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This reflects the P-51 moving into a different "territory", more like that of a bomber, where max loads change through the mission. When all fighters re doing the same thing, with approximately the same internal fuel then things are comparable. With the P-51 it could carry a huge amount of internal fuel to the combat and since its whole operating procedure was ro preserve internal fuel a "normal" combat load could be considered to be 200+ gallons.The P-51 up through the D model had a G-limit that varied with weight. It was 8.0 g up to 8,000 pounds, and was 64,000/ gross weight for weights above 8,000 pounds.
So, at 10,000 pounds, for instance, that works out to 6.4 g load limit. For 7.33 g's, that works out to 8,732 pounds.
That comes from a P-51D pilot's operating manual.
Bob Chilton, the test pilot for the P-51H, said his favorite Mustang was the P-51F with the Allison V-1710-119 in it. Can't quite remember why, but he did specify that one as his personal favorite P-51 ride.
Didn't the F use the same V-1650-3/7 Merlin as the P-51B/D? I've also read that Chilton (like many others at NAA) didn't like the two stage Allisons.The P-51 up through the D model had a G-limit that varied with weight. It was 8.0 g up to 8,000 pounds, and was 64,000/ gross weight for weights above 8,000 pounds.
So, at 10,000 pounds, for instance, that works out to 6.4 g load limit. For 7.33 g's, that works out to 8,732 pounds.
That comes from a P-51D pilot's operating manual.
Bob Chilton, the test pilot for the P-51H, said his favorite Mustang was the P-51F with the Allison V-1710-119 in it. Can't quite remember why, but he did specify that one as his personal favorite P-51 ride.
Regarding the XP-51J:I was able to read an excerpt from a book on the development of the P-51H Mustang, and it stated that the XP-51 series that begant the H's development was designed for 6+Gs in flight for loading (basically British recommendations during World War II for fighter aircraft), while the USAAF preferred 7.33Gs (of note, all P-51s from the NA73X through the D/K were designed for 8 Gs at approx. 8000lbs gross TO weight). Is there any truth to that statement?
Also, it does bring up a point on how strong is strong enough for a World War II era fighter. If the Spitfire was designed to what the book alleged was RAF standards, I'd have to argue aside from landing gear that the Spitfire was more than strong enough, given that at least one was dived at more than 600mph (corrected for compressiblity) with no damage, albeit on accident in 1952 over Hong Kong.
And it's been written on here that the 8 G for 8000 lbs for the P-51D dropped as low as 6.3 Gs depending on gross weight, so not too far from Spitfire/LW Mustang standards for their gross weights.
Thus, is the statement that I'm referring to about the XP-51's correct or in error? And what G loading standards were too much, just right or not enough for the era?
What was the Spitfire dive speed limit according to the pilot manual. Wasnt the Spitfire dived to 600MPH fitted with a prop that could be feathered just for that purpose and dived under very controlled, non combat conditions?So that's a pretty low dive speed limit, given that Spitfires could be dived at over 500 mph without issue (and at least one was dived at over 600 mph without damage to plane or pilot). I wonder what gives there. It should also be noted at the 8g/8000 lbs limit the P-51D's g limit for combat weight drops to as low as 6.3 gs, and had no trouble with high speed dives.
BTW, I wish that such details were accessible and such for all the late Mustangs and even the Twin Mustang. Lots of tech drawings and info about earlier variants, not nearly as much as the variants after the D model.
