New Cylinder AD's released by FAA

[jdeakin]

What about all those aircraft in WW2 flying for hours in the flight levels? Pretty sure their fuel would have been supercool, wouldn't have this issue come up well before cessna made a turbocharged twin?

By this reasoning shock cooling due fuel would have cracked many heads as I'd imagine a P-47 or equivalent escort aircraft would go from high altitude cruise to combat down to low levels, mixture control pushed into auto-rich.

Excellent point!

1) The fuel in those engines entered the air charge at the blower inlet and had a considerable distance to travel and heat up before getting to the combustion chambers. Walter is talking about the Cessna system where raw fuel gets sprayed directly on the cylinder, inside the inlet port, and the sudden change in temperature caused by the increased flow of very cold fuel.

2) "Auto-Rich" and "Auto-Lean" (big radials) were both RICH MIXTURES, that is, on the RICH side of peak, and therefore the change in cooling would not be quite as much. (Except for the B-24, which had the mixtures set for LOP in "Auto Lean." That's the reason for their astonishing range, compared to the other aircraft.)

(I'd like to think the ghost of that man who set up the B-24 carburetors that way is hovering up the rafters of our classroom, smiling in approval. )

John Deakin
jdeakin // at // advancedpilot.com