Maintenance issues on straight vs. turbo charged Twin Comman

[Eric Koch]

I sold my T210 that I owned for 14 years, retired, been without wings for over 3 years and am evaluating the pros and cons of the turbo/non turbo Twin Commanches. Have flown the normally aspirated, but that was over 40 years ago. What are your opinions on maintenance issues, tip tanks on normally aspirated, best years to look at etc. Also could consider a 400 Commanche, which I also flew on charters 40 some years back. It will actually do our trip from Hickory, NC to San Antonio 30 minuets quicker and only use 6 gallons more fuel. Who would have thought? But I hear the overhaul on the 720 is out of this world! Thoughts anyone?

[N3322G]

Hi Eric,

I can speak to the Twin questions. I've been flying NA for 45 years - to, through and over the Rockies and around the world. With good planning, never really felt the need for a turbo. If I want more power at higher altitudes, I just run the props at 2700 rpm. If you normal mission is the NC to TX you mentioned, don't see a lot of need for the Turbo. If you are doing your own maintenance, a turbo might not cost you much more to maintain otherwise the complexity will simply add to maintenance costs.

The later models of Twins have better access to the fuses and usually panel layout but it has been so many years, I wouldn't reject anything based on year becasue it could have been changed by now.

IMO best speed mod on any aircraft is more fuel tanks - tip tanks are nearly free as when you use them, gross weight goes to 3750 vs 3600.

Raced a 400 once and noise was a big factor but this was before noise cancelling headsets and frankly, I just like that second engine. You have to practice single engine stuff to stay proficient so eveyrthign is a trade-off.

Whatever you decide to do, be sure to get Taylor's DVDs, take one of the 3-day training courses, buy Alice Fuch's how to fly a Twin book and make sure it comes with a POH or buy the Killough one.

Hope you are in a Comanche soon.

[AlanBreen]

Hi Eric,

If you don't need to fly high the N/A would be my choice hands down.

The N/A will be cheaper to run and below 6000' the N/A is slightly faster.

I don't know much about the 400, I certainly wouldn't discount owning one.You can go fast or pull the black knob back and go at 250 speeds burning the same as a 250 so I've been told. I would expect overhaul costs to be commensurate with the number of cylinders, i,e, 4 v 6 v 8. Though I have heard 720 specific items like crankshafts can be hard to source if you need to replace them.

[Eric Koch]

Good thoughts all. Is the 3 day course something run by the ICS and how often do they run them or is it by an another provider. How realistic is flying the N/A at 11, 12 or even 13,000 feet, ie. does it climb fast enough to these altitudes to make it worth while on say a 3 hour trip and what kind of true's are you getting up there? I'm used to the T210 and normally flew it between 13,000 to 20,000 from Chicago to North Carolina. I got used to the options it gave me, but today is a new day. Retired and on a fixed income! I was concerned that there might be heat, corrosion or other issues. I like the idea that you don't have to use the turbos when they are not needed, but on the other hand, I do not do my own maintenance and want to reduce my cost's as much as possible. Do most of the turbo charged engines make it to TBO?

[AlanBreen]

The courses are run by the CFF (Comanche Flyer Foundation?) which operates hand in hand with ICS.

I've run our N/A PA30 at 11,000 no problem, though not always at max weight. I don't go up there much so I don't recall the TAS. TAS at around 7000 is right on book figures of 168 KTAS. For the N/A TAS drops off above this altitude. I'm not home right now so I don't have access to the manual to give you any figures.

A N/A twin, with tips, will give you 950 to 1000 nm range with reserves, at 75% power, at optimum altitude, nil wind. Max range range with tips is about 1200 nm.

I'm sorry I cannot give you any data on the turbo version.

[N3322G]

I fly my NA Twin wherever the winds result in the fastest time except in the Rockies, then I'm regularly at 12 and 14K. I flight plan 160 and regularly see 170kt

www.comanchetraining.com is also a training offering. One of the instructor's flies a Twin.

[N3322G]

Correction on the tip tanks GW goes from 3600 to 3725.