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Re: Flight time in the Aircraft log-Book

Posted: Wed Oct 03, 2018 7:20 pm
by astaib
Ok! Thanks.
Anyway Diamond has wrote me today :
« As a follow up to our conversation, when Diamond Aircraft states ‘flight time’ within it’s AMM, the term refers to the time between wheels up and wheels down of the aircraft operation. »

Re: Flight time in the Aircraft log-Book

Posted: Wed Oct 03, 2018 9:59 pm
by linzhiming
Rich, I am not sure I agree/follow about it being ignored and impractical: The G1000 shows TTIS (total time in service) and measures time in service almost in line with the 14 CFR 1.1 definition. I even have an entry in my aircraft logbook that says "Tach = xxx.x and is AFTTIS". All my maintenance entries are based on the G1000 TTIS and airworthiness directives normally reference TIS for which the mechanics use the G1000 TTIS as well.

Wolfgang

Re: Flight time in the Aircraft log-Book

Posted: Wed Oct 03, 2018 10:06 pm
by Rich
linzhiming wrote:Rich, I am not sure I agree/follow about it being ignored and impractical: The G1000 shows TTIS (total time in service) and measures time in service almost in line with the 14 CFR 1.1 definition. I even have an entry in my aircraft logbook that says "Tach = xxx.x and is AFTTIS". All my maintenance entries are based on the G1000 TTIS and airworthiness directives normally reference TIS for which the mechanics use the G1000 TTIS as well.

Wolfgang
Well, I did say "almost". The G1000 may be "almost" in line and the VM1000 is a pretty good approximation (one inaccuracy tending to cancel out another), but not precise. My KT74 is probably the best approximation, triggering based on airspeed, but the timer resets for every power cycle. And mechanical tachs (still the vast majority) are nowhere near attempting to track this. Yet that's what is used.

Re: Flight time in the Aircraft log-Book

Posted: Fri Oct 05, 2018 7:26 pm
by Thomas
Hi Arnaud,
I confirm that Dave is right, also in the EASA environment, for your personal logbook it’s Block on/off and for the A/C it’s airborne time. Means time between the maintenance checks is airborne time.
I use the IPad Jepp Flight Deck App and a garmin area 600 for the time recording. The VM1000 shows something different. (More). In the Airline ops we did the same.

Re: Flight time in the Aircraft log-Book

Posted: Fri Oct 05, 2018 10:43 pm
by RMarkSampson
Depends on your equipment too. I have an STC for my engine instrumentation. I use to have the VM1000 but replaced it with JPI's EDM-900. My tach time is no longer a simple function of engine RPM time above 1,500. According to their website, JPI Tach Time is calculated based on the average cruise RPM for your aircraft. Tach Time is accumulated once per second, using the following calculation: Tach Time = Tach Time + (Current RPM / Average Cruise RPM). Tach Time is true (counting at 1:1 with HOBBS), only when your current RPM is at the Average Cruise RPM setting in the EDM. When your RPM is less than Average Cruise RPM (when taxiing, decent, etc), Tach Time will count slower than HOBBS Time. When your RPM is higher than Average Cruise RPM (during takeoff, climbing, etc), Tach Time will count faster than HOBBS Time.

Fuzzy math...