L'Infantry Tank Mk IV "Churchill"

L'Infantry Tank Mk IV "Churchill" fu un carro armato per fanteria britannico prodotto durante la seconda guerra mondiale, famoso per la sua spessa corazza, la sua robustezza e la sua facilità di impiego come veicolo duttile e robusto. Deve il suo nome a Winston Churchill, all'epoca anche Ministro della Guerra britannico, che fu uno dei più grandi sostenitori dello sviluppo dei carri armati già dalla prima guerra mondiale.

Storia

Nel settembre 1939 il comando dell'esercito inglese si rese conto del fatto che la Gran Bretagna non aveva alcun carro pesante in grado di competere con i carri tedeschi più potenti (come il Panzer IV) o di accompagnare efficacemente la fanteria contro obiettivi fortificati. Inoltre, di lì a poco, i tedeschi, dopo aver conquistato la Francia e il Benelux, sarebbero diventati una minaccia reale per la stessa Gran Bretagna. Era quindi necessario porre rimedio, al più presto, a questa mancanza. È vero che l'esercito inglese disponeva già del discreto Mk II Matilda, ma ci si accorse presto che non sarebbe stato in grado di tenere il passo con i sempre più potenti Panzer tedeschi: il carro Churchill sostituì quindi l'ormai obsoleto Matilda dopo il 1942.

Sviluppo

Una ditta irlandese la Harland and Wolff ebbe l'incarico di progettare questo nuovo carro e, sebbene fosse già la fine del 1939, tutti i modelli studiati subivano ancora l'influenza dell'impiego dei mezzi corazzati durante la Prima guerra mondiale: vennero studiati mezzi pesantissimi e corazzatissimi, persino con armamenti appesi su gondole laterali. Progettati essenzialmente per la guerra di trincea, e quindi superare ostacoli, buche provocate dall'artiglieria, demolire ostacoli come filo spinato, e colpire difese statiche, tutte operazioni che non necessitavano di un veicolo rapido, ma di un veicolo lento e pesantemente corazzato.

I risultati si videro dopo solo un anno: il mezzo che ne risultò, pur non essendo un ritorno totale ai vecchi schemi, aveva alcune peculiarità tipiche dei carri della Grande Guerra. Il prototipo era il carro "A20", armato con due cannoncini ai lati e un terzo sulla torretta centrale.

Con la capitolazione della Francia, le innovazioni della Blitzkrieg, e le numerosissime perdite di carri lasciati in mano tedesca dopo l'evacuazione di Dunkerque, l'esercito inglese si rese conto che era necessario lo sviluppo rapido di un nuovo carro armato veloce da produrre, e con caratteristiche tecniche più moderne, anche in vista di difendere il suolo inglese da una sempre più vicina minaccia di attacco tedesco. Così i disegni furono rivisti dal dott. H.E. Merritt, direttore del Tank Design Woolwich Arsenal, e nel giugno 1941 iniziò una produzione febbrile dei nuovi carri A22 denominato ben presto Churchill. A causa della sua celerità il progetto non fu privo di difetti, il motore era sottodimensionato, l'accesso allo stesso difficoltoso e l'armamento debole, fattori che contribuirono al fallimento in azione dei primi carri, soprattutto a Dieppe nell'agosto 1942.

Nel marzo del 1943, dopo una sospensione della produzione a favore del più affidabile carro Mk VIII Cromwell, comparve il Churchill Mk III, l'evoluzione del precedente, che fu utilizzato durante la seconda battaglia di El Alamein, dove i carri si comportarono bene e resistettero molto efficacemente alle artiglierie e ai raid aerei tedeschi. Le campagne degli Alleati continuarono così come lo sviluppo del Churchill, che presentò un grosso miglioramento con il modello Mk VII, utilizzato in Normandia, armato con un cannone da 75 mm.

Per la sua versatilità il Churchill fu utilizzato e sviluppato in molte varianti, da "gettaponti" a veicolo "anfibio" fino a "lanciafiamme", e anche l'Unione Sovietica ricevette circa 300 Churchill Mk III ed Mk IV. Fu un carro longevo in quanto rimase in servizio con l'esercito inglese fino al 1952, e nella versione gettaponti addirittura fino al 1970.

Tecnica

Il carro era dotato di larghi cingoli avvolgenti, i quali gli garantivano un'ottima manovrabilità, una buona tenuta di strada e il vantaggio degli accessi laterali, che permettevano agli occupanti un agevole accesso e, all'occorrenza, una rapida fuga dal mezzo. Gli stessi cingoli avvolgenti davano però qualche problema di manutenzione ed esponevano il carro ai colpi sulle fiancate, tutti questi erano vantaggi e svantaggi tipici dei mezzi con cingoli avvolgenti. I cingoli erano mossi da undici ruote da 10 pollici, solo nove di queste però sostenevano il peso del carro, mentre le altre, assieme alla ruota motrice anteriore e a quella di richiamo posteriore, fungevano da "bilanciamento" nel caso il carro si trovasse nella condizione di superare ostacoli come trincee percorrere terreni molto sconnessi.

La corazzatura era la caratteristica più importante del carro Churchill: spessa fino a 100 mm nella parte frontale e ancor di più in torretta. L' Mk VII addirittura arrivava ad avere una corazzatura spessa fino a 152 mm, nessuna corazza del 1942 era in grado di competere con quella del Churchill (tranne quella del Panzer VI Tiger I tedesco); l'aumento di corazzatura però era proporzionale ad un aumento di peso, mentre l'Mk I pesava 39.118 kg e l'Mk III, pesava 39.626 kg, l'Mk VII pesava 40.643 kg, ciò lo rese un mezzo pesante e di conseguenza lento, l'Mk VII arrivava appena ad una velocità di 21 km/h, l'autonomia, di circa 150 km, era, invece, nella media.

Anello debole del Churchill era l'armamento, che fino alla versione Mk VII montava un cannone Ordnance QF 75 mm in grado di competere con i Tiger, ma non sempre alla pari, anche perché una delle debolezze del Churchill è sempre stata la potenza di fuoco.

