Flicking through some MPDs, a doubt came to me: For those maintenance tasks under "Flight Hours", are they really FH or BH ?
For example, for those commercial airplanes, in which sometimes a taxi phase could be as long as the duration of the flight, the taxi time must be considered for a maintenance interval ?
Okay, so ground tests don't count. But for a normal flight, in the maintenance logbook, the time should be registered since the airplane starts moving by itself and end when parked at the gate ?
The MPD uses the word "FH", but since all systems are in normal operation during taxi, it should be refered to Block Hours, right ?
No it is flight hours, airbourne till touch down. You have heard of OOOI ? The Mk 1 ACARS recorded Out Off On and In times. i.e. Out to On was block time, and Off to On is Flight time. Both are recorded in the maintenance system but FH is usually used. Some things are different, like APU and the original Carousel INS, but most else is flight hours (or landings). (look up OOOI in google)