Logbook hours
 

How do people fill in their hours in the logbook? Do you use hours or minutes, or decimal?

I have always used decimal, in this format:

0.1 5mins 0.2 10mins 0.3 15mins 0.4 20mins 0.4 25mins 0.5 30mins
0.6 35mins 0.7 40mins 0.7 45mins 0.8 50mins 0.9 55mins 1.0 1hr

...and so on. This method I have always used, and have marked a clear table in the front of my logbook. Having just tried entering a logbook in hours and minutes I have only got about 15hours into my total hours and already the decimal total is out by 20mins, when converting say 16.3 to a hhmm total of 16:15.

This leads to a question. I have now amassed over 600 hours in decimal. When the total flying is less than 30mins it seems I am overcounting my hours, by when the total is more than 30mins per hour I am undercounting it, so it should even out over the hours.

No instructor I have flown with or anyone in the CAA has queried my method.

Can anyone clarify this? Should I carry on using the decimal figures, or run a correction to my total hours at the end of a page and then change my method?

I think decimal is normal (at least that's what I do ;)). Otherwise totaling the pages would be far more difficult to do. As you say, rounding errors tend to be small and cancel out anyway.

Courtman - your method is doomed to inaccuracy because you are not equating the correct proportion of an hour to the corect decimal. If you use 6 minute increments, every 6 minutes is 0.1 of an hour. If 6 minutes is too large an increment for your purposes, every 3 minutes is 0.05 of an hour. So you are likely, by rounding up or down to the nearest 0.05 to be much more accurate than the method you are using at present.

If periodically, you then need to convert the deimal recording to hours and minutes, of course the hours will be accurate anyway, and you simply multiple whatever aggregate fraction of an hour you happen to have, by 60, in order to record the correct number of logged minutes.

As has already been noted, .1 of an hour is six minutes, not five, therefore there is always a possibility of error in logging individual flights using this schema.

As to what's 'normal' - on my site the majority of english pilots log brakes-off to brakes-on in 5 minute increments, and log time elapsed in 5 minute increments. It's American pilots who tend to log decimals of hours for elapsed times - and most of them don't log brakes-off to brakes-on time at all.

As to the CAA's opinion. Well, one thing which prompted me to create the website was to improve my own accuracy of logging flights and summing the types of hours because I was worried about this. Since then loads of pilots have set up profiles, and many of them have quite large innacuracies in their data.

These are very experienced pilots, some of them professionals, many with 100s of hours, and they're logging P1s all over the place, they're logging dual time when they were P1, they're logging in command time when they were dual - all sorts of errors, causing some quite large discrepencies in their totals, and none of them has ever commented to me that the CAA ever even noticed.

I reckon that the examination they give to our treasured records is entirely cursory for most of the time - it's only when they're suspicious (or when they're researching accident causes), that they pay any real attention.....


Steve R

In the UK it's normal practice to log 5 minute increments. Civil pilots log chock to chock, whilst military pilots log take-off to landing. [Used to really p&*^ us of at BDN that when doing a ground handling trial.] The exception is glider pilots, who have too many 2 or 3 minute flights to make 5 minute increments sensible.

Frankly, I think that if you've got enough hours to make a significant error, does it really matter if you have 150 or 160 hrs P1 (or 2000 or 2100) in a particular type? I try to keep my logbook as accurate as possible (and incidentally, most scientific calculators will add up hours and minutes) but don't lose any sleep over it.

G

I have always logged in decimal, fits in very nicely with the Hobbs meter as well.

I normally deduct 0.3 from the total for mucking about on the ground and log this is the actual.

Julian.

It seems to me that only Americans and the Army use decimal hours. The rest of us are able to add up minutes correctly - or use the DMS>DD function on calculators to add up the total on a logbook page.

How many clocks have decimal minutes?

