Why do piston airplanes are rented by hobbs and not flight hour?

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cirrusmx

Line Up and Wait
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If you have to wait on a long line before take off on a piston engine the hobbs is running and you are getting pounded. Piston engines burn a neglible amount of gas when idling and the wear and tear on the engine is close to non existent. However, if you are waiting on the ground in a turbo prop it only costs you the gas burn at idle which is not much. Also, when renting by .the hobbs people will be prone to fast taxi, not even let the engine warm up enough, and take off as quick as possible. That is counter productive and dangerous. any toughts?
 
For the same reason a dog licks his butt.
 
Arent they logging PIC/Dual/whatever other time in their logbook while waiting/taxi/etc? focusing on just flight school perspective for a moment, if they are logging the time, why wouldnt they be charged for it?

Im sure there isnt that much money to be made by renting an aircraft out.
 
cirrusmx said:
If you have to wait on a long line before take off on a piston engine the hobbs is running and you are getting pounded. Piston engines burn a neglible amount of gas when idling and the wear and tear on the engine is close to non existent. However, if you are waiting on the ground in a turbo prop it only costs you the gas burn at idle which is not much. Also, when renting by .the hobbs people will be prone to fast taxi, not even let the engine warm up enough, and take off as quick as possible. That is counter productive and dangerous. any toughts?
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You're going to get pounded if you rent anyway. I guarantee you that if you go to a place that rents by the tach, they will have factored all that in to their rates.
 
cirrusmx said:
If you have to wait on a long line before take off on a piston engine the hobbs is running and you are getting pounded. Piston engines burn a neglible amount of gas when idling and the wear and tear on the engine is close to non existent. However, if you are waiting on the ground in a turbo prop it only costs you the gas burn at idle which is not much. Also, when renting by .the hobbs people will be prone to fast taxi, not even let the engine warm up enough, and take off as quick as possible. That is counter productive and dangerous. any toughts?
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From a business perspective, are they going to kludge up a hobbs install and add some sort of airspeed sensing switch just to leave money on the table with every rental?

Or should they just trust you that the actual flight hours you tell them are honest?

Most heavily flown rentals seem to easily make TBO, so warm up doesn't seem to be a problem.
 
not talking about flight school. Just general rentals. if you are an owner and your airplane is idling in the ground waiting to take off it will only cost you a cup of starbucks in gas. maybe a few milliliters of burnt oil.
 
cirrusmx said:
not talking about flight school. Just general rentals. if you are an owner and your airplane is idling in the ground waiting to take off it will only cost you a cup of starbucks in gas. maybe a few milliliters of burnt oil.
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OK, if you are that owner ... are you so charitable that you're going to give rental income away on every flight, when you are trying to stay right side up to start with ... and most of your competition is doing the same thing?



Wayne nailed it, as usual.
 
I remember a flight school i rented from. The CFI wanted to divert to another airport to get cheaper gas. I didnt allowed that. Hell no, they save a few bucks on gas and I go through .4 more hobbs and instructor time, on whats already an expensive rate. Places like that loose my business rather quickly. I have observed a certain penny pinching trend in aviation. Ah, but when you put them in line they get offended.
 
cirrusmx said:
not talking about flight school. Just general rentals. if you are an owner and your airplane is idling in the ground waiting to take off it will only cost you a cup of starbucks in gas. maybe a few milliliters of burnt oil.
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There are more factors in operating costs than just fuel and oil burn. There's insurance liability, both risk to the airplane and risk of you taxiing into someone else while waiting. Plus, the aircraft is depreciating every second it is running, whether flying or not. Costs do not accrue only while you're in the air.
 
cirrusmx said:
I remember a flight school i rented from. The CFI wanted to divert to another airport to get cheaper gas. I didnt allowed that. Hell no, they save a few bucks on gas and I go through .4 more hobbs and instructor time, on whats already an expensive rate. Places like that loose my business rather quickly. I have observed a certain penny pinching trend in aviation. Ah, but when you put them in line they get offended.
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If you're with the CFI working towards a rating and that .4 is needed flight time then it doesn't really matter. If not then I'm on your side and screw the divert.

I used to get amused when students would complain about checking the lights and stall horn on preflight. The hobbs was tied to the master switch so sometimes you would turn it on and it would click over .1.

I'd hear how checking the stall horn and lights cost them $20. Yeah, well at the end of the program you need 'X' number of hours. You are paying for 'X' and that light check is going into your logbook too. Don't sweat it.
 
