Cost of operation?

[flyingclay]

Anyone have the average, annual, fixed $ cost of operation per hour of usage on the LSA with a Rotax 912 (100hp), (excluding the plane cost)? In other words, what does it cost to have required maintenance inspections, required overhalls or engine replacement cost when the time comes etc...

[drseti]

Anyone have the average, annual, fixed $ cost of operation per hour

Question is confusing as asked. Fixed costs are independent of flight hours, thus are not computed on a per hour basis. Examples of fixed costs are hangar rental, insurance, static/transponder/altimeter checks, and annual inspections. Variable costs are costs that (obviously) vary with flight hours, so computing a cost per hour makes sense for them. Examples of variable costs are oil changes, tires, fuel, brakes, filters, engine TBO reserve, 100 hour inspections (if required), recurring service bulletins, and mandatory overhaul/inspection of such time-limited components as the propeller gearbox and carburetors.

It is my experience that the variable costs of operating a new Rotax-powered LSA run about $50/hr. My fixed costs average $9000/yr (and $5200 of that is insurance). Of course, mine is a flight school aircraft, so insurance costs are much higher than a private owner's will be.

[flyingclay]

Thanks drseti. Sorry for the confusion. Since I am new to LSA, I am in the learning process of what cost to anticipate and plug in some estimates of hours of plane used per year so I can eventually get it down to what the plane is costing per hours used. I understand fixed and variables, however wanting to be sure I don't overlook miscelaneous items. I guess I would be curious as to what you would estimate the hours used in the plane might average per year with an estimated $9000 annual cost.
Average cost $9000/average (estimated) hours flown?

[flyingclay]

drseti: PS reason for understanding and learning about these numbers is I am tinkering with beginning a LSA/Flight instruction program marketed within a chain of Health Clubs I own, as an extra benefit of membership.
The business model/blueprint that I am gravitating towards is focusing more on an outlet that enables them to have simple access to the opportunity to enjoy affordable flying in new, safe, fun, neat S-LSA aircraft. Variations of directions beyond that will be available, as expected, but the target market is, "enjoy the simple experience of flying first"............
Thanks for sharing your experience.

[drseti]

I would be curious as to what you would estimate the hours used in the plane might average per year with an estimated $9000 annual cost.

My business plan was predicated upon an estimated 240 flight hours per year per plane. That assumes 40 flyable weeks per year (limited here by weather), at a conservative one tach hour per day of flying, six days a week. Given $9000 fixed costs, and $50/hr variable costs times 240 hours per year, we're looking at $21,000 fixed plus variable costs, divided by 240, or $87.50/hour total operating costs. The plane rents for $99/hour wet, which discounts to $90/hr with the purchase of prepaid blocks of instruction. In other words, at 240 hours per year, the plane is roughly breaking even.

Instructor time is billed separately, of course.

[Skyranger]

Anyone have the average, annual, fixed $ cost of operation per hour of usage on the LSA with a Rotax 912 (100hp).......? In other words, what does it cost to have required maintenance inspections, required overhalls or engine replacement cost when the time comes etc...

As drseti already said, fixed costs are costs that stay the same regardless of how many hours you fly.... hanger, insurance, mainly.

As for the costs you are asking about that are hourly dependent, my costs on our 912 to keep it in the air for an hour are significantly lower than drseti reports.I figure it is costing me approximately $20 per hour to stay aloft for an hour.

IMO most LSA owners per hour cost is likely to be somewhere between what drseti reported and what I`m estimating.

The important word in my estimate is ``approximately.`` It depends very much on how long we will go on the engine before needing either a major overhaul or replacement.
We fly an ELSA for personal use only so we are not tied, as drseti is with his commercial use of his aircraft, to having to replace or overhaul at 2000 or any particular hours. 912s in use in flight schools, etc, have to be overhauled or replaced at 2000 hours whether it`s needed or not.
Based on what we see on other experimentals with long lived 912 engines, and our the compression tests, filter dissections, exam of plug magnets at oil changes, etc, it is not unreasonable to believe that we could get 4000 hours on this engine (which currently has about 800 hours.) That`s the big variable. Makes a huge difference in hourly cost whether you have to replace or overhaul your engine at 2000 hours or 5000.

Other higher costs per hour for a 912 used in a flight school, or an SLSA that we with our ELSA don`t necessarily have can include these:
Some owners of SLSAs with Rotax engines are forced to change out all the rubber in the 912 every 5 years regardless of the condition, number of hours, and storage temperatures. That can cost close to $4000 parts and labor. If that aircraft has been flown, say, 200 hours in that five years that`s adding ~$20 per hour to the cost per hour. (Yeah, I suppose you could say that 5 year rubber change out is a fixed, not hourly, cost, but a dollar is a dollar.)
Gearboxs have to be inspected every 600 hours.
While we have to do an annual inspection, flight schools and other certain classes of aircraft operators have to do the equivalent of an annual inspection every 100 hours (if they put 300 hours on the plane in one year that`s three inspections. Not cheap.
What`s more I took the FAA 16 hour Light Sport Mechanic/inspector course and can do my own annual inspections rather than paying anywhere from $350 to $1500 for an FAA A&P to do that.
What`s more anyone with an experimental aircraft (not a SLSA), regardless of whether they got the LSA Mechanic/inspector certification I did, can do any maintainance and repair they trust themselves to do or hire anyone they trust to do such work. Don`t have to pay and FAA certified A&P $80+ per hour. We (me and co-owner) do much of our own mechanical work.

