Impressions of the 39

[Squire]

Seems a few are getting P-39D mixed up with P-39Q.

...Other than being 30 mph slower with a crappier climb rate? I cant think what a P-40E has on a P-39Q.

If I want my P39Q with 800 lbs of extra ballast for no reason? cool, ill roll a P-40E.

[Widewing]

Yup I prefer P40E over it.

Some people simply like a certain aircraft for reasons they can't explain. I have a few I fly often despite being absolute dogs. However, the P-39Q is superior to the P-40E (which is modeled like a later P-40K, as the E did not have WEP).

Here's the data compiled by Mosq and me..



Any questions?


My regards,

Widewing

[ShrkBite]

i'd take the 39 over a 40E anyday

[dedalos]

Any questions?


My regards,

Widewing

Yes, where or how do you get this data?

[Yknurd]

I keep seeing people prefer the P40 over the P39 but I found that the P39 is much more maneuverable than the P40.

Do I fly the P40 wrong?

[dedalos]

I keep saying people prefer the P40 over the P39 but I found that the P39 is much more maneuverable than the P40.

Do I fly the P40 wrong?

Probably.  Those numbers do not tell you how a a fighter will do in a fight, in my opinion at list.  The way it responds at low speeds when you have to roll over the enemy, what speed flaps come out, how it retains the little e left, can it pull its nose up just a enough for a shot, etc, is what makes the difference.

For example, some planes will nose over and point at the enemy while others will float to the earth.  You cant see that in any graphs.  WW is right that people like a plane but don't really know why.  Its the feel of the plain.  Assuming his numbers are true for AH, I still find the P40 a better fighter.  If it was me vs me P40 vs P39, P40 would win

[Shuffler]

I think 39 use will be on the rise more than it is now. Even when the new wears off. It's a deadly fighter. The 80th flies it some as our namesake Squad did so back in the day. But as usual to each his/her own. <S>

[Widewing]

Yes, where or how do you get this data?

Well Ded, it's a lot of work. Both Mosq and I have spent dozens of hours each test flying the P-39s. We have our own flight test cards, not unlike those used by real-world test pilots. Virtually every aspect of the flight envelope is explored and quantified.

For example, speed testing is done at increments of 5,000 feet, beginning at sea level (50ft). When I find myself close to the best altitude, I then test in 1,000 foot increments. I've actually broken it down to 100 foot increments on occasion. In the case of the P-39Q, it can reach 383 mph at 12,000 feet, with 383 mph at 13,000 feet and 381 mph at 14k. The P-39Q is a bit faster than the P-38J from 8k thru 13k and about 15 mph faster than the 190A5 at 12k... It's not a rocket, but it is competitive with most fighters between 8K and 14K.

Sea level speed is 329 mph, which is 30 mph faster than the P-40E. Comparing the La-7 to the 109G-14 produces the same speed ratio. Thus, it is quite significant. Moreover, the P-39Q is 10 mph faster at sea level using MIL power than the P-40E is using WEP. Again, this is substantial and an important fact.

Testing shows that the P-39Q accelerates faster and climbs faster than the P-51B or any of the -1 type Corsairs. Clean, it out turns them quite easily. The F4Us are better with flaps, but first they have to survive long enough to slow down and get them out.

So, why does the P-39Q out-perform the P-40E by such a margin? It's really rather easy to understand when you realize that the P-39 is much lighter, has more horsepower and similar wing area. It also has a much lower drag coefficient, which translates into speed.

My regards,

Widewing

[GFShill]

So, why does the P-39Q out-perform the P-40E by such a margin? It's really rather easy to understand when you realize that the P-39 is much lighter, has more horsepower and similar wing area. It also has a much lower drag coefficient, which translates into speed.

My regards,

Widewing

It also has the mid-engine design, which shifts the CG.  It also has a smaller nose area vs the P-40's large intake by the prop and the round front of air-cooled engines.

[BaDkaRmA158Th]

Awesome read WW. 

[TienLung]

I dnt kno if u boys can fly it it might just take a girl to fly 39q i find evrything about the 39 is great other than the poor vis lookin behind u but other than that keep it fast lol dnt get low and slow first couple flights in the 39 i landed 17 kills total 3 sorties my first 3 but i use to play flight sims and alot of other stuff but now im stay at home mom lol but ya was just sayin cause 39 is 1 of my fav planes in this game now

[Squire]

It really seems to be able to hold its energy well, I had several 1 vs 1 fights at 15k-ish vs P-51s, and it kept up with them if they decided to turn and merge fight. Its a very "slick" bird when you get her up to speed. The real "clincher" I think is its ability to dive fast, it doesn't compress, and you come down like a rocketship if you have to, unlike a P-38, where you always look at the TAS nervously as it passes 450 mph, and its zoom climb is very respectable.

[SAS_KID]

I am surprised no one has really noted the "interesting" stall characteristics of the plane. For me at low speeds it's like trying to ride a bull. It's mid-rear engine just makes the plane feel unstable as a grass hut in a hurricane.

[Widewing]

I am surprised no one has really noted the "interesting" stall characteristics of the plane. For me at low speeds it's like trying to ride a bull. It's mid-rear engine just makes the plane feel unstable as a grass hut in a hurricane.

I mentioned it in the Aircraft and Vehicle forum. The difference between the onset of shake and actual departure from controlled flight is almost nothing. So, when it begins to shake, it's mighty close to dumping the inside wing. Flaps are nearly useless for low speed maneuvering. They improve the turn radius by little more than 90 feet (in contrast to 300 feet in the F4Us), and the turn rate suffers badly. So, keep your speed up around 250 mph and it shines. Get below 200 mph and it can get into trouble against the better stall fighters.

My regards,

Widewing

[kamilyun]

Widewing,

At roughly 3700 ft/min, isn't the P39Q's one of the best climbing US, non-perked US planes?  Granted that's only for 8K and below, but that's a lot of AH action.

The Spixteen outdoes it considerably, as does the La7.  But planes like the F6F, P38, Typhoon, Hurricane don't match it at low alts and those see considerable LW usage.

Edit:

And as far as acceleration goes, is there any relationship between climb rate and acceleration?  Do you do a test for acceleration?

Thanks for the info...