Captain said:
Yeah, well at the end of the program you need 'X' number of hours. You are paying for 'X' and that light check is going into your logbook too. Don't sweat it.
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Outside of the big flight schools, most students are not buying into a program.

FAA requirement is 40 hours for private.

National average is 60 to 80 hours (and increasing), depending on which source I google.

I'd be pretty sure there's some padding going on out there.
 
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the hobbes time represents the time you deprive the owner of the asset as well as setting the depreciation on the asset and the elapsed time toward hour-based inspections and maintenance. Why would the rental be based on anything else ?
 
ElPaso Pilot said:
Outside of the big flight schools, most students are not buying into a program.

FAA requirement is 40 hours for private.

National average is 60 to 80 hours (and increasing), depending on which source I google.

I'd be pretty there's some padding going on out there.
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Training can be completed in the minimum hours, depending on location. Time gets racked up on the ground at busy airports waiting for clearances or long taxi. Flying to smaller airports for more efficient pattern operations of first solos away from a busy towered field.

And leading cause of long hours to complete? My guess would be when the student does not fly 2-3 times a week, takes a few weeks off, etc. lessons need to be relearned taking up time.
 
The next question is to ask what turns on the Hobbs. Oil pressure standard, airspeed better and master switch bad.
 
cirrusmx said:
I remember a flight school i rented from. The CFI wanted to divert to another airport to get cheaper gas. I didnt allowed that. Hell no, they save a few bucks on gas and I go through .4 more hobbs and instructor time, on whats already an expensive rate. Places like that loose my business rather quickly. I have observed a certain penny pinching trend in aviation. Ah, but when you put them in line they get offended.
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It's not real easy keeping training aircraft flying on the line in any way, physically or financially. If I can do the operators a little favor during any training I will, it usually comes back around if everyone lives long enough.
 
cirrusmx said:
how much does a vintage ceesna bugsmasher depreciates? isnt maintenance done by tach time?
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Value depreciation and tax depreciation are totally different critters. Value depreciation is a market function rather than a use function, as can currently be proven by comparing 2012 prices with 2007 prices and then 1999 prices. Values for most planes actually increased between 1999 and 2007. Prices have plummeted since 2007.

MX cost is driven by a combination of clock hours, calendar time and other factors (landings or cycles). For most light planes the annual inspection triggers the most significant maintenance expense, although flight school airplanes can be different due to high usage.
 
Okay I am confused yet once again. I have been using Hobbs hours for determining flight lengths, training expenses, and for rental time when I have rented. Engine maintenance which for me had only been oil changes, and engine related items have been based on tach times. My understanding was Hobbs times were based on true hours and fractions(and thus a truer representation of actual time) though start and end changes between different plane models and years, and tach time was derived from rotation of the prop and was not a true time as a result. What am I missing?

Doug
 
Dunno. But whatever it is, I'm missing it too. Back in the day, one of my planes had an hour meter as well as a tach, so I tracked the hour meter numbers over time just to see how they compared to tach time used for reporting. The ratio was ~1.1:1.

douglas393 said:
Okay I am confused yet once again. I have been using Hobbs hours for determining flight lengths, training expenses, and for rental time when I have rented. Engine maintenance which for me had only been oil changes, and engine related items have been based on tach times. My understanding was Hobbs times were based on true hours and fractions(and thus a truer representation of actual time) though start and end changes between different plane models and years, and tach time was derived from rotation of the prop and was not a true time as a result. What am I missing?

Doug
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You think you have it bad?

When I rent a car, the time starts while I'm at the checkout desk and includes the sprint out to the parking lot and the time to look for a parked car, get my bags and family ensconced into their proper seats, seat belts adjusted and the parking brake released. Then, it also includes the time spent unloading same, staying at the hotel overnight, and then it includes getting everyone into the car again and the sprint back to the checkout desk.

Bummer. I pay for all that.
 
AuntPeggy said:
You think you have it bad?

When I rent a car, the time starts while I'm at the checkout desk and includes the sprint out to the parking lot and the time to look for a parked car, get my bags and family ensconced into their proper seats, seat belts adjusted and the parking brake released. Then, it also includes the time spent unloading same, staying at the hotel overnight, and then it includes getting everyone into the car again and the sprint back to the checkout desk.

Bummer. I pay for all that.
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yeah, but that only runs you 40 dollars per day, not 40 dollars per .1 hobb.
 
