Aircraft Log Books

[140kias]

On the advice of an old sage Ive just taken possession of our logbooks from our maintenance company. Just trying to get my head round them. A few questions;

Aircraft log has flights logged in hours and minutes whereas engine and prop have them in hours and 1/10 hours. Is this normal? Seems to be a recipie for confusion and error. Especially as we log everything to the nearest 5 mins.

Aircraft log has total flights and hours per day. Whereas engine and prop has a single rolled up entry at each 50 / annual. Is this normal / permitted.

thanks
140kias

[Tall_Guy_In_a_PA28]

Aircraft log has flights logged in hours and minutes whereas engine and prop have them in hours and 1/10 hours. Is this normal?

Yes.

This is because flights are logged from your watch / clock but engine and prop times are recorded by the tacho.

[SteveC]

Aircraft log has flights logged in hours and minutes whereas engine and prop have them in hours and 1/10 hours. Is this normal?

Yes.

This is because flights are logged from your watch / clock but engine and prop times are recorded by the tacho.

Not in my logbooks they are not. Everything is logged in airborne time in decimal using standard rounding.

[aerofurb]

As Steve said, normally the times are equal and recorded in the same format. For 'normal' aero engines (Lycomings and Continentals) the time recorded is take-off to touch down. Alternatively, it may be 'brakes off' to 'brakes on' less 5 or 10 minutes (or 0.1/0.2).

Rotax state that any time the engine is operated then that is counted as engine life. Most Rotax operators record airframe hours as airborne and 'brakes on/off' for the engine or use 'tacho' time for the engine and airborne for the airframe.

Remember that 'tacho' time is set up to record one real hour at 75% engine power. On our RV we have set the Dynon SkyView tacho time as one hour equals one hour at 5000 rpm - ie normal cruise.

Recording bulk hours in the engine log book is a maintenance/Subpart G company being lazy IMHO - their should be an entry for each day's flying as per the airframe log book.

Filling in our customers log books at check time, it never ceases to amaze me how complicated indviduals and groups make flight recording! By far the easiest way on a privately operated aircraft is the Pooley Journey Log, record flights in decimal hours (to one decimal place) and count up from zero when a check is complete to 50 - flight time being 0.1 off taxy time (0.2 at big places). Trying to subtract flight times to the nearest minute or two decimal place tach hours often leads to big errors by the time 50 hours has been amassed....

[dont overfill]

If the CAA are happy with rolled up times that's fine.

I remember being surprised renting in the USA after carefully documenting 20 separate flights then being told by the rental company they only needed the total time. It does make life simple.

D.O.