Varianti

Modelli convenzionali

Le caratteristiche sopraelencate sono comuni a tutte le versioni, salvo qualche piccola differenza di peso, e di spessore della corazza, quel che distingue una versione dall'altra è soprattutto l'armamento principale:

• Mk I - Il primo modello prodotto aveva come arma principale un obice Ordnance QF 3 inch da 76,2 mm in casamatta, questo significava che per puntare l'arma era necessario ruotare l'intero carro, inoltre il 76,2 mm non era un calibro eccezionale, se usato come obice di artiglieria. In torretta era montato un cannone anticarro Ordnance QF 2 lb da 40 mm, lo stesso del Mk II Matilda, del Mk VI Crusader e di molti altri carri inglesi costruiti durante la prima metà del conflitto. Per la difesa ravvicinata il carro disponeva di una mitragliatrice BSA Besa da 7,92 mm in torretta e un Bren da 7,7 mm montato in posizione antiaerea.
• Mk II - A partire da questo modello, si è preferito sostituire l'obice da 76,2 mm, costoso e di difficile utilizzo, con un'altra mitragliatrice da 7,92 mm, montata nella parte frontale del veicolo. Il resto degli armamenti fu mantenuto.
• Mk III - Successivamente ci si accorse che il cannone da 40 mm era diventato insufficiente per contrastare i carri nemici, quindi, quando il Mk III fu prodotto, questo fu sostituito dal più potente cannone anticarro Ordnance QF 6 lb da 57 mm, lo stesso del Mk III Valentine.
• Mk IV - In questa versione la torretta era realizzata per fusione, anziché con piastre saldate, questo serviva per renderla più resistente ai colpi diretti.
• Mk V - In questo particolare modello di carro pioniere il cannone fu sostituito con un mortaio medio Ordnance QF 95 mm, da usare per il tiro ravvicinato contro postazioni fortificate. Durante il D-Day fu usato un particolare Mk V denominato "AVRE" (Armoured Vehicle Royal Engineers) che montava un mortaio pesante Petard da 290 mm, un calibro 3 volte più grande del mortaio standard.
• Mk VI - In questa versione il cannone da 57 mm, ormai obsoleto e pressoché inutile contro carri pesanti come il Panzer V Panther e il Tiger I, fu sostituito dal cannone da 75 mm, lo stesso che verrà usato anche per il Mk VIII Cromwell.
• Mk VII - Infine questo modello, rimasto in servizio per molti anni nel dopoguerra, disponeva delle stesse armi del Mk VI, ma era stato costruito con una sagoma completamente ridisegnata. In particolare il Mk VII (assieme all'AVRE) ebbe l'onore e l'onere di rappresentare i mezzi corazzati pesanti inglesi durante il D-Day e la successiva campagna di liberazione.
• Mk VIII - In questa versione fu sostituito il cannone principale con un obice da 95 mm con 47 colpi.
• Mk IX - In pratica era un Churchill III (o IV) con la torretta dell'Mk VII, con corazzatura extra, cambio e sospensioni modificate.
• Mk X - Gli stessi miglioramenti della versione Mk IX, ma applicate a un carro Mk VI.
• Mk XI - Praticamente un Churchill Mk V con armi extra la torretta dell'Mk VIII.
• Mk XIII - Sviluppo con il cannone da 75 mm, e corazza rinforzata, ma con una nuova cupola di visione del capocarro simile a quelle montate sui carri tedeschi che permetteva di vedere al di fuori senza dover uscire dal portello. In servizio la prima volta in Normandia, rinominato A42 nel 1945.

Modelli speciali

A seconda del loro uso vennero creati alcuni tipi di Churchill "speciali" per svolgere determinati compiti:

• Churchill Oke - Semplicemente dei Churchill Mk II o Mk III armati di lanciafiamme Ronson, fu chiamato Oke in onore del suo ideatore, il maggiore J.M. Oke. Il serbatoio contenente il combustibile liquido era montato nella parte posteriore, con un tubo che lo portava dalla carena anteriore a sinistra, lasciando la parte anteriore con il cannone libero. Furono sviluppate tre versioni Boar (Cinghiale), Beetle (Maggiolino) e Bull (Toro), utilizzati a Dieppe con scarsi risultati e presto abbandonati.
• Churchill anfibio Alcuni modelli del tipo Mk1, Mk2 e Mk3 furono resi anfibi, in occasione del fallimentare sbarco a Dieppe. Dotati di speciali prese d'aria e marmitte, essi avrebbero dovuto entrare in funzione contro le postazioni tedesche subito dopo lo sbarco. Non andò così, gli alleati subirono gravi perdite e molti mezzi, ancora perfettamente funzionanti, vennero catturati dai tedeschi.
• Churchill NA75 - Dei Churchill Mk III / IV armati con il cannone da 75mm già montato sugli M4 Sherman, e adeguato spostando il caricatore da sinistra a destra, come la prassi inglese impone, e tagliando via la parte anteriore della torretta per far posto al cannone.
• AVRE - Un Mk V che montava un mortaio spigot pesante da 290 mm, realizzato appositamente per i Royal Engineers, i genieri dell'esercito britannico in occasione del D-Day. Questo mezzo era in grado di sparare proiettili pesanti 18 kg (di cui 12 di alto esplosivo) ad una distanza di poco inferiore ai 100 metri, la frequenza di tiro era di 3 colpi al minuto. Il loro scopo era di attaccare a distanza ravvicinata, e distruggere, i bunker sulla spiaggia per poter garantire un passaggio sicuro alla fanteria, e ai veicoli leggeri.
• ARV (Armoured Recovery Vehicle) - Attrezzato per il recupero dei carri danneggiati sul campo di battaglia, montava un braccio anteriore capace di trainare circa 7,5 tonnellate, e un verricello capace di trainare 25 t. All'interno oltre all'equipaggio di tre uomini c'era abbastanza spazio per l'equipaggio soccorso.
• ARK (Armoured Ramp Carrier) - Un Churchill con rampe ad entrambe le estremità poggiate lungo lo scafo in modo da formare un ponte mobile.
• Churchill Great Eastern - Evoluzione dell'ARK, con una rampa più grande per l'attraversamento di ostacoli di circa 20m (60 ft), ne furono costruiti una decina consegnati due nel 1945, ma mai utilizzati in azione.
• Kangaroo - Churchill convertito in APC
• Carpet Layer - Questo modello era uno speciale Churchill AVRE in grado di stendere un "tappeto" di canapa che serviva per creare un sentiero sicuro, anche se momentaneo, attraverso a terreni infidi come una palude o un acquitrino. Molto spesso questo carro era dotato degli stessi sistemi di galleggiamento dei carri Churchill anfibi usati a Dieppe.
• Crocodile - Questo modello di Churchill fu il principale veicolo lanciafiamme usato dall'esercito britannico. Nel Churchill il tubo lanciafiamme sostituiva la mitragliatrice di scafo; il liquido infiammabile proveniva da un rimorchio, agganciato alla parte posteriore del carro, contenente una riserva di quasi 2.000 litri di fluido e, in caso di emergenza, il rimorchio poteva essere sganciato dall'interno. Il lanciafiamme del Crocodile aveva una portata di oltre cento metri.
• Churchill gun carrier - Semovente cacciacarri ottenuto dalla struttura di un Churchill IV cui era stata tolta la torretta per installare al suo posto una grossa casamatta rettangolare armata con un cannone navale QF 3-inch cwt; poteva avere un motore Meadows D.A.V. oppure un Bedford twin-six. Il progetto rimase allo stadio di prototipo
• Black Prince - L’ultimo modello di Churchill, rimasto allo stadio di prototipo, fu il Black Prince, esso aveva una corazza frontale di circa 150 mm e montava l'ottimo cannone anticarro da 17 libbre calibro 76,2, lo stesso montato sulle versioni modificate dai britannici degli M10 Wolverine e M4 Sherman, denominate rispettivamente Achilles e Sherman Firefly.

