Getting robbed,"taxy time"
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Had a share in two groupe A/C. The Piper J3 came into our base for a check. While I was looking carefully at things, I found a note on the drive cable to the tacho. " We know what you are doing XXXX" ( a member) so stop it! Seems he was disconnecting the tacho to 'reduce' his hours. Not cricket!
Join Date: Jan 1999
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As someone who supplies aircraft to flying clubs I had to change from charging from take off to landing according to the entry's made by pilots in the aircraft log, however it became clear that a small number of the people had difficulty in getting the numbers right and always seemed to find tailwinds.
I changed to charging using the tachometer times, I was very careful to set the tachometer rate at one that would reflect the rate for take off to landing rate and not disadvantage those who had previously accurately recorded flying times.
I changed to charging using the tachometer times, I was very careful to set the tachometer rate at one that would reflect the rate for take off to landing rate and not disadvantage those who had previously accurately recorded flying times.
Join Date: Dec 1999
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" We know what you are doing XXXX" ( a member) so stop it! Seems he was disconnecting the tacho to 'reduce' his hours. Not cricket
Join Date: May 2003
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Re the OP I find the charging policy unusual unless the nominal rate is set low to be an enticement and needs to be jacked up by 16%.
Our school charges for brakes off to brakes on either a dual or solo rate as appropriate as Brakes off to brakes on is what goes in the logbook.
We also record tacho time and airborne time and generally tacho time and airborne time usually come close to brakes off to brakes on plus 10. it varies a bit depending on the home runway in use and the proficiency of the pilot/student.
The tip for all prospective students is do a proper comparison of cost per logbook hour. This includes any additional bits for briefing / debriefing/ fuel surcharges etc.
The other potential gotcha is with landings. Is it one price for the whole detail irrespective of the number of landings per detail or do you pay for each landing /touch and go? It can make a considerable difference to the overall cost for each lesson.
Lack of transparency and "sweetheart" rates too good to be true are a common problem in the flight training field.
Don't be afraid to ask for sample invoices.
Our school charges for brakes off to brakes on either a dual or solo rate as appropriate as Brakes off to brakes on is what goes in the logbook.
We also record tacho time and airborne time and generally tacho time and airborne time usually come close to brakes off to brakes on plus 10. it varies a bit depending on the home runway in use and the proficiency of the pilot/student.
The tip for all prospective students is do a proper comparison of cost per logbook hour. This includes any additional bits for briefing / debriefing/ fuel surcharges etc.
The other potential gotcha is with landings. Is it one price for the whole detail irrespective of the number of landings per detail or do you pay for each landing /touch and go? It can make a considerable difference to the overall cost for each lesson.
Lack of transparency and "sweetheart" rates too good to be true are a common problem in the flight training field.
Don't be afraid to ask for sample invoices.
It's confusing but let's see what we can do to clarify;
Old(er) aircraft may not originally have or have had a Hobbs meter.
Installing can be costly as it needs to be wired into the electrical system and tapped into the oil pressure line. Yes a true Hobbs meter runs on oil pressure and not on the Master switch on.
If you accidentally leave the master switch on or take 10 min to read a checklist with the Master switch on the Hobbs should not run.
If it does then it's only wired into the electrical system.
So Hobbs time should be true engine run time and is for all intends and purposes (by the FAA) legal to log as flight time in your logbook although operating time is probably a better word.
A Tacho runs even with clock time at a high powers setting.
So if somebody comes back after an hour clock time with 1.0 Tach time they've run it balls to the wall.
Anything less then (almost) full power the tach runs slower then clocktime.
In normal flight training operations this is usually a factor of 1.25 meaning that one hour of Tach is really 1hr 15 min of engine run time.
0.8 Tach is around one hour clock time.
So if the school or club charges by Tach and Tach only they're basically robbing themselves because fuel is still being burned, instructors are still providing their time and wear and tear and depreciation is still taking place.
So lets say the airplane is $100/hr and the instructor is $50/hr and the school uses teh Tach:
1.0 Tach = 1.25 x$100 + 1.25 x $50 = $125 + $62.5 = $187.5
This would not include briefing and debriefing time for which the instructor needs to be paid. So let's say 15 min pre and 15 min post for another $25.
Final bill $212.5 and you expected $150 because you don't know how the billing works.
Old(er) aircraft may not originally have or have had a Hobbs meter.
