SISTEMA TROPHY A.P.S.

Trophy (Israel Defense Forces designation מעיל רוח, lit. "Windbreaker") è un sistema di protezione attiva militare (APS) per veicoli. Intercetta e distrugge i missili in arrivo, i razzi e i proiettili HEAT con un'esplosione simile a un fucile da caccia. Il suo scopo principale è integrare l'armatura dei veicoli corazzati leggeri e pesanti. Sviluppato da Rafael Advanced Defence Systems Ltd. di Israele e attualmente schierando oltre 1.000 sistemi su tutte le principali piattaforme israeliane di combattimento terrestre (Merkava Mark 3 & 4 e Namer APC ), così come gli Abrams statunitensi M1A1 / 2, e testato sugli APC Stryker e Bradley AFVs. Trophy protegge da un'ampia varietà di minacce anticarro, massimizzando al contempo la capacità del veicolo di identificare la posizione del nemico per gli equipaggi e la formazione del combattimento, fornendo in tal modo maggiore sopravvivenza e manovrabilità in tutti i teatri di combattimento.




Trofhy APS
  • Luogo d’origine Israele
  • Sistema attivo per difesa blindati e carri
  • progettista Rafael Advanced Defense Systems e Elta Group.

PROGETTO

Il primo contratto di produzione di Trophy è stato firmato nel 2007. La certificazione di sicurezza è stata concessa nel 2010. Le prime consegne sono iniziate subito dopo. Il design include il radar antincendio Elta EL / M-2133 F / G con quattro antenne a schermo piatto montate sul veicolo, con un campo visivo a 360 gradi. Quando viene rilevato un proiettile, il computer interno calcola un vettore di approccio quasi istantaneamente, prima che arrivi. Una volta che l'arma in arrivo è completamente classificata, i computer calcolano il tempo e l'angolazione ottimali per sparare le contromisure. La risposta arriva da due lanciatori rotanti installati sui lati del veicolo che sparano un numero molto ridotto di MEFP (Multiple Explosive Formed Penetrators) che formano una matrice molto stretta e precisa, puntata su un punto specifico delle minacce dell'arma anticarro testata. Il sistema è progettato per avere una zona di impatto molto piccola, in modo da non mettere in pericolo il personale adiacente al veicolo protetto. Trophy è un sistema modulare che consente la connettività ad altri sistemi, come soft-kill, sistemi C4I, stazioni di armi telecomandate, ecc.
Il sistema è progettato per funzionare contro tutti i tipi di missili anticarro, missili e proiettili HEAT, comprese armi portatili come granate a propulsione a razzo o fucili senza rinculo. Il sistema è in grado di ingaggiare contemporaneamente diverse minacce provenienti da direzioni diverse, è efficace su piattaforme fisse o mobili ed è efficace contro minacce sia a corto che a lungo raggio. Le versioni più recenti del sistema includono una funzione di ricarica per più scatti. Il piano di sviluppo del Trophy include un'unità di contromisure potenziata che sarà disponibile in futuro per la protezione contro i penetratori di energia cinetica.




VANTAGGI

Il ruolo principale di Trophy è la difesa dagli attacchi missilistici, in particolare per i veicoli più leggeri, che sono molto vulnerabili agli attacchi missilistici. Dal 2011, il sistema ha ottenuto il 100% di successo in tutti gli eventi di combattimento a bassa e alta intensità, in terreni diversificati (urbano, aperto e fogliame). Il sistema ha intercettato una varietà di minacce, tra cui Kornet ATGM, RPG-29, ecc., L'esercito degli Stati Uniti ha riportato un successo simile nei test. "Ho cercato di colpire il carro armato Abrams 48 volte e ho fallito", ha detto il colonnello dell'esercito americano Glenn Dean. Secondo Rafael, entro il 2017, Trophy ha accumulato oltre 500.000 ore di funzionamento nella distribuzione, portando il sistema ad un livello di massima affidabilità. Al fine di garantire un danno collaterale minimo e una bassa penetrazione residua, Rafael ha selezionato un meccanismo unico per il Trophy, con un effetto chirurgico. Il sistema utilizza un EFP in miniatura che penetra nell'involucro della minaccia e disintegra le testate a una distanza di sicurezza dal veicolo. Nel caso dell'ATGM, l'EFP influenzerà il getto di energia chimica, riducendo drasticamente la sua capacità di penetrazione in piattaforme di medie dimensioni. Inoltre, è stato dimostrato nei test e in tempo di guerra che un tale meccanismo di abbattimento presenta un rischio estremamente basso attorno al veicolo e quindi non influisce sulle consuete tattiche, tecniche e procedure delle armi combinate (TTP). Al fine di fornire migliaia di sistemi ai propri clienti, Rafael ha creato la prima linea di produzione in Israele nel 2007, ed ha iniziato la consegna nel 2010. Nel 2012 è stata stabilita una linea di produzione aggiuntiva negli Stati Uniti, che ha iniziato le consegne nel 2015, con un primario scopo di fornire sistemi trophy all'IDF come parte dell'FMF (Foreign Military Funding). Entrambe le linee di produzione saranno utilizzate per il contratto statunitense e altre.
Il radar del Trophy è responsabile della ricerca, del rilevamento, della classificazione, della localizzazione e della segnalazione di potenziali minacce alla rete di computer di bordo del veicolo, oltre alla rete tattica, creando una funzionalità di rilevamento del fuoco ostile (HFD), che avvisa l'equipaggio e la formazione dalle minacce in arrivo, e fornisce istantaneamente la posizione esatta del tiratore sul display della piattaforma esistente. Se il Trophy identifica che la minaccia non colpirà la piattaforma, non attiverà la contromisura ma fornirà la posizione del tiratore, consentendo un ingaggio istantaneo da parte della squadra di combattimento, impedendo ulteriori attacchi. Il vantaggio della capacità HFD integrata nella guerra simmetrica è la sua capacità di fornire anche la posizione del carro armato nemico, consentendo alla squadra di combattimento di contrattaccare.




SVANTAGGI

Il sistema non è attualmente in grado di annientare le testate ad energia cinetica. Prima della dichiarazione della Rafael della variante del trophy di protezione attiva dei veicoli di medie dimensioni (Trophy MV / VPS), c'erano affermazioni relative alle dimensioni e al peso del Trophy HV.
Precedentemente noto come "Trophy Light", "Trophy MV / VPS" è stato presentato da Rafael Advanced Defense Systems al DSEi britannico 2007. Mentre il Trophy standard è stato progettato per i principali carri armati, Trophy MV / VPS è progettato per l'integrazione con corazzati leggeri e medi veicoli, come Stryker, Bradley, ecc. Si prevede che avrà circa il 40% in meno di peso e dimensioni del Trophy standard e costi inferiori pur mantenendo le stesse prestazioni e affidabilità della variante Trophy HV, questo a causa dell’uso degli stessi elementi critici principali: la suite di sensori, il computer di missione, usando gli stessi algoritmi di combattimento. Leonardo DRS, partner di Rafael per Trophy negli Stati Uniti, fornirà il caricatore automatico modificato per il sistema. Nell'estate del 2018, Rafael ha condotto una vasta serie di test di qualificazione per il Trophy MV / VPS in Israele, con la presenza di oltre 130 decisori ed esperti tecnici provenienti da oltre 15 paesi. I test sono stati condotti in scenari estremi, utilizzando sia missili che ATGM. La percentuale di successo riportata è stata superiore al 95%.
Nel giugno 2014, Rafael ha presentato Trophy LV, un'applicazione più leggera del sistema progettata per offrire protezione ai veicoli militari leggeri (meno di 8 tonnellate) come jeep e 4x4. Pesa 200 chilogrammi (440 libbre), significativamente meno rispetto ad altre applicazioni del trofeo.
Nel dicembre 2014, Rafael, IAI e Israel Military Industries hanno concordato di sviluppare congiuntamente un sistema di difesa attiva di prossima generazione per veicoli, basato su una combinazione del Rafael / IAI Trophy e IMI Iron Fist. Rafael fungerà da appaltatore principale, sviluppatore e integratore di sistemi e IAI e IMI saranno subappaltatori. Il ministero della Difesa ha spinto le compagnie a lavorare insieme e combinare i loro sistemi. Da allora non sono stati registrati progressi.