An other point worth noting re flying costs: In some ways the more you fly the cheaper per hour it gets: If you`re paying $1200 a year for a hanger and $1200 a year for insurance if you fly only 10 hours that year you better figure each hour cost you a whopping $240 (in addition to the fuel, depreciation, tires, oil changes, inspections, etc.) Fly 1000 hours that year and your hanger and insurance adds only $2.40 per hour to your cost of flying.
What`s more generally your insurance will be lower if you are a 1000 hour pilot with no accidents than as a 200 hour pilot with no accidents.

Al

[MovingOn]

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[Skyranger]

Welcome to 2010.

Thank for the welcome.

Cost of operation is as, if not more, relevant today as it was when the thread started.

Al

[CTLSi]

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[MrMorden]

I just took a quick SWAG at this question, and came up with about $56/hr. That is hangar, fuel, insurance, condition inspection, etc but excludes unscheduled maintenance and any upgrades. I expected my number to be a little higher than Paul's...his insurance is much more than mine, but he probably flies a LOT more hours than me since his airplane is a trainer. My calculus is based on 100 hours per year; the per hour cost goes down with more hours as fuel and routine maintenance costs goes up but fixed costs stay...fixed (and are a larger proportion of the total).

[David]

I just took a quick SWAG at this question, and came up with about $56/hr. That is hangar, fuel, insurance, condition inspection, etc but excludes unscheduled maintenance and any upgrades. I expected my number to be a little higher than Paul's...his insurance is much more than mine, but he probably flies a LOT more hours than me since his airplane is a trainer. My calculus is based on 100 hours per year; the per hour cost goes down with more hours as fuel and routine maintenance costs goes up but fixed costs stay...fixed (and are a larger proportion of the total).

My swag is in your ballpark at $60.00. Calculated at 100 hour a year

[drseti]

In the four years or so since this thread was started, several unanticipated factors have conspired to raise my operating costs:

Ethanol-free mogas has become unavailable in my area. Since the manufacturer of my airframe prohibits ethanol, I've had to go to 100LL, more than doubling my fuel costs.

I've found students to be very hard on tires and brakes, necessitating replacing them far more often than on an individually owned aircraft.

I reached five years of engine life, requiring the notorious Rotax five-year rubber replacement.

In 1000 hours of operation, I've had to replace two fuel pumps, three oil pressure sensors, one propeller, a voltage regulator, and two exhaust systems. I've done one gearbox inspection/overhaul, and am coming due for a second one.

A couple of mandatory Service Bulletins raised their ugly heads.

My hangar rent goes up on the order of 5% per year.

Insurance costs have remained flat.

I continue to bank $10 per hour for engine TBO, and $5 per hour for airframe depreciation

Still, the overall operating costs have inched up, not soared. My actual costs (fixed and variable) run about $120 an hour now, as compared to $90 an hour 4 1/2 years ago. Thus, my effective inflation rate is around 5% per year (and I have to adjust my prices accordingly). So far, nobody's complained (not my students, and -- even more significantly -- not my wife.)

[MovingOn]

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[Skyranger]

Hi Paul,
You wrote, in part --
``.....I reached five years of engine life, requiring the notorious Rotax five-year rubber replacement....``

It is a very ugly policy that makes no sense to me, and quite a few more skilled than me, to have as a blanket replacement time.
Doesn`t matter if the engine has 120 hours in five years (not unheard of) and has been stored in a climate controlled hanger it`s whole live or 1900 hours and has been parked out in the Arizona sun for five years heating and cooling the engine to extremes...... factors which clearly effect rubber life.*

As an LSRM and CFI and with more hours and more skin in the game than I do you probably know the rules of what`s really required far better than I, but unless I`m remembering wrong (and if I am it would not be the first time) one very competant LSRM told me that Rotax, despite its language of ``required``, etc, can not set the rules about what is legally mandatory.... and that rubber replacement can be done on-condition. I know he was not just talking about our ELSA. But perhaps your situation of running a flight school, or something the aircraft manufacturer throws in the pot, boxes you in firmly on that?

Pardon my soap box and digression a bit off the original topic. IMO unreasonable requirements and recommendations (a) increase the cost of flying and (b) reduce the credibility of the source`s recommendations.... Can become a situation where important info is disregarded as the source has lost credibility.

Alex

* I know of one 912 over 15 years old never had the Rotax five year complete rubber replacement, just occassional hoses on-condition, engine mounts replaced (which AFAIK technically isn`t even part of the Rotax engine rubber replacement..part of the aircraft)and rubber in carbs during carb rebuild, passing annuals, no indications of lack of complete replacement being any problem.

[Skyranger]

As CTLsi noted earlier ``The cost question is incredibly complex and hard to answer given the wide number of variables.``
I'm sure I`m on the very low end of hourly costs even after amortizing in fixed costs and taking a less optimistic view of how many hours we can put on our Rotax before full overhaul.

One factor I don`t think I mentioned that lowers my real cost per hour to stay aloft is I own our ELSA with a partner, so our fixed costs (hanger, insurance, unscheduled upgrades, etc) cost each of us half as much as if either of us owned 100%.

The upper end hourly costs showing up in this thread... which I'm sure are reasonable... make a bit of a case that renting may actually be a cheaper way to fly (ignoring the advantage of no big upfront investment) for folks that don't fly large numbers of hours per year. One A&P I know says it is not unusual for him to do an annual on a private aircraft that has only been flown 25 hours per year. That owner is clearly paying a high hourly rate from the fixed costs and time-depreciation.
Also makes a good economic case for flying via a club if that's an option... in part because fixed costs are being spread over many pilots and adding little to the hourly cost.

Possibly the most salient comment that I've seen related to this topic is supposedly IIRR from a low time new pilot:
``In my ground school I was taught that the Bernoulli principle is what keeps an aircraft in the air.
It's not true. It's money.``

Alex