Installing can be costly as it needs to be wired into the electrical system and tapped into the oil pressure line. Yes a true Hobbs meter runs on oil pressure and not on the Master switch on.
If you accidentally leave the master switch on or take 10 min to read a checklist with the Master switch on the Hobbs should not run.
If it does then it's only wired into the electrical system.
So Hobbs time should be true engine run time and is for all intends and purposes (by the FAA) legal to log as flight time in your logbook although operating time is probably a better word.
A Tacho runs even with clock time at a high powers setting.
So if somebody comes back after an hour clock time with 1.0 Tach time they've run it balls to the wall.
Anything less then (almost) full power the tach runs slower then clocktime.
In normal flight training operations this is usually a factor of 1.25 meaning that one hour of Tach is really 1hr 15 min of engine run time.
0.8 Tach is around one hour clock time.
So if the school or club charges by Tach and Tach only they're basically robbing themselves because fuel is still being burned, instructors are still providing their time and wear and tear and depreciation is still taking place.
So lets say the airplane is $100/hr and the instructor is $50/hr and the school uses teh Tach:
1.0 Tach = 1.25 x$100 + 1.25 x $50 = $125 + $62.5 = $187.5
This would not include briefing and debriefing time for which the instructor needs to be paid. So let's say 15 min pre and 15 min post for another $25.
Final bill $212.5 and you expected $150 because you don't know how the billing works.
I think there is some incorrect information in many of the above posts.
There are three times that are of interest.
1. Time in Service (TIS). This is the time that *must* be logged to track inspection & maintenance requirements. It is defined as when the aircraft becomes airborne until it lands. As long as that *minimum* time is tracked, then you are legal. You could use a system that incurs TIS at a greater rate but not one that under records. The disadvantage of recording more time than minimum is that maintenance will fall due sooner than is strictly necessary. That makes the cost of operating the aircraft greater.
Acceptable methods include:
- Log airborne & landing times using your watch or the aircraft's clock.
- Use some sort of meter eg Hobbs. The issue becomes how is the meter activated. At a minimum it must start by the time the wheels leave the ground, and stop once they're back on the ground. Common methods (in increasing amounts of time added to the minimum) include weight-on-wheels (WOW) switch, airspeed (triggered at some reasonable airspeed just prior to becoming airborne), oil pressure, & master/battery. Also gear up/down activated.
Only the 1st two could be considered accurate. All the others except gear up/down record additional, and unnecessary, TIS. Gear up/down isn't legal because it records TIS sometime *after* the aircraft leaves the ground until sometime before it lands ie it fails to record time that is required to be recorded.
*Note: Many places use the hour meter on a tachometer. It is usually calibrated to clock 1 hour in time at cruise RPM. At lower revs it under records, at higher revs it over records. As long as it doesn't under-record for the whole of the flight than that's ok. But if it records some amount of time less than the true TIS (as defined) then it isn't legal. Doesn't mean that many organisations don't use it, but to follow the strict interpretation of the rules...
Note that TIS does not include engine starts, taxi, or any other operation of the aircraft other than airborne time.
2. Pilot flight time: From when the aircraft 1st moves under its own power until it comes to rest at the completion of the flight. Note that this includes taxi time, unlike TIS.
Required to show compliance with minimum experience requirements, currency etc.
3. Company time for billing: This can be any method that company wants to use to cover costs and, hopefully, give a profit margin. It could be number of clouds in the sky, or TIS, or Hobbs activated by one of many switches, on the clock or whatever.
Ultimately it costs $x.yy / hour for the company or owner to cover costs (and, hopefully, have a profit margin). Whether it charges a lower rate using a faster clocking method, or a higher rate using a slower clocking method doesn't matter.
The only way to compare costs is to check the total cost for any given flight using each of the offered charging schemes.
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I've ignored maintenance that falls due based on cycles or calendar. Usually cycles also includes an airborne requirement eg starting an engine without also getting airborne doesn't necessarily accrue a cycle. Depends on what the manufacturer has specified for that item or part.
There are three times that are of interest.
1. Time in Service (TIS). This is the time that *must* be logged to track inspection & maintenance requirements. It is defined as when the aircraft becomes airborne until it lands. As long as that *minimum* time is tracked, then you are legal. You could use a system that incurs TIS at a greater rate but not one that under records. The disadvantage of recording more time than minimum is that maintenance will fall due sooner than is strictly necessary. That makes the cost of operating the aircraft greater.
Acceptable methods include:
- Log airborne & landing times using your watch or the aircraft's clock.
