What to expect from your shiny new P39-L1

[[CPT]Pike*HarryM]

[Panthera]

false, but really not pertinent here.

 

you are still a relative newbie around here, but believe me, multiple threads on the P39 engine limits will appear and be endlessly discussed once the plane is released. 

 

So you're telling me the engine will fail right after the 5 min mark? I think there's plenty of proof that didn't happen  

 

The time limits were there to ensure longevity, not to warn the pilot that the engine would explode/fail if he exceeded them. 

[Panthera]

For that similar ~1300 HP power, the P-39N does around 550 km/h and the P-39Q around 530 km/h. Maybe this can be explained because the Q model has .50 cals in the wings in external gunpods, if im correct this was standard in the early Q models and it's also mentioned in the report.

 

I dont know if there are significant aerodynamical differences between the N and the L, but maybe the 550 km/h value from the N can be a good approximation.

 

The -63 engine in the L had 1325 HP at 51" for 5 minutes as war emergency power.

 

There is this graph that shows around 308 mph (495 km/h) for the military power which is 42", for 15 minutes. Which is 1150 HP.

 

http://www.wwiiaircraftperformance.org/P-39/P-39K_Performance_Chart-1400.jpg

 

I have seen a picture from a Russian document showing 60" for 5 minutes for this engine, for a total of 1580 HP. It does note that this setting isn't mentioned in the official american V-1710-63 manual. I don't know if the Soviets used this very high regime.

 

But if so, I think this would increase its performance considerably maybe putting it at the high 500s km/h speeds, close to the La-5FN and 1.65 ata Fw 190 As.

 

https://forum.il2sturmovik.com/uploads/monthly_08_2017/post-16698-0-17910100-1503083316.png

 

It was mighty fast at low alt, but I do have my doubts that it could reach the ~585 km/h at SL of the Fw190A5 running at 1.58 ata (1,870 PS).

 

The P-39Q achieved 529 km/h with 1355 HP at SL, so 560-565 km/h at 1,580 HP seems plausible depending on weight. 

[gorice]

-high top speed

-fast dive

-good energy retention

-slow roll

-good elevator authority

-mediocre sustained turn

 

Sounds like it's going to be a very smooth transition from the MiG. No wonder Pokryshkin liked it.

[-=PHX=-SuperEtendard]

It was mighty fast at low alt, but I do have my doubts that it could reach the ~585 km/h at SL of the Fw190A5 running at 1.58 ata (1,870 PS).

 

The P-39Q achieved 529 km/h with 1355 HP at SL, so 560-565 km/h at 1,580 HP seems plausible depending on weight.

And there is the P-39N graph with 553 km/h at 1300 HP. A good way to find out could be to ask Holtzauge, he can extrapolate the parameters he needs from the 495 km/h at 1150 HP for the P-39K, as it is almost the same as the L variant, and then run the simulation with both 1325 and 1580 HP.

 

Although I doubt we will have the 60" setting available, it would be interesting to see how it compares.

[Finkeren]

I wonder if Holtzauge’s model takes into account the propeller’s ability to convert the engine’s power to thrust? The main difference between the K and L versions of the P-39 was the installation of the larger Curtis propeller, which I suppose was more efficient with the uprated Allison engine?

[BRADYS555]

It will likely put every other plane in the game in a more favorable light handling wise.

[Finkeren]

It will likely put every other plane in the game in a more favorable light handling wise.

Why would you think that? Everything i’ve read about the P-39 describes pleasant handling within the flight envelope and only slight issues with lateral stability. I think it should only be once you go outside the envelope, that it becomes vicious. We already have a few aircraft like that, most notably the Fw 190 and the I-16.

Edited January 29, 2018 by Finkeren

[Pail]

Why would you think that?

 

You haven't read my links (in other posts where I was extolling the possible not so excellence of the P-39) Mr Finkeren....

 

Airacobra or Iron Dog? http://www.chuckhawks.com/airacobra_iron_dog.htm

 

 

Flying American Combat Aircraft of World War II: 1939-1945

""However, the Airacobra was never a popular aircraft with the U.S. Army Air Force. Its short cruising ... It was variously described as "disappointing," of no use for operations "except in an emergency," "suited for wide, low and slow circles," and the "widow maker" by pilots and historians of the army air force."

 

Interestingly someone says he had never known an engine to come loose and squash anyone...

 

https://books.google.com.au/books?id=P0KiPMJuXkUC&pg=PA107&lpg=PA107&dq=widowmaker+airacobra&source=bl&ots=bSYTRkUfZx&sig=MspoD4Cs44wJeaycHzDtjg2dRe0&hl=en&sa=X&ved=0ahUKEwiF78G_9fbYAhUKfLwKHZ7rDwEQ6AEIPzAJ#v=onepage&q=widowmaker%20airacobra&f=false

 

"Not to say that the P-39 was a completely useless dogfighting platform......Performance-wise, however, the P-39 was devoid of any truly exceptional qualities when compared to the fighter types that were purpose-built for the role including the heavy Republic P-47 Thunderbolts. "

 

https://www.militaryfactory.com/aircraft/detail.asp?aircraft_id=140

 

https://www.awm.gov.au/articles/blog/p-39-airacobras-defence-australia

 

https://www.pacificwrecks.com/aircraft/p-39/index.html

 

http://www.aviation-history.com/bell/p39.html

 

http://www.adf-serials.com.au/research/Airacobra.pdf

 

I'm obviously very interested to see how it turns out....somewhere I saw that it climbed as bad or worse than a P-40 (anecdotally) but I can't seem to find that now.

 

I also must apologize that my typing is often brief and I paste and link a lot...

Edited January 30, 2018 by Pail

[hedger72]

I'm obviously very interested to see how it turns out....somewhere I saw that it climbed as bad or worse than a P-40 (anecdotally) but I can't seem to find that now.

 

I can't imagine that this will the be experience in-game; the P-39 being a much aerodynamically cleaner design, weighing approximately 350kg less and driven by an engine producing ~200hp more.

Edited January 30, 2018 by hedger72

[GridiroN]

I can't imagine that this will the be experience in-game; the P-39 being a much aerodynamically cleaner design, weighing approximately 350kg less and driven by an engine producing ~200hp more.

 

Why did you scratch that out? The Allison in the P39 is better than the Allison in the P40.

[hedger72]

Why did you scratch that out? The Allison in the P39 is better than the Allison in the P40.