Well the Hobbs meter, for one :rolleyes:

In my logbook I use Hours and Minutes, Eg. having flown 1 hour 5 minutes, brakes off to brakes on, this would be entered 1:05 and so on. I recently got my PPL and this method was not questioned. If you are happy with the method you are using stay with it, as changing to another method half way through may cause confusion to anyone who has not looked at your logbook.

Hey BEagle

Better add the Kiwis to the list of fools that account for their hours in decimals, or at least this fool was taught that way... :cool:

Actually, individual flights are accounted for in decimals, but each page is totalled up in hours and minutes....perhaps I was not listening in school on that first day? :D

I've always used hours and minutes, rounded to 5 minute blocks, chock to chock. Seems to me the logical way to record data which is based on actual clock-time which is universally in minutes.

My practice is to book actual chock to chock for each flight, except for those occasions at an international airport (when the hold for IFR movements would sometimes be better measured with a calendar...) then its t/off and land each +5 mins ie flight time + 10 mins.

Adding up minutes and hours on the ground in a logbook shouldn't be a problem, after all ETAs etc are in hours/minutes, not decimals, and the brain is frequently multi-tasking at the time!

Hobbs meter is ... a meter, which stops and starts with usage, and can record whatever units its calibrated for. A clock is "kept in motion" (OED) and I haven't seen a decimal one yet.

Julian, at least there's no VAT, whether minutes or decimal-hours! :D :D

SlipSlider

In private flying of which this is a forum, the hobbs starts on engine start and stops at engine stops.

It is prudent for hour building to log in 6 minute intervals and get more for your money.

I have always used whole hours and then mins (eg 1:15 being 1 hour, 15mins). I find this easiest, but as someone has said before, if you are happy with the way you do it, why change? I don't think the CAA care which way you use.

Slipslider - Quite right mate, although keep it quite or HMG may try and tax that as well to pay for Johnny Two Jags running expenses :D

Forgive me if this comes off as critical:

this seems a bit backwards--the problem with logging decimal is the inaccuracy when converting from clock time*. The problem with using minutes is that they are harder to add and more subject to errors in the adding.

It seems you've got the worst of both and introduce two possible errors-one on the conversion to decimal and one on the conversion back. Once the hours are in decimal I see no reason to convert back to minutes-after all there are no requirements that hinge on the number of minures you have ["you need 3 hours and 11 minutes of night flying to get this rating"]. All requirements that I know of are in terms of whole hours, so might as well keep it in decimal.

As to logging entirely in minures--that makes sense to me too.


*not a problem here in the states where we log hobbs time

:)

Ah the penny has dropped!
So now my question is - why doesn't everyone log Hobbs time? Seems far more sensible, with the added benefit of being decimal :D
Surely that's the whole point? The fact that the meter does just that means that there can be no argument about what is logged, for both pilot and maintenance.

[ 01 November 2001: Message edited by: sanjosebaz ]

sanjosebaz

What?????? log decimal time???? We Brits have been around for thousands of years and I can tell you that we never logged decimal time back in the 1600s when you American guys were just colonials!

Preposterous!

You may NOT log 'Hobbs' time in a UK personal logbook! Whereas the hire of the aircraft may be charged by using 'Hobbs time', the flight time in a personal logbook MUST be recorded as 'from the time the aircraft first moves under its own power for the intention of taking off (i.e. 'chocks away') to the time of completion of the normal taxying process after landing (i.e. 'chocks under')'. Anyone logging 'Hobbs time' has not recorded their flight time in the required manner.

Decimal time - OK for thickos who never learned how to add up hours and minutes perhaps, but for the rest of us it has no relevance.

[ 02 November 2001: Message edited by: BEagle ]

I used to be syndicated on an aircraft with a bit of a starting problem (once it started it was always fine). That's where I discovered that on failed starts a Hobbs can jump forward. My record was 0.7hrs without leaving the chocks.

Needless to say, I had to pay by the Hobbs reading, but my personal logbook could only log chock to chock.