Impieghi operativi

Superata con successo la fase di test, il Churchill, con tutte le sue varianti, prese parte ad ogni operazione militare inglese. I suoi più importanti impieghi operativi furono, come è stato già specificato, l'incursione a Dieppe e lo sbarco in Normandia; comunque il Churchill prese parte a molte altre battaglie come la guerra in Nordafrica, la campagna d'Italia e la campagna in Francia, oltre a molte altre battaglie minori, tanto che i più avanzati modelli di Churchill saranno usati in alcuni eserciti molti anni dopo la fine della guerra. L'ultimo Churchill fu ritirato dal servizio nel 1960.

ENGLISH

The Tank, Infantry, Mk IV (A22) Churchill was a British heavy infantry tank used in the Second World War, best known for its heavy armour, large longitudinal chassis with all-around tracks with multiple bogies, its ability to climb steep slopes, and its use as the basis of many specialist vehicles. It was one of the heaviest Allied tanks of the war.

The origins of the design lay in the expectation that war in Europe might be fought under similar conditions to those of the First World War and emphasised the ability to cross difficult ground. The Churchill was rushed into production to build up British defences against a possible German invasion. The first vehicles had flaws that had to be overcome before the Churchill was accepted for wide use. After several marks had been built, a better-armoured version, the Mark VII, entered service. The improved versions performed well in the later stages of the war.

The Churchill was used by British and Commonwealth forces in the North Africa campaign, in Italy, and in northwest Europe. In addition, a few hundred were supplied to the USSR and used on the Eastern Front.

Name

The Churchill tank was named after Prime Minister Winston Churchill, who had promoted the development of the tank in the First World War. Churchill told Field Marshal Jan Smuts "That is the tank they named after me when they found out it was no damn good!"

The name only incidentally matched what became the British Army practice of giving service names beginning with C to cruiser tanks, such as the Covenanter, Crusader, and the later Cromwell, Cavalier and Comet. Infantry tank naming had no particular pattern. Post-war, the merging of the cruiser and infantry tank lines in the 'universal' or main battle tanks continued with C names: Centurion, Conqueror, Chieftain, and Challenger.

History

A20

Initially specified before the outbreak of the Second World War, the (General Staff designation) A20 was to be the replacement for the Matilda II and Valentine infantry tanks. In accordance with British infantry tank doctrine and based on the expected needs of World War I-style trench warfare, the tank was required to be capable of navigating shell-cratered ground, demolishing infantry obstacles such as barbed wire, and attacking fixed enemy defences; for these purposes, great speed and heavy armament were not required.

The vehicle was specified initially to be armed with two QF 2 pounder guns, each located in a side sponson with a coaxial BESA machine gun. A third BESA and a smoke projector would be fitted in the front hull. The specification was revised to prefer a turret with 60 mm of armour to protect against ordinary shells from the German 37 mm gun. Outline drawings were produced based on the A12 Matilda turret and the engine of the Covenanter tank. Detail design and construction of the A20 was given to the Belfast shipbuilders Harland and Wolff, who completed four prototypes by June 1940. During the construction period, the armament was reconsidered, including fitting either a 6-pounder or a French 75 mm gun in the forward hull. In the end, a 3-inch howitzer was chosen. The A20 designs were short-lived, however, as at roughly the same time the emergency evacuation of the British Expeditionary Force from Dunkirk occurred.

At 43 tons, with a 300 hp flat-12 Meadows engine, the A20 had limited power compared to the 18-ton Covenanter. This was a less serious limitation than it might appear, owing to the British distinction between the high-speed cruiser tanks and the slow-speed infantry tanks. Vauxhall were approached to see if they could build the A20 and one example was sent to Vauxhall at Luton to see if they could provide an alternative engine. To this end, they developed a flat-12 petrol engine. For speed of production, this engine was based on a Bedford six-cylinder lorry engine, giving rise to its name of “Twin-Six". Although still a sidevalve engine, the engine was developed with high squish pistons, dual ignition and sodium-cooled exhaust valves in Stellite seats to give 350 bhp.

A22

With France lost, the scenario of trench warfare in Northern Europe was no longer applicable and the design was revised by Henry Merritt, Director of Tank Design at Woolwich Arsenal, based on the combat witnessed in Poland and France. These new specifications, for the A22 or Infantry Tank Mark IV, were given to Vauxhall in June 1940.

With a German invasion of Britain looking imminent, and the loss of a substantial amount of military vehicles in the evacuation from France, the War Office specified that the A22 had to enter production within a year. By July 1940, the design was complete and by December of that year the first prototypes were completed; in June 1941, almost exactly a year as specified, the first Churchill tanks began rolling off the production line.

A leaflet from the manufacturer was added to the User Handbook saying:

Fighting vehicles are urgently required, and instructions have been received to proceed with the vehicle as it is rather than hold up production.

All those things which we know are not as they should be will be put right.

The document then described known faults, with work-rounds and what was being done to correct the problem.

Because of its hasty development, there had been little testing and the Churchill was plagued with mechanical faults. Most apparent was that the Churchill's engine was underpowered, unreliable, and difficult to access for servicing. Another serious shortcoming was the tank's weak armament, the 2 pounder (40 mm) gun, which was improved by the addition of a 3-inch howitzer in the hull to deliver a HE shell, albeit not on a howitzer's usual high trajectory.

Production of a turret to carry the QF 6 pounder gun began in 1941, but problems with the plate used in an all-welded design led to an alternative cast turret also being produced. These formed the distinction between Mark III and Mark IV.

