XP-39 and the Claims

[DerAdlerIstGelandet]

Not exactly an earful.

Except that little to no stall warning is an example of bad stall characteristics. Your unwillingness to comprehend that doesn't make it not true.

 

[P-39 Expert]

Obviously I don't. Pardon me for wasting your valuable time.

 

[DerAdlerIstGelandet]

Obviously I don't. Pardon me for wasting your valuable time.

Sorry, not trying to belittle you, but your post about stall characteristics says just that. I don't think you are stupid, I don't think you want to see it.

How an aircraft behaves before it enters a stall is part of its stall characteristics. To say that an aircraft has good or decent characteristics but hardly any warning is contradicting itself. Pilots learn what the aircraft feels like before a stall to keep it from entering a stall.

But we have been down this rabbit hole already way more times than we should have.

 

[Shortround6]

A number of post war or even jets in the 60s had artificial stall warning devices installed, like stick shakers, that would artificially shake the control column if the airspeed got too close to the stall speed.

See. Stick shaker - Wikipedia

In many pre WW II or WW II aircraft the aerodynamic forces were such that the ailerons would snatch and shake the stick side to side near the stall, in others the elevator would oscillate givng a for and aft shake to the stick. Other aircraft just have part of the aircraft vibrate or make drumming noises(?). Some planes just sort of mushed. Obviously on aircraft without powered flight controls (which are almost always irreversible (moving the flight control surface outside the plane will not move the stick in the cockpit) it was a lot easier for the pilot to feel these movements of the control surfaces through the stick giving the pilot warning of the impending stall.

The F4U might have had a worse stall than the P-39 (dropping one wing rather sharply) but may have given more warning.

 

[pbehn]

You evidently don't know what stalling characteristics are.
How much warning a aircraft gives before it stalls is one of the more important stall characteristics.
When you're in the middle of a dogfight, you have to have you eyes outside the cockpit, not looking at the airspeed gauge, turn and bank, etc.
A aircraft that gives you no clue it's about to depart controlled flight isn't considered to have good stalling characteristics.

As I understand it an aircraft can hold both properties, the Fw 190 was completely predictable and nice to fly in low "g" flying but would let go in a spectacular way when pushed in high "g" power on situations.

 

[Glider]

Good stalling characteristics, just not much warning.

The very definition of poor (make that very poor) stalling characteristics, in one line.

 

[GregP]

The P-39 POH says it has "good stalling characteristics" and stalls at about 105 mph flaps up to 90 mph flaps down. It also says the airplane will "mush" considerably down around stall and, to completely unstall the center section, you need 130 - 140 mph! So, we have a plane that has "good stalling characteristics," but needs a 30 - 50 mph "cushion" of airspeed to be completely unstalled.

I think that describes "bad stall characteristics." Perhaps I am mistaken, but all the planes I have flown or flown in (includes warbirds) certainly don't need an airpseed "cushion" to untsall.

 

[DerAdlerIstGelandet]

A number of post war or even jets in the 60s had artificial stall warning devices installed, like stick shakers, that would artificially shake the control column if the airspeed got too close to the stall speed.

See. Stick shaker - Wikipedia

In many pre WW II or WW II aircraft the aerodynamic forces were such that the ailerons would snatch and shake the stick side to side near the stall, in others the elevator would oscillate givng a for and aft shake to the stick. Other aircraft just have part of the aircraft vibrate or make drumming noises(?). Some planes just sort of mushed. Obviously on aircraft without powered flight controls (which are almost always irreversible (moving the flight control surface outside the plane will not move the stick in the cockpit) it was a lot easier for the pilot to feel these movements of the control surfaces through the stick giving the pilot warning of the impending stall.

The F4U might have had a worse stall than the P-39 (dropping one wing rather sharply) but may have given more warning.

That is how the Cherokee I fly is (granted, it's not a high performance warbird). When it gets close to a stall, the controls get mushy, and the airplane sort of begins to sort of wobble or porpoise (can't really think of a word for it). Then the nose drops as the stall occurs. The plane recovers on its own once the nose drops. Of course if you are not coordinated when the stall occurs you run the risk of an inadvertent spin. I still remember my instructor yelling at me "Right rudder! Right rudder! Right rudder!"

 

[XBe02Drvr]

I understand that it had stalling characteristics that were worse than most other aircraft.

Good stalling characteristics, just not much warning.

Except that little to no stall warning is an example of bad stall characteristics.

The very definition of poor (make that very poor) stalling characteristics, in one line.

