P-51 Mustang Engine Runs

[Milt]

We ageing ex Mustang pilots used to do a full power run up of the engine before each day of peacetime flying. I think the procedure was to satisfy the engineers that any adjustments they had made were acceptable. Trouble was the Mustang engine could only be taken to about 50 inches of boost with the aircraft against chocks. This meant having to tie down the tail utilising a steel bar through a purposeful hole through the rear fuselage. The steel bar was then anchored to strong tie down points or to large concrete blocks. Then one could run the engine up to full power of 61 inches. I seem to remember that without the tie down the Mustang would tip on to its nose at about 45/50 inches.

During Korean war ops I think we relied on doing the full power checks very early during a take off and if there were any hick-ups from an engine we would abort.

Can anyone remember the actual engine boost which would cause the chocked Mustang tail to lift and what pre flight engine checks were done for Mustangs in WW2?

What do you lucky guys/gals who still fly Mustangs do pre-flight now ?

[Brian Abraham]

Milt, the only mention in the US Army Air Corp “Pilots Flight Operating Instructions” is briefly, warm up at 1300 RPM, check mags at 2300 RPM, exercise prop to cause a 300 RPM drop, and to check that the automatic manifold pressure regulator does not exceed one inch Hg difference between the 2300 and 2000 RPM when exercising the prop. No mention of performing full power runs although a note says “WARNING – Prior to any ground run up, the tail of the airplane should be anchored securely to a fixed object.”

[kimberleyEx]

Hi Milt.

Although Im not rated on type. I have witnessed a number of times, full power run ups of a Mustang whilst fully tied down as you explained above.

The Merlin changes tune somewhat when the power is above 2300 RPM!!

Last time I recall running at 3000RPM and 61 inches was after a prop overhaul, and to ensure the governor was governing at rated 3000RPM when full take off power was required! Sounded so, so goood!:D

Cheers.

K-Ex