TEST DA PARTE DELL’U.S. ARMY

Il Trophy è stato valutato con test approfonditi su un veicolo Stryker per la possibile adozione da parte dell'esercito americano, e di un LAV III canadese. L'esercito ha testato il sistema Trophy nel 2017, per essere messo in campo entro due anni come capacità provvisoria fino a quando il programma Modular Active Protection System (MAPS) non produce un sistema.  Un contratto da 193 milioni di dollari per Trophy è stato assegnato a Leonardo DRS, partner americano di Rafael, nel giugno 2018, al fine di dotare un numero significativo di Abrams M1A1 / A2 MBT con Trophy. 
A seguito della serie di test del sistema Trophy, l'IDF Ground Forces Command ha dichiarato operativo il Trophy nell'agosto 2009. Era previsto che fosse installato in un intero battaglione di carri armati israeliani del Corpo entro il 2010.
Il 1 ° marzo 2011, stazionato vicino al confine di Gaza, un Merkava MK IV equipaggiato con il sistema Trophy sventò un attacco missilistico puntato su di esso e divenne il primo successo operativo del sistema di difesa attiva Trophy. Il 20 marzo 2011, un missile è stato lanciato contro un carro armato Merkava MK IV equipaggiato con un sistema di trophy all'interno dell'area israeliana lungo il recinto perimetrale della Striscia di Gaza. Il sistema rilevò l'attacco, ma stabilì che non metteva in pericolo il carro armato e non lo intercettò; passò le informazioni all'equipaggio, che attaccò la fonte del fuoco. Il 1 ° agosto 2012, Trophy ha intercettato con successo un missile anticarro lanciato dalla Striscia di Gaza in un carro armato Merkava vicino all'incrocio di Kissufim.
Il 14 luglio 2014, il sistema Trophy ha intercettato con successo un missile anticarro Kornet 9M133 sparato da Gaza contro un carro armato IDF. Dall'inizio dell'operazione israeliana Protection Edge al 20 luglio 2014, almeno quattro carri armati israeliani di comandanti senior sono stati protetti dal sistema nella Striscia di Gaza. Secondo i resoconti del fronte, sin dall'inizio dell'operazione a terra, il sistema ha intercettato con successo cinque missili anticarro contro i veicoli corazzati IDF a Gaza. Il 22 luglio 2014, secondo un video di un gruppo palestinese, il sistema Trophy installato su un carro armato Merkava IV ha intercettato con successo un razzo RPG-29 sparato contro il carro armato. Secondo Debkafile, Hamas ha cercato di fermare i carri armati israeliani con due tipi di missili anticarro guidati avanzati, il russo Kornet-E e il Konkurs 9M113, ma Trophy li ha intercettati con successo. La comparsa di piattaforme terrestri mobili quasi invulnerabili suggerisce che potrebbe essere necessario rivedere l'attuale paradigma di guerra. Il Trophy è attualmente operativo su tutti i carri armati Merkava Mark-IV della 401a brigata corazzata dell'IDF, così come con i nuovi carri armati 75° battaglione della 7a brigata corazzata del Merkava IV. A luglio, il MOD israeliano ha annunciato di aver completato l'integrazione di Trophy nella sua prima compagnia di brigata di APC NAMER. a novembre 2016 è stato annunciato che l'IDF acquisterà centinaia di altri sistemi Trophy da installare su quasi tutti i suoi Merkava 4 MBT e NAMER APC / IFV.
Nessun carro armato è stato danneggiato durante l' operazione di protezione del bordo, con il sistema Trophy Active Protection che esegue oltre una dozzina di intercettazioni di armi anticarro tra cui Kornet, Metis e RPG-29. Il sistema, identificando la fonte del fuoco, a volte ha anche permesso ai carri armati di annientare la squadra anticarro di Hamas. 
Giora Katz, capo della divisione terrestre di Rafael, dichiarò che si trattava di una "svolta, perché è la prima volta nella storia militare in cui un sistema di difesa attiva è stato utilizzato in combattimenti intensi". Durante la guerra, Trophy si convalidò in dozzine di eventi, proteggendo carri armati ed equipaggi per tre settimane di operazioni di manovra ad alto rischio in aree costruite senza un singolo colpo alle piattaforme difese e zero falsi allarmi ".




ENGLISH

The Merkava (Hebrew: מרכבה, [mɛʁkaˈva], "chariot") is a main battle tank used by the Israel Defense Forces. The tank began development in 1970, and entered official service in 1979. Four main variants of the tank have been deployed. It was first used extensively in the 1982 Lebanon War. The name "Merkava" was derived from the IDF's initial development program name.
Design criteria include rapid repair of battle damage, survivability, cost-effectiveness and off-road performance. Following the model of contemporary self-propelled howitzers, the turret assembly is located closer to the rear than in most main battle tanks. With the engine in front, this layout is intended to grant additional protection against a frontal attack, so as to absorb some of the force of incoming shells, especially for the personnel in the main hull, such as the driver. It also creates more space in the rear of the tank that allows increased storage capacity and a rear entrance to the main crew compartment allowing easy access under enemy fire. This allows the tank to be used as a platform for medical disembarkation, a forward command and control station, and an infantry fighting vehicle. The rear entrance's clamshell-style doors provide overhead protection when off- and on-loading cargo and personnel.

Development

During the late 1960s, the Israeli Army began collaborating on design notes for the Chieftain (tank) which had originally been introduced to British Army service, with a view to Israel purchasing and domestically producing the vehicle. Two prototypes were delivered as part of a four-year trial. However, it was eventually decided not to sell the marque to the Israelis (since, at that period of time in the late 1960s, the UK was more friendly towards the Arab states and Jordan than to Israel), which prompted them to follow their own development programme.
Israel Tal, who was serving as a brigade commander after the Suez Crisis, restarted plans to produce an Israeli-made tank, drawing on lessons from the 1973 Yom Kippur War, in which Israeli forces were outnumbered by those of the Middle East's Arab nations.
By 1974, initial designs were completed and prototypes were built. After a brief set of trials, work began to retool the Tel HaShomer ordnance depot for full-time development and construction. After the new facilities were completed, the Merkava was announced to the public in the International Defense Review periodical. The first official images of the tank were then released to the American periodical Armed Forces Journal on May 4, 1977. The IDF officially adopted the tank in December 1979.
Primary contractors
The lead organization for system integration of the Merkava's main components is Israel Military Industries (IMI). The Israeli Ordnance Corps are responsible for final Merkava assembly. More than 90% of the Merkava 4 tank's components are produced locally in Israel by Israeli defense industries.

Contributors to the vehicle include:

IMI manufactures the 105 mm and 120 mm main guns and their ammunition;
TGL SP Industries LTD develop and production of the Road Wheels.
Urdan Industries assembles and constructs the hull, drive- and powertrains, and turret assemblies;
Soltam manufactures the 60 mm internal mortar;
Elta designs and manufactures the electronic sensors and infrared optics;
Elbit delivers the ballistics computer, fire-control system (FCS) and electric turret and gun control system;
Tadiran provides cabin air conditioning, crew cabin intercom and radio equipment;
El-Op, Elisra and Astronautics implement the optics and laser warning systems;
Rafael Advanced Defense Systems builds and installs the Rafael Overhead Weapon Station and Trophy active protection system;
L-3 Communication Combat Propulsion Systems produces licensed copies of Germany's MTU MT883 1500 hp diesel engine powerplant and RENK RK325 transmissions;
Motorola supplies Tadiran communication encryption systems;
DuPont supplies the Nomex, ballistic, and fire-retardant materials used by Hagor;
Russia Military Industries helped to design the KMT-4 & -5 anti-mine rollers and the ABK-3 dozer blade, now built by Urdan;
FN Herstal supplies 7.62 mm (MAG 58) and 12.7 mm (M2) coaxial and pintle-mounted machine guns;
Caterpillar assisted with an Israeli-designed track system.
Bental Industries, a TAT Technologies subsidiary, produced the brushless motors used in the Mark IV's turret and gun control system.

General characteristics

Firepower

The Merkava Mark I and II were armed with a 105 mm M64 gun, A license built variant of the M68. The Mark III, Mark III Dor Dalet BAZ kassag, and the Mark IV are armed with an IMI 120 mm smoothbore gun which can fire all versions of Western 120 mm smooth bore tank ammunition.
Each model of the Merkava has two roof mounted 7.62 mm machine guns for use by the commander and loader and another mounted co-axially with the main gun. A 60 mm mortar is also fitted for firing smoke rounds or suppressing dug-in infantry anti-tank teams.
All Merkava tanks are fitted with a remote-controlled M2 Browning .50 heavy machine gun, aligned with the main gun and controlled from within the turret. The .50 machine gun has proven to be useful and effective in asymmetric warfare.
Mobility
The tank's 1,500 horsepower turbocharged diesel engine was designed by MTU and is manufactured under license by L-3 Communication Combat Propulsion Systems (formerly General Dynamics). The Mark IV's top road speed is 64 km/h.

Variants

Merkava Mark I

The Mark I, operational since 1978, is the original design created as a result of Israel Tal's decision, and was fabricated and designed for mass production. The Mark I weighed 63 tonnes and had a 900 horsepower (670 kW) diesel engine, with a power-to-weight ratio of 14 hp/ton. It was armed with the 105 millimeter M64 L71A main gun (a licensed copy of the British Royal Ordnance L7), two 7.62 mm machine guns for anti-infantry defense, and a 60 mm mortar mounted externally, with the mortar operator not completely protected by the tank's hull.
The general design borrows the tracks and road wheels from the British Centurion tank, which had seen extensive use during the Yom Kippur war and performed well in the rocky terrain of the Golan.
The Merkava was first used in combat during the 1982 Lebanon War, where Israel deployed 180 units. Although they were a success, the M113 APCs that accompanied them were found to have several defects and were withdrawn. Merkavas were converted into makeshift APCs or armored ambulances by taking out the palleted ammunition racks in storage. Ten soldiers or walking wounded could enter and exit through the rear door.
After the war, many adjustments and additions were noted and designed, the most important being that the 60 mm mortar needed to be installed within the hull and engineered for remote firing—a valuable feature that the Israelis had initially encountered on their Centurion Mk3s with their 2" Mk.III mortar. A shot trap was found beneath the rear of the turret bustle, where a well-placed shot could jam the turret completely. The installation of chain netting to disperse and destroy rocket propelled grenades and anti-tank rockets before impacting the primary armor increased survivability.

Merkava Mark II

The Mark II was first introduced into general service in April 1983. While fundamentally the same as the Merkava Mark I, it incorporated numerous small adjustments as a result of the previous year's incursion into Lebanon. The new tank was optimized for urban warfare and low intensity conflicts, with a weight and engine no greater than the Mark I.
The Mark II used the same 105 mm main gun and 7.62 mm machine guns as the Mark I, but the 60 mm mortar was redesigned during construction to be located within the hull and configured for remote firing to remove the need to expose the operator to enemy small-arms fire. An Israeli-designed automatic transmission and increased fuel storage for increased range was installed on all further Mark IIs. Anti-rocket netting was fitted for increased survivability against infantry equipped with anti-tank rockets. Many minor improvements were made to the fire-control system. Updated meteorological sensors, crosswind analyzers, and thermographic optics and image intensifiers gave greater visibility and battlefield awareness.
Newer versions of the original Mark II were designated:

Mark IIB, with thermal optics and unspecified updates to the fire control system.
Mark IIC, with more armor on the top of the turret to improve protection against attack from the air.
Mark IID, with modular composite armor on the chassis and turret, allowing rapid replacement of damaged armor.

