SaparotRob
Unter Gemeine Geschwader Murmeltier XIII
FWIW I just checked to see if there really was a Rolls Royce Pelican.
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Anyway, how was the roll rate for a mosquito?
T ThomasP? I think I have lost track of the discussion.
Some number for comparison.
re the wings, BHP, and weights of the Whirlwind and F5F and P-38
____________________Whirlwind__________XF5F__________ P-38F
Wing Span___________ 45' 0"____________42' 0"___________52' 0"
Wing Airfoil_NACA___ 23015*___________23015* __________23016-4412
Wing Area (gross)______ 250 ft2___________304 ft2__________ 328 ft2
Aspect Ratio__________8.10_____________ 5.80_____________8.24
TOGW (clean)_______10,350 lbs________10,138 lbs**______15,000 lbs
Wing Loading _________41.4 lb/ft2________33.4 lb/ft2* ______ 45.7 lb/ft2
Horse Power_________ 1770 BHP________2000 BHP________2000 BHP (all at 15,000 ft)
Power/Weight ratio___ 0.171 HP/lb______ 0.197 HP/lb______ 0.133 HP/lb
Vmax at 15,000 ft***___~350 mph________~350 mph________~350 mph
*The NACA 23015 is the airfoil for the inner wing section for both the Whirlwind and the XF5F-1. I do not know if the outer wing panels used the same airfoil - they may have been a thinner airfoil. Does anyone have any info on the outer wing panel airfoil sections?
Some observations.
As far as Wing Loading goes, you could increase the TOGW of the Whirlwind by 1,075 lbs and end up with the same Wing Loading as the P-38F. The XF5F-1 is clearly the winner in terms of lower wing loading at 33.4 lb/ft2 for the prototype, and still clearly superior at the projected TOGW of the combat ready F5F-1 airframe at 36.2 lb/ft2.
As far as Power/Weight ratio goes, the XF5-1 is clearly the winner, followed by the Whirlwind, and then the P-38F. The combat ready F5F-1 is still superior - though not as much so - at 0.18 HP/lb.
As far as the Wing T/C ratio goes the Whirlwind and XF5F were the same 15%*, and the P-38 is an average of 14%. The P-38F is slightly superior in the T/C category and this combined with the high Aspect Ratio probably gives it the edge in Cd for the wings.
re a developed Peregrine II engine.
The Peregrin I was slightly more efficient than the Merlin III in terms of HP/in3. If it had been developed further and given the same tweaks as the 'Hookerized ' Merlin, there is (I think) no reason the power could not have been similar to the Merlin 45 in terms of HP/in3 at +9 lbs boost - ie 0.73 BHP/in3. So a 'Hookerized' single-speed Peregrin II should give about 950 BHP at ~15,000 ft.
FWIW I just checked to see if there really was a Rolls Royce Pelican.
Gentlemen
Attached is a chart which gives rate of roll for selected aircraft with 30 lb stick force, including the Mosquito
Eagledad
? I think I have lost track of the discussion.
Some number for comparison.
re the wings, BHP, and weights of the Whirlwind and F5F and P-38
____________________Whirlwind__________XF5F__________ P-38F
Wing Span___________ 45' 0"____________42' 0"___________52' 0"
Wing Airfoil_NACA___ 23015*___________23015* __________23016-4412
Wing Area (gross)______ 250 ft2___________304 ft2__________ 328 ft2
Aspect Ratio__________8.10_____________ 5.80_____________8.24
TOGW (clean)_______10,350 lbs________10,138 lbs**______15,000 lbs
Wing Loading _________41.4 lb/ft2________33.4 lb/ft2* ______ 45.7 lb/ft2
Horse Power_________ 1770 BHP________2000 BHP________2000 BHP (all at 15,000 ft)
Power/Weight ratio___ 0.171 HP/lb______ 0.197 HP/lb______ 0.133 HP/lb
Vmax at 15,000 ft***___~350 mph________~350 mph________~350 mph
*The NACA 23015 is the airfoil for the inner wing section for both the Whirlwind and the XF5F-1. I do not know if the outer wing panels used the same airfoil - they may have been a thinner airfoil. Does anyone have any info on the outer wing panel airfoil sections?
**It was estimated that the TOGW (clean) of a combat ready F5F-1 (ie 4x .50 cal, armour, SSFT, radios, etc) would have been about 11,100 lbs, which would give a wing loading of 36.5 lb/ft2, and a Power/Weight ratio of 0.18 HP/lb.
***The Vmax are for the equivalent of Normal power using 100/130 grade fuel and in temperate conditions. The seemingly slow~350 mph for the P-38F is due to field tests where it was found that the intercoolers and turbosupercharger could not sufficiently cool the charge at higher power settings, causing the V-1710 engines to experience detonation at said higher power settings below about 20,000 ft.
Some observations.
As far as Wing Loading goes, you could increase the TOGW of the Whirlwind by 1,075 lbs and end up with the same Wing Loading as the P-38F. The XF5F-1 is clearly the winner in terms of lower wing loading at 33.4 lb/ft2 for the prototype, and still clearly superior at the projected TOGW of the combat ready F5F-1 airframe at 36.2 lb/ft2.
As far as Power/Weight ratio goes, the XF5-1 is clearly the winner, followed by the Whirlwind, and then the P-38F. The combat ready F5F-1 is still superior - though not as much so - at 0.18 HP/lb.
As far as the Wing T/C ratio goes the Whirlwind and XF5F were the same 15%*, and the P-38 is an average of 14%. The P-38F is slightly superior in the T/C category and this combined with the high Aspect Ratio probably gives it the edge in Cd for the wings.
re a developed Peregrin II engine.
The Peregrin I was slightly more efficient than the Merlin III in terms of HP/in3. If it had been developed further and given the same tweaks as the 'Hookerized ' Merlin, there is (I think) no reason the power could not have been similar to the Merlin 45 in terms of HP/in3 at +9 lbs boost - ie 0.73 BHP/in3. So a 'Hookerized' single-speed Peregrin II should give about 950 BHP at ~15,000 ft. This increase would give the Whirlwind a Power/Weight ratio of 0.181 HP/lb, basically the same as the combat ready F5F-1, and clearly superior to the P-38F.
NOTE All of the above obviously ignores the superior altitude rating of the P-38F with its turbosupercharger system. Presumably, the P-38 would steadily reduce any performance differences as altitude increases above 15,000 ft and probably surpass the Whirlwind and XF5F-1/F5F-1 at any altitudes above about 20,000 ft. With the later intercooler/turbocharger arrangements the Vmax for the P-38F was about 370 mph at 15,000 ft.
Maybe, see attached.That! Is! A! Nice! Chart! I hadn't seen before. Too bad it's barely legible. Anybody got a better scan of that?
Maybe, see attached.View attachment 712985
Great chart - interesting that the three Mustang versions had such different characteristics
At low speeds, beware the rolling Hampden?!Maybe, see attached.View attachment 712985
At low speeds, beware the rolling Hampden?!
As its nickname was the flying suitcase, I think maybe rather it had a tendency to end up in the wrong airport.Was the Hampden the one that had a problem with a tendency to fly sideways if left unattended?