 

I would happily stand corrected, but based on chart posted by [CPT]Pike at the top of the page, and the information listed within the forum's Aircraft Flight and Technical Specifications and Operation Details post for the P-40, the V-1710-39 & -63 seem to produce the exact same horsepower at War Emergency Power (1150 HP).

[Pail]

 

 

I can't imagine that this will the be experience in-game

 

I'm pretty sure it was referring to later model P-40s than the in game one and not something based on real statistics of any kind....

[GridiroN]

I would happily stand corrected, but based on chart posted by [CPT]Pike at the top of the page, and the information listed within the forum's Aircraft Flight and Technical Specifications and Operation Details post for the P-40, the V-1710-39 & -63 seem to produce the exact same horsepower at War Emergency Power (1150 HP).

 

As far as I can tell, the subversion of Allison engine also has subversions that produce less or more horsepower. The -63 version in the P39K through L version use the E6 version, of 1350hp. The -39 in the P40 is a D version I think with only 1150 maximum. 

 

15min of 1350hp should be equivalent to the 5min MiG3 boost, which would be quite good if the devs use these figures. 

Edited January 30, 2018 by GridiroN

[ShamrockOneFive]

As far as I can tell, the subversion of Allison engine also has subversions that produce less or more horsepower. The -63 version in the P39K through L version use the E6 version, of 1350hp. The -39 in the P40 is a D version I think with only 1150 maximum. 

 

15min of 1350hp should be equivalent to the 5min MiG3 boost, which would be quite good if the devs use these figures. 

 

Yep. So far as I can tell you're right on the money for horsepower figures and the sub version of Allison. The P-39L-1 won't just have a cleaner airframe but definitely more power than the P-40E-1.

[hedger72]

Yep. So far as I can tell you're right on the money for horsepower figures and the sub version of Allison. The P-39L-1 won't just have a cleaner airframe but definitely more power than the P-40E-1.

 

...and lower weight 

 

Really, really, reeeeally looking forward to this bird!

 

As an aside, I found the following posted by horseback some time ago over at the old IL-2 Ubi forum - very interesting read:

 

https://forums.ubi.com/showthread.php/159314-Whats-with-the-p39-Forums

 

P-39 IN THE USSR by Yefim Gordon

 

The Bell P-39 Airacobra was the most numerous foreign fighter in the Soviet air force inventory. Under the Lend-Lease agreement the USSR received 5,578 Airacobras between December 1941 and February 1945. Some 4,952 of them actually saw service; the Red Army Air Force Import Directorate states that this accounts for 36 per cent of the fighters and 27 per cent of all aircraft supplied by the Allies. In Soviet service the Airacobra was operated mainly by Guards units. The famous ace A.I. Pokryshin (one of three thrice-awarded Heroes of the Soviet Union –HSUs) and 11 of the 27 fighter pilots twice awarded the HSU title flew P-39s.

 

Soviet pilots had their first look at the Airacobra in Great Britain when a group of pilots was sent to No. 601 Sqn at RAF Duxford for training. After a brief period of negotiations, the British were only too glad to turn the disappointing P-400s over to the Russians. Some of the 212 of the 675 Airacobra Is originally ordered by the RAF were to be delivered to the USSR, instead, along with a number of Hurricanes. However, 54 of the Cobras were lost en route when the ships carrying them to Soviet ports were sunk.

 

Crated Airacobras unloaded at Soviet northern ports traveled along several routes. Many aircraft arriving in Murmansk were reassembled there and delivered directly to units operating on the nearby Karelian front, or to the Northern Fleet’s air arm. Most Cobras, however, went to Ivanovo, where the 22nd ZAP (Zapasnaya Aviapolk-Reserve Fighter Regiment) was based in late 1941. there, imported aircraft of all types arriving as knockdown kits were reassembled and test-flown prior to being ferried to front-line bases. Destinations varied widely – from the Leningrad front up north to the Voronezh front in the south.

 

A small portion of imported fighters was assembled in Arkhangel’sk. To this end, an airfield with a wood-planked airstrip (!) was built in dense woods 25 km (15 miles) south of the city. Aircraft assembled there were flown to Ivanovo via Vologda.

 

The Soviet high command treated the Airacobra with much more trepidation than other imported aircraft which had seen service in the USSR. It is difficult to say now what the main reason was – the bad reputation the P-39 had earned in US and British service, the Airacobra’s unconventional design or the great trouble involved in adapting the Spitfire and Hurricane to the Russian environment. Anyway, the first Cobras arrived in late December 1941 or early January 1942 but it was not until May that they became operational.

 

SERVICE TESTING

Only a single Airacobra Mk I (AH718) of the initial batch of 20 was delivered to the 22nd ZAP in 1941. Soviet specialists were very strict when accepting the Cobras. NII VVS sent a special ‘task force’ to the regiment, which included lead engineer I.G. Rabkin, V.I. Usatov, P.S. Ivanov, and V.F. Nikishin. Test pilot V. Ye. Golofastov was to try out the reassembled fighters.

 

“The very first days of service in January-February 1942 revealed a very serious shortcoming in the Airacobra’s oil system,” Rabkin reminisced. “The engine oil could not be emptied fully. The oil left in the engine sump, reduction gearbox, oil cooler, and certain oil lines would freeze, and all of these required lengthy warming=up with hot air before the engine could be started. We had to install de-oiling ***** in the oil lines and invent a special manifold which led hot air to all the necessary locations at once. This gadget was tested successfully and recommended for all units operating the type.”

 

The pilots were in for a lot of surprises, too. Golofastov, who made the first taxi test on a fighter with tricycle landing gear, praised the excellent view from the cockpit and the aircraft’s ability to taxi at high speed over a snow-covered ramp with virtually no risk of standing on its nose. The first flight around the airfield went smoothly. Golofastov learned much about the aircraft in addition to what was in the American flight manual. However, on 18 January 1942, the Allison V-1710-E4 engine (c/n 4132) quit during a turn and Golofastov had to bail out. The accident investigating board ruled that an explosion had occurred in the intake manifold.

 

Despite this mishap, the Airacobra Mk I finished the NII VVS tests successfully. One of the test aircraft (AH628) operated from Kol’tsovo air base near Sverdlovsk, another (AH644) was based at Chkalovskaya air base near Moscow. These two aircraft were flown by Colonel A.G. Kochetkov and Colonel Avtonomov respectively; A.G. Kubyshkin, I.Ye. Golofastov and A.F. Moshin also took part in the flying. The pilots reported that the Cobra was fairly nimble, with light control forces. The aircraft was stable during turns with normal C of G, shuddering and trying to straighten out if the stick was pulled too far back but showing no inclination to spin.