G

[ 02 November 2001: Message edited by: Genghis the Engineer ]

Progress to anything beyond a piston and suddenly you won't have a Hobbs any more. Mind you you will have a clock with good old-fashioned hours and minutes.

regards
wizzy

Precisely!!

Surely time is sexagesmal and to record it in decimal is grossly incorrect, my two euros worth!

what a bunch of crap ! Hobbs time is just as accurate as 'watch time' especially when you go to add up the time you have at the end of the 24 months, and you keep making mistakes !

so what if the odd minute here or there is incorrectly logged...it'll even out ? Do pilots loggin instrument time have a 'cloud timer' to log time in actual IMC ? Thought not ! At the end of the day if I time myself using my wrist watch and I log take off at 'about 12:30' and landing at '14:32', then I'm sure errors are going to creep in, more so than using a Hobbs. Besides, my theory is that as soon as the engine is started, then the PIC is IC of the AC!!

englishal - it's you who's talking cr@p, I'm afraid. The Hobbs meter is not a sufficiently accurate method for recording valid flight time. Which is the time from 'chocks away' to 'chocks under' in any case - not from engine start/battery master on. If you've been logging hours by the Hobbs and have used those hours for licensing purposes, technically you could be considered to have falsely represented your flight time....

You become 'Commander of the aeroplane' long before the engine is started; if one of your passengers falls off the wing when embarking, it's you who will be held to blame if you haven't briefed them properly....

[ 04 November 2001: Message edited by: BEagle ]

I'm sure a Hobbs is more accurate than many wind up wrist watches!

At the club I fly at in the UK we log time from take-off to landing, for billing purposes, then add 0.1 (or 6 minutes for the non decimal loggers) either side for taxy, for log book purposes. Hardly accurate is it? So as far as I'm concerned people can log the time how they see fit (as long as its not grossly in error), as inaccuracies will creep in using which ever method. All this arguement does is add to the already growing mound of beauracy which is boggin down GA in the UK to such an extent that people no longer want to fly there !

If the Hobbs meter is not deeemed accurate then why is it used to schedule maintenance regimes, ie. 100 hr, do we have unsafe aircraft flying around????

Final 3 Greens Maybe that's the whole problem - just like the market trader in Sunderland who refuses to weigh his goods in decimal. I do see both sides of this argument - my point was that logging Hobbs was straightforward and difficult to argue with (I was clearly wrong!)... The real arguments in this thread seem to revolve around "that's the way it's always been" - maybe it's worth questioning things once in a while... (and I can add up hours and minutes - just think that the yanks have it right with this one! :eek:

Lastly, I am a Brit, I'm afraid - just living in the warmth for a few years to thaw out :D

Our company has a hobbs in every plane and the op's manual say's logbook time is hobbs time plus .1 for every landing. :)

Oh yea, the hobbs is also based on oil pressure and or airspeed, so simply switching on the Master won't start it counting....

Beagle::

:) :) Do you actually brief your passengers not to fall off the wing? :) :)

Hell look at the other side of flying , someday you won't be bothered logging time in your personal log as it will have no meaning to you anymore.

............................................

:D The hardest thing about flying is knowing when to say no. :D

The day that happens, I'll give it up. Your log book is your history of the priviledge you have had every time you get airbourne. I will always log my flying to the day I die. To stop suggests you have learnt all there is to know which in my book means a quick road to a statistic.

Is it not a JAR requirement that flights be logged to the nearest minute?

I know in Jerez the CFI had Pooleys print us all up new logbooks that complied with the CAA inspection rules for JAR Approval and in them we were clearly instructed that decimal was no longer allowed. Which rained on my parade a little.

Or is this not the case?

WWW

Captain Airprox

I agree with you entirely,to fly and not log it, is to not fly at all !

My logbook is kept with clinical accuracy and I cherish each flight I enter, the same now as I did on my first lesson eleven years ago.

A logbook is not just a record of flights made, it a record of your acheivement.

Long live the logbook !

