STC for 180 to 250/260?

[Quint Van Deman]

I've seen random internet references that one might exist, does anyone know the details, or better yet have knowledge of one that's been through the process?
Thanks,

-Quint

[Jay]

I know it's been done in the past on a field approval basis, but I don't think that there is an active STC. In any event, although I understand the attachment to a current airplane, it would be fare cheaper to sell the 180 and trade up to a 250 or 260.

Jay

[Kristin Winter]

I would spend the money on speed mods and then count my savings at the pump.

[Zach Grant L1011jock]

180 to 250 is as "simple" as replacing all of the parts as specified in the parts manual that are different between the two. You will simply change the designation of the aircraft with a logbook entry as that is how Piper made the aircraft, and with all the right parts, it will become a 250. Frankly, it is much better to just go get a 250 if that is what you want. There are lots of folks that want 180's!

-Zach

[Ray B]

Zack, Does that work in reverse also? 250 to 180? There are some run out 250's and 260's out there that might have a second life if there is truly a market for more 180's. The OH price could be the deciding factor. Ray B

[Zach Grant L1011jock]

Ray,
It sure does. The 59, 60, 61 250s are really the only years that are easily done as the 180's never got 4 tank wings, nor did they get electric flaps. Like I said before, ALL of the parts must be as per the Piper parts manual to do the conversion with a logbook signoff. People want 180's, but they still arent willing to pay the conversion price. Most people that want 180's are even cheaper than those with 250's...
-Zach

[David Pyle]

There are about ten 180's for sale at the major Internet listing sites. Not a lot to choose and if you wanted an autopilot most do not have one.

The argument has been made that apart from four cylinder vs six cylinder overhaul costs a 250 can be flown as economically (at reduced power) as a 180 and the extra power of the 250 is available if you need it. Also there are far more choices with 250s so you can find one equipped as you want. Yes, it will be more expensive to buy than a 180. Despite this I like the 180. It was my first Comanche (N8089P) and is still out there flying.

[Quint Van Deman]

Thanks for the info guys. I posed the question while trying to evaluate all of my options for replacing my O-360 that very suddenly was due for an overhaul, but when reality sunk in a couple of things were obvious:
A) The cost to convert vs. the cost to overhaul wasn't even in the same league
B) Biting off an overhaul this soon after purchase is hard enough, biting off a conversion would have been too much
C) I'm getting close to 140 true out of the 180, and for the time being, that's good enough for me.

Perhaps this will be useful to someone in the future though, just trying to boil the facts down is often the hardest part.

Thanks,

-Quint

[femski]

Its something I have thought about too. For 1961 onwards upgrading a 180 to 250 is just a new engine mount and a six cylinder engine. Dave Pratt of APP has done this for a few 180s (but not many lately). Dual exhaust upgrade if not already there would have to be done. My guess is that cost including new exhaust would be about $15k. Upgrade to 260 means installation of Fuel Injection - probably not worth the hassle.

Is it worth it ? Useful load would go up by 350 lbs. But you have to subtract for extra cylinders and extra fuel for same length trip. So, for long trips there will be negligible useful load increase. Range would be limited too - unless you add extra tanks. I am getting JAS wingtip which will be hard to give up. Wing Tip tanks ruin looks ! After all this - even for a 7 hr trip from New York to Florida - time saved is only 30-45 min.

OTOH, 250 will climb faster and go 15 knots faster to offset any unexpected headwinds. And for those who care 15 knots speed increase alone is worth 15k. And if cost is not such a important factor then even when oil goes to $300/barrel (circa 2020 AD) - operating cost difference would be another only $15 x 4 gph = $60/hr (plus $10/hr more for engine reserve). That's not much considering overall cost of operating a plane in a world of $300/barrel oil (more or less the cost of one barrel of Oil for a 180).

Selling and buying a 250/260 vs upgrading 180 to me depends on what you have in your 180. Price difference between 180 and 250 is negligible and may even be reversed at some point (fewer 180 than 250 and price of gas). But I have too much invested in avionics, interior and mods to think of buying another Comanche (other than may be a turbo or twin).

All said, converting from 180 to 250 at overhaul time would make sense to me if I needed some more useful load for not too long trips, and if I were willing to live with hideous looking tip tanks and needed that climb and extra speed. Right now I don't. By the time overhaul comes (1200 SMOH right now) that might change - new fuel/engine mods are on the horizon.

-Sanjay

[md11flyer]

Quint:
Just to give you some more thinking fodder... I see lots of firewall forward 250/260 engines for sale in the various
aviation circulars. Most are from parted out aztecs and either low time or mid time on the engines. Some even were selling the prop with the engine.
Now this is aviation and who knows what can of worms you will open.... but if you sell your old engine for parts..(new cylinders?) and good case as well as your old prop and other bits
and then buy a firewall forward 250 or 260..hang a new prop on it.... you might not be to far out from your 18 grand overhaul for your 180 engine.

Just a thought... goodluck.

Gary

PS Sanjay I think the tip tanks make the comanche look good!

[David Pyle]

Quint,

Why do you need an engine overhaul so soon after purchase? What was engine time when you bought it?

What are you going to do? Have you decided on an overhaul facility? Others might like to know your experience.