 

One aircraft became unserviceable when the supercharger disintegrated during tests. The test pilots were pleased by the Airacobra’s handling and performance, and lead engineer Rabkin drew up a report when testing was finished. “At flight levels above 3000m (9,840 ft) the Airacobra is superior to the YaK-1 and LaGG-3 fighters; it is one of the best aircraft as regards manoeuvrability in the horizontal plane.” Airfield performance and range in economical cruise were also praised. The test team asserted that MiG-3 and LaGG-3 pilots would have no trouble converting to the Cobra. Excellent all-around visibility, especially in the rear hemisphere, enabled the P-39 to operate in poor weather.

 

ENGINE LIMITS

On the minus side, the V-1710 lacked a constant-pressure valve regulating turbo pressure, so the engine could easily become overpressurised and disintegrate in low-level flight. The NII VVS team reminded that “the Airacobra demands correct treatment in service, and special attention has to be paid to knowing the engine’s limits and the cockpit layout during conversion training.”

 

The 145th IAP (Istrebitel’nyy Aviapolk – Fighter Regiment) was the first Soviet AF unit with which the Airacobra Mk I actually saw action. The unit took its training right on the front lines (without relocating temporarily into the rear area, as was the usual practice), using Russian-language manuals. The 145th IAP was not chosen randomly – on 4 April 1942, it was transformed into the 19th GvIAP, attaining Guards status for valour in combat on the Karelian front. In late April, 16 Airacobras arrived in crates at Afrikanda airfield; within the next month they were assembled under the supervision of the unit’s engineer, Major P. Gol’tsev.

 

On 26 April 1942, Captain P.S. Kutakhov (who went on to become Marshal) made the first training flight on the first reassembled Cobra. A few more firsts: on 15 May 1942, Soviet Air Force Cobras had their first encounter with Luftwaffe aircraft, in which neither side scored any ‘kills.’ On the next day, Airacobra I AH660 engaged in a dogfight and was damaged, being declared a total loss after a forced landing. Luckily, the pilot, Lieutenant (sg) I.D. Gaidayenko, walked away. On 15 June it was first blood to the Cobras. Six P-400s took off from Murmashi airfield to intercept six Ju 88s intent on bombing Murmansk, with 16 Bf 110s flying top cover. The Soviet pilots reported nine enemy aircraft shot down; the Germans acknowledged the loss of on Ju 88A-4 coded 4D + DR (W. Nr. 0242) of III/KG 30, though at least three more German aircraft were damaged on that occasion.

 

RAMMING ATTACK

On his 96th sorty, Lieutenant Ye.A. Krivosheyev of the 19th GvIAP rammed a German fighter over Murmansk and was killed. He was posthumously awarded the HSU title.

 

Another Airacobra unit, the 20th GvAIP, also operated up north. The operations of the 19th and 20th GvIAPs were, of course, very important, but the 22nd ZAP under Colonel I.I. Shoomov remained the main unit handling the Cobra. By the time the P-400s started arriving, the 22nd ZAP had developed into a major training centre with a well-established training programme and good technical facilities. After a theory course, pilots would begin flying training, while trainee technicians participated in the unpacking and assembly of aircraft and repaired damaged machines. The unit had four assembly teams, one of which was tasked with assembling Cobras. [Note: an RAF team of 16, including one pilot, assisted this process in January, 1942.]

 

Initially, three Airacobras Mk Is (AH610, AH653, and AH669), were used as trainers. After the trainees got their Airacobra type rating, fighter units would receive their Cobras, test-fly them and leave for the front.

 

The 508th IAP was the first unit to start Airacobra conversion training at the 22nd ZAP. However, on completing the training course the unit was ordered to convert again – this time to the LaGG-3. The reason behind this decision is hard to guess; probably the higher command decided the unit’s personnel and commanders were not nearly experienced enough to fly the P-400.

 

The 153rd IAP was next, arriving in Ivanovo from the Leningrad front on 25 March 1942. The training was completed in 27 days, the pilots averaging 12 flying hours on the Cobra. On 14 July the unit left for the Voronezh front and arrived in Voronezh on 29 June under HSU Major S.I. Mironov. On the same date another Airacobra unit arrived – the 185th IAP under Lieutenant Colonel Vasin. As the two units were pressed into action they were included in the 3rd Strike Group (later 244th Air Division) under General L.A. Gorbatsevitch. In addition to 40 Airacobras, the 244th operated 60 Douglas A-20 Boston bombers.

 

There was violent fighting on the Voronezh front, and the Cobra pilots joined the fray immediately. On 1 July alone, the P-400s flew 66 sorties. The intensity of the fighting mounted as the Wehrmacht began its summer offensive in southern Russia. Airacobra pilots claimed 16 ‘kills’, including 11 Ju 88s. There were losses too – two P-400s were shot down and one went missing. Eight more aircraft were damaged on the ground during a German air raid. Later, the Stalinskiy Sokol air force gazette (‘Stalin’s falcons’ was a popular name given to wartime SovAF pilots) reported a successful dogfight in which Airacobras took part, publishing photos of the pilots: Major Mironov, Captain Kislyakov, Captain Kapin, Lieutenant (sg) Smirnov, Lieutenant (sg) Bezrodnyy, Lieutenant (sg) Amkoladze and others.

 

The fate of the two units was different. The 185th IAP flew Cobras only briefly; in August 1942 it was disbanded and the personnel moved to the 1st PAD (Peregonochnaya Aviadiveeziya – Ferry Air Division) under P. Mazurook. The 153rd IAP, on the other hand, moved to Lipetsk and continued operations until 25 September 1942. Its pilots flew 1,070 sorties on the Voronezh front, claiming the destruction of 64 German aircraft; eight Airacobras were shot down and three pilots killed in action, three more aircraft were lost and one pilot was killed in an accident. “The fact that combat losses are so few is due to the high skill of the pilots and the high performance of the Airacobra fighter,” CO S.I. Mirinov wrote in his report. After that, the 153rd IAP became the 28th GvIAP.

 

AIRCRAFT SHORTAGE

Despite the initial combat success, Cobras were sparse on the Soviet – German front in 1942. By mid-November tactical units had a mere nine Airacobras in Karelia and 15 on the northwestern front, where the 28th GvIAP had relocated on 27 October after receiving new personnel and aircraft as attrition replacements. Nine more aircraft were operated by Moscow’s 6th PVO (air defence) corps and 12 more (all but one in non-flying condition) in the Northern Fleet’s air arm. The reasons were the painstaking (and thus slow) way in which Airacobra units were trained and the fact that only 193 Airacobras were delivered in 1941-1942. They were mainly P-400s (Airacobra Mk Is), including some aircraft which had actually seen service with the RAF, but also some P-39Ds which the USSR had ordered directly.