:)

I fly in the UK and get charged by Hobbs time which begins ticking when the master goes on. If the CAA think I should not be entitled to log all of this time then they should ensure that FTO's only charge chocks off to chocks on time.

Too right, I log all my hours...and in decimal :p

Julian.

Hi, Captairprox - Jepp - Julian:

Please allow me to elaborate further on why I no longer bother to keep a personal log book.

When I first started flying in 1953 I was as psssionate about logging every second of my flying time as you are. However, now nearly fifty years later I see no real reason to keep a personal log book to record every second. However I am writing a book that will record a great amount of the love affair I have had with flying.

On the practical side of things it is highly unlikely I will be asked by an airline to show a log book to verify my time,unless they change the over sixty rule.

I just remembered something, there is a web site where several of my short stories are available should you wish to read some very interesting flights. Go to www.ebushpilot.com and just look for the stories section of that web site and read " Arcturus the missing hours and fate" also "The tobacco fields" and I believe there is one on a trip I recently did through Africa on a ferry flight in a PBY.

If you wish to spend about thirty pounds or so buy the book " Un vol de legende sur les traces de L'Aeropostale ". The ISBN number is 2-235-02238-3

Anyhow enough of that as I do not wish to bore you just talking about me. The point I am making is that there "may" come a time in your career when you will no longer log every flight.

And oh, by the way Captairprox even though I no longer log every second of my time you are absouletly correct that we should never assume we know everything about flying. I agree with you, that is truly the sign of an idiot.

We also fly for the movie industry mostly in the U.K. e-mail me and I can give you some more web sites if any of you are interested.

And don't forget...Even though you log all your time...Remember...

.............................................

:D The hardest thing about flying is knowing when to say no. :D

[ 29 November 2001: Message edited by: Cat Driver ]

Quote: Is it not a JAR requirement that flights be logged to the nearest minute?
I know in Jerez the CFI had Pooleys print us all up new logbooks that complied with the CAA inspection rules for JAR Approval and in them we were clearly instructed that decimal was no longer allowed.

Well, I have a "US" logbook, all my flight time is logged in decimal and the CAA don't have a problem with it, indeed they issued a JAR licence based upon this offending logbook. If you ask me its just being padantic to worry about such minor things as what your log book looks like, so long as time is logged accurately. Do many British pilots really sit around for hours and discuss how their logbooks look
? (Maybe this is why the big flight training places charge so much money....).....

Logged every hour I've done. Your logbook is a diary - at least that's the way I see it. I quite often put daft comments in against entries.

Always been done in decimal, and I'm a Brit.....Forget all of this writing chox off to chox on malarky :D :D :D

White Knight - Thank god someone is like me!!! I still put the odd comment on mine, outlining a good or bad achievement. (Such as a smooth landing!!!! Doesn't happen much!!) Seriously, I even put down who I have sent first solo. It is as much a day for me as for them, to see the worry b4 then glee after stepping out the aircraft, legs like jelly. That was the day!
My old boss had tens of thousands of hours under his belt. Having retired from the RAF, and now instructing full time, he still logs them all meticulously and even sticks a picture in his book of any new aircraft that he test flies.
He says that he tries hard with his experience not to become complacent. And this should go as far as filling out his record of flying. He says you never know when you might just need it in court! I have great respect for this guy.

[ 29 November 2001: Message edited by: CaptAirProx ]

In Canada there is a requirement in law to fill out the aircraft log as soon as practical after each flight. When flying aircraft registered in other countries I record the flights for legal reasons.

Therefore should I need proof of any flight for any reason it can be found in the airplane log.

I must say though that I sometimes wish I had a personal log with pictures and comments, it would be really nice to have and I admire those who take the time to keep such a log.

However it is my opinion that not keeping a personal pilot log book has no bearing on being proessional, either in flying skills or safety.

Unless almost fifty years and in excess of 25,000 hours ( Transport Canada records )and still flying world wide for a living without an accident or incident or violation was just pure luck.

.............................................

:D The hardest thing about flying is knowing when to say no. :D