Hey TD can you look again at the Corsair..

[IceFire]

Again horseback... you have my thanks for doing the testing and getting some hard numbers. Had zero time to test but I'd like to try and replicate some of what you've done just to add to the data points... hopefully in for a quieter week (ha!). But lets get to the bottom line here... the Zero is painfully slow to accelerate? Right? The Corsair is king of the castle here. And yet people feel quite the opposite about it. This is why testable numbers get really interesting.

You know, something we can do here is get a couple of people to line up their aircraft and use a dogfight or COOP mission to test and see. If someone wants to host, I'd join in.

[ElAurens]

Wow.

This explains why F4Fs will leave the A6M in level flight like it was tied to the ground. Also explains my preference for flying IJA aircraft in the sim over the Zeke.

[horseback]

As I said, the results from the 190 and the Zero don't make sense to me; I wonder if these aircraft flown by AI would get better numbers, because they sure seem faster when I'm flying against them in a QMB or a campaign. Maybe having Insta-Trim confers more Mojo than even I thought it does.

I'll want to try the F4F-3 and -4, the P-40E, the Ki-43 and maybe the Ki-27 (which was active over the Philippines as well as China during the early war). We might want to check the IJN/IJA fighters vs the USN/early USAAF fighters at 5000 ft as well; the early contests of 1942 often took place at lower alts. If the Japanese birds perform better there, it might start to give us a better picture.

The FW results are the ones that make least sense to me; the tests I recall reading seem to indicate that it was both quicker & faster than the Corsair and Hellcat, and initially quicker than the P-47D, if not quite as fast over all, particularly at higher alts. I would like to think that I'm either running it at its worst altitude for comparison or that I'm doing something wrong.

I'd really like to get some numbers from people who really know these birds well; maybe a track or two from the pros demonstrating three 'runs' in the QMB Crimea Map at noon starting at 3050m and 270/280 kph Indicated, properly trimmed and at the appropriate supercharger stage and mixture heading west over the sea. Just slam everything forward and do your best to keep it straight & level until it reaches top speed or has been in overheat without getting any more speed for a minute or two. Then open your radiator or cowl gills, drop your Prop pitch and throttle setting and go back to where you started; usually your engine is completely cooled and happy to take another sprint. I've noticed that overall, the time to top speed, like the overheat, is fairly consistent--it's the times in the middle that can vary by a bit.

I'm also wondering if we couldn't test and compare dive acceleration in a similar way...

cheers

horseback

[EJGr.Ost_Caspar]

Very interesting! Not sure, what it means for Fw190, but Zero isn't surprising me. Its not known as a fast plane. However, this shows clearly, how much a 'feeling' can fail.

But I have a theory, what could cause this: E-bleeding
I suppose, planes are much different here. If you don't trim properly, then you bleed E all the time and this may be much more worse for a F4U than for a Zero or even Fw190. And in dogfight this is more important than max speed and pure positive acceleration.

I think, you can leave out the Ki-27 - it will not show any surprising numbers, being the weakest and slowest with its fixed gear and fixed propellar. But Ki-43 vs. A6M or Ki-84 vs. Corsair could contain some interesting results.

[majorfailure]

Originally Posted by horseback

As I said, the results from the 190 and the Zero don't make sense to me; I wonder if these aircraft flown by AI would get better numbers, because they sure seem faster when I'm flying against them in a QMB or a campaign. Maybe having Insta-Trim confers more Mojo than even I thought it does.

While the Zero makes perfect sense to me, it is out of its ideal performance envelope almost into the beginning of the test, the Fw190 is a bit astonishing - maybe not its best altitude though. Or maybe it is the way it is -similar power/weight, but more power at the Corsair - if it has a comparable front area that would then give it an edge.

Originally Posted by horseback

I'll want to try the F4F-3 and -4, the P-40E, the Ki-43 and maybe the Ki-27 (which was active over the Philippines as well as China during the early war). We might want to check the IJN/IJA fighters vs the USN/early USAAF fighters at 5000 ft as well; the early contests of 1942 often took place at lower alts. If the Japanese birds perform better there, it might start to give us a better picture.

I'd be interested in P-39s, I somehow have the feeling the later ones accelerate pretty good. Maybe I get to testing some this week -I'm intrigued by what's been done.

Originally Posted by horseback

I'm also wondering if we couldn't test and compare dive acceleration in a similar way...

I don't see how - the problem beeing the dive angle - would have to test parallel or flying pursuit.

Originally Posted by horseback

cheers

horseback

Thanks for getting all the data - especially as it didn't back up your original claim -other people wouldn't have had the balls to post it.

[gaunt1]

Interesting tests!