In an "uncontrollable dive"!!!!There were those trials, and one that was dived at those speeds on accident over Hong Kong in 1952:
"On 5 February 1952, a Spitfire 19 of 81 Squadron based at Kai Tak in Hong Kong reached probably the highest altitude ever achieved by a Spitfire. The pilot, Flight Lieutenant Edward "Ted" Powles,[132] was on a routine flight to survey outside air temperature and report on other meteorological conditions at various altitudes in preparation for a proposed new air service through the area. He climbed to 50,000 ft (15,000 m) indicated altitude, with a true altitude of 51,550 ft (15,710 m). The cabin pressure fell below a safe level, and in trying to reduce altitude, he entered an uncontrollable dive which shook the aircraft violently. He eventually regained control somewhere below 3,000 ft (910 m) and landed safely with no discernible damage to his aircraft. Evaluation of the recorded flight data suggested he achieved a speed of 690 mph (1,110 km/h), (Mach 0.96) in the dive, which would have been the highest speed ever reached by a propeller-driven aircraft if the instruments had been considered more reliable.[129]"
Greg - Chilton and Barton despised the NA-105B P-51J (with Allison). Chilton's favorite Mustang was the NA-105 P-51F with 1650-3 engine. The Two P-51Js had a total of 5 troubled hours when they gave them to Allison.The P-51 up through the D model had a G-limit that varied with weight. It was 8.0 g up to 8,000 pounds, and was 64,000/ gross weight for weights above 8,000 pounds.
So, at 10,000 pounds, for instance, that works out to 6.4 g load limit. For 7.33 g's, that works out to 8,732 pounds.
That comes from a P-51D pilot's operating manual.
Bob Chilton, the test pilot for the P-51H, said his favorite Mustang was the P-51F with the Allison V-1710-119 in it. Can't quite remember why, but he did specify that one as his personal favorite P-51 ride.
Greg - Chilton and Barton despised the NA-105B P-51J (with Allison). Chilton's favorite Mustang was the NA-105 P-51F with 1650-3 engine. The Two P-51Js had a total of 5 troubled hours when they gave them to Allison.
SDAM interview of Chilton, April 27 1986. They have a copy but nobody I have contact with knows where to find it.It DOES seem meager, especially given the raw performance of the type. I'd think EVERYONE who might have been a potential customer would have been interested, but the remaining documentation seems meager, as you say.
Hi Bill. Was going on a talk given by a historian at a museum. Didn't check it out personally before posting. Do you have a good source for Chilton stories? Curiosity only from me. I never really looked at the F, G, and J because they made only two each (I believe the S'Ns were 44-76027 & 44-76028 for the J's), and never got deployed anywhere, so didn't affect any outcomes.
I've seen a report saying the P-51J was a great performer, but the report was short summary of performance; nothing in much detail. It's been awhile, but it seems like it was maybe two paragraphs. Would be nice to see some actual flight test reports.
My friend Joe Yancey has some parts from a -119 Allison ... a one-off manifold going into an intercooler instead of the large intake tube and a supercharger housing that looks different from all other ALlison housings I have seen including the G-series housings. It appears to be a 2-speed unit and definitely fits a V-1710 power section.
Cheers.
First. As stated before, All NAA aircraft design standards (until, and exclusively for, the LW Fighters) were per Materiel Command Airframe Standards. As a side note, Lee Atwood's first job after graduation from Univ. Texas was as a structural engineer at MC before later being recruited by Kindelberger at Douglas Aircraft. Atwood was Chief, Structureses under Kindelberger before both left for the new NAA. The same standards at Douglas and Boeing and Curtiss, etc - were adopted at NAA.I was able to read an excerpt from a book on the development of the P-51H Mustang, and it stated that the XP-51 series that begant the H's development was designed for 6+Gs in flight for loading (basically British recommendations during World War II for fighter aircraft), while the USAAF preferred 7.33Gs (of note, all P-51s from the NA73X through the D/K were designed for 8 Gs at approx. 8000lbs gross TO weight). Is there any truth to that statement?
Also, it does bring up a point on how strong is strong enough for a World War II era fighter. If the Spitfire was designed to what the book alleged was RAF standards, I'd have to argue aside from landing gear that the Spitfire was more than strong enough, given that at least one was dived at more than 600mph (corrected for compressiblity) with no damage, albeit on accident in 1952 over Hong Kong.
And it's been written on here that the 8 G for 8000 lbs for the P-51D dropped as low as 6.3 Gs depending on gross weight, so not too far from Spitfire/LW Mustang standards for their gross weights.
Thus, is the statement that I'm referring to about the XP-51's correct or in error? And what G loading standards were too much, just right or not enough for the era?