 

Nearly all Airacobras delivered to the USSR at the time were armed with the reliable drum-fed 20-mm Hispano Mk 404 cannon instead of the 37-mm Oldsmobile cannon which equipped most USAAF P-39s, and which was notoriously prone to jamming. In addition, Soviet Cobras had two synchronized 12.7-mm machine-guns in the nose and four 7.62-mm machine-guns in the wings.

 

HIGH-LEVEL APPROVAL

In late 1942 the Soviet leaders (Stalin, Molotov, Mikoyan, etc.) were beginning to get reports of Soviet pilots’ combat experience on foreign aircraft. For example, in late September engineer Lieutenant Colonel A.G. Kochetkov reported from the Karelian front where he was evaluating the combat capabilities of various US fighters: “The Airacobra clearly shows the best combat results. Even young pilots flying it successfully oppose Bf 109E and Bf 109F fighters.” The Soviet air force top command voiced a complaint that was very much in line with this report: “The Americans produce the P-39 by the thousand, and all we get is a few aircraft.” The air force command requested that deliveries of the Curtiss P-40B and P-40E Kittyhawk be reduced and deliveries of the Airacobra be increased instead.

 

On 7 October 1942 Stalin addressed Roosevelt accordingly: “I am told that delays in deliveries are caused mainly by the lack of capacity in freighters. To alleviate this problem, the Soviet government is prepared to agree to a reduction in deliveries of US war materials to the Soviet Union. We are prepared to do without deliveries of tanks, artillery, ammunition, handguns, etc. However, we need an urgent increase in the deliveries of up-to-date fighter aircraft, notably the Airacobra.” Stalin went on to request that deliveries of P-39s be increased to 500 aircraft per month.

 

Roosevelt replied that currently all Airacobras were delivered to front-line USAAF units straight off the production lines. Nevertheless, he promised to increase P-39 production at the expense of other types and send some of the Cobras to the USSR. He was as good as his word; in 1943, Soviet air force units alone (i.e., not counting naval aviation units) received 2,627 Airacobras.

 

PILOT OPINION

In the spring of 1943, a number of newly-formed regiments, most in southern Russia, were equipped with Airacobras. G.G. Golubev, who went on to become an HSU, recalls how the Soviet pilots reacted to the P-39: “The first impression was rather negative. The aircraft seemed too heavy and sluggish when compared to the nimble Polikarpov I-16. But when we retracted the undercarriage and entered the aerobatic zone we quickly found out that the first impression had been wrong. One thing we particularly liked was the radio. For the first time we could manoeuvre using ground control commands and not the flight leader’s signals. Now we would give the ‘mesers’ the old what-for!”

 

“Performing aerobatics on the Cobra called for a steady hand. At the slightest inaccuracy during a tight turn, a yo-yo manoeuvre or at the top of a loop the aircraft would go into a spin – often a flat spin (from which the P-39 could not recover). This was one of its main drawbacks.”

 

The famous Soviet ace A.I. Pokryshin, then holding the rank of captain and serving with the 16th IAP, related his judgement. “It was a shapely aircraft. One thing that I particularly liked about the Airacobra was the armament. That was really something to shoot the enemy down with – a hard-hitting 37-mm cannon, two fast-firing heavy machine-guns and four normal calibre machine-guns. I wasn’t put off when other pilots warned me that the Cobra was dangerously prone to spinning because the C of G located well aft.”

 

It should be noted that in early 1943 Soviet pilots tested the P-39’s spinning characteristics. Test pilot V.Ye. Golofastov reported that, at C of G positions between 25.7 and 29 per cent MAC, the aircraft recovered quickly if the spin recovery manoeuvre was executed immediately after entering a spin. The US standard operational procedure for a spin recovery was rejected as too complicated.

 

KUBAN CLASHES

The Airacobra made itself prominent during the fierce battles over the Kuban’ region in late April 1943. Each day, 30 to 40 clashes with German aircraft would take place over the Myskhako peninsula and later over the stanitsas (Cossack villages) of Kiyevskaya and Moldovanskoye. On 9 March 1943, the 45th IAP under Lieutenant Colonel I.M. Dzoosov arrived at Krasnodar airfield and went into action immediately. Eighteen of the unit’s 45 pilots had been in combat at the time of arrival. April 1943 was the most successful period for the unit, for the pilots and commanders had got to know the aircraft and tactics well. Within a month, Lieutenant I.I Babak shot down 14 enemy aircraft, and Lieutenant (sg) Glinka and Sergeant N.D. Koodrya scored six ‘kills’ each.

 

However, the 45th IAP suffered losses too. On 15 April alone, D. Glinka, V.I. Sap’yan, M. Petrov and I. Bebabnov were shot down. As soon as fighting in the Kuban region ceased, four 45th IAP pilots (B.B. Glinka, P.M. Berestenev, N.D> Koodrya and D.I. Koval’, who had 15, 1`0, 11 and 10 ‘kills’, respectively) became HSUs. The units CO was promoted to colonel and given command of the 9th GvIAD (ex-216th IAD). (The 45th IAP later became the 100th GvIAP.)

 

The 16th GvIAP had attained the prestigious Guards status even before converting to the P-39. Between 9 and 30 April, the unit flew 289 sorties on the Airacobra, claiming the destruction of 81 enemy aircraft, including 75 fighters. Within the same time frame, 18 P-39s were shot down or went missing, two more were written off in accidents and 11 pilots were killed. However, 19 new aircraft were delivered in the same month and the unit retained operational capability.

 

NEW TACTICS

The 16th GvIAP went on to become the most famous unit in the Soviet air force – or so it seems. The winning tactics employed by the unit were worked out over the Kuban’. This was the birthplace of the ‘Kuban’ ladder’ – a multi-layer squadron formation in which the top pair flew 200-300 m (650-980 ft) above the bottom pair and each pair was placed farther away from the sun than the one flying below. This formation gave the pilots good all-around visibility and the ability to manoeuvre freely, and facilitated co-ordination between pairs in a dogfight. The man behind this tactic was A.I. Pokryshin, who got his first HSU title on 24 May 1943, for scoring 1`3 ‘kills’ plus six shared ‘kills’. On the same day another ace, Captain V.I. Fadeyev, was awarded the HSU title – posthumously. He was one of the best fighter pilots of the 4th VA (Vozdooshnaya Armiya –Air Army), with 20 ‘kills’ to his credit.