In 2015 the IDF had begun a plan to take the old models out of storage and repurpose them as heavy armored personnel carriers. Cannons, turrets, and spaces used to store tank shells inside the hull were removed to create a personnel carrier that outperforms the lighter M113 APC. Converting hundreds of Mark II chassis provides a low-cost way to upgrade support units' capabilities to perform medical, logistical, and rescue missions. By late 2016, after 33 years of service, the last conscripted brigade to operate Merkava IIs was scheduled to transition to Merkava III and Merkava IV tanks for battlefield missions, relegating the vehicles to reserve forces for border patrols during conflicts and conversion to personnel carriers.

Merkava Mark III

The Merkava Mark III was introduced in December 1989 and was in production until 2003. As of 2016, the Merkava III is by far the most numerous tank in frontline IDF service. Compared to the Merkava II, it has upgrades to the drivetrain, powertrain, armament, and electronic systems. The most prominent addition was the incorporation of the locally developed IMI 120 mm gun. This gun and a larger 1,200 horsepower (890 kW) diesel engine increased the total weight of the tank to 65 tonnes (143,000 lb), but the larger engine increased the maximum cruising speed to 60 km/h (37 mph).
The turret was re-engineered for movement independent of the tank chassis, allowing it to track a target regardless of the tank's movement. Many other changes were made, including:

External two-way telephone for secure communications between the tank crew and dismounted infantry,
Upgraded ammunition storage containers to minimize ammunition cook-off,
Addition of laser designators,
Incorporation of the Kasag modular armor system, designed for rapid replacement and repair in the battlefield and for quick upgrading as new designs and sophisticated materials become available,

BAZ System

The 1995 Mark III BAZ (Hebrew acronym for ברק זוהר, Barak Zoher, signifying Shining Lightning) had a number of updates and additional systems including:

NBC protection systems,
Locally developed central air-conditioning system,
Added improvements in ballistic protection,
The Mark IIID has removable modular composite armor on the chassis and turret.

Dor-Dalet

The last generation of the Mark III class was the Mark IIID Dor-Dalet (Hebrew: Fourth Generation), which included several components as prototypes to be introduced in the Mark IV.
Upgraded and strengthened tracks (built by Caterpillar, designed in Israel),
Installation of the R-OWS.

Merkava Mark IV

The Mark IV is the most recent variant of the Merkava tank that has been in development since 1999 and production since 2004. The upgrade's development was announced in an October 1999 edition of the Bamachaneh ("At the Camp") military publication. However, the Merkava Mark III remained in production until 2003. The first Merkava IVs were in production in limited numbers by the end of 2004.
Removable modular armor, from the Merkava Mark IIID, is used on all sides, including the top and a V-shaped belly armor pack for the underside. This modular system is designed to allow for damaged tanks to be rapidly repaired and returned to the field. Because rear armor is thinner, chains with iron balls are attached in order to detonate projectiles before they hit the main armored hull.
It is the first contemporary tank with no loaders hatch in the turret roof, because any aperture in the turret roof increases risk of penetration by ATGMs.
Tank rounds are stored in individual fire-proof canisters, which reduce the chance of cookoffs in a fire inside the tank. The turret is electrically-powered (hydraulic turrets use flammable liquid that ignites if the turret is penetrated) and "dry": no active rounds are stored in it.
Some features, such as hull shaping, exterior non-reflective paints (radar cross-section reduction), and shielding for engine heat plumes mixing with air particles (reduced infrared signature) to confuse enemy thermal imagers, were carried over from the IAI Lavi program of the Israeli Air Force to make the tank harder to spot by heat sensors and radar.
The Mark IV includes the larger 120 mm main gun of the previous versions, but can fire a wider variety of ammunition, including HEAT and sabot rounds like the APFSDS kinetic energy penetrator, using an electrical semi-automatic revolving magazine for 10 rounds. It also includes a much larger 12.7 mm machine gun for anti-vehicle operations (most commonly used against technicals).
The Mark IV has the Israeli-designed "TSAWS (Tracks, Springs, and Wheels System)" caterpillar track system, called "Mazkom" (Hebrew: מערכת זחלים קפיצים ומרכובים, מזקו"ם) by troops. This system is designed to reduce track-shedding under the harsh basalt rock conditions of Lebanon and the Golan Heights.
The model has a new fire-control system, the El-Op Knight Mark 4. An Amcoram LWS-2 laser warning receiver notifies the crew of threats like laser-guided anti-tank missiles, which can fire smoke grenade launchers to obscure the tank from the laser beam. Electromagnetic warning against radar illumination is also installed.
The tank carries the Israeli Elbit Systems BMS (Battle Management System; Hebrew: צי"ד), a centralised system that takes data from tracked units and UAVs in theater, displays it on color screens, and distributes it in encrypted form to all other units equipped with BMS in a given theater.
The Merkava IV has been designed for rapid repair and fast replacement of damaged armour, with modular armour that can be easily removed and replaced. It is also designed to be cost-effective in production and maintenance; its cost is lower than that of a number of other tanks used by Western armies.
The tank has a high performance air conditioning system and can even be fitted with a toilet for long duration missions.

Mark IVm (Mk 4M) Windbreaker

The Merkava Mark IVm (Mk 4M) Windbreaker is a Merkava Mark IV equipped with the Trophy active protection system (APS), designated "Meil Ruach" (Hebrew: מעיל רוח; "Windbreaker" or "Wind Coat"). The serial production of Mark IVm tanks started in 2009 and the first whole brigade of Mark IVms was declared operational in 2011. The Trophy APS successfully intercepted rocket-propelled grenades and anti-tank missiles, including 9M133 Kornets, fired by Hamas before and during Operation Protective Edge in 2014.

Iron Vision helmet-mounted display system

In mid-2017, the IDF will begin trials of Elbit's Iron Vision, the world's first helmet-mounted display for tanks. Israel's Elbit, which developed the helmet-mounted display system for the F-35, plans Iron Vision to use a circular review system as a number of externally mounted cameras to project the 360° view of a tank's surroundings onto the helmet-mounted display of its crew members. This allows the crew members to stay inside the tank, without having to open the hatches to see outside.

Combat history

The Merkava has participated in the following actions.

1982 Lebanon War

The Merkava was used widely during the 1982 Lebanon War. The tank outperformed contemporary Syrian tanks (mostly T-62s) and proved largely immune to the anti-tank weapons of the time (the AT-3 Sagger and RPG-7) that were used against it. It was judged to be a significant improvement over Israel's previously most effective main battle tank, the Centurion. Israel lost dozens of tanks during the conflict, including a number of Merkavas.

Second Intifada

In February 2002, a Merkava III was destroyed by a roadside bomb near Netzarim in the Gaza Strip. The tank was lured into intervening in an attack on a settler convoy. The tank went over a heavy mine (estimated 100 kg TNT), which detonated and totally destroyed the tank. Four soldiers were killed in the blast. This was the first main battle tank to be destroyed during the Second Intifada. A second Israeli tank, a Merkava II or Merkava III, was destroyed a month later in the same area and a further three soldiers were killed. A third Merkava II or III tank was destroyed near the Kissufim Crossing, when one soldier was killed and two wounded.

2006 Lebanon War

During the 2006 Lebanon War, five Merkava tanks were destroyed. Most of the tanks engaged were Merkava IIIs and earlier versions; only a few of the tanks used during the war were Merkava Mark IVs since by 2006 they had still only entered service in limited numbers. Hezbollah fired over 1,000 anti-tank missiles during the conflict against both tanks and dismounted infantry. Some 45 percent of all tanks and armoured vehicles hit with antitank missiles during the conflict suffered some form of armour penetration. In total, 15 tank crewmen were killed by these ATGM penetrations. The penetrations were caused by tandem warhead missiles. Hezbollah weaponry was believed to include advanced Russian RPG-29 'Vampir', AT-5 'Konkurs', AT-13 'Metis-M', and laser-guided AT-14 'Kornet' HEAT missiles. The IDF reported finding the state-of-the-art Kornet ATGMs on Hezbollah positions in the village of Ghandouriyeh. Several months after the cease-fire, reports have provided detailed photographic evidence that Kornet ATGMs were indeed both in possession of, and used by, Hezbollah in this area. Another Merkava IV tank crewman was killed when a tank ran over an improvised explosive device (IED). This tank had additional V-shaped underside armor, limiting casualties to just one of the seven personnel (four crewmen and three infantrymen) on board. In total, five Merkava tanks (two Merkava IIs, one Merkava III, and two Merkava IVs) were destroyed. Of these two Merkava Mark IVs, one was by powerful IEDs, and the other by Russian AT-14 'Kornet' missiles. The Israeli military said that it was satisfied with the Merkava Mark IV's performance, and attributed problems to insufficient training before the war. In total, 50 Merkava tanks (predominantly Merkava IIs and IIIs) were hit, eight of which remained serviceable on the battlefield. 21 tanks suffered armour penetrations (15 from missiles, and 6 from IEDs and anti-tank mines).
After the 2006 war, and as the IDF becomes increasingly involved in unconventional and guerrilla warfare, some analysts say the Merkava is too vulnerable to advanced anti-tank missiles, that in their man-portable types can be fielded by guerrilla warfare opponents. Other post-war analysts, including David Eshel, disagree, arguing that reports of losses to Merkavas were overstated and that "summing up the performance of Merkava tanks, especially the latest version Merkava Mark IV, most tank crews agree that, in spite of the losses sustained and some major flaws in tactical conduct, the tank proved its mettle in its first high-saturation combat." On a comparison done by the armor corps newsletter, it was shown that the average number of crewmen killed per tank penetrated by missile/rocket was reduced from 2 during the Yom Kippur War to 1.5 during the 1982 Lebanon War to 1 during the 2006 Lebanon War proving how, even in the face of the improvement in anti-tank weaponry, the Merkava series tanks provide increasingly better protection to its crew. The IDF wanted to increase orders of new Merkava Mark IV tanks, and planned to add the Trophy active defense system to Merkava Mark IV tanks, and to increase joint training between crews and Israeli antitank soldiers.

