Test Group #4: Yak-9, La-5F, and the Spitfire LF Mk IX at 80% and 100% prop pitch (2700 rpm and 3000 rpm, respectively).

Crimea map, noon, 3050m, 270 kph IAS, due west over the Black Sea.

From 270 to 350 kph: La-5F, 23 seconds; Yak-9, 17 seconds, Spit IX @80%, 14 seconds; Spit IX @100%, 12 seconds.

To 370 kph: La-5F, 30 seconds; Yak-9, 24 seconds, Spit IX @80%, 18 seconds; Spit IX @100%, 16 seconds.

To 380 kph: La-5F, 34 seconds; Yak-9, 28 seconds, Spit IX @80%, 21 seconds; Spit IX @100%, 18 seconds.

To 390 kph: La-5F, 40 seconds; Yak-9, 31 seconds, Spit IX @80%, 24 seconds; Spit IX @100%, 21 seconds.

To 400 kph: La-5F, 48 seconds; Yak-9, 35 seconds, Spit IX @80%, 28 seconds; Spit IX @100%, 23 seconds.

To 410 kph: La-5F, 58 seconds; Yak-9, 39 seconds, Spit IX @80%, 32 seconds; Spit IX @100%, 26 seconds.

To 420 kph: La-5F, 1 minute 8 seconds; Yak-9, 43 seconds, Spit IX @80%, 36 seconds; Spit IX @100%, 29 seconds.

To 430 kph: La-5F, 1 minute 17 seconds; Yak-9, 49 seconds, Spit IX @80%, 42 seconds; Spit IX @100%, 32 seconds.

To 440 kph: La-5F, 1 minute 47 seconds; Yak-9, 56 seconds, Spit IX @80%, 48 seconds; Spit IX @100%, 35 seconds.

To 450 kph: Yak-9, 1 minute 7 seconds; Spit IX @80%, 54 seconds; Spit IX @100%, 39 seconds.

To 460 kph: Yak-9, 1 minute 35 seconds; Spit IX @80%, 1 minute 4 seconds; Spit IX @100%, 43 seconds.

To 470 kph: Yak-9, 2 minutes 5 seconds; Spit IX @80%, 1 minute 20 seconds; Spit IX @100%, 48 seconds.

To 480 kph: Spit IX @80%, 1 minute 40 seconds; Spit IX @100%, 56 seconds.

To 490 kph: Spit IX @100%, 1 minute 5 seconds

Yak-9 overheats fairly consistently at 1 minute 40 seconds and La-5F overheats like clockwork right before reaching 440 kph, at a minute forty as well. I had expected the La-5F to be a bit faster, but the Yak is a beast by comparison; too bad it shoots BBs (and only carries about 10 of them). Things may be different at 1500-2000m.

All three aircraft twist & shake like a wet dog when full throttle is applied, usually resulting in a short climb and turn before I (over)compensate with stick & rudder; I can't help but think that I lose a couple of seconds of initial acceleration as a result, but it's harder to avoid than having to kiss that aunt with the big hairy mole at family reunions...

At 80% Prop Pitch Spit IX is still superior to most aircraft of the time, and not prone to overheat; however, if someone is shooting at me, I will take the (minor) chance of overheat and the much greater acceleration that comes with it.

The Spitfire IX wants to roll slightly right all the time, regardless of speed or power setting; since I calibrated my CH Combatstick before starting, I have to think it isn't me (although I also tend to roll right). It can't be trimmed out with rudder, and there apparently is no aileron trim. This results in little jerks of the stick as you catch the wings starting to come out of level. I have to mention that the climb indicator and the turn & bank thingie seem a good bit less accurate than on the Spit Mk Vb.

