Logging Hours for Test Phase

[Tomfox]

I am in the test phase for my aircraft.


I realize I don't know the method of counting hours toward the 40 hour requirement.


a) Hobbs
b) Tach
c) My logbook


Thanks
Tom Livermore
S7 Supersport

[jonstark]

I have both Hobbs and tiny tach and they are both super accurate and maddeningly sloooow. This 40 hours is taking forever! I wish I had your SoCal itchybelly weather.

In my airframe logbook I’m logging each flight as follows...
Date / location / hobbs start / hobbs stop / time flown this flt / landings / flight test task / pilot

Jon

[rv9ralph]

Any of those methods work... just don't log schafer time.

Also, use the time to work through the recommended testing tasks in AC 90-89A, AMATEUR-BUILT AIRCRAFT AND ULTRALIGHT FLIGHT TESTING HANDBOOK, not just burn holes in the sky, but you know that.

Ralph

[PapuaPilot]

I couldn't find an definitive answer to your question, but I think it would be flight time because it is called "Phase 1 Flight Testing".

If that is the case you would need to use the instrument that shows the aircraft flight time. That would be either Flight Time with a digital panel or Tach Time if you are using a tachometer.

It wouldn't be Hobbs time (that is normally used for billing purposes) or your logbook time (chock to chock).

[efwd]

That's interesting. If Hobbs is incorrect then I acquired my private pilot ticket in under 40 hours. Somewhere, the FAA has info on when to begin logging time. I thought it was from the time the airplane leaves the parking spot for the purpose of flying. That leaves the question as to when time stops since, as stated, chock to chock is not right either.
I noticed that my panel has the engine time and the aircraft time. What parameter does an EFIS use to log aircraft time?

[rv9ralph]

So, if I remember correctly...

Hobbs time starts when there is oil pressure and stops when there is no oil pressure (on most systems). Time is clock time.

Tach Time counts revolutions and count time based on average expected RPM at cruise. If flight includes a lot of working stalls, slow flight or approach to landing, the time will record less than clock time.

EFIS, depending on system will starting counting either on oil pressure, RPM or Air Speed reaching a certain preset level. Check your EFIS specs for which.

As to what to use to count your Phase 1. Play it safe and use flight time, wheels up to down. It you do more hours it is to your benefit. The time in the Operation Limitations are a minimum time, during which you should be documenting your aircrafts performance and conformance.

Ralph

[PapuaPilot]

Somewhere, the FAA has info on when to begin logging time. I thought it was from the time the airplane leaves the parking spot for the purpose of flying. That leaves the question as to when time stops since, as stated, chock to chock is not right either.

I noticed that my panel has the engine time and the aircraft time. What parameter does an EFIS use to log aircraft time?

From 14 CFR 1.1 "Definitions"
Flight time means: (1) Pilot time that commences when an aircraft moves under its own power for the purpose of flight and ends when the aircraft comes to rest after landing. Where I work we call this "chock to chock".

For the G3X the installation manual states:

Total Time - Records Flight Time when aircraft is airborne as determined by GPS data and the indicated airspeed.

Engine Time – Engine Time records the total operating time of the engine, in hours. Engine time will be recorded whenever engine RPM exceeds 100 RPM.

FYI, I called my Phase 1 testing done when the total time reached 40 hours.

[Tomfox]

Thanks all. I understand what to do.


Tom

[GWright6970]

If I remember correctly, AC 90-89A has included taxi tests as a task to be included in the 40 hours. (Just to muddy things up! Sorry!)

[efwd]

Awesome...