Operation Cast Lead

The Merkava IV was used more extensively during the Gaza War, as it had been received by the IDF in increasing numbers since 2006, replacing more of the Merkava II and III versions of the tank that were in service. One brigade of Merkava IVs managed to bisect the Gaza strip in five hours without Israeli casualties. The commander of the brigade stated that battlefield tactics had been greatly revised since 2006. Tactics had also been modified to focus on asymmetric or guerilla war threats, in addition to the conventional war scenarios that the Merkava had primarily been designed to combat.
The IDF also deployed the Merkava II and III during the war.

Gaza Border areas

By October 2010, the IDF had begun to equip the first Merkava IVs with the Trophy active protection system, to improve the tanks' protection against advanced anti-tank missiles which use tandem-charge HEAT warheads. Added protection systems included an Elbit laser-warning system and IMI in-built smoke-screen grenades.
In December 2010, Hamas fired an AT-14 Kornet anti-tank missile at a Merkava Mark III tank stationed on the Israel-Gaza border near Al-Bureij. It had hitherto not been suspected that Hamas possessed such an advanced missile. The missile penetrated the tank's armour, but caused no injuries among its crew. As a result of the attack, Israel decided to deploy its first Merkava Mark IV battalion equipped with the Trophy system along the Gaza border.
On March 1, 2011, a Merkava MK IV stationed near the Gaza border, equipped with the Trophy active protection system, successfully foiled a missile attack against it, marking the system's first operational success.

Operation Protective Edge 2014

No tanks were damaged during Operation Protective Edge. The Merkava Mk. IVm (Merkava Mk 4M) tanks, fitted with the Trophy Active Protection system, intercepted anti-tank missiles and RPGs on dozens of different occasions during the ground operation. During the operation, the system intercepted anti-tank weapons, primarily Kornet, as well as Metis-M and RPG-29, proving itself effective against man-portable anti-tank weapons. By identifying the source of fire, Trophy also allowed tanks to kill the Hamas anti-tank team on one occasion.
Giora Katz, head of Rafael's land division, stated that it was a "breakthrough because it is the first time in military history where an active defense system has proven itself in intense fighting."
401st Brigade (equipped with Merkava Mk. IVm tanks) alone killed between 120–130 Hamas militants during the ground fighting phase of Operation Protective Edge, according to the IDF.

Export

In May 2012, Israel offered procurement of Merkava IV tanks to the Colombian Army. The sale would include 25–40 tanks at an approximate cost of $4.5 million each, as well as a number of Namer APCs. With the threat of the expanding Venezuelan military, it would strengthen Colombian armored forces against Venezuelan T-72 tanks.
In 2014, Israel reported that exports of the Mk. 4 have started with the country's name not disclosed for security reasons.

Derivatives

Following the Second Intifada the Israel Defense Forces modified some of their Merkavas to satisfy the needs of urban warfare.

Merkava LIC

These are Merkava Mark III BAZ or Mark IV tanks, converted for urban warfare. The LIC designation stands for "Low intensity conflict", underlining its emphasis on counter-insurgency, street-to-street inner-city asymmetrical type warfare of the 21st century.
The Merkava is equipped with a turret 12.7 mm caliber coaxial machine gun, which enables the crew to lay down fairly heavy cover fire without using the main gun (which is relatively ineffective against individual enemy combatants). Like the new remote-operated weapon station, the coaxial machine-gun is fired from inside the tank without exposing the crew to small-arms fire and snipers.
The most sensitive areas of a tank, its optics, exhaust ports and ventilators, are all protected by a newly developed high-strength metal mesh, to prevent the possibility of explosives charges being planted there.
Rubber whip pole-markers with LED tips and a driver's rear-facing camera have been installed to improve navigation and maneuverability in an urban environment by day or by night.

Merkava Tankbulance

Some Merkava tanks have been fitted with full medical and ambulance capabilities while retaining their armament (but carrying less ammunition than the standard tank). The cabin area has been converted for carrying injured personnel and has had two stretchers and life support medical station systems added with a full medical team complement to operate under combat conditions with a Merkava battalion. The vehicle has a rear door to facilitate evacuation under fire, and can provide covering fire.
The "tankbulance" is not an unarmed ambulance and as such is not protected by the Geneva Conventions provisions regarding ambulances, but it is far less vulnerable to accidental or deliberate fire than an ambulance or armored personnel carrier.

Merkava IFV Namer

Namer is equipped with a Samson Remote Controlled Weapon Station (RCWS) armed with either a .50 M2 Browning Heavy Machinegun or a Mk 19 Automatic Grenade Launcher. It also has a 7.62 mm MAG machine gun, 60 mm mortar and smoke grenades. Like the Merkava Mark IV, it is optimized for high level of crew survival on the battlefield. The Namer has a three-man crew (commander, driver, and RCWS gunner) and may carry up to nine infantrymen and a stretcher. An ambulance variant can carry two casualties on stretchers and medical equipment.
The Golani Brigade used two Namer IFVs during Operation Cast Lead. During Operation Protective Edge more than 20 vehicles were operated with great success and post operation analysis recommended procuring more of them.

Merkava ARV Nemmera

The Merkava armored recovery vehicle initially called Namer (Hebrew: leopard), but subsequently renamed Nemmera (Hebrew: leopardess). It is an armored recovery vehicle based on a Merkava Mark III or IV chassis. It can tow disabled tanks and carries a complete Merkava back-up power pack that can be changed in the field in under 90 minutes.
There are two versions of Nemmera: the heavier equipped with a 42 ton-meter crane and a 35 ton-meter winch, and the smaller equipped with a smaller crane.

Merkava Howitzer Sholef

Two prototypes of Sholef ("Slammer", Hebrew slang for "Gunslinger") 155 mm self-propelled howitzer with an automatic loading system were built by Soltam in 1984–1986. The 45-ton vehicle had a long 155 mm gun barrel giving a range of 45+ km. Using GPS, inertial navigation, and an internal fire control computer, it was also capable of direct fire while on the move. It never entered production.
The Slammer is a heavily armored artillery gun mounted on a modified Merkava Mk 1 chassis. Many of these vehicles are Merkava Mk 1 that were retired after the Merkava Mk 2 and Merkava Mk 3 came into service. The Slammer has a long 52-caliber gun barrel that allows +10% range. Reload speed may be decreased to 1 for one minute every 10 minutes through use of an automatic loader. Ammunition racks are large. The Slammer is ready for autonomous operation (without an FDC) if the target's location is known within 15 seconds of a halt, using GPS, inertial navigation, and an internal fire control computer.
The Slammer 155 mm self-propelled howitzer is based on a modified Merkava MBT chassis fitted with a new welded steel turret, designed by Soltam Systems.
Development commenced in the 1970s. The project was considered of high national priority and incorporated the newest technological developments. Instead the Israeli Defense Forces selected an upgraded version of American M109 howitzer.
The Sholef's chassis, aside from a few minor modifications, is identical to that of the Merkava Mk.III. The glacis plate is unchanged, except for the addition of a support bracket for the gun turret, which is folded down when not in use. As such, the Sholef and Merkava series share a large percentage of common components. The front-left side of the chassis has a prominent exhaust louver, along with a much smaller port just in front of it; the exact function of this port is uncertain, though the soot seen around it in photos of the Sholef suggests it may be a new or additional exhaust port, or perhaps an outlet for a smoke generator.
The Sholef can be ready to fire only 15 seconds after coming to a complete stop, and fire three projectiles in only 15 seconds. It is compatible with standard NATO 155 mm ammunition, and a total of 75 projectiles can be stowed in one Sholef, 60 of which are ready for combat.
The Sholef's 155mm/52 gun is an original design created by Soltam, though it bears a resemblance to South Africa's G5 Howitzer. It has a fume extractor and muzzle brake, and is kept stationary by a travel lock while the vehicle is on the move. This gun has a maximum rate of fire of 9 rounds/min, and a range in excess of 40,000 m when firing an ERFB-BB round. Though loaded automatically, the gun may be cycled and fire manually if the need arises. While the gun is normally carried by a travel lock as with most other self-propelled howitzers while the Sholef is on the move, the weapon is stabilized and can actually be used for direct-fire while the vehicle is moving, giving it much greater self-defense capability than most other vehicles of its type.
A crew of four is required to fully operate the Sholef. Air conditioning and heating for the crew are provided, as is a ration heater.
The hull has the same ballistic protection as the Merkava Mk.III. The armor on the turret is sufficient to defeat small arms fire, shell splinters, blast overpressure, and most heavy machine gun rounds. The armor is augmented by spall liners, and the same overpressure NBC system as the Merkava Mk.III is fitted. There is also a back-up collective NBC system.
The running gear consists of six unevenly spaced rubber-tired roadwheels on each side, and five return rollers, the second from the rear of which is noticeably larger than the others. The drive sprocket is forward, and the conspicuously spoked idler is rear. These may be partially obscured by track skirts, of which the Merkava Mk.III has ten panels, with a wavering underside, and little coverage of the sprocket or idler.
The ordnance is fitted with a fume extractor and a double-baffle muzzle brake. When travelling, the ordnance is held in position by a travel lock that is mounted on the forward part of the glacis plate and this is remotely operated from the crew compartment.
Firing an ERFB-BB projectile, the 155 mm 52 calibre ordnance has a maximum range of 40,000+ m.
The 155 mm 52 calibre ordnance and recoil system is of the companies well-proven type already used in its towed weapons. The breech block assembly is of the semi-automatic wedge type that contains an automatic primer feeding system that enables manual reloading of the primer without opening the breech. Turret traverse and weapon elevation is hydraulic, with manual controls for emergency use.
A maximum rate of fire of 9 rds/min can be achieved due to the automatic computerised loading system, and a burst rate of fire of three rounds in 15 seconds.
The high rate of fire can be achieved using the onboard ammunition supply or from ground-piled ammunition. The loading cycle is operated by two turret crewmen only, with the commander operating the computer and charge loader.
The automatic loader has five main subsystems: projectile storage system; projectile transfer system; loading tray with flick rammer; charge loading tray and elevator for external charge supply; and projectile elevator for reloading the external storage or directly loading the gun.
The internal projectile storage contains 60 projectiles ready for automatic loading with the remaining 15 stored in other locations. The system enables the handling of all kinds of projectiles in use without any adaptation.
Charge loading is accomplished manually using a loading tray with the ignition primer being inserted automatically. All systems have a manual back-up so that, in the case of failure, the loading system may be operated partly or completely manually by only three crewmen, so allowing a continuous firing rate of 4 rds/min. The computer also controls the functioning of the gun. The Loader Control System (LCS) consists of five main units: The commander's panel provides the means for the commander to control the automatic loader and has a dedicated keyboard and supporting electronic circuits
The Central Control Unit (CCU) is based on the Intel 80286 CPU-8086 and produces all of the system's logic equations. The unit transfers commands through the serial communications (RS-422) to the computerised units and controls the display on the commander's panel
The Terminal Units (TUs) are based on the 8031 controller for purposes of independent control of the drive elements according to a functionally determined division. With the assistance of the terminal unit, a local mode can also be used in working with selected elements
For guiding operators and making round identification and fuzing, the Operator's Panel](OP) includes an LCD display with fixed instructions and one dot matrix line.
The Loader Keyboard Panel (LKP) includes breech block closing switch, fire and local activation of the trays.
The main operational roles are: firing from internal storage; firing for elevator - ground-piled ammunition; loading from elevator - external pile; synthesising fire programs; unloading; manual firing; identification; and fuzing and checks.
Standard equipment includes an NBC system of the overpressure type and an inertial navigation and aiming system designed for autonomous operations.
According to Soltam Systems, the 155 mm/52 calibre ordnance and automatic loader, or parts of the system, could be installed in other self-propelled artillery systems and used to upgrade other self-propelled systems such as the US-designed and built 155 mm M109 and M44.

