How to log with decimals?

[Dibies]

Hello,

I used to fly in the US where I logged Hobbs time (1.5, 1.6, etc). Now I am flying with an UK FTO, and I end up with times like 1h10, 1h20, 1h50, etc.

The thing is that in my logbook I use decimals and I would like to keep it that way.

So my question is pretty simple: I would like to know how to log for instance 1h10 in decimals (logbook pro round it to 1.2).

Is it the correct way to do it? Is there an official document about it? (UK CAA). I don't want to have any problem with my CPL issuing because I was rounding the times.

Thank you for your help!

[zondaracer]

I kept my logbook in decimals and I rounded conservatively. In the end, my logbook ended up being .2 hours less than what the school had. The UK CAA has never had any problems with my logbook being kept in this format.

[chrisbl]

Just draw yourself up a table say in 5 minute increments for the fractions of an hour, keep it in the back of your logbook as a reference.

[Genghis the Engineer]

Surely logging Hobbs is a somewhat dodgy practice anywhere, since it will include allowances for time before the brakes are on but the engine is running? Hobbs should only be used for what it was designed - logging engine running time.


There's no absolute rule of-course; personally I've logged to 5 minutes for years, although this year made a decision to switch to per minute - my personal decision, and completely unnecessary, but suits me.

A simple solution is that you keep your plog to the nearest minute, then just use the obvious conversion - 6 minutes = 0.1 hours. Round to the nearest 6 minutes (6, 12, 18, 24...), log to the nearest 0.1, problem solved.

G

[Dibies]

@zondaracer: Thank you for sharing your experience (again :D ).

@the others: thank you for the advices.

I will just round as Logbook pro does.

[Dibies]

Surely logging Hobbs is a somewhat dodgy practice anywhere, since it will include allowances for time before the brakes are on but the engine is running? Hobbs should only be used for what it was designed - logging engine running time.

I completely agree with you. But this is the way my former school was doing it (apparently commun in the US).

[B2N2]

Surely logging Hobbs is a somewhat dodgy practice anywhere

No it's not, it has been an FAA authorized method of logging time for years.
Tach time should be used for logging engine run time.
You are going to trust a pilot with a wristwatch to log flight time :eek:

[mcgoo]

I've always logged Hobbs, never had a problem with the FAA or CAA and its been scrutinised by both many times!

[Whirlygig]

You are going to trust a pilot with a wristwatch to log flight timeYes. :hmm:

I log time to the nearest five minutes according to my Seiko watch. Datcon and Hobbs readings were used for the Tech Log ... but, as I would wind up the throttle, I looked at my oversized watch (only oversized because it was my late father's and I have girly wrists) ...as I landed and let the aircraft cool down, I noted the time.

Personally, I find it difficult to think of time in other than five minutes intervals; decimals are fine to a point but decimals are designed for a base ten system whereas time is a base twelve system. Old money was in base twelve and base twenty.

Perhaps it helps if you were born in a time where L S D meant more than a recreational, mind-altering drug :8

[Genghis the Engineer]

The whole system relies upon integrity; we trust a pilot to behave in all sorts of safe an appropriate ways, correctly writing down the flight time is just one of those.

I always let my engine warm up, and usually do avionics checks before taxiing. (Usually = some aeroplanes I fly don't have any avionics to speak of!). I always let engine temperatures settle after putting brakes on before shutting down. Therefore if my logbook showed Hobbs time I would be artificially inflating my hours.

G

[Tinstaafl]

Hobbs doesn't necessarily align with engine start & stop. It depends on the way the switch is wired. Variations I've come across:

* Oil pressure
* Gear up/down
* Squat switch (weight on wheels)
* Airspeed switch
* Master on

I log using decimal time in my log book, noting off & on blocks times, and airborne & landing times. One for my log, and one for the aeroplane. If the plane has a Hobbs (and its maintenance is based on it) then that's what I record for aircraft flight time.

[B2N2]

Agree with all of the above Genghis but with the engine running you are excercising the priviliges of your certificate and acting as PIC, captain of the ship, the big kahouna, whatever the title is.
You carry the responsibility you can log the time.
Now I have to admit this was all much more important when my time was still in double digits then it is now.
Part of my duties are now to play the logbook-police and make sure these little critters don't log stuff they're not entitled too.

You log what you pay or you get paid for what you log, either way.

[Bealzebub]

Obviously decimals are simply six minute increments. It isn't too difficult to round the time up or down to the nearest six minutes without ever being more than 3 minutes adrift. This can be further honed by adjusting the time of start and finish to refine the total "error" to a minute or two per sector in most cases. Similarly, if one sector has you gaining a minute or two, the next sector likely can be adjusted downwards to keep the margin of specific error in check.

[Reverserbucket]

Dibies question raises a question: his former school recorded flight time (training) using Hobbs but his current school uses hours and minutes recorded using a chrono. Am I correct in saying that the UK CAA accept a maximum of 15 minutes (or 18/0.3 if we're being pedantic) taxy time for each sortie? i.e. a 1:30 logged lesson cannot contain 1:00 taxy time as is allowed by the FAA. Recording training time without regard for taxying time (as implied by measuring the hobbs duration in a flying logbook) surely gives the student a significant disadvantage over the former with respect to the amount of actual airborne time? I've flown from U.S. airports where taxy time was considerable and would have been of little value to a student.

I don't recall anything in JAR-FCL concerning the recording of training flight time and can't see anything in EASA-FCL's. Was this only a UK thing?