 

The 289th IAP, another Airacobra unit, was the most successful ‘Hun hunter’ in the Kuban’ region. It entered action on 17 March 1943, operating from Korenovskaya airfield. Until 20 August the unit was in the thick of the action, making 1,625 sorties and downing 167 enemy aircraft – 112 of them during three tremendous battles staged between late April and early June. On 24 August the 289th IAP was transformed into the 104th GvIAP as recognition of its combat success. The unit’s CO, I.A. Taranenko, was awarded the HSU title and promoted; Major V.G. Semenishin, also the HSU, took over as CO. The unit continued to fly the P-39, acting as part of the 9th GvIAD.

 

At the time, the proportion of Cobras in the Soviet tactical fighter inventory was still small. As of 1 July 1943, 27 P-39s were in action in Karelia, 30 on the Leningrad front, 45 in the Kuban’ region, and 64 more were ready to counter the German offensive on the central front. By then, Airacobras made up about 5 per cent of the Soviet fighter force.

 

SOVIET IMPROVEMENTS

Earlier, the Airacobra I had been tested at NII VVS and found satisfactory. Then it was compared with the YaK-1 and LaGG-3, both powered by the Klimov M-105P, and the Bf 109F. However, in the year that followed, both Germany and the Allied forces had vastly improved their combat aircraft. The new Soviet La-5 and YaK-9 fighters were up against the Bf 109F-4, later joined by the Bf 109G-2 and Bf 109G-4. The Cobra compared poorly with these two types. Soviet specialists were well aware of this, and attempts to improve the P-400’s performance were made as early as late 1942. One Airacobra I (BX382) was progressively lightened by removing the 7.62-mm wing guns and part of the armour, then the radio set, battery, and oxygen bottles and finally, reducing the fuel load by 100 kg (220 lbs). The NII VVS test report recommended modifying the Airacobra Mk I by removing the wing guns, half the armour plates and the lead ballast in the rear fuselage.

 

The Northern Fleet’s air arm followed these recommendations and reduced the P-400’s weight by 247 kg (544 lbs). Test pilot A.G. Kochetkov, who was dispatched to the Northern Fleet’s 2nd GvIAP in April 1943, reported that, even without wing guns, the Airacobra I had sufficient armament to shoot down enemy aircraft effectively. The time required to reach 5000 m (16,400 ft) and the practical ceiling was reduced by 1.3 minutes and 9 minutes, respectively; short-field performance was also improved. Still, most aircraft were delivered unmodified.

 

P-39L

Meanwhile, new models of the Airacobra were tested at NII VVS. In July 1943, engineer P.S. Opoprienko and test pilot V.Ye. Golofastov put P-39L-1 42-4666 through its paces. They reported that the aircraft was well equipped for bad-weather flying – it was fitted with the MN-26 DF set and had wing, tailplane, and propeller blade de-icing.

 

The P-39L had other improvements too. Combat reports had led to changes in armour protection (armour plate was added to the cockpit and removed from unimportant areas) and the introduction of a stiffened nosewheel fork. The cockpit, oil tank, and armament bay were heated by air from the engine. The 1,150 hp (858 kW) Allison V-1710-35 (E4) powering early P-39 models was replaced by a V-1710-63 (E6) rated at 1,325 hp (988-kW) for take-off. As with most Airacobras delivered in 1943, the P-39L-1 had a 37-mm M-4 cannon firing through the propeller hub, two 12.7-mm Colt-Browning machine-guns in the nose and four 7.62-mm Colt-Browning machine-guns in the wings.

 

Unlike earlier and later Cobra tests at NII VVS, the aircraft was filled with US 100-octane avgas and the performance in the take-off mode (i.e., at full military power with turbo pressure increased from 1,070 to 1,150 mm Hg) was also recorded. This boosted speed from 490 km/h (304mph) to 530 km/h (329 mph) at ground level and from 554 km/h (344 mph) to 591 km/h (366 mph) at 3000 m (9,840 ft). At the time, high octane fuel was nowhere to be found in front-line units, so pilots were advised against using full military power. In general, the test reports were deemed satisfactory; the report indicated that at low and medium altitude, the P-39L-1 was almost equal in performance to the current Bf 109G-2 and Fw 190A-4.

 

ACTION ON THE SOUTHERN FRONT

The famous 9th GvIAP under I.A. Morozov was one of the units flying the P-39L-1. In August 1943, soviet forces launched an offensive on the southern front, and the unit participated in the breaking-up of the German defences near Molochnaya River and in the liberation of Taganrog. Captain Ahmet-Khan Sultan, later twice HSU and test pilot, earned fame in these battles, downing two German bombers near Kalinovka on 20 August. On the next day, six P-39s flying combat air patrol cover in the same region spotted 12 Ju 88s. The Soviet pilots came in head-on, sending the bombers scattering in all directions, and making them drop the bombs prematurely, and shot down three of them – one of the ‘kills’ being scored by Ahmet-Khan. Hardly had this fight ended when a group of 15 He 111s put in an appearance. Again, the Soviet pilots attacked head-on; Ahmet-Khan downed one more bomber, which fell near Uspenskaya village.

 

Ahmet-Khan’s group returned home safely. It so happened that General F.I. Tolbookhin, C-in-C of the southern front, had watched this battle from beginning to end. He immediately decorated Ahmet-Khan with the Order of the Combat Red Banner. During the nine most action-packed days, the 9th GvIAP’s pilots flew 247 sorties on the Cobras, had 22 group dogfights, and destroyed 35 aircraft.

 

Not all sorties ended well, however. In the spring of 1944, fierce battles started in the Crimea, culminating in the liberation of Sevastopol’ and the whole peninsula on 12 May. During this period, the 9th GvIAP suffered heavy losses. Of the 39 Airacobras (including three in non-flying condition) it had at the start of the campaign, five were shot down by enemy aircraft and two by flak; two went missing; another two were lost in accidents.

 

In the second half of 1943, Airacobra deliveries to the USSR continued to grow. The aircraft were mostly ferried to the 22nd ZAP at Ivanovo via Fairbanks, Alaska, and to the 25th ZAP at Adjikabul’ via Abadan (Iran). (Often they wore spurious markings, such as red stars superimposed on white roundels; these high-vis white portions were painted out as soon as the aircraft reached the conversion training units.)

