P-47B глазами молодого тест пилота (English)
Опубликовано в FLIGHT JOURNAL
In june 1943 I was selected to be the test pilot for the turbocharged Hellcat, but there was on fly in the ointment; I had never flown with a turbocharger. To give me a required turbosupercharger training, Bob Hall arranged for me to spend a week flying P-47 Thunderbolt at nearby Republic Avalon. I made six, most interesting flights, on of which was of the type I’m glad didn’t happen often
My mentor at Republic was chief production test pilot Carl Bellinger. He was most amiable and spent much time en educating me about the rather complicated turbo-supercharging system and the flight characteristics of the high-wing-loading fighter (the P-47’s wing loading was 48 pounds per square foot; the Hellcat’s was 36 pounds per square foot). He warned me which aerobatic maneuvers I should not attempt in the P-47: spins, low-altitude spilt-S maneuvers ( a half roll followed by a half-loop) and slow rolls at airspeeds of below 150mph. The Hellcat allowed them because of its much lower wing loading
Carl didn’t have to convince me about low-altitude spil-S’s: during the winter of 1943; I saw the five holes in the ice of Long Island’s Great South Bay that were result of Army Air Corps P-47B pilots following their leader in a spli-S maneuver below 15000 feet. His very detailed explanation were most informative to a young and “invulnerable” (euphemism for egocentric) test pilot who was still in the highly overconfident and dangerous 500-hour flight time range.
Four particularly interesting notation in the Pilot’s Handbook applied to all pilots, but not, I was sure, to me:
1.Never make turns at less then 150mph in the landing pattern.
2.Don’t stall; don’t ever stall; never, ever stall; these are the three rules for a forced landing
3.Spin recoveries. Remember this. When your airplane goes out of control or is out of control below 4000 feet, jump!
4.Under no circumstances do a split-S at less then 15000 feet with the power on. The speed builds up at a dizzying rate. If started at speeds of more than 250mph, you can loose as much as 15000 feet before you can complete a recovery.
Re: P-47B глазами молодого тест пилота (English)
These admonishments were probably written into Handbook because of the 56th Fighter Group’s high accident rate. It was the first Army Air Corps group to fly the Thunderbolts, and it lost 13 pilots and 41 aircraft during training at Mitchel Field, New York, before leaving for Europe!
The P-47 has often been written of as being “tremendous” in size. True, it was considerably bigger then Bell P-39 and Curtiss P-40, but to me, it wasn’t much bigger that the Hellcat because it had the same wingspan and was only 3 feet longer. It was soon to find out that its much greater weight- and consequent 130-percent higher wing loading – would soon make me a respectful P-47B pilot.
The first obvious difference I noted during take off was the deep, muffled faraway exhaust noise sounded more like that of a Cadillac than of a fighter. Compared with that, the Hellcat’s take-off exhaust racket – with the exhaust stacks very near cockpit sounded like an unturned hot-rod’s
The P-47B’s additional gross weight exceeded the Hellcat’s by 3000 pounds and seemed to give it an all too disinterested acceleration rate when it tried to reach its 125mph take off speed. I immediately thought that Republic’s 5000 foot runway was much too short, especially with main assembly plant right at the end of it. A few seconds later I was pleased that I had remembered to unlock the ground landing gear downlock. Had I not done this, I would have had to look back into the cockpit during takeoff to unlock it just when I wanted to be sure I would clear that onrushing factory roof. I found that P-47’s lingering takeoff impressive.
I never did used to the long wait for the P-47 to leave the ground. One my first of several takeoff’s, I instinctively looked back at the engine instruments several times, hoping that the throttle could be pushed much farther forward. I failed to ask why they don’t use partial flap deflection to shorten its ground run.
The P-47’s best climb speed was 45 mph higher than the Hellcat’s 125mph, and that added to the long wait required to get away from the earth’s crust, which seemed to scrape its fuselage bottom. At 10 000 feet I felt at home, so I moved the controls more then I moved my eyeballs.
Remembering the POH rebuke as I set up to do a stall, I very slowly reduced the P-47B’s airspeed with the flaps and landing gear retracted . At 120mph it started to buffet, and at 110 it stalled. Surprisingly, it had very little wing drop, so I recovered and rechecked it several times with similar results. I then tried an accelerated stall at 125mph and found that even when I pulled the stick fairly hard it’s stall was also preceded by pronounced buffeting, and very little wing drop. It seemed too good to be true. With the wheel and flaps down, it again stalled very gently, and the stall was preceded by an even stronger buffet warning and with absolutely no wing drop.
I was amazed because it’s stall characteristics were better then the Hellcat’s, but stall speed was 21mph higher. I was even more impressed when I returned from the flight and inspected the wing’s leading edge expecting to find stall “fixes” such as a cambered leading edge or leading-edge spoilers that would give it required a more raid and larger throttle motion during the recovery to minimize altitude loss. It’s heavier wing loading was quite noticeable during recovery.
