Peter wrote:
airborne time (which is what maintenance is based on)
Huh?? It’s Tach time, at least around here. Airborne time is totally meaningless and I don’t know any organization that tracks it (neither in the US nor in Europe, for that matter).
172driver wrote:
Huh?? It’s Tach time, at least around here. Airborne time is totally meaningless and I don’t know any organization that tracks it (neither in the US nor in Europe, for that matter).
I always thought an aircraft owner/operator had to keep track of both: engine time (for each engine individually obviously) and airframe time (airborne time).
Not in the US (and I’m not aware of it anywhere else) certainly not for private ops (Part 91 here). Perhaps in an airline context…
We’ve been through this before… Nobody with a time recording device in the US keeps a flight log, at least nobody I have ever met, and FAA regulation is that either tach time or Hobbs time can be used for maintenance logbook entries. I use tach time because I don’t have a Hobbs meter or need one. The number recorded is in most cases unimportant because for Part 91 operations the plane is generally maintained based on condition, not hours.
172driver wrote:
Huh?? It’s Tach time, at least around here. Airborne time is totally meaningless and I don’t know any organization that tracks it (neither in the US nor in Europe, for that matter).
Airborne time for maintenance is what I know (Europe).
Snoopy wrote:
Airborne time for maintenance is what I know (Europe).
Interesting. Was never recorded where I flew in Europe.
172driver wrote:
Interesting. Was never recorded where I flew in Europe.
It varies a lot, each plane is different. For my own P28 I use airborne time for maintenance, tach time for renters (usually less than 5% difference), and block time for my logbook. For our clubs YAK-18T, that is rented from Lithuania we log engine start to shutoff + airborne + tach. As I vaguely remember, the YAK’s POH had uses for each time.. The SF25C TMG had engine maintenance based on tach hours and all the rest based on airborne hours.
172driver wrote:
Airborne time is totally meaningless and I don’t know any organization that tracks it (neither in the US nor in Europe, for that matter).
Airborne time is tracked for maintenance in Europe. Depending on your operations and engine management practises, tacho time may be quite a bit higher so with tacho time you may need to do scheduled maintenance more often.
Also, some places (e.g. my club) charge rental by airborne time, not tacho.
Did this before many times. Airborne time for maintenance (engine and airframe logbooks) and total vehicle moving time for the pilot logbook. Search for e.g. “airborne time” (with the quotes). Example. France was reported by @Guillaume as having a different legal requirement. But IMHO most deviations from this are due to people not being bothered, ignorance of what is legitimate even if doing so costs more, etc. If you are running a school then you are passing on all the costs to clients anyway, so why bother?
I have a feeling 75% of this thread comes from the mostly-rental european scene vs mostly-owned us scene 