The poor speed of the Churchill nearly caused production to be ceased in favour of the forthcoming Cromwell tank; it was saved by the successful use of the Mk III at the Second Battle of El Alamein in October 1942.

In the same year, the Churchill was also used at the Dieppe Raid.

The second major improved Churchill, the Mk VII, was first used in the Battle of Normandy in 1944. The Mk VII improved on the already heavy armour of the Churchill with a wider chassis and the British 75 mm gun, which had been introduced on the Mk VI. It was primarily this variant, the A22F, which served through the remainder of war. It was re-designated A42 in 1945.

The Churchill was a versatile project and was used in numerous specialist roles.

Design

The hull was made up of simple flat plates, which were bolted together in earlier models and were welded in later models. The hull was split into four compartments: the driver's position at the front, then the fighting compartment including the turret, the engine compartment, and the gearbox compartment. The suspension was fitted under the two large "panniers" on either side of the hull, the track running over the top. There were eleven bogies either side, each carrying two 10-inch wheels. Only nine of the bogies normally took the vehicle weight, the front coming into play when the vehicle nosed into the ground or against an obstacle, the rear acting in part as a track tensioner. Due to the number of wheels, the tank could survive losing several without much in the way of adverse effects as well as traversing steeper terrain obstacles. As the tracks ran around the panniers, escape hatches in the side could be incorporated into the design. These were retained throughout the revisions of the Churchill and were of particular use when the Churchill was adopted as the AVRE.

The Bedford Vehicles engine was effectively two engines in horizontally opposed configuration ("flat twelve") on a common crankshaft. There were four Solex carburettors each on a separate manifold that fed three cylinders formed as a single cylinder head. The elements of the engine and ancillary components were laid out so they could be reached for maintenance through the engine deck covers. Air for the engine was drawn from the fighting compartment through air cleaners. Cooling air was drawn into the engine compartment through louvres on the sides, across the radiators and through the engine compartment by a fan driven by the clutch. This fan blew the air over the gearbox and out the rear of the hull. By opening a flap between the fighting compartment and the engine compartment, this airflow could be used to remove fumes produced by firing the armament. The 1,296 cu in (21.238 L) capacity engine was rated at 350 bhp at 2,000 rpm, delivering 960 lb⋅ft (1,300 N⋅m) torque over an engine speed range from 800 to 1,600 rpm.

The gearbox featured a regenerative steering system that was controlled by a tiller bar instead of the more commonplace brake levers or, as with the German Tiger I heavy tank, a steering wheel. The tiller was connected, with servo assistance, hydraulically to the steering brakes. The Churchill was also the first tank to utilise the Merritt-Brown triple differential gearbox, which allowed the tank to be steered by changing the relative speeds of the two tracks; this effect became more pronounced with each lower gear, ultimately allowing the tank to perform a "neutral turn" when no gear was engaged, where it could fully pivot within its own length. There were final reduction gears, of the planetary type, in the driving wheels.

The first turrets were of cast construction and were rounded in shape, providing sufficient space to accommodate the relatively small 2 pounder gun. To fulfil its role as an infantry support vehicle, the first models were equipped with a 3-inch howitzer in the hull in a layout very similar to the French Char B1. This enabled the tank to deliver a useful high-explosive capability while retaining the anti-tank capabilities of the 2 pounder. However, like other multi-gun tanks, it was limited by a poor fire arc - the entire tank had to be turned to change the aim of the hull gun. The Mk II dispensed with the howitzer and replaced it with a bow machine gun and on the Mk III, the 2 pounder was replaced with the 6 pounder, significantly increasing the tank's anti-tank capabilities. The tank underwent field modification in North Africa with several Churchills being fitted with the 75 mm gun of destroyed M4 Shermans. These "NA75" variants were used in Italy. The use of the 75 mm increased the effectiveness of the tank, as it was a generally superior weapon to the 6 pounder, possessing similar anti-tank capabilities, while also being considerably more effective when used in infantry support roles.

Churchills made use of the Vickers Tank Periscope MK.IV. In the Mark VII, the driver had two periscopes as well as a vision port in the hull front that could be opened. The hull gunner had a single periscope as well as the sighting telescope on the BESA machine gun mounting. In the turret, the gunner and loader each had single periscope and the commander had two fitted in his hatch cupola.

The armour on the Churchill, often considered its most important feature, was originally specified to a minimum of 16 millimetres (0.63 in) and a maximum of 102 millimetres (4.0 in); this was increased with the Mk VII to a range from 25 millimetres (0.98 in) to 152 millimetres (6.0 in). Though this armour was considerably thicker than its rivals (including the German Tiger I tank, but not the Tiger II) it was not sloped, reducing its effectiveness. Earlier models were given extra armour by the expedient of welding on extra plates.

On the Mark VII, the hull front armour was made up of a lower angled piece of 5.5 in (140 mm), a nearly horizontal 2.25 in (57 mm) plate and a vertical 6 inch plate. The hull sides, were, for the most part, 3.75 in (95 mm). The rear was 2 in (51 mm) and the hull top 0.525 in (13.3 mm). The turret of the Mark VII was 6 in (150 mm) to the front and 3.75 in (95 mm) for the other sides. The turret roof was 0.79 (20 mm) thick. Plate was specified as IT 80, the cast sections as IT 90.

The A22F, also known as "Heavy Churchill", was a major revision of the design. The most significant part was the use of welding instead of riveted construction. Welding had been considered earlier for the Churchill but, until its future was assured, this was no more than testing techniques and hulls at the firing ranges. What welding reduced in the overall weight (estimates were around 4%), the thicker armour of the A22F made up for. Welding also required fewer man-hours in construction. The hull doors changed from square to round which reduced stresses. A new turret went with the new hull. The sides, which included a flared base to protect the turret ring, were a single casting while the roof, which did not need to be so thick, was a plate fitted to the top.

Since the engines on the Churchill were never upgraded, the tank became increasingly slow as additional armour and armament was equipped and weight increased; while the Mk I weighed 39,120 kg (40 long tons) and the Mk III weighed 39,630 kg, the Mk VII weighed 40,640 kg. This caused a reduction in the tanks' maximum speed from its original 26 km/h (16 mph) down to 20.5 km/h (12.7 mph).

