Are you referring only to geared supercharged twins, or the entire old, high dollar, piston twin fleet? I ask because I'm starting to look at Aerostars, and if that's the opinion of an AEST owner, well... time to reconsider.

Agreed with Forrest. Piston twins are generally pretty bad investments these days, but they do give great performance for those who want that.

685 is not a great choice, and me and Charles explain why in this thread:

http://www.beechtalk.com/forums/viewtopic.php?f=49&t=99562&hilit=685

Your best option is to go turboprop. MU-2 or Commander, probably. They won't cost much more to operate than the old fire breathing pistons. Here's a 690A that's only $200K. Good times on engines, but needs two of the big SB's. That's probably the wing spar mod and the aft pressure bulkhead mod. The aft pressure bulkhead is a $60K fix. The wing spar is a $100K fix, or, you can inspect it every 3 years for about $15K. Still, worst case scenario you're in a 690A with halftime engines for $275-360K. Not a terrible deal, if you ask me.

http://www.controller.com/listingsdetail/aircraft-for-sale/COMMANDER-690A/1973-COMMANDER-690A/1397359.htm

The piston options in the Commander line the 680F that was mentioned, the 560F also has 1500nm range and can land on a dime. The 500B's can also have aux fuel tanks installed taking their range up to 1500nm, but you might get a little challenged on useful load unless you have the 350hp Merlyn conversion.

That should be me apologizing. Thanks Forrest.

There are some unpressurized long body 680s running around with io720 conversions. Try gary gadberry at air enter in chattanooga

Very interesting! Do you happen to know the useful load and fuel burn/speed at cruise?

Jim

I see all the advice about turboprops but I'm not sure I see the point about them being less expensive to operate than a piston. It looks to me like the entry point for a turboprop is around $500k and that fuel burn realistically is going to be around 75-100 gph and of course there are the hot section inspections, etc.

I'm seeing commanders, panthers, etc. around $200-250K and expect fuel burn in the 40-50 range?

I have a C55 now that is dirt cheap to operate (23-26 gph), gives me the range, speed, and take-off distance I need but with the existing 1800lb useful load only leaves me about 950 lb for passengers/baggage when I take the necessary fuel. It's also a bit anemic in the mountains (NA). With a turbo and another 400 lb useful the Baron would be perfect. I didn't think it would take another $400k upfront and another 50-70 gph to get me to the level I need (1300 lb passengers/baggage + 800 nm fuel + one hour fuel reserve + FL 20s).

I was hoping one of the 500U, B, Shrike Commanders might have a gross wt increase STC (with tip tanks or long range tanks) that would give me the UL I need. The small piston commanders have the speed, short field, and FLs I need but fall short in UL.

Jim

No, it's not going to be cheaper. But perhaps not that much more, making it an option. Hey, I totally understand - I'm budget restrained too and tend to buy at the bottom and improve as I go for money earned.

Per NM many of the Garrett powered turbines are already on par with most avgas twins, for sure. 55-65gal/hr to go 80-150kts faster (depending on model), on a fuel that's much cheaper, makes for less cost per NM compared to avgas many times. Also, easier to find a good deal on Jet A1 than on avgas.

Here's a recent trip I did in a friends old Commander 681. We were doing about 240kts here economy cruise. You can see the FF is 360pph in total, which is less than 54gal/hr. Averaging a $3.50/gal Jet A1 price, that works out to about $0.78/nm. Most Avgas twins would be on par with that, or perhaps even above it in price. These planes can be had for sub $300K, many times sub $200K with decent times left on engines.

In any case, you can't go wrong with a piston Commander either. If you need that kind of range, I'd look at a 680F or a 560F, or the 680E or 560E. The 560's will do 1500nm, the 680's a little bit less.

Last night, FL270, 64 GPH (430 pph), 285 knots true, on $3.26 fuel.

$0.73/nm (still air, not counting tailwind) for fuel and doing close to 300 knots. 120 gallons burned, $391 fuel for this leg (had some tailwind, 15-20 knots).

http://flightaware.com/live/flight/N305 ... /KICT/KEVV

Takeoff to FL270 20 minutes at 800 pounds under gross (full fuel, 400 pounds in cabin), temps ISA+5.

Airliners were getting light to moderate chop from FL300 to FL380, too heavy to go higher, unwilling to go lower (presumably due to fuel burn). Glass smooth at FL270 for me. Just depends on where the air is shearing against itself.

Mike C.

Delete "piston", insert "turboprop".

Now, no problem on shorter runways, and WAY safer all around.

Mike C.

Are you referring only to geared supercharged twins, or the entire old, high dollar, piston twin fleet? I ask because I'm starting to look at Aerostars, and if that's the opinion of an AEST owner, well... time to reconsider.

There is a lot of give and take here about the comparative operating cost between a piston twin and a turboprop like the MU-2 and Turbine Commanders.

If you want a quick analysis of what the comparative costs are it's simple: ask the commercial operators who have them.

Find out the hourly rental on a 58 Baron, not too hard to do, and then call a training operation that has a turboprop. I made a "I wonder" call to a company that specializes in MU-2 training. The hourly rate for a MU-2 dry is $750. Add a couple of hundred for fuel per hour and you are right at $1000 per hour.

Several years ago, I had access to Conklin & Dedecker's cost program. All basic turboprops came in at about $1200/hour wet. That was with double the fuel prices of today.

Jgreen

Thanks John, I appreciate the reply. Is it worth it? I'm still mulling that question over.

Hope you feel better!

I posted awhile back about my alternate counting system for money. It is

1) not enough
2) enough
3) more than enough

If you can operate a twin and stay in box 3, then it's worth it. If the twin pushes you into box 2, probably not.

I posted awhile back about my alternate counting system for money. It is

1) not enough
2) enough
3) more than enough

If you can operate a twin and stay in box 3, then it's worth it. If the twin pushes you into box 2, probably not.