None of these aircraft want to trim out with button trim, particularly at their top ends; you have to be alert for little climbs and dives all the time, and at the very ragged edge, where the engine is straining to get to the next 10 kph of speed, a tiny variation in angle of attack can make a big difference in how long it takes. If you need to get outa Dodge in a hurry, put the nose down a fraction and fool the guy behind you into thinking you're still flying straight and level for that critical first couple of seconds.

cheers

horseback

Again, completely fascinating. Many thanks!

It isn't you. I can't keep the Spit IX straight with rudder trim alone, too. At least not at 110% power. And it is difficult to impossible to trim out exactly level, and needs quite a bit of nose down trim at higher speeds.

I wouldn't have thought the Yak to be that good at acceleration, but it makes sense, at least it looks aerodynamically clean. The La-5F is a surprise - it seems the additional drag from radial engines carries quite some penalty in this game. And that it does not get near the Spits and Yaks top speed is strange, too.

Thanks Horseback!

Im not really surprised about the La-5F. La-5 and La-5FN are both UFOs, but strangely, the F performs worse than the real one up to 4000m*, about 10 km/h too slow @ both 1500 and 2750m.

*above that, its way too fast however

Acceleration Chart #5
P-51C @2700rpm (prop pitch 80%) & 3000rpm (prop pitch 100%), La-5FN, LaGG-3 (66), Seafire LF Mk III, & P-38J

Start 270 to 350kph: LaGG-3, 21 seconds; La-5FN, 20 seconds; P-38J, 16 seconds; Seafire LF III, 16 seconds; P-51C @ 2700rpm, 14 seconds; P-51C @ 3000rpm, 14 seconds.

To 370kph: LaGG-3, 28 seconds; La-5FN, 25 seconds; P-38J, 22 seconds; Seafire LF III, 22 seconds; P-51C @ 2700rpm, 19 seconds; P-51C @ 3000rpm, 18 seconds.

To 380kph: LaGG-3, 32 seconds; La-5FN, 28 seconds; P-38J, 25 seconds; Seafire LF III, 26 seconds; P-51C @ 2700rpm, 22 seconds; P-51C @ 3000rpm, 21 seconds.

To 390kph: LaGG-3, 36 seconds; La-5FN, 33 seconds; P-38J, 28 seconds; Seafire LF III, 26 seconds; P-51C @ 2700rpm, 26 seconds; P-51C @ 3000rpm, 24 seconds.

To 400kph: LaGG-3, 41 seconds; La-5FN, 38 seconds; P-38J, 32 seconds; Seafire LF III, 34 seconds; P-51C @ 2700rpm, 30 seconds; P-51C @ 3000rpm, 28 seconds.

To 410kph: LaGG-3, 46 seconds; La-5FN, 38 seconds; P-38J, 37 seconds; Seafire LF III, 41 seconds; P-51C @ 2700rpm, 34 seconds; P-51C @ 3000rpm, 31 seconds.

To 420kph: LaGG-3, 53 seconds; La-5FN, 51 seconds; P-38J, 43 seconds; Seafire LF III, 47 seconds; P-51C @ 2700rpm, 38 seconds; P-51C @ 3000rpm, 34 seconds.

To 430kph: LaGG-3, 1 minute 3 seconds; La-5FN, 1 minute flat; P-38J, 48 seconds; Seafire LF III, 57 seconds; P-51C @ 2700rpm, 42 seconds; P-51C @ 3000rpm, 37 seconds.

To 440kph: LaGG-3, 1 minute 10 seconds; La-5FN, 1 minute 13 seconds; P-38J, 54 seconds; Seafire LF III, 1 minute 7 seconds; P-51C @ 2700rpm, 47 seconds; P-51C @ 3000rpm, 41 seconds.

To 450kph: LaGG-3, 1 minute 20 seconds; La-5FN, 1 minute 27 seconds; P-38J, 1 minute 3 seconds; Seafire LF III, 1 minute 29 seconds; P-51C @ 2700rpm, 52 seconds; P-51C @ 3000rpm, 46 seconds.