 

NEW UNITS

In 1943, 17 fighter regiments equipped with P-39s were formed, as compared to 14 in 1942. Later, the Soviet high command decided not to form any more Airacobra units and to deliver new aircraft to existing units as attrition replacements. Cobra units were, if possible, grouped into fighter divisions, of which there were eight. Two of them – the 190th and 239th GvIADs (the latter became the 5th GvIAD) – constituted the 11th IAK under General G.A. Ivanov, the only all-Cobra fighter corps in the Soviet air force.

 

In late 1943, new Cobra models started arriving: the P-39M, powered by the V-1710-83 and with a slightly improved high-altitude performance, the P-39N, and P-39Q with the V-1710-85. The N and Q models were the most common in the SovAF. Both were tested at NII VVS, P-39N-0 42-8734 in July 1943 and P-39Q-10 42-20561 in October 1943. The aircraft differed only in detail: the P-39Q had the four wing mounted 7.62-mm machine-guns of the earlier models replaced by 12.7-mm machine-guns in underwing pods. In overload configuration, the P-39Q-10 could carry a 530-kg (1,168-lb) drop tank or a 234-kg (516-lb) bomb on the centreline rack, although this noticeably affected the aircraft’s stability. Another quirk of the Q was its increased sensitivity to elevator inputs during aerobatics. Pulling the stick back just a little too far was enough to send the aircraft into a spin.

 

US INTEREST

In October 1943 US ambassador Averill Harryman remarked in a conversation with V.M. Molotov that “there is one aircraft type, namely the Airacobra, that the Soviet air force employs with considerable success. The Russians seem to Know how to use it even better than the Americans. It would make sense for Soviet pilots to share their experience with General Vandenberg (one of the top commanders in the USAAF)…This is why Vandenberg would like to come and visit the Soviet air force squadrons flying the Airacobra.”

 

The Bell Aircraft Corporation expressed a similar request, and the Soviet leaders went along. General Vandenberg and company representatives visited the 6th ZAB (Zapasnaya Aviabrigada –Reserve Air Brigade) in Ivanovo, and the 67th and 30th GvIAPs. The soviet pilots had some request, e.g., they wanted an improvement in the ballistics and rate of fire of the 37-mm cannon. They claimed that late P-39Qs were much less stable than the early …Cobras and that the armored headrest introduced on this model impaired rearward visibility. (Despite this, one P-39Q flown by ace G.I. Rechkalov sported no fewer than 57 victory stars on the gun cowling) Bell representatives said they would take this into account.

 

The US delegation’s visit to the 6th ZAB was marred by the crash of a P-39Q-5 when the pilot became disoriented after recovering from a spin and had to bail out. It turned out that the spin had been caused by a too-far-aft centre of gravity.

 

FATAL SPINS

The Airacobra’s propensity to spin caused many accidents, some fatal. Lieutenant Colonel I.M. Dzoosov recalled that some pilots even developed an uncontrollable fear of aerobatics. Three experienced NII VVS pilots were killed when the P-39 spun in – K.A. Groozdev on 2 February 1943, K.A. Avtonomov on 3 January 1944, and K.I. Ovchinnikov on 27 April 1944. In October 1943, P-39Q-10 42-20561 with underwing 12.7-mm machine-guns was tested at NII VVS specifically with a view to determining it spinning characteristics. Major V.Ye. Golofastov executed 115 spins, doing 180 turns in all. The flights were made with five different C of G positions ranging from 28.4 to 30.9 per cent MAC and at weights of 3486 to 3578 kg (7,685 to 7,888 lb). The results were quite satisfactory – the report stated the “the spin manoeuvre on the P-39Q-series fighter is safe and recovery is possible within the usual C of G limits, provided the recovery manoeuvre is executed immediately and energetically, and the altitude is sufficient.” The institute recommended that pilots study the recovery procedure once again and be careful about keeping the aircraft’s C of G within its limits. Still, accidents continued.

 

STRUCTURAL DEFECTS

When two fatal accidents, one non-fatal accident and one minor incident happened in the 11th IAK under General Ivanov, NII VVS lead engineer I.G. Rabkin and test pilots V.Ye. Golofastov and D.G. Pikulenko were sent to the corps’ location on the northwestern front to investigate. Rabkin recalled that, on examining the wreckage of the Airacobras, he and the pilots discovered structural damage to the aft fuselage and cracks in the horizontal tail spars that were not caused by the impact.

 

An immediate inspection of all the unit’s Airacobras was made. Fifteen aircraft were found to have structural damage at the same locations, which, if it grew any worse, could cause catastrophic failure. Test conducted at TsAGI showed that US structural strength requirements were less stringent than the Soviet ones, and some aircraft could not withstand the stress when carrying bombs. After that, the 11th IAK Cobras were field-modified – the rear fuselage and tail unit were strengthened according to TsAGI recommendations.

 

In the US, a number of P-39Qs were converted to unarmed TP-39Q trainers by installing a second cockpit for the instructor with a conventional sideways-opening canopy in the gun bay forward of the original cockpit. A shallow ventral fin and sometimes a dorsal fillet were added to make up for the increased side area forward of the C of G. Since these were field-modified aircraft, the TP-39Qs had numerous detail differences. At least two TP-39Qs were delivered to the Soviet air force. Regrettably, accurate identification is impossible for the aircraft wore neither original USAAF serials nor Soviet tactical codes. One aircraft had a dorsal fillet but the other did not; the shape of the ventral fin and the forward canopy frame was also different.

 

NII VVS maintained a close interest in the Airacobra throughout the war. The following test programmes were undertaken successfully in the second half of 1944 alone: spinning and aerobatics tests of P-39Q-10 43-2467, which showed that the Q spun more powerfully and irregularly than early P-39 models; tests of the same aircraft determining the maximum safe dive angles with 100-kg (220-lb) FAB-100 and 250-kg (551-lb) FAB-250 GP bombs, after which the Airacobra was deemed suitable for the fighter-bomber role; tests of P-39Q-30 44-71117 with the elevator trim tab locked in the neutral position; and spinning and aerobatics tests of P-39Q-15 44-29115 with altered C of G position and reinforced tail unit and rear fuselage. The P-39 saw active service in the Soviet-German front until the end of the war. Eight fighter divisions and 25 regiments operated the type. As of 9 May 1945, the SovAF inventory included 1,178 Cobras, including 536 aircraft serving with the PVO, 478 in the naval fighter arm, and 164 in tactical fighter units.

 

In the closing stage of the war, the Airacobra of A.I. Pokryshkin’s unit operating from tactical airfield in Germany used the excellent German highways as landing strips. One photo depicting a P-39Q taking off from the Berlin-Breslau highway has been published often.

