On Wed, 20 Oct 2004 19:28:26 +0100, Peter
wrote:

How does one know which of the two should be used for the airframe,
engine and prop time?


Peter.

Airframe, engine and prop can be logged wheels off to wheels on like
they do in large aircraft. For convienience, I think most operators
of light aircraft use what large aircraft don't have - a hobbs or tach
meter. FAA doesn't care. Pilots can log time in motion e.g. block
time.