FMCV

On July 14, 2011, The Jerusalem Post reported that the IDF had begun developing a successor for the Merkava series of tanks. The development was started in part by the arrival of the Trophy active protection system. With the system's ability to intercept threats at a stand-off distance, there was a review of the need for vehicles like the Merkava to have thick, heavy layers of armor. The Merkava Tank Planning Directorate set up a team to study principles for a future tank and present ideas for an armored fighting vehicle to provide mobile firepower on a future battlefield. The team reviewed basic design principles including lessening its weight, armor thickness compared to an APS to intercept anti-tank threats, reducing the crew size, and the type of main gun. Horsepower capabilities and heavy and light track systems compared to a wheeled chassis were also considered. With future battlefield condition developments affecting design features, the vehicle may not be considered a "tank" in the traditional sense. By July 2012, details began to emerge of considerations for developing technologies for the new design. One possibility is the replacement of the traditional main gun with a laser cannon or an electromagnetic cannon. Other improvements could include a hybrid-electric engine and a reduced crew of two. The goals of the new tank are to make it faster, better protected, more interoperable and lethal than the current Merkava.
The 65-ton Merkava is not regarded as useful for missions other than conventional warfare. The Israeli Army Armored Corps wants a lighter and highly mobile vehicle for rapid-response and urban warfare situations that can fill multiple roles. In 2012, the Defense Ministry drafted a program for development of a new family of light armored vehicles called Rakiya (Horizon), a Hebrew acronym for "future manned combat vehicle" (FMCV). The FMCV is planned to weigh 35 tons and have sufficient armor and weapons for both urban and conventional military operations. Instead of one multi-mission chassis, separate vehicles in distinct variants will perform different roles with all vehicles using common components. Vehicles are likely to be wheeled to maneuver in urban environments and move troops and equipment around in built-up areas. While the FMCV will be a fifth-generation vehicle as a follow-on to the Merkava IV, it will not be a replacement for the tank. The Merkava and Namer heavy tracked vehicles will remain in service for decades, while FMCV vehicles are to address entirely different operational requirements. Although the program seems similar to the American Future Combat Systems effort, which failed to produce a family of rapidly deployable lightweight ground vehicles, program officials say they learned from the American experience and that the FMCV was more focused and driven by simpler and more reasonable requirements based on cost considerations. Officials expect requirements for a range of configurations for FMCV light armored vehicles to be approved in 2014 and solicited to Israeli and American companies. The IDF hopes for the FMCV family of vehicles be operational by 2020.

A.P.S. TROPHY

Trophy (Israel Defense Forces designation מעיל רוח, lit. "Windbreaker") is a military active protection system (APS) for vehicles. It intercepts and destroys incoming missiles, rockets, and tank HEAT rounds with a shotgun-like blast. Its principal purpose is to supplement the armour of light and heavy armored fighting vehicles. Developed by Rafael Advanced Defense Systems Ltd. of Israel and currently fielding over 1,000 systems to all major Israeli ground combat platforms (Merkava Mark 3 & 4 and Namer APCs), as well as U.S. Abrams M1A1/2, and tested on the Stryker APCs and Bradley AFVs. Trophy protects against a wide variety of anti-tank threats, while also maximizing the vehicle's ability to identify enemy location to crews and combat formation, thereby providing greater survivability and maneuverability in all combat theatres.
Design
Trophy's first production contract was signed in 2007. Safety certification was granted in 2010. First deliveries started immediately afterward. The design includes the Elta EL/M-2133 F/G band fire-control radar with four flat-panel antennas mounted on the vehicle, with a 360-degree field of view. When a projectile is detected, the internal computer calculates an approach vector almost instantly, before it arrives. Once the incoming weapon is fully classified, the computers calculate the optimal time and angle to fire the counter-measures. The response comes from two rotating launchers installed on the sides of the vehicle which fire a very small number of a MEFPs (Multiple Explosive Formed Penetrators) which form a very tight, precise matrix, aimed at a specific point on the threats Anti-Tank weapon's warhead. The system is designed to have a very small kill zone, so as not to endanger personnel adjacent to the protected vehicle. Trophy is a modular system that enables connectivity to other systems, such as soft-kill, C4I systems, remote-controlled weapon stations, etc.
The system is designed to work against all types of anti-tank missiles, rockets, and tank HEAT rounds, including handheld weapons such as rocket propelled grenades or recoilless rifles. The system can simultaneously engage several threats arriving from different directions, is effective on stationary or moving platforms, and is effective against both short- and long-range threats. Newer versions of the system include a reloading feature for multiple firings. The Trophy development plan includes an enhanced countermeasures unit to be available in the future for protection against kinetic energy penetrators.
Advantages
The primary role of Trophy is defence against missile strikes, particularly for lighter armored personnel carriers, which are very vulnerable to rocket attacks. Since 2011, the system has achieved 100% success in all low and high-intensity combat events, in diversified terrain (urban, open and foliage). The system has intercepted a variety of threats, including the Kornet ATGM, RPG-29, etc. the U.S Army has reported similar success in tests. “I tried to kill the Abrams tank 48 times and failed,” said US Army Col. Glenn Dean. According to Rafael, by 2017, Trophy has accrued over 500,000 operating hours in deployment, bringing the system to a maximum reliability level. In order to ensure minimal collateral damage and low residual penetration, Rafael selected a unique kill mechanism for Trophy, with a surgical effect. The system uses a miniature EFP which penetrates the threat envelope and disintegrates RPGs at a safe distance from the vehicle. In the ATGM's case, the EFP will affect the chemical energy jet, dramatically decreasing its penetration capability into medium-sized platforms. Moreover, it has been proven in tests and wartime, that such a kill mechanism poses an extremely low risk to dismounts around the vehicle, and therefore does not affect usual combined arms tactics, techniques, and procedures (TTP). In order to provide thousands of systems to its customers, Rafael established the first Trophy production line in Israel in 2007, which began delivery in 2010. An additional production line was established in the U.S in 2012, which started deliveries in 2015, with a primary purpose of providing Trophy systems to the IDF as part of the FMF (Foreign Military Funding). Both production line will be used for the U.S. contract and others.
Maneuverability enabler
Trophy's radar is responsible for searching, detecting, classifying, locating, and reporting potential threats to the vehicle's onboard computer network and beyond to the tactical network, creating a Hostile Fire Detection (HFD) capability, which alerts the crew and formation from incoming threats, and instantly provides the exact shooter location on the existing platform display. If Trophy identifies that the threat is going to miss the platform, it will not activate the countermeasure but will provide the shooter location, enabling instantaneous engagement by the combat team, preventing further attacks. The advantage of the built-in HFD capability in symmetric warfare is its ability to provide enemy tank location as well, enabling the combat team to counter-attack the enemy tank.

Disadvantages

The system is currently incapable of defeating kinetic energy tank rounds. Prior to Rafael's declaration of its Medium-sized vehicle active protection Trophy variant (Trophy MV/VPS), there were claims regarding Trophy HV's size and weight.