To 460kph: LaGG-3, 1 minute 37 seconds; La-5FN, 1 minute 57 seconds; P-38J, 1 minute 15 seconds; P-51C @ 2700rpm, 59 seconds; P-51C @ 3000rpm, 52 seconds.

To 470kph: LaGG-3, 2 minutes 2 seconds; P-38J, 1 minute 33 seconds; P-51C @ 2700rpm, 1 minute 5 seconds; P-51C @ 3000rpm, 57 seconds.

To 480kph: P-38J, 1 minute 54 seconds; P-51C @ 2700rpm, 1 minute 12 seconds; P-51C @ 3000rpm, 1 minute 2 seconds.

To 490kph: P-38J, 2 minutes 34 seconds; P-51C @ 2700rpm, 1 minute 20 seconds; P-51C @ 3000rpm, 1 minute 11 seconds.

To 500kph: P-51C @ 2700rpm, 1 minute 31 seconds; P-51C @ 3000rpm, 1 minute 22 seconds.

To 510kph: P-51C @ 2700rpm, 1 minute 42 seconds; P-51C @ 3000rpm, 1 minute 43 seconds.

To 520kph: P-51C @ 2700rpm, 1 minute 53 seconds; P-51C @ 3000rpm, 2 minutes 3 seconds.

To 530kph: P-51C @ 2700rpm, 2 minutes 15 seconds; P-51C @ 3000rpm, 3 minutes 3 seconds.

NOTES:
1. LaGG-3 and La -5FN were both in supercharger stage 2, 100% Mixture, radiators closed; both exhibited a 'twist' from the torque as the engine had full power applied, causing an abrupt nose up and left motion; compensating with stick & rudder until trim could catch up (sort of) usually resulted in overcompensation and loss of altitude on the order of 20-30 meters. LaGG was faster than I would have expected, La-5FN somewhat slower. Positions may be reversed below 2000m.
2. Both Mustangs were tested at 70% fuel (to simulate non overload condition), as the fuselage tank was not supposed to be over 30 US Gal. when entering the combat zone. Every historical source states that the fuselage tank was added for the sake of extended range, and compromised safety when the aircraft was flown with the tank full. 70% fuel simulates a fuselage tank at the 'safe' level.
3. The Mustang accelerated somewhat faster at 3000rpm between 350 and 500 kph, but couldn't reach 530 kph in level flight and it was much more difficult to trim for semi-level flight; it seemed to porpoise (go up and down by 10-15m in very short periods) unpredictably at the higher speeds.
4. The Lightning was the USAAF's acknowledged champion in climb and straight line acceleration; Il-2 '46's version is extremely stable and easy to keep level, but it should NOT be slower to accelerate than the Mustang at any altitude, even one without a fuselage tank installed.
5. P-38J was the only aircraft in this group that did NOT exhibit a 'twist' when the throttles were slammed forward; the Lightning did, however, try to go straight up. It was exceptionally easy to keep trimmed and straight and level, once you learned to anticipate the tendency to (rapidly) climb as speed increased.
6. Seafire LF III is apparently at the high end of its combat envelope at 3050m; after doing the regular test runs, I took it down to 1500m and throttled up from 350kph--every interval was blazing fast from 350 to around 450 IAS, at which point it slowed to more mortal intervals until it reached 490 kph (540 kph true), or 40 kph faster indicated than it did at 3050m (and about 2 kph faster in TAS at 3050m). At either altitude, it is the twitchy-est Spit version tested so far.

cheers

horseback

The P38s have never met their historic performance figures in '46.

If you don't mind, I'd be interested to see the CW-21 vs the A6M2 and/or Ki-43 - been flying it a bit lately and absolutely fell in love, it's incredibly easy to fly and alarmingly sporty. I have a feeling it'll walk all over the Japanese fighters in every area bar the Zero's cannons, but I could very well be wrong. It's very sluggish to pick up speed on the ground (which strikes me as very odd), but in the air it's an entirely different story.

