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Comment by jabl | Hacker News Reader

Hum, that's the first time I have heard that explanation. What I've heard was that negative G caused the carburetor to flood, yes, but the result was the engine stalling, not fuel spilling into the cockpit. Which IMHO sounds more plausible..

Perhaps you're thinking of the typhoon & tempest which had a problem of exhaust leaking into the cockpit. Solution: pilot wad required to always use the oxygen mask.

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I read about this problem in one of many accounts on flying Spits in combat. Yes, it was the gas, not an exhaust leak. Sorry I don't have a cite.

The Merlin engine had other issues - it was very sensitive to battle damage. This is in contrast to the engine on the P47, which could take a lot of damage and keep running.

Bug or intentional design tradeoff? When you choose an inline V12 over a radial engine, you're implicitly choosing to be more sensitive to battle damage.

But the R-2800 Double Wasp is an engineering triumph in its own right. Hellcat, Corsair, Thunderbolt, Black Widow, Bearcat... they put it in everything.

"Bug or intentional design tradeoff? When you choose an inline V12 over a radial engine, you're implicitly choosing to be more sensitive to battle damage."

@Agathos you have to remember history to understand why the RAF selected this design.

The conflicting design problems at the time (mid 1930's) dictating power plant choice? How do we create a fighter with enough power and speed that will allow bombers & fighters to be shot down using the limited resources we have (dollars, manpower and materials) post, "great depression"?

The answer, the Rolls Royce V12, inline Merlin. It did the job. Especially in '39 and 1940, when the only thing separating a full out invasion by Nazi Germany was 22 miles of water and the sky.

References:

- https://en.wikipedia.org/wiki/Radial_engine#Radial_versus_in...

- http://aviation.stackexchange.com/questions/2920/why-are-inl...

- http://www.warbirdsforum.com/topic/545-radial-vs-inline-engi...

A brief search reveals lots of info about power loss in negative g maneuvers:

https://en.wikipedia.org/wiki/Miss_Shilling%27s_orifice

edit: I see now that gp2000 had posted that link hours before I commented. I had missed it, but ended up at the same place.

Radial engines did their own cooling, didn't they? Coolant loss would cause any in-line engine to seize up, Merlin, Allison, or whatever it was that the ME-109 used.

It wasn't just the coolant. My dad, who flew both P-51s and P-47s, had an incident in each where the engine swallowed a valve. The P-51 immediately lost power, and clearly wasn't going to keep running for more than a few minutes, and required an immediate emergency landing. The P-47 kept producing power as if nothing had happened, and enabled my father to bring it home.

loved this story @WalterBright and not the first time I've heard a description of a Bolt returning home, shot to bits but functionally intact. Pity the pilots who had trouble with a '51 with a full tank of fuel at take-off.

A great article to read, "Chuck Hawks" and "Rip Collins" (who flew both) comparison of 47 and 51. ~ http://www.chuckhawks.com/p47.htm

Thanks for the great link! The P-51 is a thing of grace and beauty, but in combat I'd rather be in a P-47.

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