Trophy MV/VPS

Previously known as "Trophy Light", "Trophy MV/VPS" was unveiled by Rafael Advanced Defence Systems at Britain’s DSEi 2007. While the standard Trophy was designed for main battle tanks, Trophy MV/VPS is designed for integration with light and medium armoured vehicles, such as the Stryker, Bradley, etc. It is expected to be about 40% less in weight and size of the standard Trophy and cost less while maintaining the same performance and reliability as the Trophy HV variant, this as a result of the use of the same major critical elements - the sensor suite, the mission computer, and the hard-kill mechanism, using the same combat algorithms. It has been reported that Leonardo DRS, Rafael's partner for Trophy in the U.S will provide the modified auto-loader for the system. In the Summer of 2018, Rafael conducted an extensive series of qualification tests for Trophy MV/VPS in Israel, with the presence of over 130 decision makers and technical experts from over 15 countries. The tests were conducted in extreme scenarios, using both rockets and ATGMs. The reported success rate was over 95%.

Trophy LV

In June 2014, Rafael unveiled Trophy LV, a lighter application of the system designed to offer protection to light military vehicles (less than 8 tons) such as jeeps and 4x4s. It weighs 200 kilograms (440 lb), significantly less than other Trophy applications.

Combination with Iron Fist

In December 2014, it was revealed that Rafael, IAI, and Israel Military Industries had agreed to jointly develop a next-generation active defense system for vehicles, based on a combination of the Rafael/IAI Trophy and IMI Iron Fist. Rafael will act as the main contractor and system developer and integrator, and IAI and IMI will be subcontractors. The Defense Ministry had pushed the companies to work together and combine their systems. No progress has been reported since then.

Acquisition and tests by the United States

Trophy has been evaluated with extensive testing on a Stryker vehicle for possible adoption by the US Army, and a Canadian LAV III. The Army tested the Trophy system in 2017, to be fielded within two years as an interim capability until the Modular Active Protection System (MAPS) program produces a system. A 193 million dollar contract for Trophy was awarded to Leonardo DRS, Rafael's American partner, in June 2018, in order to equip a significant number of Abrams M1A1/A2 MBTs with Trophy.
Combat history
On March 1, 2011, stationed near the Gaza border, a Merkava MK IV equipped with the Trophy system foiled a missile attack aimed toward it and became the first operational success of the Trophy active defence system. On March 20, 2011, a missile was fired at a Merkava MK IV tank equipped with Trophy system inside the Israeli area along the perimeter fence of the Gaza Strip. The system detected the attack, but determined that it did not endanger the tank and did not intercept it; it passed information about the shooting to the crew, who attacked the source of fire. On August 1, 2012, Trophy successfully intercepted an anti-tank missile launched from the Gaza Strip at a Merkava tank near Kissufim junction.
On July 14, 2014, the Trophy system successfully intercepted a 9M133 Kornet anti-tank missile fired from Gaza at an IDF tank. Since the beginning of the Israeli Operation Protective Edge to July 20, 2014, at least four Israeli tanks of senior commanders were protected by the Trophy system in the Gaza Strip. According to reports from the front, since the beginning of the ground operation, the system successfully intercepted five anti-tank missiles that were aimed at armored IDF vehicles in Gaza. On July 22, 2014, according to a video by a Palestinian group, the Trophy system installed on a Merkava IV tank successfully intercepted an RPG-29 rocket fired at the tank. According to Debkafile, Hamas has tried to stop Israeli tanks with two kinds of advanced guided anti-tank missiles, the Russian Kornet-E, and the 9M113 Konkurs, but Trophy intercepted them successfully. The appearance of near-invulnerable mobile land platforms suggest the current warfare paradigm may need revising. Trophy is currently operational on all Merkava Mark-IV tanks of the IDF's 401st Armored Brigade, as well as with the 7th Armored Brigade 75th Battalion new Merkava IV tanks. In July, the Israeli MOD announced it has completed the integration of Trophy on its first brigade company of NAMER APCs. in November 2016 it was announced that the IDF will purchase hundreds more Trophy systems to be installed on almost all of its Merkava 4 MBTs and NAMER APC/IFVs.

Operation Protective Edge

No tanks were damaged during Operation Protective Edge, with the Trophy Active Protection system performing over a dozen interceptions of anti-tank weapons including Kornet, Metis and RPG-29. The system, by identifying the source of fire, on occasion also allowed tanks to kill the Hamas anti-tank team.
Giora Katz, head of Rafael's land division, stated that it was a "breakthrough because it is the first time in military history where an active defense system has proven itself in intense fighting.” During the war, Trophy validated itself in dozens of events, protecting tanks and crews over three weeks of high-threat maneuvering operations in built-up areas without a single hit to defended platforms and zero false alarms".

Cost

The Trophy "Heavy" system costs around US$ 900,000 to mount on a Merkava Mk. IVM

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mercoledì 29 gennaio 2020

L'AMSTc (Advanced Medium STOL Transport competition): concorso indetto negli anni ’70 dall'USAF per sostituire i C-130 Hercules.



L'AMSTc (Advanced Medium STOL Transport competition): concorso indetto negli anni ’70 dall'USAF per sostituire i C-130 Hercules; dopo anni di sperimentazioni, nacque finalmente il BOEING C 17 GLOBEMASTER III !




Uno dei due finalisti era il Boeing YC-14 era un bimotore turboventola da trasporto tattico ad ala alta con caratteristiche STOL realizzato dall'azienda statunitense Boeing negli anni settanta.
Proposto come il McDonnell Douglas YC-15 nel programma AMST della USAF rimase, come il concorrente, allo stadio di prototipo per l'avvenuta cancellazione del programma.

Storia del progetto

Nel 1971 la United States Air Force promosse una serie di programmi di sviluppo per la valutazione di nuovi velivoli atti a sostituire il parco velivoli esistenti, il Lightweight Fighter (LWF) per un aereo da caccia leggero ed il Advanced Medium STOL Transport (AMST) (aereo STOL da trasporto medio avanzato).
L'AMST mirava ad ottenere un velivolo in grado di sostituire i Lockheed C-130 Hercules in dotazione ai reparti da trasporto USAF. Le specifiche emesse riguardavano la necessità di poter decollare in una distanza massima di 2 000 ft (610 m) da una superficie semi-preparata e di poter operare con un carico di 27 000 lb (12 000 kg) in un raggio d'azione di 400 nm (740 km). Le aziende avrebbero dovuto fornire i progetti per la valutazione iniziale e, dopo la prima fase, due prototipi per le valutazioni comparative.
Al concorso risposero cinque aziende tra cui la Boeing e la McDonnell Douglas, poi contattate per la realizzazione dei velivoli, in quanto giudicati i più meritevoli allo sviluppo, ai quali vennero rispettivamente assegnate le designazioni ufficiali YC-14 e YC-15.
Le prove comparative si svolsero tra il 1975, anno in cui volò per la prima volta l'Y-15, fino al 1979, quando il programma venne cancellato in favore del Programma C-X, che nella decade successiva avrebbe generato il McDonnell Douglas C-17 Globemaster III. Anche se sia l'YC-14 che YC-15 si rivelarono un successo, nessuno dei due aerei venne avviato alla produzione in serie.




Impiego operativo

Il primo Boeing YC-14 (numero 72-1873) volo la prima volta il 9 agosto 1976. Vennero costruiti due aerei, il secondo con numero di coda numero 72-1874. L'avversario, lo YC-15 aveva iniziato a volare quasi un anno prima. i test di volo testa a testa vennero effettuati alla Edwards AFB agli inizi di novembre 1976. Al completamento dei test a fine estate 1977, i prototipi del YC-14 vennero rimandati alla Boeing. I prototipi non vennero demoliti, e uno venne immagazzinato presso lo AMARC, alla base aerea Davis-Monthan e l'altro venne messo in mostra al vicino Prima Air & Space Museum.
A questo punto il programma AMST era già in procinto di essere cancellato. Nel marzo del 1976 il generale dell'Air Force David C. Jones chiese allo Air Force Systems Command se si potesse usare un solo modello per entrambi i modelli di trasporto tattico e strategico, o alternativamente, se si sarebbe potuto sviluppare un derivato non-STOL per il trasporto strategico. Questo portò ad una serie di studi, che in sostanza mostrarono che una tale modifica non sarebbe stata facile, e avrebbe richiesto degli sviluppi sostanziali da inserire nel progetto per poter produrre un aereo più grande. Sia l'YC-14 che l'YC-15 raggiunsero o addirittura superarono le aspettative dell'AMST sotto molti punti di vista. Tuttavia, la crescita dell'importanza di un trasporto strategico rispetto ad uno tattico portarono alla fine del programma AMST nel dicembre 1979 a favore di uno nuovo che portò al C-17 Globemaster III.



L'USB (upper-surface blowing, i motori posti sopra l'ala e col flusso che viene diretto sui flap), utilizzato nella progettazione dell'ala del velivolo, rimase un concetto raro nell'uso, ed è stato usato solo su pochi altri aerei, come sull'Antonov An-72.
  • Utilizzatori: Stati Uniti - United States Air Force.


Il McDonnell Douglas YC-15 è un aereo da trasporto tattico quadrimotore, sviluppato nel corso degli anni settanta, concorrente nell'AMSTc (Advanced Medium STOL Transport competition), indetto dall'USAF per sostituire la propria linea da trasporto tattico composta da C-130 Hercules. Al termine delle valutazioni però, né l'YC-15 né il suo diretto avversario, il Boeing YC-14, vennero dichiarati vincitori. Tuttavia, i progetti dell'YC-15 furono in seguito impiegati per la realizzazione del più noto C-17 Globemaster III.