 

The P-39 stayed in Soviet service until the early 1950s. When the original US armament became unserviceable it was replaced by Soviet 20-mm B-20 cannon and 12.7-mm Berezin UBS machine-guns. In general, the Airacobra was a reliable aircraft which matched the requirements of contemporary warfare and was remembered with affection by Soviet pilots. In fact, it was the best-liked of all the Lend-Lease aircraft.

[GridiroN]

Yep. So far as I can tell you're right on the money for horsepower figures and the sub version of Allison. The P-39L-1 won't just have a cleaner airframe but definitely more power than the P-40E-1.

 

In fact, it will have more horsepower than most Russian frames currently in the sim equipped with a Klimov at 1250hp. This plane really does look more and more interesting, especially if we get several weight saving mods, and people taking it out with low gasoline in the tanks.

Edited January 30, 2018 by GridiroN

[ShamrockOneFive]

In fact, it will have more horsepower than most Russian frames currently in the sim equipped with a Klimov at 1250hp. This plane really does look more and more interesting, especially if we get several weight saving mods, and people taking it out with low gasoline in the tanks.

 

The removed .30 cals and removed armor plate are already confirmed as being modifications apparently totaling 200kg of weight reduction. Very interesting as an aircraft indeed!

[A_radek]

 

So why did they choose a symmetrical airfoil?

Full of surprises and this one was new to me. I really can't think of a reason for them to do this. Apart from someone figuring a fighter should behave neutrally in all situations, this out of the box thinking does go in line with the rest of it's unconventional design. If it had a moving stabilizer things would get even more interesting.

 

 

Using a symmetrical airfoil isn't the best idea from an efficiency point of view. You need angle of attack to create lift, which typically gives you higher drag than a cambered airfoil which creates the same lift at a lower angle of attack. Also, you get a fairly low maximum lift coefficient. On the plus side you get a constant, low moment coefficient, making strength and stability calculations easy. You don't get unwanted pitch up or pitch down behaviour from the main wing as you change angle of attack, so you can easily counteract it with the tail.

 

Compared to fighting a cambered airfoils increasing lift generation in a high speed dive, as in decreasing angle of attack, a lot. Would a symmetrical airfoil not create far less drag in that same situation? It's the only positive thing I can think of where this airfoil could be an advantage. Perhaps inverted flight as well but guess stabilizer/wing incidence is not 0 anyway, leading to excessive negative elevator (and drag) to keep it level when inverted.

Edited January 30, 2018 by a_radek

[SYN_Ricky]

-high top speed

-fast dive

-good energy retention

-slow roll

-good elevator authority

-mediocre sustained turn

 

Sounds like it's going to be a very smooth transition from the MiG. No wonder Pokryshkin liked it.

 

There also some aspects that Russian pilots liked in the P-39, and in lend-lease aircraft in general, that cannot translate in our simulation:

 

• Good radio receivers and emitter, allowing good communication and effective team work.
• Good quality of the cockpit glazing, offering a good view around. In some cases Russian pilots preferred to fly with an open canopy due to the bad quality of the glass.

[Sgt_Joch]

good post, especially these little tidbits:

 

 

ENGINE LIMITS
On the minus side, the V-1710 lacked a constant-pressure valve regulating turbo pressure, so the engine could easily become overpressurised and disintegrate in low-level flight. The NII VVS team reminded that “the Airacobra demands correct treatment in service, and special attention has to be paid to knowing the engine’s limits and the cockpit layout during conversion training.”

 

(...)



P-39L

Unlike earlier and later Cobra tests at NII VVS, the aircraft was filled with US 100-octane avgas and the performance in the take-off mode (i.e., at full military power with turbo pressure increased from 1,070 to 1,150 mm Hg) was also recorded. This boosted speed from 490 km/h (304mph) to 530 km/h (329 mph) at ground level and from 554 km/h (344 mph) to 591 km/h (366 mph) at 3000 m (9,840 ft). At the time, high octane fuel was nowhere to be found in front-line units, so pilots were advised against using full military power. In general, the test reports were deemed satisfactory; the report indicated that at low and medium altitude, the P-39L-1 was almost equal in performance to the current Bf 109G-2 and Fw 190A-4.

 

 

[Lusekofte]

At the same time the least successful USAAF fighter, of those that were produced and fielded in numbers; it will be interesting.

 

I think we all are a little bit afraid for the P 40 effect on this one. 

 

 

Good radio receivers and emitter, allowing good communication and effective team work.

 

This might be the answer on many things, never thought about it this way before, Many thanks. 

To be fair, this sim never could simulate the huge number of human resources either. Witch helped the Red Army in all branches most of all 

[CIA_Yankee_]

-mediocre sustained turn

 

Where did that one come from? From other comments I've seen, it apparently does very well in the horizontal at low altitude, and good energy retention generally leads to better sustained turns.

good post, especially these little tidbits:

 

Aye... looks like we'll be minding the manifold pressure just like we do in the P-40. Though in this case we will have much better leeway for going into higher power regimes at least.

 

As for the 100 octane fuel... well that might be a good example for why the engine timer limit might make sense... lower octane fuel at high pressure would definitely end up causing damage to the engine.

[gorice]

Where did that one come from? From other comments I've seen, it apparently does very well in the horizontal at low altitude, and good energy retention generally leads to better sustained turns.

 

Aye... looks like we'll be minding the manifold pressure just like we do in the P-40. Though in this case we will have much better leeway for going into higher power regimes at least.

 

As for the 100 octane fuel... well that might be a good example for why the engine timer limit might make sense... lower octane fuel at high pressure would definitely end up causing damage to the engine.

 

I've read conflicting things, and never seen data on turn performance, but one often encounters the sentiment that the plane was heavy and underpowered. FWIW, wikipedia gives a wing loading of 169kg per m2 for the P-39Q, and my rough calculation based on the figures in the document JtD linked is over 170kg per m2 for the P-39D, which is a bit higher than most fighters in game.

[von-Luck]

I see that wing loading as being comparable to Yak 1b. Admittedly I pulled these numbers from the wiki pages so take it with a grain of salt.

