I’ve been following this thread for some time and it is quite clear that there’s a lot of confusion out there. It’s now quite clear that this confusion arises from the incorrect interpretation and use of terminology.
First of all, the original question, i.e. “When do you start logging time?” was vague and ambiguous. Most of the responders thought it referred ‘flight time’ and replied accordingly.
Quite simply, the definition of ‘flight time’ varies from one airworthiness authority to another and you must abide by the prevailing definition. The two principal definitions are from ‘engine/s start’ to ‘engine/s stop’ and ‘from when the aircraft first moves under its own power until it comes to rest after landing’. In regards the latter, I thought Posts #72, #73 and #74 were amusing (actually I wanted to say puerile but that may upset some people).
I’ve always preferred the former definition of ‘flight time’, i.e. ‘engine/s start’ to ‘engine/s stop’, as this is the period when the pilot is exercising the privileges of his/her licence and is therefore entitled to enter it in his/her personal flying log book as a record, or proof, of experience.
Later in the thread, the penny had dropped and then the confusion really set in as some though that the original poster was referring to ‘time in service’ which is the time the aircraft is in flight, i.e. airborne, only. This confusion is best illustrated in Post #87:
“It does make you wonder about a/c hours, when the tech log total time says 13,000hrs and only flight time is logged. None sat waiting. Non whilst pax embark/disembark. None from engine start until taxi. Say 10 mins a day, a/c sometimes over 15yrs old. Do the math.”
Here the writer is using the term ‘flight time’ while discussing ‘time in service’. ‘Time in service’ does NOT include engine start, it does NOT include taxiing, it does NOT include waiting for ATC clearances, it does NOT include waiting on a helideck during crew change, etc. etc.
‘Time in service’ is entered into the aircraft Flight Log, or Tech Log, or Journey Log or whatever it’s called in you part of the world and is used by the engineers to plan scheduled maintenance of the aircraft, its systems and components etc.
There are probably many reasons for this on-going confusion with terminology but I believe we old-timers may be largely responsible as we tend to use the term ‘flight time’ in a generic sense. We really must start to learn to use ‘flight time’ and ‘time in service’ properly. Perhaps another reason is that many of the old-timers are now working for the airworthiness authorities and are unwittingly passing on this bad-habit to the younger generation.
Also, it’s still quite common the see a Flight Log, Tech Log or Journey Log that has columns titled ‘engine start’, ‘engine stop’ and ‘flight time’. These should be changed to ‘take-off’, ‘landing’ and ‘flight time’ at the next reprinting.
So remember, ‘flight time’ is used by pilots in his/her personal flying log book to record their time at the controls of an aircraft while ‘time in service’ is recorded in the Flight Log, Tech Log or Journey Log and used by the engineers to determine the time the aircraft was airborne. They are NOT the same, they are NOT supposed to be the same and for any given flight they SHOULD differ, sometimes quite considerably.