Maybe something is indeed wrong with the 190. On eastern front, its very easy to catch it with anything, except the I-153, Rata, and maybe the LaGG-3 S4. Or maybe russian planes are accelerating too well, who knows

Anyway, I'd be also interested in P-39 tests, especially the D-1/D-2. Would be interesting to compare it to P-40. Never understood why americans didnt like the Cobra, it was a really good plane.

[EJGr.Ost_Caspar]

Originally Posted by gaunt1

Never understood why americans didnt like the Cobra, it was a really good plane.

Not at the altitudes, where they fought (high up with the bombers). Not suited for carriers use and not having the necessary range for default PTO operations, it was best used in ground attack and low alt fight - as especially the russians use to do it.

If it had got the turbocharger, that prototypes had, then the picture would have been different maybe.

Later in the war, after D-Day, when ground attacks in Europe became more important, there were already better types available, like P-47 and P-51 (which could as well fly all the way with the buffs too).

[majorfailure]

Originally Posted by EJGr.Ost_Caspar

Not at the altitudes, where they fought (high up with the bombers). Not suited for carriers use and not having the necessary range for default PTO operations, it was best used in ground attack and low alt fight - as especially the russians use to do it.

And there was the Issue of the reacquired P-400s that did have British oxygen supply - and couldn't go higher than the pilot could endure the thin air. Add pilots not well versed with the type and its temperamental low speed handling - at a time when fighter doctrine was still to dogfight. And to some there was too much innovation in it, car doors, engine behind the pilot, sitting on the prop shaft, tricycle landing gear -bah that has to be bad. The 37mm cannon was not liked in the beginning, too - as its trajectory needed well trained marksmen. And then add psychology, a pilot not confident with his plane will not perform as well as one convinced of its superiority.

Originally Posted by EJGr.Ost_Caspar

If it had got the turbocharger, that prototypes had, then the picture would have been different maybe.

That would have been a hell of an interceptor. But the rather short range was still there.

Originally Posted by EJGr.Ost_Caspar

Later in the war, after D-Day, when ground attacks in Europe became more important, there were already better types available, like P-47 and P-51 (which could as well fly all the way with the buffs too).

Don't forget Northern Africa and Italy. There were some P-39s present.
And the Cobra could not have been that bad even in US service -of the ~10000 produced, only half went to the VVS. Okay some were used as trainers, but that still leaves a few thousand used in combat.

[horseback]

Originally Posted by EJGr.Ost_Caspar

Not at the altitudes, where they fought (high up with the bombers). Not suited for carriers use and not having the necessary range for default PTO operations, it was best used in ground attack and low alt fight - as especially the russians use to do it.

If it had got the turbocharger, that prototypes had, then the picture would have been different maybe.

Later in the war, after D-Day, when ground attacks in Europe became more important, there were already better types available, like P-47 and P-51 (which could as well fly all the way with the buffs too).

The campaigns the RAF and the USAAF (and very quickly for the USN, after the first carrier battles) fought more or less required ever increasing altitudes; an attacking force would be forced (by radar) to come in as high as possible to make interception both more difficult and hopefully in lesser force. P-39s were found next to useless at Guadalcanal as most attacks air attacks came from over 20,000 ft, which they simply could not reach and be effective at (regardless of the official maximum altitude figure; a lot of early war US fighters were plagued with quality issues in the first 18 months of the war).

In the Soviet campaigns, the Soviets and the Germans were largely unable to strike at each others' strategic assets from the air, and had to attack them as they approached the battlefield, or on the battlefield itself. Striking from high altitudes in this sort of situation made any useful accuracy almost impossible, so everyone was forced to fight at lower altitudes, even though the German fighters were able to use their better high alt performance to patrol and strike from on high. Had the Soviets been able to develop a similarly capable fighter for medium/high alt combat that was still capable (by their definition) at lower alts, they probably would have put it to wide use.

Instead, they mostly kept their fighters operating at their best altitudes and made the Germans come to them. They may have figured they were sitting ducks either way, and their chances of surviving and inflicting damage to the enemy were better at their best altitudes rather than at Fritz's.

Part of the reason that the P-39 couldn't get the turbochargers was that the USAAF preferred to put them in their bombers or in the more promising P-38 and P-47 designs. Remember that the decision was made before we entered the war, and that the company that made them had other priorities (odd as that sounds, it was just more profitable to make other stuff to sell to the public rather than to make very difficult high tech/high cost products for the rather parsimonious (cheap) US military of the 1930s). It was late 1942 before the turbocharger production even began to sort itself out; production and development of the P-38 and P-47 was affected, and it was a bottleneck for the B-17 and B-24 as well at times.

Putting the turbocharger on the Airacobra would also have made it heavier, meaning less fuel tankage and less range, plus there would be poorer performance at low and medium altitudes, limiting its usefulness in support of the Army's ground forces.

cheers

horseback