Another problem was the tank's relatively small turret that prevented the use of powerful weapons; definitive versions of the tank were armed with either the QF 6-pounder or the derivative QF 75 mm gun. The 6-pdr was effective against armoured vehicles, but less so against other targets; the 75 mm was a better all-round weapon, but lacked in effectiveness against armour. Although the Churchills with their 6 pounders could outgun many contemporary German medium tanks (like the Panzer IV with the short-barrel 75 mm gun, and the Panzer III armed with the 50 mm gun) and the thick armour of all Churchill models could usually withstand several hits from any German anti-tank gun, in the later years of the war the German Panther tank had a 75 mm high-velocity cannon as its main armament along with increased protection, against which the Churchills' own guns often lacked sufficient armour penetration to fight back effectively.

The Churchill had many variations, including many specialised modifications. The most significant change to the Churchill was that it was up-gunned from 2 pounder to 6 pounder and then 75 mm guns over the course of the war. By the war's end, the late model Churchill Mk VII had exceptional amounts of armour – considerably more than the German Tiger tank. However, the firepower weakness was never fully addressed. The Mark VII turret that was designed for the 75 mm gun was of composite construction – cast with top and bottom plates welded into position.

While it had weaknesses, the Churchill could cross terrain obstacles that most other tanks of its era could not. This capacity frequently proved useful, especially during the fighting in Normandy. One action in Normandy where the tank's ability to surmount obstacles was found to be of value was the capture of Hill 309 on 30/31 July 1944 (Operation Bluecoat) conducted by VIII Corps.

Production

The Churchill tank was produced with Vauxhall as the design parent. Subcontracted work on some tanks was provided by Whessoe Foundry & Engineering, Metropolitan‑Cammell Carriage and Wagon, Babcock & Wilcox Ltd., Newton, Chambers & Co. and the Gloucester Railway Carriage & Wagon Company produced some complete vehicles. Other contractors produced hulls and turrets which went to Vauxhall, Charles Roberts & Co., and Dennis Brothers for final assembly.

Service history

Dieppe Raid

The Churchill first saw combat on 19 August 1942, in the Dieppe Raid in France. The Dieppe raid was planned to temporarily take control of the French port of Dieppe using a strong force of about 6,000 troops – mostly drawn from inexperienced Canadian units. The operation, codenamed Rutter, would test the feasibility of opposed landings. Nearly 60 Churchill tanks from the 14th (Reserve) Army Tank Regiment, (The Calgary Regiment (Tank)), were allocated to support the infantry and commandos; they would be put ashore by Landing Craft Tank vessels, along with the supporting engineers. Some problems were anticipated and allowed for: waterproofing of the hulls, canvas carpets to aid the tanks crossing the shingle beach, engineer teams to demolish obstacles and a few of the tanks were fitted with flame-throwers.

In the event, the German defences were stronger than expected. The shingle "chert" of the beach was also a problem: according to history professor Hugh Henry, the German defenders had previously considered it impassable to tanks. Only the 30 Churchills in the first two waves of 10 LCTs made the beach, landing under heavy fire: the latter two waves were turned away. One Churchill was trapped in its LCT by shellfire. Of the 29 remaining (eight Mark I/IIs, three Oke flamethrower tanks, and 18 Mark IIIs), two sank en route to shore, and 11 were immobilized on the beach due to a combination of the chert shingle and indirect fire. Only 15 would get off the beach and over the sea wall onto the Dieppe promenade. Although these tanks were effective in engaging the defenders in the town's buildings, their further progress was blocked by concrete defences; the engineer demolition teams – killed or pinned on the beach – had not been able to accompany the tanks. Ten of these Churchills were able to return to the beach once the withdrawal had been signalled but they could not be evacuated. According to Henry, no Churchills were penetrated by German antitank fire while still manned. These surviving tank crews fought to cover the withdrawal of the infantry from the beach, and almost all were captured with their vehicles, having exhausted their main gun ammunition. The tank regiment's commanding officer, Lieutenant-Colonel Johnny Andrews, was among those killed in action. Nearly 70% of the Canadians were killed, injured or captured and none of the raid's objectives were met other than the secret raid on the radar station on a headland.

North Africa

Six Mk III Churchills (with the 6 pounder) saw action in the Second Battle of El Alamein in October 1942. This detachment, called "Kingforce", supported the attack of 7th Motor Brigade. The Churchills were fired on many times by Italian and German anti-tank guns, but only one was knocked out and partially caught on fire. One tank was said to have been hit up to 80 times.

Kingforce, formed to test whether the Churchills could operate in Africa, was disbanded after El Alamein. The 25th Army Tank Brigade of three regiments was sent to Africa, and went into action in February 1943 during the Tunisian campaign.

Churchill tanks took part in containing the German offensive of Operation Ochsenkopf in February – March 1943. At a place called Steamroller Farm, two Churchill Mk III tanks of 51 RTR got ahead of their squadron. They came across an entire German transport column, which they ambushed and completely shot up before they rejoined. The end result was the destruction of two 88 mm, two 75 mm and two 50 mm, four lesser anti-tank guns, 25 wheeled vehicles, two 3-inch mortars, two Panzer III tanks and infliction of nearly 200 casualties.

A Churchill tank in a hull down defensive position made a particular contribution to Allied success. In one encounter, on 21 April 1943, during the start of the Battle of Longstop Hill, a Churchill tank of the 48th Royal Tank Regiment got the better of a German Tiger I heavy tank. A 6 pounder shot from the Churchill lodged between the Tiger's turret and turret ring, jamming the turret and injuring the German crew. They abandoned the Tiger, which was subsequently captured by the British. Known as Tiger 131, this Tiger was the first captured by the Western Allies and was particularly useful for intelligence. Tiger 131 has since been restored to full working condition and is now on display at The Tank Museum in Dorset, UK.

Italy

As the mainstay of the Tank Brigades, which operated in support of the infantry, Churchill units were in operation more often than other tank units.

The "NA75" conversions of Churchill Mark IIIs to carry the US 75 mm gun were used in Italy. As the Churchill proved to be a better gun platform than the Sherman, the effective range of the 75 mm was increased.

North-West Europe

Churchills saw widespread action in Normandy during the Battle of Hill 112 and Operation Bluecoat, as well as subsequent operations in the Low Countries and into Germany, such as the fighting in the Reichswald during Operation Veritable.

The Churchill was able to cross the muddy ground and force through the forests of the Reichswald; a contemporary report expressed the belief that no other tank could have managed the same conditions.

Burma and India

A single Churchill, possibly a Mk V, was trialled in Burma in 1945. It was operated by the 3rd Dragoon Guards (Carabiniers) from the end of April 1945 for about a month. Although it proved impossible to bring the Churchill into action, on approach marches the tank proved at least the equal to the M3 Lee then in service.