AuntPeggy said:
You think you have it bad?

When I rent a car, the time starts while I'm at the checkout desk and includes the sprint out to the parking lot and the time to look for a parked car, get my bags and family ensconced into their proper seats, seat belts adjusted and the parking brake released.
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Boy you have an odd rental car company. My time starts when I drive off the lot and stops when the agent walks up to my car on the return. I haven't been near a rental car desk in a long time.
 
Dave Krall CFII said:
It's not real easy keeping training aircraft flying on the line in any way, physically or financially. If I can do the operators a little favor during any training I will, it usually comes back around if everyone lives long enough.
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I definitely thought about that. but this place charged for everything, swiping your card to pay them, borrowing a headset if you forgot yours, etc. And on top of that the customer service was horrible. i have just seen that trend in flight schools/rentals. They are very short sighted when dealing with customers. What this people didnt realize is that for being that stingy they lost a couple of hundred hours worth of sales.
It doesnt make sense to go through .3 hobbs just so they can save 15 cents per gallon filling up a 172. Theirs saving really come by sqeezing those extra .3 hobbs.
 
An airplane is intended to be an income producing assets for a business. If you charge by actual flight time, which is really more like only half or less of the actual time an aircraft is rented - you will not make any money. . .
 
cirrusmx said:
I definitely thought about that. but this place charged for everything, swiping your card to pay them, borrowing a headset if you forgot yours, etc. And on top of that the customer service was horrible. i have just seen that trend in flight schools/rentals. They are very short sighted when dealing with customers. What this people didnt realize is that for being that stingy they lost a couple of hundred hours worth of sales.
It doesnt make sense to go through .3 hobbs just so they can save 15 cents per gallon filling up a 172. Theirs saving really come by sqeezing those extra .3 hobbs.
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Hey, if you don't like the way the flight school works, start your own like I'm trying to do. Problem is that it's VERY expensive to run a flight school. If they charge you by the flight hour, you can BET that the rates will go up for the flight hours. I know that for every .1 of use on my aircraft I need to charge X dollars to break even. I can tie that to a number of hours on the tach (don't have a hobbs) or by watch time. Either way, I still need to make X dollars for an approximate amount of time to break even or make a (very small) profit. Trust me, EVERY single flight school I've ever worked with was always a step away from going out of business. The margins ARE that small.

The good thing is that if you figure for inflation, and the actual value of your money, it's not really that much more expensive than it used to be. Go find out how much it will cost you to buy approximately $6 worth of silver coins (like old quarters, dimes, etc...) and then consider that I'll take $2 in silver face (look it up) for my hour of instructor time and $4 face for the aircraft's hour, and I'll probably be fine!

Customer service IS important, and a lot of flight schools aren't great at it, but don't tie monetary stuff in with that. If I have a headset that I let people use for free (and I do), consider that when one of them breaks it (and two have) then I'm out $75 or more. And merchants charge a fee to use a credit cart terminal (look up the rates) so if your flight school has figured out that they need an extra $2 to cover that because their margins are that tight, then bring cash and avoid it.

Ryan
 
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I do not have a hobbs in my a/c so everything is by tach.

It doesn't matter whether you use hobbs or tach but the rate would be slightly higher by tach hour.

I suspect it works out exactly the same either way you measure it you have to over your costs divided by the number of hours rented. If rented hours goes down the rental rate has to adjust up to compensate.
 
Actually, there are two factors in the airplane rental: block time which the aircraft is not available for other people to rent out and engine running time where fuel (if rented wet) and maintenance money (is burned). The rest are pretty much fixed costs that are averaged across whatever timeing you have (unless you're in a club situation where these come out of dues).

Many FBOs actually do have a hybrid above. You get billed by the running time, but if you block out the plane (i.e., you take it XC for the day or more) there is a minimum number of hours you must pay for (used or not).
 
cirrusmx said:
I definitely thought about that. but this place charged for everything, swiping your card to pay them, borrowing a headset if you forgot yours, etc. And on top of that the customer service was horrible. i have just seen that trend in flight schools/rentals. They are very short sighted when dealing with customers. What this people didnt realize is that for being that stingy they lost a couple of hundred hours worth of sales.
It doesnt make sense to go through .3 hobbs just so they can save 15 cents per gallon filling up a 172. Theirs saving really come by sqeezing those extra .3 hobbs.
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Weren't you doing some practice maneuvers along both ways?
 
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