After Flight paper work
 

Hey All,

Some will be aware nearing my test but not really sure on the flight log you should fill in after. I no each clubhave there own different ones but part I dont seem to graspe is the tacho time.

So I get if tacho read 22.0 at start then 23.0 at finish that would be 1.0 tacho time. But its the bit in the middle i seem to get stuck on so would 22.0 to 23.5 be 1.5 tacho time?

Sorry might seem a bit dumb but get confused if it was 22.0 at start and 22.7 at the end?

Thanks

The Tacho time measures the time the engine has run over a predetermined RPM and therefore gives a reasonably accurate time for engine overhaul purposes. Some regard it as a measure of airborne time however; if you do a lot of PFLs it will under-read. It counts in minutes. To convert this to flight time, brakes off to brakes on, you need to add time and this could be a simple addition of 10 minutes or the addition of a percentage to the tacho reading. At the end of the day the most accurate time is off your watch.

22.0-22,7 is 0.7 hours Tacho time which equates to about 0.9 hours flight time which you log.

Why not just record the time that you take off and and the time that you land?

You can then add in taxi and shutdown time to get a more accurate reading than the tacho.

Are they all the same?
 

Whopity - I didn't realise that the tacho only started counting from above a certain engine speed. Our club log tacho time as total time, and take time off to get airborne time. The club aircraft tachos always seem to match up to actual time, so could some tachos work differently?

tacho
 

Thanks guys.

I was told to log brakes off to brakes on in the log book which I do. My issue is adding up the tacho time just for the logs after.

So if its 10minutes addition 22.0 to 23.0 is 1.0 so would 22.0 to 23.5 be 1.3 or 1.5?

This seems silly but just cant seem to graspe it.

? Can't see what the problem is unless you have a wildly different tech log at your club to any I've seen. You just put the tacho reading at landing and the Hobbs if you have one. No maths to be done.

I don't know what you're trying to add and subtract.

Edit: for landing I mean shutdown.

Kevin, to get the Tacho hours for the tech log you simply subtract the opening tacho number from the closing number. So 22.0 to 23.5 would of course be 1.5. Its simple. no magic, nothing else to take into account.

I fail to see what you find difficult to grasp?

Before you start up write down the tacho time

Write down brakes off then take off time

Write down landing and brakes on time

Note the tacho time after you shutdown

You have everything you need.

It is not a difficult concept really, decimal time. 0.1 hr = 6 minutes.

1.0 to 2.7 = 1.7 hr

1673 to 1684 = 1.1 hr

1692.55 to 1693.45 = 0.9 hrs (but I normally forget the last digit).

1.1 Tach hrs= 1hr 6 mins

You can always use a calculator.

But I log TO to LD in the aircraft logbooks, and I normally get this from my watch, or some other nifty timing device like the transponder or GPS. My logbooks (flying) I get from my watch normally, if I remember. If not I use as above.

Not quite what he said. The tacho time actually counts cumulative revolutions. It matches real time at a certain rpm. For example the tacho time might be set to advance by .1 hours every 13800 engine revolutions. If you were running at an average of 2300 rpm, it would take exactly 6 minutes (0.1 hours) to tot up this many rpms and tach time would equal 'real' time. If you were running at 1100 rpm it would take over 12 minutes to add 0.1 tach hours.

Kev31 The addition is a fudge factor used by some schools to get a time they charge you for (the problem I assumed you were referring to); its an alternative to Hobbs time which starts counting the minute you switch on the Master Switch, so you are paying for your pre-flight electrics walk around! If they use this they will have the process written down with their charging info. For the Tech Log you simply log the Tacho as stated and take one from the other.

(10 minutes is 0.166 hrs normally rounded up to 0.2)

If a school is charging tachometer time plus 0.2, then I would go to another school. In my experience, tach time is about the same as bLock time so you will probably be paying for more time than the block to block time you should be using in your personal log.

Our school charges for airborne time ( measured by a timer attached to an air switch) plus 0.2 to cover all taxying. This is a great system since it does not encourage students to save money by taxying too fast or skimping on the warm up. Students often pay for less time than they log, especially on the early lessons. It's fair for the school too, because most of their costs are based on airborne time.

My club charges block time as determined by what the hirer tells the invoice writer it was.

(In the very rare cases where the hirer doesn't have a clue because they didn't note the times, calling ATC will get take-off and landing times to which 10 minutes is added.)

Seems to be that all the complications to do with the various inaccurate metering systems are purely there because the business doesn't trust its customers not to routinely defraud them? Makes for a great relationship, no?

Gertrude - exactly the same here. Note take-off and landing times, add five minutes each end, call ATC if unsure. No need for anything more complicated if everyone trusts each other!

If your hour building you want to be charged on the Tacho.

You just cruise around just in the green arc and get 20% more hours in your log book than you pay for.

Tricky when the club examiner checks your log book against the club invoices to make sure you're not claiming Parker Pen hours!

It's not Parker Pen hours. The rules specify the pilot logs from 1st movement for the purposes of flight until at rest after landing. How the aircraft operator chooses to charge for its use is irrelevant. It could be via weight on wheels switch, speed switch, oil pressure switch, gear UP switch, tacho 'hours', some defined clock time or how many clouds are in the sky that day. Unfortunately many people & organisations conflate the two

The tacho hour meter is calibrated to clock over 1.0 in a real time of one hour at a certain RPM, typically cruise RPM. Run the revs faster & the tacho will clock over 1.0 faster than a clock hour elapses. Run the engine at low revs & the tacho will clock over 1.0 significantly slower than real time elapses. If the operator is charging via tacho time, and you do as MJ suggested, you will accrue - quite correctly - more loggable time than you will be charged.

Using anything other than clock times to separately track both pilot loggable time and maintenance time (or Hobbs/VDO meters that reflect the clock times) is a fudge for convenience.

I'm with Mad Jock on this : He is not claiming just to multply your tach hours by 1.2 (which would amount to logging parker pen hours). He is just saying : if your flight school / flying club is charging you tacho hours then it pays to fly bottom of the green arc if your only objective is to get loggable hours and you don't have to be somewhere by a certain time.

The time to log would be the time from taxiing the aircraft towards a take-off until switching off on the parking stand which, for short haul flights, amounts to around 20% more flight time logged if you took to a conservative RPM setting.

So the club examiner wants to check the log-book he can check it against the invoices if he wants to, but then what ? real flight time hours are real flight time hours, right ? That is quite different from billed hours, which can be based on whatever scheme (hobbs hours based on oil pressure measurement, hobbs hours based on landing gear pressure, tach time, GPS distance,...) the operator deems appropriate.

And why would the cub examiner get anywhere near my log book?

And even if I did let one, what's in my log book is nothing to do with them unless they are signing for anything. And its the tower logs that count not the invoices.