The 254th Indian Tank Brigade returned to India from Burma, arriving at Ahmednagar during July 1945. The Brigade immediately began conversion from the Lee to the Churchill, the intention being for the newly equipped Brigade to return to operations in October 1945. At the time, it was assumed that the war against Japan would continue and that the new battleground would be Malaya. Although a small number of tanks were delivered, and some training undertaken, the end of the war against Japan meant that the conversion was not completed. At the end of September, the 254th Indian Tank Brigade was re-assigned and posted away from Ahmednagar. All the Churchills delivered up to that point were returned to the Ordnance Depot at Kirkee (Khadki) by the end of November-early December 1945. Of the three regiments (battalions) involved, the 3rd Dragoon Guards accompanied the 254th Brigade when posted away while the 149th Regiment Royal Armoured Corps and the 150th Regiment Royal Armoured Corps were eventually disbanded at Ahmednagar on 28 February 1946, the majority of personnel already having been repatriated to the United Kingdom or posted to other units.

Other theatre

In mid-1944, at the request of Britain's War Office, the Churchill was tested by the Australian Army, along with the M4 Sherman. The results were to be used to determine any modifications required for use in the tropics; Matildas were used as a reference point in the tests at Madang, New Guinea. The Churchill was found to be, overall, superior to the other tanks for jungle warfare.

It was not used in the Pacific War; only 46 of the 510 Churchills ordered by Australia were delivered by the end of the war, and the remainder of the order was cancelled.

Korean War and after

In late 1950, a Churchill Crocodile squadron (C squadron, 7 Royal Tank Regiment) was sent to Korea. In action against the Chinese, they mostly fought as gun tanks, for example in the Third Battle of Seoul. To restore 1st Battalion, Royal Northumberland Fusiliers' position during the defence of Seoul, Brigadier Thomas Brodie of the 29th Infantry Brigade sent four Churchill tanks as reinforcement; their contributions to the battle were widely praised by British and American historians. These were the last use of the Churchill in action by the British. The tank remained in the service of the British Army until 1952 with one, a bridge-layer, remaining in service well into the 1970s.

USSR

The Soviet Union was sent 344 Churchill Mk III and Mk IV types as part of the Lend-Lease programme. 91 were lost en route on the Arctic Convoys.

In 1942-1943, it used Churchills in the Battle of Stalingrad (47th and 48th regiments of heavy tanks - 42 Churchills). In 1943, the Soviet 5th Guards Tank Army used Churchills in the Battle of Prokhorovka (15th and 36th regiments of heavy tanks - 42 Churchills) during the Battle of Kursk, and in the Fourth Battle of Kharkov. It was also used in other battles until 1944 (82th regiment of heavy tanks).

Irish Army Service

The Irish Army took delivery of three Churchill Mk VI tanks in 1948 and a fourth in 1949. These were rented from the British War Office as trials vehicles until 1954, when they were purchased outright. This purchase was despite the fact that the supply and transport corps workshops, which maintained them, had reported that spares had all but run out. Experiments were carried out involving replacing the existing Bedford engine with a Rolls-Royce Merlin engine salvaged from an Irish Air Corps Seafire aircraft. The experiment was not a success, although the reasons are not recorded. By 1967, only one Churchill remained serviceable, and by 1969 all were retired. One remains preserved in the Curragh Camp.

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L'aereo "stealth" F 35 (il topo) e il radar passivo tedesco Hensoldt “TwInvis” (il gatto)...

La storia che segue è un'istantanea nel gioco del gatto e del topo tra aerei da combattimento - progettati per essere invisibili al radar - ed i produttori di sensori che cercano di annullare questo vantaggio. 

Nel caso dell'F-35, la promessa di invisibilità al radar è così pronunciata che ha colorato gran parte della dottrina di impiego del jet, conferendo un'aria di invincibilità all'arma: il nemico non l'ha mai visto arrivare.

Ma i salti tecnologici durano solo per poco tempo, e Russia e Cina sono note per il loro lavoro su di una tecnologia che mira a distruggere tutto ciò che i paesi della NATO hanno cercato di costruire.

Di recente, il radar-maker tedesco Hensoldt afferma di aver tracciato due F-35 per 150 chilometri dopo il Berlin Air Show del 2018 in Germania alla fine di aprile dello stesso anno. 

Il sistema radar passivo dell'azienda, chiamato “TwInvis”, è solo una delle generazioni emergenti di sensori e processori così sensibili e potenti che promette di trovare attività non rilevabili in un dato spazio aereo.

Quello che è successo a Berlino è stata la rara possibilità di sottoporre il velivolo - caratteristiche di design furtivo, rivestimento speciale e tutto il resto - ad una prova nella reale operatività per vedere se la promessa di bassa osservabilità è ancora valida.

Le storie dell'incontro f-35-vs.il radar passivo “TwInvis” sono state pubblicate dai media da quando Hensoldt ha aperto un negozio sulla pista dell'aeroporto Schönefeld di Berlino: il suo sensore è calibrato per tenere traccia di tutte le dimostrazioni di volo dei vari velivoli sulla linea di volo. I media avevano fpubblicizzato il sistema, che viene fornito in un furgone o un SUV e vanta un'antenna pieghevole, utilissima nell’ambito della difesa aerea.

Allo stesso tempo, il produttore dell’ F-35 Lockheed Martin era ancora in gara per sostituire la flotta tedesca dei Tornado, un'opportunità strategicamente importante per vendere gli F-35 ad uno stato membro fondamentale nella difesa dell'Unione Europea. L'azienda ha allestito uno chalet di grandi dimensioni all'air show, portando opuscoli e cappelli che raffigurano l'aereo insieme ad una bandiera tedesca.

Showtime a Schönefeld

Gli elementi di marketing più convincenti per Hensoldt dovevano essere due F-35 della Luke Air Force Base, Arizona. Il viaggio transatlantico segnò il più lungo volo non-stop dei jet, a più di 11 ore, dicono i funzionari dell'epoca.

Ma Lockheed e l'U.S. Air Force non hanno fatto volare i jet durante lo spettacolo in modo che i suoi ingegneri - e chiunque si avvicini allo stand dell'azienda, per inciso - potesse vedere se l'aereo avrebbe prodotto una traccia radar su un grande schermo come gli altri aerei.

I giornalisti non hanno mai avuto una risposta diretta sul perché gli F-35 sono rimasti a terra. Una delle spiegazioni era che non c'era un programma di dimostrazione aerea approvato per gli aerei che si adattassero alle limitazioni dello spazio aereo dello show di Berlino.

