XP-39 II - The Groundhog Day Thread
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What is there to be scared of?
1. All of us supposed scared people have an understanding of weight and balance and CG, and how not to get into that type of situation.
2. None of scared people will ever actually fly that overrated thing, so...
Peter Gunn
Master Sergeant
What is there to be scared of?
1. All of us supposed scared people have an understanding of weight and balance and CG, and how not to get into that type of situation.
2. None of scared people will ever actually fly that overrated thing, so...
Resp:
1). A few belts of this and I'll wager different:
2). See number 1
Not a fan of Ouzo. Now you throw in a good Birnen Schnapps or a quality Scotch or Irish Whiskey and you might be on to something.
Are you saying P-39 Exper...
...ehr, I'll just call him P-39, drinks too much Ouzo?
...ehr, I'll just call him P-39, drinks too much Ouzo?
fubar57
General
Schnapps....yikes. I got my ear pierced after drinking this
Peter Gunn
Master Sergeant
Actually I'm not a fan of Ouzo either, except that I will say the two most alcohol induced "dumbass" moments came at the hands of said Ouzo.
One involving a Corvette and another involving a mailbox (and a very nice police officer)...
One involving a Corvette and another involving a mailbox (and a very nice police officer)...
I will have to take a picture of my good stuff later. You should be able to taste the fruit in a good quality schnapps. Every year when I go home to Germany, I bring some back.
My understanding was that the Russians also pushed the Allison way past the USAAC's limits. The price was more frequent overhauls. It would be interesting to know how many V-1710s the USA sent to Russia. outside of those mounted in aircraft.So the Soviets got such an impreesive performance by removing some excess weight from the P-39? More victories than the P-51!
I would then rather suggest a more plausible reason: the Soviet pilots were simply superior to the American pilots. Perhaps we should add to the good old 'Overpaid, oversexed, overthere'.... overrated?
windhund116
Senior Airman
- 360
- Jul 3, 2017
F15 is not fly-by-wire?
GregP
Major
Have we bought any of the latest F-15s or are they just offered for sale? The F15EX is being touted right now as a good choice and is FBW. I think we ordered 8 of them, but am not exactly sure.
The USAF has placed an order for brand new F-15EX's.
Boeing lands the first order of the F-15EX
My office is just upstairs from the F-15 line. Sometimes I go down there to use the bulk mail room. I know a few guys on the line. Needless to say they are all pretty stoked about it. In the same building they will be manufacturing the T-7.
The F-15QA (Qatar), the late model F-15SA (Saudi) and F-15EX are all FBW. The rest are not. However, it's a great flying plane.
Cheers,
Biff
windhund116
Senior Airman
- 360
- Jul 3, 2017
At least it'll grow over, most people end up with regretful tattoos!
I have read that P-40's were standing around awaiting overhaul/ new engines , but whether that was just one unit or whether it was general I'm not sure. It's one thing, though, to excced the redline limits in a critical situation and get out of dodge; but if it's to bridge a performance gap with the enemy on a regular basis, then it's a less effective combat aircraft, imo.
In other words, when you're trying to recover from the unwarned high G stall/snaproll out of your turn when you were trying to pull enough lead on your victim to get a shot, and there you are recovering from an upset right in front of his wingman's guns. GAME OVER. That matter of fact test pilot language is full of pitfalls for those who don't understand the context.
Once again you missed the context. That statement was made in reference to simple, coordinated, one G stalls in various configurations and maneuvers. It then went on to glaze the reader's eyes over with a lengthy discussion of sideslip angles and control surface deflections ("test pilot talk"), the gist of which was that any stall at higher G with even the slightest sideslip will result in a sharp roll without warning AGAINST aileron deflection. After you've read that sort of test pilot verbiage and then gone out and banged your helmet HARD against the side of the canopy while your world turned sharply upside down in the hands of Zeus a few times, you develop a sense of context. If you're as hard headed as I am, it takes a few tries and an aching neck before enlightenment dawns. Once preconceived notions give way to understanding, it's kind of fun. You're no longer sitting in the airplane and driving it; you're wearing it like a tightly strapped backpack, and it becomes an extension of your body and your will.
Cherry picking again. In several places it stated in low key unobtrusive language that the test aircraft fell short of USAAF published standards in one way or another, most notably stick free static stability (displacement oscillation damping) and stick force gradient/G. That last one is a biggie. A 14.4 lb pull (thumb and fingertips of your right hand) can put 8Gs on you and your aircraft at "normal" (30.2% MAC) CG. The plane can take it; you can't. This is well below USAAF minimum standard, and WAY below desirable values.
That super light stick force gradient combined with the no-warning abrupt stall under G load sets up a scenario which may not be apparent to nonflyers, the accelerated secondary stall. If the pilot pulls hard enough in a high G maneuver to stall the plane and the ailerons and rudder aren't perfectly coordinated, the resulting sudden snap AGAINST the ailerons is apt to set the adrenaline pumping and the right arm tensing. As the plane sorts itself out and is once again flying and the windshield is full of trees getting bigger FAST, the resulting pull on the stick is apt to be greater than the 7-8 pounds required for a smooth manageable pullout, and a secondary stall results at 4 or 5 Gs with another departure from controlled flight, recovery, and panicked secondary stall, until altitude runs out. Desirable stick force gradients are a lesson written in blood.
BTW, they somehow managed to ballast the test airplane to a 24% MAC CG, where it managed a much more reasonable stick force gradient.
Not trying to scare anybody, just verifying some of the less than complimentary opinions that have circulated about the plane. No silk purses here.
Ahhhhh you're scaring me!!
Hello XBe02Drvr,
One of the other things worth noting is that with the CoG at 30.2% MAC, the stick only needs to move 1 inch to go from CL 0.2 to CLmax of 1.4.
In combination with very light stick forces, this is not a good thing.
This is why I have commented that control harmony was poor. Aileron forces were noted as fairly high.
It gets a bit better at 2.7 inches with CoG at the forward end of the range.
- Ivan.
One of the other things worth noting is that with the CoG at 30.2% MAC, the stick only needs to move 1 inch to go from CL 0.2 to CLmax of 1.4.
In combination with very light stick forces, this is not a good thing.
This is why I have commented that control harmony was poor. Aileron forces were noted as fairly high.
It gets a bit better at 2.7 inches with CoG at the forward end of the range.
- Ivan.
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