I think very few people who don't fly can truly wrap their head (and their gut) around "departure from controlled flight" as an experience. The gentle straight ahead pitchdown of a straight and level practice stall is so removed from a "departure" under G load as to seem almost unrelated to each other. A walking pony vs a bucking bronco. Even docile planes like a 152 or 172 can give you a pretty convincing rendition of a "departure" if you push them hard enough (only do this in Utility Category W&B conditions). A useful tool when dealing with an arrogant student who's gotten a bit too big for his britches. The T34 could really rattle your fillings and smack you against the canopy if you abused it under G load, while swapping sky for sea several times in quick succession. And it was just a glorified Bonanza. Someone should take our favorite Xpurt up and let him experience it for himself.

 

[SaparotRob]

Read somewhere a long time ago that spins could be recovered from by letting go of the stick and giving the plane hard right rudder. This was developed by a pilot who bailed out his spinning plane only to see the empty plane recover by itself.

 

[GrauGeist]

Our Cherokee Warrior got what felt like a tremor as the controls went soft.
But like Chris', as soon as it got nose-down attitude, she'd snap out of it.

 

[DerAdlerIstGelandet]

I think very few people who don't fly can truly wrap their head (and their gut) around "departure from controlled flight" as an experience. The gentle straight ahead pitchdown of a straight and level practice stall is so removed from a "departure" under G load as to seem almost unrelated to each other. A walking pony vs a bucking bronco. Even docile planes like a 152 or 172 can give you a pretty convincing rendition of a "departure" if you push them hard enough (only do this in Utility Category W&B conditions). A useful tool when dealing with an arrogant student who's gotten a bit too big for his britches. The T34 could really rattle your fillings and smack you against the canopy if you abused it under G load, while swapping sky for sea several times in quick succession. And it was just a glorified Bonanza. Someone should take our favorite Xpurt up and let him experience it for himself.

I hear you. I was not trying to compare a controlled induced training stall to a real departure from controlled flight. All stalls I have performed were always controlled. My point was only that our friend is contradicting himself.

 

[XBe02Drvr]

Read somewhere a long time ago that spins could be recovered from by letting go of the stick and giving the plane hard right rudder.

Well actually, hard rudder against the rotation. Planes can spin to the right, as well, you know. Docile, lightweight General Aviation aircraft usually recover by relaxing the back pressure on the yoke, but heavier, higher performance planes often require a positive forward push to break the stall. Especially so if they're tending to flatten out in the spin.

 

[XBe02Drvr]

I hear you. I was not trying to compare a controlled induced training stall to a real departure from controlled flight. All stalls I have performed were always controlled. My point was only that our friend is contradicting himself.

I had no intention of rebutting or correcting you. I was just affirming your observation of the nonsensical nature of Xpurt's assertion.

 

[GrauGeist]

Bill Overstreet's experience with a P-39's shenanigans:

Bill was in combat training in June 28th, 1943 when he had his first crash, at the controls of an Bell P-39 Airacobra, which went into a dreaded flat spin, a condition uniquely devastating for the model and which claimed many a pilot's life. Bill and his squadron-mates were practicing aerobatic maneuvers when his plane strated tumbling and he couldn't control it. Bill went to release the Airacobra's doors but the air pressure prevented them from opening. He finally managed to get a knee against one door with his shoulder against the other, trying to overcome the pressure, and the moment he got out, he pulled the ripcord on his parachute. The moment the chute snapped open Bill found himself standing amidst the wreckage of his plane right by the propeller. He was so close to the ground when he escaped his doomed plane that none of his flight-mates even saw his chute deploy, Bill belives he was perhaps the first pilot to survive the crash of a tumbling P-39, and he made a point on tracking down the man who packed his chute to personally thank him for a job well done.

(Bill's P-39 crash site near Oroville, California)

 

[SaparotRob]

Well actually, hard rudder against the rotation. Planes can spin to the right, as well, you know. Docile, lightweight General Aviation aircraft usually recover by relaxing the back pressure on the yoke, but heavier, higher performance planes often require a positive forward push to break the stall. Especially so if they're tending to flatten out in the spin.

I thought that story was a bit simplistic. That procedure had fit in entirely too close to my "do nothing" approach to life.

 

[tyrodtom]

Read somewhere a long time ago that spins could be recovered from by letting go of the stick and giving the plane hard right rudder. This was developed by a pilot who bailed out his spinning plane only to see the empty plane recover by itself.[/QUOTE

Pilots had figured out how to recover from spins several years before pilots started using parachutes.

