It's not Parker Pen hours. The rules specify the pilot logs from 1st movement for the purposes of flight until at rest after landing. How the aircraft operator chooses to charge for its use is irrelevant. It could be via weight on wheels switch, speed switch, oil pressure switch, gear UP switch, tacho 'hours', some defined clock time or how many clouds are in the sky that day. Unfortunately many people & organisations conflate the two
The tacho hour meter is calibrated to clock over 1.0 in a real time of one hour at a certain RPM, typically cruise RPM. Run the revs faster & the tacho will clock over 1.0 faster than a clock hour elapses. Run the engine at low revs & the tacho will clock over 1.0 significantly slower than real time elapses. If the operator is charging via tacho time, and you do as MJ suggested, you will accrue - quite correctly - more loggable time than you will be charged.
Using anything other than clock times to separately track both pilot loggable time and maintenance time (or Hobbs/VDO meters that reflect the clock times) is a fudge for convenience.
Last edited by Tinstaafl; 1st September 2013 at 20:47.