Indipendentemente dal motivo, senza alcun volo dell'F-35, le compagnie non hanno potuto provare le loro tecnologie su uno dei casi di prova forse più illustri. Le apparecchiature radar passive calcolano un'immagine aerea tracciando i segnali delle comunicazioni civili che rimbalzano sugli oggetti in volo. La tecnica funziona con qualsiasi tipo di segnale presente nello spazio aereo, comprese le trasmissioni radio o televisive e le emissioni delle stazioni di telefonia mobile. La tecnologia può essere efficace contro i progetti di aerei furtivi, che hanno lo scopo di rompere e assorbire i segnali provenienti dai tradizionali emettitori radar in modo che nulla si rifletta sui sensori delle stazioni a terra, lasciando di fatto gli operatori dei radar difensivi al buio.

Poiché non ci sono emettitori, il radar passivo è nascosto, il che significa che i piloti che entrano in un'area monitorata non sono consapevoli di essere seguiti.

Ci sono dei limiti alla tecnologia: il sistema dipende dall'esistenza di segnali radio, che potrebbero non essere un dato di fatto nelle aree remote del globo. Inoltre, la tecnologia non è ancora abbastanza precisa per guidare i missili, anche se potrebbe essere utilizzata per inviare armi a infrarossi su di un bersaglio.

La società Hensoldt ha confermato che varie stazioni radio che trasmettono nella zona, in particolare un gruppo di forti emittenti FM polacche che trasmettono in profondità in Germania, ha migliorato la calibrazione del radar passivo TwInvis durante lo show di Berlino. Il confine è a circa 70 chilometri dall'aeroporto di Schönefeld.

Durante una dimostrazione del sistema da parte della Hensoldt alla mostra, gli ingegneri dell'azienda si sono riuniti attorno ad un grande schermo del TwInvis che mostrava la traccia di un Eurofighter che eseguiva una esibizione aerea nelle vicinanze. 

Ma il prezioso obiettivo di opportunità dei due F-35, rimase senza seguito.

Alla fine dell'evento, la Hensoldt ha tenuto d'occhio ogni movimento degli F-35 pesantemente sorvegliati sul campo d'aviazione. Quando gli espositori hanno iniziato a sgombrare, sembrava che la possibilità di tracciare gli aerei durante la loro inevitabile partenza di ritorno a casa sarebbe andata perduta.

Ma nel racconto della Hensoldt, qualcuno ebbe l'idea di installare il sistema TwInvis fuori dall'aeroporto, che finì per trovarsi ubicato in un campo per l’allevamento di cavalli nelle vicinanze.

Accampati tra gli equini, gli ingegneri ebbero conferma dalla torre di Schönefeld della imminente partenza degli F-35 quando già erano sulla pista per il decollo. Una volta che gli aerei erano in volo, l'azienda iniziò a tracciarli ed a raccogliere dati, utilizzando i segnali dei transponder ADS-B degli aerei per correlare le letture dei sensori passivi.

Una portavoce del Joint Program Office dell'F-35 dichiarò di non essere in grado di commentare in tempo per la stampa l'affermazione della società Hensoldt di aver monitorato l'aereo a Berlino o sulla vulnerabilità generale dell'aereo ai radar passivi.

Ci sono diverse fattorie di cavalli e pony nelle vicinanze dell'aeroporto di Schönefeld, che offrono di tutto, dalle lezioni di equitazione ai campi estivi a tema equestre per bambini. Una donna che rispondeva al telefono nel business più vicino all'aeroporto, "Keidel Ranch", un paio di chilometri ad ovest,  confermò che "qualcuno" del Berlin Air Show si era presentato e si era fermato per "due o tre giorni".

La Hensoldt ribadì che il rilevamento passivo-radar funzionava indipendentemente dal fatto che l’aereo F35 in questione abbia o meno installato riflettori radar (le cosiddette lenti Luneburg). Queste caratteristiche - piccole manopole sulle radici delle ali dell'F-35 - possono essere viste nelle foto pubblicate dal Dipartimento della Difesa degli Stati Uniti in occasione del viaggio a Berlino.

I riflettori sono spesso montati sugli aerei furtivi per renderli visibili alle autorità locali del traffico aereo durante le missioni amichevoli, come le apparizioni in spettacoli aerei. Essi creano artificialmente una sezione trasversale radar nelle bande di frequenza in cui operano i radar di deconflessione dello spazio aereo, in modo che i tradizionali sistemi radar per la difesa sappiano di cosa si occupano.

Secondo una fonte vicina al programma, le lenti Luneburg montate sugli F-35 in partenza renderebbero certa la tracciabilità dei jet, suggerendo che la situazione sarebbe diversa senza i riflettori installati.

Quando l'F-35 non vola in missioni operative che richiedono la furtività - ad esempio, in occasione di spettacoli aerei, voli in traghetto o di addestramento - assicurano che i controllori del traffico aereo e altri siano in grado di tracciare il loro volo per gestire la sicurezza dello spazio aereo. 

La società tedesca Hensoldt sostiene che il rilevamento passivo-radar funziona in uno spettro diverso, rendendo irrilevante la presenza (o l'assenza) di riflettori. In termini profani, il radar passivo segue l'intera forma fisica degli aerei, contro l'attivazione di elementi angolari più piccoli sul corpo di un jet.

A prescindere dalle affermazioni della Hensoldt, l'esercito tedesco ha abbracciato il radar passivo come tecnologia emergente chiave per le capacità future, compresa la difesa aerea. All'inizio di quest'anno, la Luftwaffe era in procinto di creare un percorso di acquisizione formale per il rilevamento radar passivo.

Questo passo è arrivato dopo che il Ministero della Difesa ha sponsorizzato una settimana di "campagna di misurazione" nella Germania meridionale lo scorso autunno, volta a visualizzare il traffico aereo dell'intera regione attraverso il sistema passivo  TwInvis.

Degno di nota anche il fatto che nell'anno e mezzo che ha seguito lo spettacolo aereo, l'enfasi sulle caratteristiche stealth per il programma franco-tedesco-spagnolo “Future Combat Air System”, destinato ad essere l'aereo da combattimento di nuova generazione in Europa, è molto diminuita.

I funzionari dei team industriali coinvolti nel programma convergono sempre più attorno all'idea che lo stealth, come sappiamo, ha perso il suo splendore - questo è il seguito delle voci che girano intorno alla scena della difesa tedesca su come la Hensoldt era riuscita o meno ad illuminare e tracciare l'aereo stealth F35 sullo schermo radar.

