Peter, let's be careful with stereotypes. As said, a TBM landing gear has nothing to do with it being a turbine, more to do with its weight.
Please remember not all turbine (or cirrus) owners are stupidly led along by a maintenance outfit.
Why are you talking about turbines being expensive and then comparing a TB20 to a TBM? Is that really relevant?
Why are you talking about turbines being expensive and then comparing a TB20 to a TBM? Is that really relevant?
If you rank lots of different types, from small to large, in one table, it's reasonable to point out there are other factors that affect the operating cost.
Please remember not all turbine (or cirrus) owners are stupidly led along by a maintenance outfit.
Instead of writing one line, could you supply details of the applicable maintenance regime?
Well all I know is Mirage vs Meridian. I use Part 91 on condition so have no idea what the official schedule is. Other than engine they are very similar, far more so than TB20/TBM850.
Engine has 3600hr TBO. Very little to do unless you stuff it by overtemping.
Otherwise 5-10k/year I would suggest. Maybe 20-30% more than a Mirage but no more.
If you rank lots of different types, from small to large, in one table, it's reasonable to point out there are other factors that affect the operating cost.
Not necessarily, it wasn't purporting to be a cost of ownership study, just a look at fuel consumption.
Whilst I understand the purpose of the original thread, and understand the figures quite well from my own experience, the big factor in Turbine operations is the maintenance, which is mainly systems/weight related, but perhaps more importantly the engine overhauls and the intermediate hot section inspections. THis can be alleviated by an engine plan, like TAP for Williams engines, but that's not cheap, on a CJ2+ it adds about $145/engine/hour
A meridian has a TBO of 3600hrs with an HSI at 1800 unless you are on a trend monitoring plan. The trend monitoring costs $1200/yr. While of course an overhaul is expensive, in the interim you spend far less on the engine than with a piston.
While of course an overhaul is expensive, in the interim you spend far less on the engine than with a piston.
That's what I was thinking as well. I know our maintenance costs for the PA31 were higher than the C208, but in its defense it had two engines. On the other hand, there really wasn't a whole lot being done to the engine on the 208 and PWC even allow for extended TBOs up to (but not necessarily limiting) 7000 hrs. I believe ours ran up to 5400 hrs, with the HSI:s being done at 1800 intervals.
Indeed, under Part 91, the TBO at 3600 is not mandatory either.
My Jetprop annuals are running around USD 5-6K per year, with me doing about 55% of the work.
The P&W Hot Section Inspection is waivered on condition if you are under trend monitoring which I am, and I get my trend analysis done via a P&W engineer in Australia at around AUD 200 per year.
The PT6 engine has to be one of the simplest 100 hour inspections out there. A few filter changes, (most of which can be cleaned and reused (a fair few times) and new packing. Every 400 hours or so we have to swap out the fuel nozzles (similar to carb jets in principle), but an easy job which takes less than 3 hours to complete. Think of your central heating gas boiler and you are in the right realm in terms of servicing needs.
Where turbine costs do get eye watering are on repairs, especially over temp, or hot start operations.
The clever metallurgy in these engines comes at a very high price. The Compressor section has 61 titanium blades in the -35, each costing USD 1,500 just for the blade, and are the first casualty of over temping.
It was drummed into me very early on to be extremely vigilant of the operational management of this engine, and after a while, it becomes second nature. I would never go back to a piston at this level of GA. The smile after each flight, 5 years on says it all…
And performance wise, I have never been weight restricted, but legal payload wise is a different story. :-)
E
achim, I know what you mean, these figures are indeed surprisingly good, i.e. slightly better than POH. I should add, however, that this particular a/c has a brand new engine and prop. I'll fly her again in a few weeks when back in the US and will try to get precise figures. Will report back then.
OK, I promised to report back, here goes. For various reasons I couldn't do the long x-country I had planned to do, but just yesterday went KSMO-KSBP (San Luis Obispo). In the 182RG, this is about a 60 min flight, plus taxi, runup, etc.
The entire trip had 2.5 hrs on the Hobbs with a total fuel consumption of 29.43 USG, giving an hourly burn of 11.77 USG. This of course includes taxi, runup, climb (to 10.5k going, 7.5k coming back). TAS was 150kts.
So, the 11 USG/hr in cruise is realistic.