 

[Glider]

I think very few people who don't fly can truly wrap their head (and their gut) around "departure from controlled flight" as an experience. The gentle straight ahead pitchdown of a straight and level practice stall is so removed from a "departure" under G load as to seem almost unrelated to each other. A walking pony vs a bucking bronco. Even docile planes like a 152 or 172 can give you a pretty convincing rendition of a "departure" if you push them hard enough (only do this in Utility Category W&B conditions). A useful tool when dealing with an arrogant student who's gotten a bit too big for his britches. The T34 could really rattle your fillings and smack you against the canopy if you abused it under G load, while swapping sky for sea several times in quick succession. And it was just a glorified Bonanza. Someone should take our favorite Xpurt up and let him experience it for himself.

Going back far too many years I was an apprentice artificer in the FAA which is pretty much the lowest of the low, but I was an Air Experience Instructor in the gliding club. A group of Midshipmen who were learning to fly helicopters came to try gliding and I was tasked with taking one of them up. I was also only eighteen and everyone else was a fair bit older than me by which I mean twenty one plus so I did stand out. As luck would have it the one I was going to take up was very arrogant and really didn't like the idea of me taking him up, he had a PPL and had 'done it all before' and 'what could I teach him'. He moaned and bitched so much when we got to about 3,500 ft I gave him control and waited. It didn't take long and soon he was clearly getting into trouble and tried to give control back to me but I refused pointing out that 'he had done it before', so he could sort it out. In a couple more minutes he was really losing it, we were down to about 2,500ft when he stalled it and we entered a spin. He started yelling at me, so I took control sorted it out and we landed.
He got out hugely embarrassed in a furious temper, all his friends were asking him what happened which he dared not answer. The CFI just asked me with a smile if everything was OK having a pretty good idea what had happened.
Never saw him again, result all round. Practice over theory in one lesson, but to be fair spinning at about 1,500 to 2,000ft is a little scary the first time you do it.

 

[special ed]

In reading the book "Red Eagles" I learned the white stripe down the center of the MiG-23 instrument panel was to center the stick in line with the stripe and allow the aircraft to correct itself if in a spin or other departure from normal flight. I have since seen the stripe on the panels of museum pieces of MiG-17 and others. The MiG 23 had another feature which is not normally known, and that is when at high speed if throttle is pulled back quickly, an automatic device retards the throttle slowly to prevent pitchup. Good reading, "Red Eagles" as well as "Dark Eagles" and "Skunk Works".

 

[XBe02Drvr]

Never saw him again, result all round. Practice over theory in one lesson, but to be fair spinning at about 1,500 to 2,000ft is a little

I was out for last flight of the day with one of the working students from the youth program collecting his compensation for the day's labors. Thermals were dying down, but there was a strong westerly flow aloft and the tug dragged us over under a lenticular WAY above, found us some nice lift, "rocked us off", and headed for home. There we were in a high speed elevator that seemed endless and were soon above all terrain within hundreds of miles, when the kid in front goes: "Hey, look at that cloud deck creeping in!". A cap cloud was rapidly forming above the mountains in front and below our altitude, and expanding outward towards us.
Holy crapola! A teachable moment. "We gotta get down, NOW! Full spoiler, nose down, max turbulence speed, we gotta find us some sink, quick! Read the sky. Visualize the wave. See that lennie overhead? We're in the lift now, gotta find the sink!" Still the smooth elevator wafting us upward despite all our efforts to shed altitude, and the cloud bank reaching out to envelop us. "Must be some mighty humid air coming in on this wind." Suddenly Godzilla has us in his fist and is shaking us silly. "There, that's the rotor. Sink should be on the other side." With a whump we exit into smooth air and the vario needle pegs down. Sink at last! But will we get below cloud base level before the deck catches us? Doesn't look good. We're diving away from it, but it's catching us.
"Okay, while we still have some visual reference, get stabilized, let the compass stop swinging, and trim for a descent at penetration speed....Alright, we're in it now, hands off the stick, feet lightly on the rudder pedals, and keep the compass steady with your feet. This won't keep you safe for long. Eventually the compass will get to swinging too much for you to keep up with and we'll wind up in a spiral which will quickly get out of hand. So what to do? Safest thing to do now is spin it. This baby stabilizes nicely in a spin, slow rotation, moderate descent rate, low airspeed, and minimum altitude loss in recovery. We're over the valley now, the wind is blowing us away from the mountains, so show me the smoothest spin entry of your life, and when she goes, hold full rudder into the spin and full back stick until we drop out the bottom....There you go, nice job! See, we've still got almost three thousand feet under the clouds and enough altitude to make the field, easy. Still, you better close the spoilers for now. How you feeling? You did great. A day to remember."
That student is now a 777 captain ten years from retirement.