Storia

Sviluppo

Nel 1968 l'USAF intraprese lo sviluppo di una serie di prototipi che sarebbero stati presentati in occasione dei programmi AMST e Light Weight Fighter. Il bando di gara venne ufficializzato nel gennaio del 1972, ed i requisiti minimi richiesti ai velivoli furono quelli di poter operare da piste semipreparate di lunghezza massima pari a 2 000 m aventi un carico di 12 400 kg ed un raggio d'azione pari a 740 km.
Altri velivoli furono proposti da Bell, Boeing, Fairchild, McDonnell Douglas e Lockheed/North American Rockwell. Il 10 novembre 1972, furono resi noti i nominativi dei velivoli vincitori i quali risultarono essere i prototipi proposti da Boeing e McDonnell Douglas. Alle aziende venne perciò richiesta la realizzazione di ulteriori due esemplari dei rispettivi velivoli. La McDonnell Douglas decise di designare, in questa occasione, il proprio velivolo con la sigla YC-15.




Tecnica

Il progetto della McDonnell Douglas prevedeva la realizzazione d'un velivolo con profilo alare supercritico, risultato di numerosi studi della NASA condotti da Richard Whitcomb. Quest'ala offriva una resistenza aerodinamica del 30% inferiore a quelle con profilo convenzionale, ed allo stesso tempo era in grado di generare un'eccellente portanza alle basse velocità. La maggior parte degli aerei fino ad allora prodotti erano soliti utilizzare ali a freccia per diminuire la resistenza nel fluido, ma ciò portava inevitabilmente ad un volo molto instabile alle basse velocità che li rendeva inadatti per operazioni STOL (Short Take Off and Landing).
La squadra di progettisti, scelse quindi di impiegare un rivoluzionario sistema d'ipersostentatori a soffiaggio esterno con lo scopo di aumentare la portanza. Questo sistema impiegava doppi flap per direzionare parte della spinta dei motori verso il suolo, mentre il resto dei gas di scarico veniva fatto passare attraverso questi seguendo il profilo alare generando un effetto Coandă. Il loro impiego tuttavia non fu realizzabile fino a quando non vennero introdotti i propulsori turboventola il cui flusso di gas di scarico risultava essere meno concentrato e rovente; il problema venne temporaneamente rimandato con l'adozione di ugelli più voluminosi. I propulsori impiegati furono i Pratt & Whitney JT8D, largamente utilizzati sul Boeing 727. L'YC-15 prese in prestito numerose parti dagli altri velivoli prodotti dalla McDonnell Douglas: la prua proveniva dal DC-8 mentre il cockpit dal DC-10.

Impiego operativo

Vennero realizzati due YC-15, uno avente apertura alare di 33,5 metri, l'altro di 40,2 metri. Entrambi erano motorizzati da quattro propulsori turboventola Pratt & Whitney JT8D-17, ognuno capace di 68,9 kN di spinta.
Il primo volo avvenne il 26 agosto 1975. Il secondo prototipo fu portato in volo nel dicembre successivo. Nel 1976, quando furono pronti anche gli esemplari prodotti da Boeing, entrambi i prototipi furono trasferiti presso la Edwards Air Force Base per una serie di test comparati, tra i quali figuravano il trasporto di carichi voluminosi, carri armati e pezzi d'artiglieria, dalla pista semi preparata del Graham Ranch.
L'YC-15 completò l'intero programma, pari a 600 ore di volo, nel 1977. Nel marzo 1976, il capo di stato maggiore dell'aeronautica statunitense il Gen. David C. Jones chiese all'Air Force Systems Command se fosse possibile utilizzare uno solo degli esemplari del progetto AMST per entrambi i ruoli cargo: tattico e strategico. Tutto ciò portò ad una serie di studi che constatarono la difficoltà nel realizzare tali modifiche, che potevano essere più radicali del previsto.
Entrambi i velivoli, sia l'YC-14 che l'YC-15, si rivelarono più efficaci del previsto rispondendo largamente alle richieste del programma AMST. Tuttavia, il bisogno di disporre d'un velivolo da trasporto strategico si fece sempre più strada tanto da portare alla chiusura del programma di sviluppo nel dicembre del 1979. Così nel novembre dello stesso anno, venne istituita la C-X Task Force, con l'obiettivo di riuscire a sviluppare un velivolo dalle caratteristiche differenti. Dal programma C-X venne selezionato un esemplare più capiente dell'YC-15 che fu poi sviluppato nel C-17 Globemaster III.
I prototipi dell'AMST furono destinati all'AMARC, presso la Davis-Monthan Air Force Base. Uno di essi venne successivamente esposto presso il vicino Pima Air & Space Museum. Il primo esemplare realizzato dell'YC-15, (matricola 72-1875) tornò in volo nel 1996 ed ancora nel 1997 per conto della McDonnell Douglas nell'ambito della realizzazione del Globemaster. Un problema tecnico legato al cattivo funzionamento di uno dei propulsori, reputato troppo oneroso, lo relegò per diversi anni presso un magazzino della Boeing presso l'Air Force Plant 42 di Palmdale in California.
Attualmente è in mostra statica presso la Edwards AFB a cui è stato riconsegnato.

ENGLISH

The Boeing YC-14 was a twinjet short take-off and landing (STOL) tactical military transport aircraft. It was Boeing's entrant into the United States Air Force's Advanced Medium STOL Transport (AMST) competition, which aimed to replace the Lockheed C-130 Hercules as the USAF's standard STOL tactical transport. Although both the YC-14 and the competing McDonnell Douglas YC-15 were successful, neither aircraft entered production. The AMST project was ended in 1979 and replaced by the C-X program.

Design and development

In mid-1970, the USAF began a paper study, the Tactical Aircraft Investigation (TAI), with Boeing, McDonnell Douglas, and other companies to look at possible tactical transport aircraft designs. This study was a precursor to what became the Advanced Medium STOL Transport program. As a part of this program, Boeing began to look at various high-lift aircraft configurations. Boeing had earlier proposed an underwing externally blown flap solution for their competitor for the Lockheed C-5 Galaxy, and had put this to good use when they modified their losing entry into the Boeing 747. They had also done studies with the original Boeing 707 prototype, the Boeing 367-80, adding extensive leading and trailing edge devices using blown flaps. For the TAI studies, Boeing again looked at those mechanisms, as well as new mechanisms like boundary layer control. However, none of these studied designs were particularly appealing to Boeing.
The Boeing engineers were aware that NASA had carried out a series of "powered lift" studies some time earlier, including both externally blown flaps, as well an upper-surface blowing (USB), an unusual variation. In the USB system, the engine is arranged over the top surface of the wing, blowing over the flaps. When the flaps are lowered, the Coandă effect makes the jet exhaust "stick" to the flaps and bend down toward the ground. They searched for additional research on the concept, and found that half-span upper-surface blowing research had been conducted in the NASA Langley 12-foot (3.7 m) tunnel. An examination of the preliminary results suggested that the system was as effective as any of the other concepts previously studied. Boeing immediately started to build wind-tunnel models to verify the NASA data with layouts more closely matching their own designs. By the end of 1971, several models were being actively studied.
Another NASA project the engineers were interested in was the supercritical airfoil, designed by Richard Whitcomb. The supercritical design promised to greatly lower transonic drag, as much as a swept wing in some situations. This allowed an aircraft with such a wing to have low drag in cruise while also having a wing planform more suitable to lower-speed flight—swept wings have several undesirable characteristics at low speed. Additionally, the design has a larger leading edge radius that makes it particularly suitable for low-speed high-lift applications like a transport. Boeing incorporated the concept into their design, the first non-experimental aircraft to do so.
The request for proposal (RFP) was issued in January 1972, asking for operations into a 2,000-foot (610 m) semi-prepared field at 500 nautical miles (930 km) with a 27,000 lb (12,000 kg) payload in both directions with no refueling. For comparison, the C-130 of that era required about 4,000 ft (1,200 m) for this load. Five companies submitted designs at this stage of the competition, Boeing with their Model 953 in March 1972. On 10 November 1972 the downselect was carried out, and Boeing and McDonnell Douglas won development contracts for two prototypes each.
Wind tunnel tests continued through this period. In November, John K. Wimpress again visited Langley looking for an update on NASA's own USB program. Joe Johnson and Dudley Hammond both reported on testing and showed Wimpress data that verified the high-lift performance that Boeing had quoted in its proposal. By December 1975, Boeing and NASA Langley had arranged a contract for a full-scale USB testbed, which Boeing built at their Tulalip test facility consisting of a 1/4-scale wing with one JT-15D engine and a partial fuselage. Langley was particularly interested in the effectiveness of the D-shaped nozzle that directed the jet flow over the upper surface of the wing, as well as the resulting sound levels, at that time a major focus of NASA's civilian aerodynamics research.
Two major problems were found and corrected during testing. The first was a problem with air circulating around the wing when operating at low speeds close to the ground, which had a serious effect on the spreading of the jet flow through the nozzle. This led to flow separation near the flap, and a decrease in effectiveness of the USB system. In response, Boeing added a series of vortex generators on the upper surface of the wing, which retracted when the flap was raised above 30°. Additionally, the tail surfaces were initially placed well aft in order to maximize control effectiveness. This positioning turned out to interfere with the airflow over the wings during USB operations, and a new tail with a more vertical profile was introduced to move the elevator forward.