I don't wonder about LaGG-3 - the series 66 is a beast in game. I don't know, if it is modelled realistically or optimistically, but I rather supect later.

I wonder about P-38. I aways thought it was a quite good plane in game (I love to fly it) and found speed and climb good as I expected it (never expected it to be nimble). Reading, that it should accelerate and climb faster, is well... surprising.

From performance alone, it is a very dangerous plane to the Zero. But back then, the Japanese were just outnumbering the Dutch (and Chinese), and also had probably a better training. Which then lead to the fast destruction of the little CW-21 force, especially as they cought fire easily with their vulnerable fuel tanks.

Now in game and 1vs1 it should be a very even match.

The P-38 had a lot of power, even with that big airframe, and the turbosuperchargers let you use all of those two Allison engines' power at any altitude. It was designed and built to the pre-radar era's definition of an interceptor, so it needed excellent (not merely good) climb to height capability, and as we all know, the better an aircraft climbs, the faster it can usually accelerate. If you consider that the prototype was an eyelash short of 400mph in August of 1939, you will begin to better appreciate what a technical achievement it was; in many senses, if the United States Army had gotten it directly into production immediately, it would have been superior to the Bf 109E and the Spitfire Mk I in many important ways.

I suspect that the Lightning's reputation was 'colored' in the same way the P-40's maneuverability was; it was most effectively used in the Pacific, where the Gold Standard for maneuverability was the Oscar or the Zero--by comparison to these aircraft, a P-40 or a Lightning was 'not' very maneuverable. They were, however, faster, more heavily armed and better armored, so in that theater Warhawk and Lightning pilots traded on those strengths. In North Africa, the Lightning's sustained turn and ability to instantly turn its speed and kinetic energy into a steep zoom climb shocked the LW pilots who initially encountered it. It took a while to notice that its instant roll rate was lacking, or that it could not safely dive from 30,000 ft/10km and successfully pursue a 109 or 190 the way the P-47 or the Mustang could.

The big reason that the Lightning was not more widely used was that it needed the same turbosuperchargers required for the B-17 and B-24, it required a lot of 'hand building', one special 'handed' Allison engine that rotated in the opposite direction for each aircraft and it was simply not designed for mass production in any case; as a result, it was not available in the desired numbers during 1942-43 and the USAAF instead developed the P-47 and (grudgingly) the P-51 to the point that these aircraft approached or exceeded the Lighting's performance and range. At the same time, the design appears to have been 'frozen' in some respects in a misguided attempt to keep the production lines moving. The P-38's control layout was an ergonomic disaster for a pilot wearing the cold weather gear necessary for its poorly heated cockpit; even in moderate conditions, it was less than ideal and just plain inferior to its contemporaries/competitors.

On top of this, these types both were safer and better performing at extreme high altitudes and could (easily) counter the LW's preferred escape method at high alts: rolling and diving at a steep angle. Even so, any model of the P-38 was well-known to be able to easily out-climb and out accelerate the Thunderbolt and the Mustang even after they had been 'improved' with the paddle-blade props & water injection or the Merlin engine and an overload fuselage tank.

In any case, had the P-38 been available in close to the desired numbers early in the war, the P-47 would have remained a short ranged point defense fighter and the Mustang might never have gotten a Merlin power plant; the improvements that created these aircraft as we remember them wouldn't have been needed in 1943.

The Lightning in Il-2, like the Hellcat, does not perform to data well-known and published here in the States; I suspect that looking at these aircraft and their weights, someone in Moscow decided that those numbers just couldn't be right, and used numbers from God knows where but more to their liking. Even the 'enhanced' Lightning version is short of the published performance of the type, and the 'compressibility' model it is subject to being extended below 6500m is simply not right, in both the factual and the ethical senses of the word.

If the LaGG-3 (66) was modeled 'optimistically', then the P-38 was modeled pessimistically.

cheers

horseback