Why does aircraft maintenance cost so much

[Tomo]

What I'm trying to ask is, you hear of people doing up there Cessna engines, and the price tag is something like 40k... Why so much?

 

It's manly in the GA side of things, but I've always been interested in why working on aircraft stuff is always through the roof, and that's why a lot of people don't really like GA, because you've got to get a LAME to do your work, and that costs a fortune...

 

I was talking to an aircraft LAME the other day, and was asking whats it like in the industry, he said it is shocking pay, so you've really got to love what your doing to keep doing it... interesting...

 

I'm in the mechanical business, and to do up a 380hp engine, only cost somewhere around the 14,000 dollar mark... why on a 4cylinder aircraft engine does in cost 30 or 40k??

 

:big_grin:

 

 

[geoffreywh]

why on a 4cylinder aircraft engine does in cost 30 or 40k??

 

:big_grin:

 

It doesn't......................... you're looking in the wrong country. The problems is, I think, called "economies of scale"

 

 

[Tomo]

Thanks Geoff,

 

I may be wrong with quoting those prices, but it still costs a lot...

 

Just for interest sake, look at a Jab 2200 engine, If I remember correctly, there about 25k new...(correct me if I'm wrong) A little four cylinder air cooled engine, there pretty simple, I just wonder why when it's linked to an aircraft it has to be a lot more pricey, sure it's got to be a pretty reliable engine when it's running...

 

 

[facthunter]

Cost comparison.

 

I think some tend to look at an aero engine with the idea that it is old technology being pedalled off on us at inflated prices.

 

The thing that makes aero engines different is that all unnecessary weight is taken off the engine everywhere. This makes every part really "work". All radius's ,finish, heat treatment, deck heights have defined ranges. Crankshafts are nitrided. so that complicates resizing. A slight scratch on a radius will cause the crankshaft to fail over time.

 

Many bores are "choked". That means that they are smaller at the top . the only way to achieve this is by internal grinding with a compound slide. costly in the setting up, you can't just remove metal and not worry about it, as there are fine limits to how much can be removed. Often the top part of the cylinder is nitrided as well.

 

Cylinders are assembled eliminating the head gasket with the two parts being threaded together at high temp, for reliability. This is more or less, a permanent assembly, making repair work on them a pretty speciallised process.

 

Most exhaust valves are hollow-stemmed sodium filled for cooling. These are not cheap.

 

The end result gives the market certified engines with a TBO of up to 2400 hours. (I think the Merlin was 200 hours and wasn't certified for civilian use as the magneto drive was not duplicated. ( If one gear sheared, both mags went dead).

 

I personally don't regard even the best piston engines as super-reliable, (compared with jets, as long as you keep away from birds) but for mine currently,continental/lycoming looked after properly, has the runs on the board, preferably brand new. Expensive? perhaps not in the long run, if you consider the TBO. It's your life Ralph. Nev

 

 

[Guest ozzie]

there are also a lot of 'hidden cost involved as well. if you compare the production of say Toyota engines even just one model they build tens of thousands during a year. design and tooling costs with mass production drops and is spread over the entire run. aircraft engines even tho they have been around for many years have to recoup these cost over lesser numbers. then there is certification not cheap so it to is spread over a smaller number of units. then there is insurance. remember the carburettor manufactuer who had his premiums go right thru the roof a few years ago it threated to almost end that company. then there are the costs of AD's and product suppot just to supply the distribution of these is enormous. then the engine manufactuer has to establish manuals training for engineers ect ect ect.

 

your LAMI mate is right the pay is crap. there are many hidden cost for his workshop. In the ninties a 'safety' tax was introduced by the FAC it pushed a lot of smaller shops out. if you are hit with something like this how do you work out how to recover this when you don't know how much work you will do in the upcoming year. workshop and airport cost for keep on escalating insurance as well certifying equipment, casa fees. then you have all the 'normal' cost and tax of running a business. if you want to make money become a plumber or a sparky. If a LAME makes a mistake even in the paperwork the fines are huge. where is the incentive to work in the industry.

 

redundency for magnetos. several years ago an Islander had a total instant power failure on one engine a 250hp lyc. when it was removed and stripped it was found that the COMMON gear drive on the cam that ran both mags had sheared killing both mags. what is the use of having two mags being driven from one source.

 

I preferred to work on and fly behind turbines any day. aircraft piston engines even these rotax two stokes are so highly tuned and highly stressed and built to tight tolarences make them low life and touchy to tuning, mixtures and poor pilot management,close the throttle to fast, cool them to quick, poor fuel ect and they pop a cork real quick.

 

ozzie

 

ozzie

 

 

[Tomo]

Thanks a lot fella's...

 

I new there must have been more to the engines than what you would normally expect... but just didn't know where.

 

Like the bore size being smaller at the top, I now see why it cost a lot... and the hollow valves filled with sodium, that's very interesting...

 

And yes the helpful (when you need to use it!) but very painful insurance stuff, I think that drives all of us crazy sometimes...

 

Cheers,