- Use some sort of meter eg Hobbs. The issue becomes how is the meter activated. At a minimum it must start by the time the wheels leave the ground, and stop once they're back on the ground. Common methods (in increasing amounts of time added to the minimum) include weight-on-wheels (WOW) switch, airspeed (triggered at some reasonable airspeed just prior to becoming airborne), oil pressure, & master/battery. Also gear up/down activated.
Only the 1st two could be considered accurate. All the others except gear up/down record additional, and unnecessary, TIS. Gear up/down isn't legal because it records TIS sometime *after* the aircraft leaves the ground until sometime before it lands ie it fails to record time that is required to be recorded.
*Note: Many places use the hour meter on a tachometer. It is usually calibrated to clock 1 hour in time at cruise RPM. At lower revs it under records, at higher revs it over records. As long as it doesn't under-record for the whole of the flight than that's ok. But if it records some amount of time less than the true TIS (as defined) then it isn't legal. Doesn't mean that many organisations don't use it, but to follow the strict interpretation of the rules...
Note that TIS does not include engine starts, taxi, or any other operation of the aircraft other than airborne time.
2. Pilot flight time: From when the aircraft 1st moves under its own power until it comes to rest at the completion of the flight. Note that this includes taxi time, unlike TIS.
Required to show compliance with minimum experience requirements, currency etc.
3. Company time for billing: This can be any method that company wants to use to cover costs and, hopefully, give a profit margin. It could be number of clouds in the sky, or TIS, or Hobbs activated by one of many switches, on the clock or whatever.
Ultimately it costs $x.yy / hour for the company or owner to cover costs (and, hopefully, have a profit margin). Whether it charges a lower rate using a faster clocking method, or a higher rate using a slower clocking method doesn't matter.
The only way to compare costs is to check the total cost for any given flight using each of the offered charging schemes.
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I've ignored maintenance that falls due based on cycles or calendar. Usually cycles also includes an airborne requirement eg starting an engine without also getting airborne doesn't necessarily accrue a cycle. Depends on what the manufacturer has specified for that item or part.
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I guess the two sides of the coin are described well. One side is the cost per logbook hour, which is what the pilot feels, what she/he is interested in and what can be measured quite easily. The other side, the real TCO cost per flight hour is seldom really gathered beforehand, so discussion is always off balance on facts basis. Usually a company doing charter tries to guesstimate total costs and expected flight hours, but this is seldom done well and falls under risk of commercial operation (and as such, the uncertainty has to be paid for by itself).
Charging per Hobbs, per OffBlock/OnBlock or per Airtime is doing nothing to the total costs at the operator, it only shifts distribution throughout the users (or should do). If you complain on the way you are charged, you are trying to get money out of the pocket of another fellow pilot, please keep that in mind. Looking at the very bad commercial numbers of the usual charter businesses, I suspect that many didn't recognize this and pulled money from the survivability of the businesses.
Charging per Hobbs, per OffBlock/OnBlock or per Airtime is doing nothing to the total costs at the operator, it only shifts distribution throughout the users (or should do). If you complain on the way you are charged, you are trying to get money out of the pocket of another fellow pilot, please keep that in mind. Looking at the very bad commercial numbers of the usual charter businesses, I suspect that many didn't recognize this and pulled money from the survivability of the businesses.
When doing the costings you have to weigh up the fixed and variable costs and divide them by the hours as accurately as you can predict baed on past costs. If an aeroplane is hired on tacho then the hourly rate will be worked on 100 hours flown per 100 hourly. If on hobbs, more like 115 hours per 100 hourly. So you can hire on tacho, but it will cost 15% more, for example.
If you think you are being robbed then best to discuss this before the flight than after.
If you think you are being robbed then best to discuss this before the flight than after.
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At lower revs it under records, at higher revs it over records. As long as it doesn't under-record for the whole of the flight than that's ok. But if it records some amount of time less than the true TIS (as defined) then it isn't legal.
I used to fly an Arrow whose Hobbs was airswitched to activate above 40 knots IAS. The owner insisted that we warm the engine up properly and was willing to absorb the cost of extra time spent on the ground on cold days. It came in handy one day at an airport where the sole charge controller got so busy she forgot about us for 20 minutes while we sat at a holding point.
Using an airswitch, the only cost of engine running on the ground is the miniscule amount of fuel burnt. None of that time accrues as TIS - which is what maintenance inspections are based on.