Doing the engine run up

29 Dec 2005 Doing the engine run up

RV-List message posted by: “JOHN STARN”

I’ve posted for years on this subject. If you have heard it before delete
now.

EVERY RV (and derivatives) with a tail wheel can, have & well nose over if
too much RPM is used for run-up OR if the prop is cycled at high RPM when
the prop get a big ole bite of air. Every RV is different BUT ALL of them
can, have & will continue to nose over. Chain the tail down FIRST, do a run
up to determine YOUR comfort level.
On N561FS we use 1,700 as max RPM until on a roll. HRII 250HP IO-540. Fail
to learn from the mistakes others will result in “ding, ding, ding, clunk”.
The “dings” are the prop tips & the “clunk” is the spinner. It happens waaay
too fast to correct. 27 degrees up helps BUT 90 degrees would not be enough
if you cycle the prop at 2200 RPM with the brakes locked. IF you have done
this already consider yourself VERY Lucky. Do Not Try It once you have the
CG set.
Once it’s on it’s nose, get help, lots of it, to get the tail wheel back
down SLOWLY.
DO NOT attempt to pull it down by yourself, you will break its back. Refer
to X-15 photos for examples of what will happen.
KABONG