 

Yak 1b:

 

Maximum speed: 592 km/h at altitude (368 mph)

Range: 700 km (435 mi)

Service ceiling: 10,050 m (32,972 ft)

Rate of climb: 15.4 m/s (3,038 ft/min)

Wing loading: 168 kg/m2 (34 lb/ft2)

Power/mass: 0.31 kW/kg (0.19 hp/lb)

 

P39Q - note this is a later model P39*

 

Never exceed speed: 525 mph (845 km/h)

Maximum speed: 389 mph (626 km/h) at 10,000 ft (using emergency power)

Stall speed: 95 mph (152 km/h) Power off Flaps & undercarriage down

Range: 525 miles on internal fuel (840 km)

Service ceiling: 35,000 ft (10,700 m)

Rate of climb: 3805 ft/min (19,3 m/s) at 7,400 ft (using emergency power)

Wing loading: 34.6 lb/sq ft (169 kg/m²)

Power/mass: 0.16 hp/lb (0.27 kW/kg)

Time to climb: 15,000 in 4.5 min at 160 mph (260 km/h).

 

von Luck

[216th_Jordan]

Never exceed speed: 525 mph (845 km/h)

 

Ehehe. Everybody prepare to get seriously bounced!

[Mac_Messer]

I think we all are a little bit afraid for the P 40 effect on this one. 

 

I read this thread and see high expectations. People like digging for good things, obviously neglecting bad things.

[Pail]

 

 

If it is at least as good as the (updated) P-40, I will like it a lot.

 

I'm sure it will be very likeable but I would be disappointed if it didn't have some possibly surprising and unusual quirks to go along with that as well....but I'm no plane flying computer modeller guy...

[Max_Damage]

Here:

http://www.wwiiaircraftperformance.org/P-39/P-39N_level-speeds.jpg

and here

http://www.wwiiaircraftperformance.org/P-39/P-39Q-5_42-19615_ENG-19-1631-A.pdf

 

EDIT: Misread the speed chart, 344 mph is at 12400 ft, not SL. 329 mph (529 km/h) could be achieved at SL @ 57" Hg, still decent.

57" which will only work for 2 minutes and destroy your engine shortly after. This plane is going to be trash :O

[216th_Jordan]

57" which will only work for 2 minutes and destroy your engine shortly after. This plane is going to be trash :O

This is for the N-Model. Also Yak-1b is having about the same top speed and it isn't trash.

 

There is more to a plane than raw performance.

[Max_Damage]

yeyeyye fly a p40 against g4 and tell me about how there is more about planes than raw pwerformance haha :D

 

Unlike the yak1b it will has seriouly suicidal engine, limited time at full power, bad turning, extremely bad climbs and accelerations. Plus the cannon which is not suited for air combat

Edited January 31, 2018 by Max_Damage

[-=PHX=-SuperEtendard]

57" which will only work for 2 minutes and destroy your engine shortly after. This plane is going to be trash :O

 

At sea level, the engine in the L model at 51" had similar power to the one in the N/Q at 57" (as those were optimized for a bit higher altitude), which was cleared for 5 mins, so it would be usable.

 

 

Also what hedger posted is interesting, as it talks about a Soviet test of this particular L-1 variant.

 

P-39L

Unlike earlier and later Cobra tests at NII VVS, the aircraft was filled with US 100-octane avgas and the performance in the take-off mode (i.e., at full military power with turbo pressure increased from 1,070 to 1,150 mm Hg) was also recorded. This boosted speed from 490 km/h (304mph) to 530 km/h (329 mph) at ground level and from 554 km/h (344 mph) to 591 km/h (366 mph) at 3000 m (9,840 ft). At the time, high octane fuel was nowhere to be found in front-line units, so pilots were advised against using full military power. In general, the test reports were deemed satisfactory; the report indicated that at low and medium altitude, the P-39L-1 was almost equal in performance to the current Bf 109G-2 and Fw 190A-4..

1070 mmHg is 42.1" Hg, and at this setting they got 490 km/h, very similar to the 495 km/h speed for the US test of the P-39K with the same manifold pressure. With the 100 octane fuel they tried 1150 mmHg, which is around 45.3"Hg, and they got 530 km/h in that setting.

 

So it looks like that at the 51" war emergency power it would be closer to the P-39N's speed of 550 km/h at 57", which makes sense as the P-39Q's speed test of 530 km/h at 57" had the increased drag of the .50 cals in the external wing gunpods.

 

 

 

 

 

 I don't know if the P-39L at 51" would be exactly 550 km/h as there might be differences with the N model, but at least it appears that it will be a bit faster than 530 km/h.

Edited January 31, 2018 by -=PHX=-SuperEtendard

[A_radek]

yeyeyye fly a p40 against g4 and tell me about how there is more about planes than raw pwerformance haha :D

 

Unlike

I don't see anyone here expecting it to best a 109 in performance.

[Panthera]

57" which will only work for 2 minutes and destroy your engine shortly after. This plane is going to be trash :O

 

2 min ? Only if the developers keep their unrealistic time limits. If not we should atleast be allowed to run at this setting for 5 min.

 

The biggest danger in the P-39 (as in the P-40) should be exceeding that 57" Hg boost pressure by mistake, as the engine doesn't feature any pressure regulator.

[Dakpilot]

One thing your shiny new P-39 will get is a manifold pressure gauge that goes to 75" 

 

P-40E-1 only goes to 50" this made it impossible to see what you were setting, mistakes will be much easier to avoid with P-39

 

regardless of 'contentious' P-40 limits how were pilots supposed to fly with potentially dangerous levels of boost where they had no way of monitoring it?

 

Cheers, Dakpilot

[JtD]

as the engine doesn't feature any pressure regulator

Do we know that for certain? According to an April 1944 manual, V1710-63's had been refitted with pressure control devices in service as time and maintenance permitted. So we would need to know what exactly the Soviets got&used in 1943, over Kuban.

[Panthera]

Do we know that for certain? According to an April 1944 manual, V1710-63's had been refitted with pressure control devices in service as time and maintenance permitted. So we would need to know what exactly the Soviets got&used in 1943, over Kuban.

 

Didn't know that, thus I agree we need know wether these were fitted to Soviet P-39's by 1943. A few of the quotes seen so far indicates they might not have, careful attention to the limits of the engine being noted as esp. important.

[=RvE=Windmills]

Would the issue with engine over-revving still be present in the 39 like it is in the P40?

[Panthera]

Would the issue with engine over-revving still be present in the 39 like it is in the P40?

 

The the question we're currently trying to figure out an answer to

Edited January 31, 2018 by Panthera

[Ehret]

Didn't know that, thus I agree we need know wether these were fitted to Soviet P-39's by 1943. A few of the quotes seen so far indicates they might not have, careful attention to the limits of the engine being noted as esp. important.

 

Sounds like a good idea for an optional modification, then.