ENGLISH

The story that follows is a snapshot in the cat-and-mouse game between combat aircraft — designed to be undetectable by radar — and sensor makers seeking to undo that advantage. In the case of the F-35, the promise of invisibility to radar is so pronounced that it has colored much of the jet's employment doctrine, lending an air of invincibility to the weapon: The enemy never saw it coming.

But technology leaps only last so long, and Russia and China are known to be working on technology aimed at nixing whatever leg up NATO countries have tried to build for themselves.

Now, German radar-maker Hensoldt claims to have tracked two F-35s for 150 kilometers following the 2018 Berlin Air Show in Germany in late April of that year. The company’s passive radar system, named TwInvis, is but one of an emerging generation of sensors and processors so sensitive and powerful that it promises to find previously undetectable activities in a given airspace.

What happened in Berlin was the rare chance to subject the aircraft — stealthy design features, special coating and all — to a real-life trial to see if the promise of low observability still holds true.

Stories about the F-35-vs.-TwInvis matchup had been swirling in the media since Hensoldt set up shop on the tarmac at Berlin’s Schönefeld Airport, its sensor calibrated to track all flying demonstrations by the various aircraft on the flight line. Media reports had billed the system, which comes packed into a van or SUV and boasts a collapsible antenna, as a potential game changer in aerial defense.

At the same time, F-35 manufacturer Lockheed Martin was still in the race to replace the German Tornado fleet, a strategically important opportunity to sell F-35s to a key European Union member state. The company set up a sizable chalet at the air show, bringing brochures and hats depicting the aircraft together with a German flag.

Showtime in Schönefeld

The most convincing pieces of marketing for Hensoldt were meant to be two F-35s flown in from Luke Air Force Base, Arizona. The trans-Atlantic journey marked the jets’ longest nonstop flight, at 11-plus hours, officials said at the time.

But Lockheed and the U.S. Air Force did not fly the jets during the show so that its engineers — and anyone walking by the company’s booth, for that matter — could see if the aircraft would produce a radar track on a big screen like the other aircraft.

Reporters never got a straight answer on why the F-35s stayed on the ground. One explanation was that there was no approved aerial demonstration program for the aircraft that would fit the Berlin show’s airspace limitations.

Regardless of the reason, with no flight by the F-35, companies could not try out their technologies on perhaps the most illustrious of test cases. Passive radar equipment computes an aerial picture by reading how civilian communications signals bounce off airborne objects. The technique works with any type of signal present in airspace, including radio or television broadcasts as well as emissions from mobile phone stations. The technology can be effective against stealthy aircraft designs, which are meant to break and absorb signals from traditional radar emitters so that nothing reflects back to ground-station sensors, effectively leaving defensive-radar operators in the dark.

Because there are no emitters, passive radar is covert, meaning pilots entering a monitored area are unaware they are being tracked.

There are limitations to the technology. For one, it depends on the existence of radio signals, which may not be a given in remote areas of the globe. In addition, the technology is not yet accurate enough to guide missiles, though it could be used to send infrared-homing weapons close to a target.

Hensoldt said various radio station broadcasts in the area, especially a bunch of strong Polish FM emitters broadcasting deep into Germany, improved TwInvis calibration during the Berlin show. The border is about 70 kilometers away from Schönefeld Airport.

During a system demonstration by Hensoldt at the exhibit, company engineers convened around a large TwInvis screen showing the track of a Eurofighter performing a thundering aerial show nearby. But the prized target of opportunity, the two F-35s, remained sitting on the tarmac.

Horse country

As the event ended, Hensoldt kept a close eye on any movement of the heavily guarded F-35s on the airfield. As exhibitors began to clear out, it looked like the chance of catching the planes during their inevitable departure back home would be lost.

But in Hensoldt’s telling, someone had the idea of setting up TwInvis outside the airport, which ended up being at a nearby horse farm.

Camped out amid equines, engineers got word from the Schönefeld tower about when the F-35s were slated to take off. Once the planes were airborne, the company says it started tracking them and collecting data, using signals from the planes’ ADS-B transponders to correlate the passive sensor readings.

A spokeswoman for the F-35 Joint Program Office said she was unable to comment by press time on Hensoldt’s claim of having tracked the aircraft in Berlin or about the plane’s general vulnerability to passive radar.

There are several horse and pony farms in the vicinity of Schönefeld Airport, offering everything from riding lessons to horse-themed summer camps for kids. A woman answering the phone at the business closest to the airfield, “Keidel Ranch,” a couple kilometers to the west, confirmed to Defense News that “someone” from the Berlin Air Show had showed up and stayed for “two or three days.”

Hensoldt previously said its passive-radar detection works regardless of whether the targeted aircraft has radar reflectors (so-called Luneburg lenses) installed. Those features — little knobs on the roots of the F-35 wings — can be seen in photos released by the U.S. Defense Department on the occasion of the journey to Berlin.

The reflectors are often mounted on the stealthy aircraft to make them visible to local air traffic authorities during friendly missions, like air show appearances. They artificially create a radar cross section in the frequency bands in which airspace-deconfliction radars operate so that traditional, defense radar systems know what they are dealing with.

According to a source close to the program, Luneburg lenses mounted on the departing F-35s would make it a certainty that the jets can be tracked, suggesting that the situation would be different without the reflectors installed.

“When the F-35 is not flying operational missions that require stealth — for example, at air shows, ferry flights or training — they ensure air traffic controllers and others are able to track their flight to manage air space safety”. “The Air Force can best address questions related to their F-35s participation at the Berlin Air Show.”

Hensoldt argues that passive-radar detection works in a different spectrum, making the presence (or absence) of reflectors irrelevant. In layman’s terms, passive radar tracks the entire physical shape of planes, versus being triggered by smaller, angular features on the body of a jet.

Talking stealth

Whatever Hensoldt's claims, the German military has embraced passive radar as an emerging technology key for future capabilities, including air defense. 

That step came after the Defence Ministry sponsored a weeklong “measuring campaign” in southern Germany last fall aimed at visualizing the entire region’s air traffic through TwInvis.

Also noteworthy, in the year and a half that followed the air show, emphasis on stealth features for the Franco-German-Spanish Future Combat Air System program, meant to be Europe's next-generation warplane, shifted.

Officials from the industry teams involved in the program increasingly converged around the idea that stealth as we know it had lost its shine — this following rumors circling the German defense scene about how Hensoldt had apparently managed to light up the American aircraft on the radar screen.

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