Operational history

The first Boeing YC-14 (serial number 72-1873) flew on 9 August 1976. Two aircraft were built, the second being s/n 72-1874. The competing YC-15 had started flights almost a year earlier. Head-to-head flight testing at Edwards Air Force Base started in early November 1976. During flight testing, the YC-14 was flown at speeds as low as 59 kn (68 mph; 109 km/h) and as high as Mach 0.78 at 38,000 feet (11,600 m). However, it was found that the YC-14's drag was 11% higher than originally predicted. Modifications developed in wind tunnel testing, comprising the addition of vortex generators to the upper aft portion of the nacelles, deletion of the nozzle door actuator fairing, alterations to the aft end of the landing gear pods and the addition of aft fuselage strakes, reduced this drag increment to 7%. The YC-14 also demonstrated the capability to carry the 109,200-pound (49,500 kg) M60 Patton main battle tank, something that was not demonstrated with the YC-15.
At the completion of testing in the late summer of 1977, the YC-14 prototypes were returned to Boeing. The prototypes were not scrapped; one is stored at AMARC, located at Davis-Monthan Air Force Base and the other is on display at the nearby Pima Air & Space Museum.
By this point, the seeds of the AMST program's demise had already been sown. In March 1976, the Air Force Chief of Staff, Gen. David C. Jones, asked the Air Force Systems Command to see if it would be possible to use a single model of the AMST for both strategic and tactical airlift roles, or alternatively, if it would be possible to develop conventional derivatives of the AMST for the strategic airlift role. This led to a series of studies that basically stated that such a modification was not easy, and would require major changes to either design to produce a much larger aircraft.
Both the YC-14 and YC-15 met or exceeded the AMST specifications under most conditions. However, the increasing importance of the strategic vs. tactical mission eventually led to the end of the AMST program in December 1979. Then, in November 1979, the C-X Task Force formed to develop the required strategic aircraft with tactical capability. The C-X program selected a proposal for an enlarged and upgraded YC-15 that was later developed into C-17 Globemaster III.
Upper surface blowing remains a fairly rare concept in use, and has been seen only on a few other aircraft, such as the Antonov An-72.

Aircraft on display

Aircraft serial number 72-1873 is on display at the Pima Air & Space Museum in Tucson, Arizona. The other is in storage at the 309th AMARG boneyard at Davis Monthan Air Force Base (32.17184°N 110.84743°W).

Specifications

General characteristics
  • Crew: 3
  • Capacity: 150 troops or 69,000 lb (31,400 kg) (STOL: 27,000 lb (12,300 kg))
  • Length: 131 ft 8 in (40.14 m)
  • Wingspan: 129 ft 0 in (39.32 m)
  • Height: 48 ft 4 in (14.74 m)
  • Wing area: 1,762 sq ft (163.7 m2)
  • Empty weight: 117,500 lb (53,410 kg)
  • Max takeoff weight: 251,000 lb (113,850 kg) (conventional landing and takeoff), 170,000 lb (77,270 kg) (STOL)
  • Powerplant: 2 × General Electric CF6-50D turbofans, 51,000 lbf (230 kN) thrust each.

Performance
  • Maximum speed: 504 mph (811 km/h, 438 kn)
  • Cruise speed: 449 mph (723 km/h, 390 kn)
  • Ferry range: 3,190 mi (5,136 km, 2,734 nmi)
  • Service ceiling: 45,000 ft (13,716 m)
  • Rate of climb: 6,350 ft/min (32.3 m/s).


The McDonnell Douglas YC-15 was a prototype four-engine short take-off and landing (STOL) tactical transport. It was McDonnell Douglas' entrant into the United States Air Force's Advanced Medium STOL Transport (AMST) competition to replace the Lockheed C-130 Hercules as the USAF's standard STOL tactical transport. In the end, neither the YC-15 nor the Boeing YC-14 was ordered into production, although the YC-15's basic design would be used to form the successful McDonnell Douglas (later Boeing) C-17 Globemaster III.

Design and development

In 1968, the USAF started work on a series of prototype proposals, which would lead to both the AMST project and the Light Weight Fighter. The official Request for proposal (RFP) was issued in January 1972, asking for operations into a 2,000-foot (610 m) semi-prepared field with a 27,000-pound (12,000 kg) payload and a 400-nautical-mile (460 mi; 740 km) mission radius. For comparison, the C-130 of that era required about 4,000 feet (1,200 m) for this load. Proposals were submitted by Bell, Boeing, Fairchild, McDonnell Douglas and the Lockheed/North American Rockwell team at this stage of the competition. On 10 November 1972, the two top bids (from Boeing and McDonnell Douglas) were selected. The companies were awarded development contracts for two prototypes each. McDonnell Douglas' prototype was designated YC-15.
McDonnell Douglas's design incorporated a supercritical wing, the result of NASA research carried out by the already famous Richard Whitcomb. This wing design dramatically lowers transonic wave drag by as much as 30% compared to more conventional profiles, while at the same time offering excellent low-speed lift. Most contemporary aircraft used swept wings to lower wave drag, but this led to poor low-speed handling, which made them unsuitable for STOL operations.
The design team also chose to use externally blown flaps to increase lift. This system uses double-slotted flaps to direct part of the jet exhaust downwards, while the rest of the exhaust passed through the flap and then followed the downward curve due to the Coandă effect. Although the effects had been studied for some time at NASA, along with similar concepts, until the introduction of the turbofan the hot and concentrated exhaust of existing engines made the system difficult to use. By the time of the AMST project, engines had changed dramatically and now provided larger volumes of less-concentrated and much cooler air. For the YC-15, four engines were used, versions of the Pratt & Whitney JT8D-17 widely used on the Boeing 727 and Douglas DC-9. The YC-15 borrowed components from other McDonnell Douglas aircraft, with its nose gear coming from the Douglas DC-8 and the nose section & cockpit being derived from the Douglas DC-10. Parts borrowed from other aircraft included the Universal Aerial Refueling Receptacle Slipway Installation (UARRSI), taken from a Fairchild A-10, anti-tipover stabilizer struts from the Lockheed C-141 Starlifter, pumps taken from the McDonnell Douglas F-15 Eagle, Lockheed C-5 Galaxy, DC-9 and C-141 and actuators taken from the C-5 Galaxy and DC-10. In addition, the environmental cooling system was composed of components taken from the DC-9, C-141 and Boeing KC-135.

Operational history

Two YC-15s were built, one with a wingspan of 110 feet (34 m) (#72-1876) and one of 132 feet (40 m) (#72-1875). Both were 124 feet (38 m) long and powered by four Pratt & Whitney JT8D-17 engines, each with 15,500 pounds-force (69,000 N) of thrust.
The first flight was on 26 August 1975. The second prototype followed in December. They were tested for some time at McDonnell Douglas as the Boeing entry was not ready until almost a year later. In November 1976, both designs were transferred to Edwards Air Force Base for head-to-head testing, including lifting heavy loads like tanks and artillery from dirt airfields at Graham Ranch, off the end of Runway 22.
In Phase II of the flight test program, a "refanned" Pratt & Whitney JT8D-209 was tested in No. 1 nacelle of 72–1876 and a CFM International CFM56 was tested in the No. 1 nacelle of 72–1875. In addition, a new wing with increased chord and span was flown on 72-1875.
The YC-15s completed a 600-hour flight test program in 1977. By this point, the seeds of the AMST program's demise had already been sown. In March 1976, the Air Force Chief of Staff, Gen. David C. Jones, asked the Air Force Systems Command to see if it was possible to use a single model of the AMST for both strategic and tactical airlift roles, or alternatively, if it was possible to develop non-STOL derivatives of the AMST for the strategic airlift role. This led to a series of studies that basically stated that such a modification was not easy, and would require major changes to either design to produce a much larger aircraft.
Both the YC-14 and YC-15 met or exceeded the AMST specifications under most conditions. However, the increasing importance of the strategic vs. tactical mission eventually led to the end of the AMST program in December 1979. Then, in November 1979, the C-X Task Force formed to develop the required strategic aircraft with tactical capability. The C-X program selected a proposal for an enlarged and upgraded YC-15 that was later developed into the C-17 Globemaster III. The Lockheed C-130 Hercules would be further improved into the C-130J and remains in service.
After the flight test program, the two aircraft were stored at the AMARC, located at Davis-Monthan Air Force Base. One aircraft (72-1875) was subsequently moved to the nearby Pima Air & Space Museum in 1981, but was returned to flying status by McDonnell Douglas in 1996; and was first reflown on 11 April 1997. On 16 April 1997, the aircraft was ferried to Long Beach, California to support the C-17 program. On 11 July 1998, the aircraft suffered a massive failure of the No. 1 engine during flight and made an emergency landing at Palmdale, California. On inspection, the aircraft was deemed too expensive to repair and was stored at Palmdale. In 2008, the aircraft was moved by road to Edwards AFB, where it is now on display at the Air Force Flight Test Center Museum's "Century Circle" display area, just outside the base's west gate. The other airframe (72–1876), which had remained on Celebrity Row at the AMARC for many years, was destroyed in place in April 2012.

Specifications

General characteristics
  • Crew: 3
  • Capacity: Up to 150 troops or 78,000 lb (35,000 kg) of cargo
  • Length: 124 ft 3 in (37.9 m)
  • Wingspan: 110 ft 4 in/132 ft 7 in (33.6 m/40.4 m)
  • Height: 43 ft 4 in (13.2 m)
  • Wing area: 1,740 ft² (160 m²)
  • Empty weight: 105,000 lb (47,600 kg)
  • Max. takeoff weight: 216,680 lb (98,285 kg)
  • Powerplant: 4 × Pratt & Whitney JT8D-17 turbofans, 16,000 lbf (72.5 kN) each.

Performance
  • Maximum speed: 590 mph (510 knots, 950 km/h)
  • Cruise speed: 543 mph (471 knots, 872 km/h)
  • Range: 2,995 mi (2,600 nm, 4,800 km) with a 38,000-pound (17,000 kg) payload
  • Service ceiling: 30,000 feet (9,100 m).

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