BeechTalk - BT

Username Protected · **Posted:** 27 Oct 2020, 09:39

I'd want to know if anyone ever did any flutter testing at the highest practical altitude, and what speeds did they test to? I'm pretty sure Piper didn't test the Comanches out to 250 kts TAS at 20,000'.

Username Protected · **Posted:** 27 Oct 2020, 10:04

The whole reason the Comanche 400 exists is because Piper wanted a 190+ knot Comanche, without having to use turbocharging. They will easily do that on 21-23 GPH.

The Rajay add-on system is crude, but it does give another 20-30 knots up in the 20-25K altitude range. With the downside of high CHT's. The twin turbo setup is needed to inflate the 720 cubic inches, which it does marginally well. It really needs modern turbos, and intercoolers, to maximize the performance.

Username Protected · **Posted:** 27 Oct 2020, 10:29

There's been a Machen conversion turbo Bonanza for sale here for a while, "World's Fastest Bonanza". I'd take that one over a Comanche Turbo 400 if I wanted a "unique" and crazy-fast airplane.

But I don't want a unique airplane. :whiteflag:

Username Protected · **Posted:** 27 Oct 2020, 11:37

For some reason I clicked on this thread expecting a TWIN Comanche with 400 hp TIO720s. :bugeye:

Username Protected · **Posted:** 27 Oct 2020, 12:36

Username Protected wrote:

For some reason I clicked on this thread expecting a TWIN Comanche with 400 hp TIO720s. :bugeye:

I thought the same thing. Sure someone has done that.

Username Protected · **Posted:** 27 Oct 2020, 13:21

The IO720 climbs like a homesick angel! ...and you will need an angel when you get the bill for the overhaul and have the heart attack!

Username Protected · **Posted:** 27 Oct 2020, 13:25

Username Protected wrote:

For some reason I clicked on this thread expecting a TWIN Comanche with 400 hp TIO720s. :bugeye:

I thought the same thing. Sure someone has done that.

Username Protected · **Posted:** 27 Oct 2020, 13:58

The Comanche 400 uses the tail from an Aztec. Much larger rudder and stabilizer then the twin Comanche. No flutter problems. I don't believe there are very many knowledgeable Comanche 400 people on this forum. They were only available in 1964 and 1965.

Username Protected · **Posted:** 27 Oct 2020, 13:59

Username Protected wrote:

I'd want to know if anyone ever did any flutter testing at the highest practical altitude, and what speeds did they test to? I'm pretty sure Piper didn't test the Comanches out to 250 kts TAS at 20,000'.

I wouldn't worry about it.

Attachment:

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Username Protected · **Posted:** 27 Oct 2020, 14:24

It's still on the registry to someone in Texas. Powered by a reciprocating TPE331 according to the FAA. I think they may be a bit confused.

Username Protected · **Posted:** 27 Oct 2020, 14:51

Username Protected wrote:

The Comanche 400 uses the tail from an Aztec. Much larger rudder and stabilizer then the twin Comanche. No flutter problems. I don't believe there are very many knowledgeable Comanche 400 people on this forum. They were only available in 1964 and 1965.

Mostly true, but you no doubt are the most knowledgeable, thru experience, to reply thus far.
(Charlie has owned and operated a -400 for a long time and is a true speed freak. He KNOWS the 400!)

George

Username Protected · **Posted:** 27 Oct 2020, 15:11

A good friend of mine Lyle Powell is the 400 owner who organized about 25 other owners to pay for the Turbo 400 STC.

Username Protected · **Posted:** 27 Oct 2020, 15:23

George, I think you may have me confused with Charlie Horton who put a supercharger on a Comanche 400 at one time. I owned a turbo twin Comanche for 21 years and got to know many 400 owners. Another knowledgeable Comanche 400 person is Matt Kurke of http://comanchegear.com/

Username Protected · **Posted:** 27 Oct 2020, 16:05

What other airplanes had the IO-720?

Username Protected · **Posted:** 27 Oct 2020, 16:23

Username Protected wrote:

George, I think you may have me confused with Charlie Horton who put a supercharger on a Comanche 400 at one time. I owned a turbo twin Comanche for 21 years and got to know many 400 owners. Another knowledgeable Comanche 400 person is Matt Kurke of http://comanchegear.com/

By golly you are correct, it's so easy to get you Charlies mixed up.
But based on your choice of aircraft, you do appreciate speed. I once had an Aerostar, marvelous airplane unless you have to change a rear cylinder. Were you active in the ICS? Your name seems so familiar.

George

IO720 400hp twin turbo Comanche