RotorAndWing
Final Approach
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Rotor&Wing
RR-250s efficient? Compared to what?
Have you ever operated the allison? Ever actually seen one?
RR-250s efficient? Compared to what?
Have you ever operated the allison? Ever actually seen one?
Nope, not operated, but have seen seen several. I know for 425hp they burn about 30% more fuel than a 985.
Turbines by nature aren't very efficient.
My turbine operating experience is with PT-6s and TPE-331s.
I have worked on an A-36 with the Allison and even with tip tanks the owner was grousing about the poor range.
Abram. Paging Abram.
Dave - as I've understood it even in part 91 that's not an option to run over TBO with turbines. The difference is that the time limits are part of the type certificate which they're not with most pistons. You have no choice but to either comply or buy an STC that will put them on a condition with inspections basis.
Nope, not operated, but have seen seen several. I know for 425hp they burn about 30% more fuel than a 985. Turbines by nature aren't very efficient. My turbine operating experience is with PT-6s and TPE-331s. I have worked on an A-36 with the Allison and even with tip tanks the owner was grousing about the poor range.
Yeah, they beef up the pressure hull in certain areas - around the emergency exit, windows, doors. It's only available on the 700/Superstars, so it seems like the 350hp engines and the bigger turbos are a pre-requisite. They probably have enough bleed air to spare. So on my 601P with the 290hp this wouldn't be an option, as far as I can understand.
Dave - as I've understood it even in part 91 that's not an option to run over TBO with turbines. The difference is that the time limits are part of the type certificate which they're not with most pistons. You have no choice but to either comply or buy an STC that will put them on a condition with inspections basis.
By no means am I in the market, but my guess is the landing gear config, speed and support network are the main issues. If I were in the market, I'd buy a Pilatus.
I concur.Pretty thorough discussion of that on another board with cites. Part 91 isn't obligated to comply with manufactuer's recommendations. ADs, yes. I'd suggest anyone serious do their own research. We're comfortable as is our maintenance facility.
Best,
Dave
You are talking about airplanes that are no where near the same ballpark price. 2M versus 18M...
As Ted said, there are cycle limits. When an overhaul is done, one must look at whether it's worth replacing things with those limits. That could cause overhaul, if one runs into those limits, but TBO is a manufacturer's recommendation. There are some that disagree, but they really reach and get into things like cycle limits.
Meanwhile, in a turbine engine with parts spinning anywhere between, say, 8,000 and 45,000 RPM, you'll get there in no time.
Huh? Brand new PC12 is around 4.6M. Where did you come up with 18?
Some throw out different planes with no look to the cost of that plane: of course, some don't know what they cost. A lot more folks can afford to purchase a 500,000 older plane than can purchase a 3.5 million newer plane, just like pistons. One can fix a LOT and still have a lower total investment with that older plane. The big problem I found with older was outdated avionics. We found a nicely equipped one and that made the difference.
Best,
Dave
I didn't know used King Airs could be so inexpensive.
This one looks cheap, but I'm sure there must be some major maintenance upcoming. Anyone know what that might be?
http://www.controller.com/listingsd...-E90/1973-BEECHCRAFT-KING-AIR-E90/1292420.htm
I have heard that 90-series King Airs typically cost $900 / hr in fuel and maint. Does that sound about right?
I think you nailed it right there. The people that can afford this plane probably have greater needs in speed and capacity and can afford to pay more for those needs.Those who have $1.6M, have $3.0 and can access other first and second generation jets. . .
I didn't know used King Airs could be so inexpensive.
That was funny!
As Ken anticipated, I would argue that, although the TBM is an outstanding airplane, all of the single engine turboprops out there are really good and have their stengths.
The Meridian is a fantastic, fast and efficient airplane and the PT6 in that application generates 500 shaft HP.
Also, for the most part, you fly these airplanes to be high and fast. At FL270, you are above most of the weather most of the time, but not always. However it is far better than being in the teens. Also, most of the icing that I run into is in the teens, not in the flight levels. The turbine allows you to climb through the icing relatively quickly.
The Meridian burns less fuel at FL270, but you can keep it under FL200 and not get penalized too badly, so if you want to stay low for any reason, you can.
Ken, let me know if I missed anything!
Abram
N301D
The reason I chose the Aerostar is because it's a good plane for me to grow with and upgrade as I go along. I mostly do longer trips, so I wanted something capable. I do miss the short field/grass field capabilities of my old Commander, but you can't get a plane that does it all. This one ticks 9 out of 10 boxes. However, being steeped in the Commander world, I did look long and hard at Commander 685's. Their prices have come down a lot over the years. They're basically the same airframe as the turbines, but with piston engines. A 685 can be had for about the same price as an Aerostar, give or take.
Aero Commander 685. The same airframe as the turbine - but without the turbines.
PROS OF 685:
1. Fully de-iced.
2. Extreme long range with the 320gal tanks.
3. Bleed air pressurisation (not hydraulic like the previous 680FP and FLP's).
4. A bad shortfield performer contrary to the smaller Commanders, but can be landed on grass in a pinch, at least. Not so much with an Aerostar unless it's ballroom smooth.
5. Very quiet.
CONS OF 685:
1. Gas guzzler with those highly strung engines.
2. Geared engines. I don't fear them, but the fact is they're getting harder and harder to support and are expensive to overhaul and have crappy TBO.
3. The Aerostar is also fully supported, 685 is not.
4. I also fly predominantly alone or with few passengers - do I really need to lug around 9000lbs of airplane for one person? Seems a bit irresponsible...
5. Has to abide by all the recurring AD's of the turbine - pressure vessel integrity tests, gear system overhaul every 5 years etc, etc.
In the end the Aerostar is great bang for the buck. If the guys at EPS ever do certify that diesel they're developing, that would be a great STC mod to do. Almost turbine speeds, extreme range (1800nm) and burn Jet A1. Of course, a MU-2 would be a nice ship to upgrade to, but I simply couldn't afford to write those turbine checks. And it's not likely my income will improve much over my remaining flying years..
Trying to learn something here. Bleed air with piston engines vs. Hydraulic for cabin pressure. Can you explain that for the uninformed?