rear cowl flap motor

[John C. Noone]

hey guys,

I am looking for a rear cowl flap motor for my cessna 336 skymaster.
The motor I removed was a (Astro mec motors Co.- made in woodland hills Ca.)
which had a part number C610501-0101.
The cessna parts book uses the part number 1452506-1.
Let me know if anyone has one available and how much you need for it.
Thanks,
John Noone
TERRIAIR@msn.com
856-661-1752
PS-Has anyone installed the mechanical conversion that owen has and if so how does it work?

[RRossner]

John,
Don't waist your time and $ on any owen bell cowl flap motors. They are the worst, and he is terrible at providing warranty services to his customer.

I put one of his $1,600 motors on a P337. It stopped working on the first flight. Sent it back to him and he refused to warranty it period, plus I later found out that the core value of the motor that was originally sent to him was worth more then the motor that was purchased from him in the first place.

Ended up having to buy a serviceable motor (not rebuilt) for $1,000. I understand Cessna rebuilts are up in the $3,000 range.

So far I'm not too impressed w/ Owen Bell and the way he treats his customers.

[Ed Coffman]

Re: Owen Bell. I ordered a motor from Mr. Bell. We tested it before we put it on the plane and it made a noise that we did not like. Mr. Bell replaced the motor with another and it has worked fine ever since. We have no complaints. Even auto parts stores have problems taking back electrical items once they have been installed. Good luck.

Ed Coffman
________
Mercedes-benz atego specifications

[RRossner]

Tule River Aero Industry (the company that does the Riley conversions) have had nothing but problems with rear flap motors. 4 to be exact. Appearantly the motors that Owen Bell is sending out has the wrong gear ratio and the motor is burning it's self out trying to stay closed.

I don't believe it's a good idea to go w/ this 3rd party motor until they get the problem straightened out, especially given the fact that they don't really stand behind them 100%, at least they havn't with me and others that have had the same problems.

Rick

[Jerry De Santis]

Cowl flap motors seems to be an interesting topic for the group at Nashville. Anyone care to do some research on cowl flap motors and put on a presentation at Nashville? If so, please let me know.
Cheers
Jerry

[John C. Noone]

Thanks for the input guys. Has anyone installed the mechanical
conversion in thier skymaster to eliminate the need for the electric motor, wiring, and limit switches. I am surprised these
cowl flap motors are so expensive....can anyone tell me why?
I must be missing something here!
Oh well I heard somewhere that the mechanical conversion
is very hard to operate from the cabin....but I like the idea of
eliminating the need to ever have to buy one of these overpriced
cowl flap motors. Any input here would be greatly appreciated.

Thanks

John Noone

[Richard]

Any ideas why these things cost so much? Cessna (if they have any in stock) are asking over 3k for these. I've owned 4 Skymasters and all of them have had one or both fail. Only when I started researching, carefully, what partnumbers they were using did I discover why the rear is failing more frequently than the front.

The motor in the rear is a different motor than the front. Early Skymasters had the same motor, but I'm sure they quickly figured out the rear needed a higher gear ratio and brake. It's all too common though that I check out other peoples craft and see they are using the smaller motor in the rear. Could this be a reason for common failures?

Anyone found tips for extending the life of these units?

[Ernie Martin]

My rear cowl flap motor recently failed and I've spent the past few days researching the matter, so let me update some of the information you just posted.

A new Cessna motor now lists for $6095 and Yingling will give you a bit of a discount and sell it for $5409. Although the price seems high, it's not out of line with other aerospace itmes when you consider the size and complexity of the elements (especially the planetary gears) inside the motor and the small production number.

I have all the parts catalogs dating back to 1965 and a) the rear motor part number hasn't changed, and b) it's different from the front part number for all years. That suggests that early models did not use the same motor in the front and the rear. Perhaps the cases you have seen using the smaller motor in the rear are the result of erroneous replacement. Or perhaps the same motor was indeed used for a short while and the catalogs were later changed to reflect that they should be different.

Don Nieser at Commodore (405-503-4686) had as of this afternoon a new Cessna rear motor that he will sell for considerably less than $6000 -- in the $3,000 to $4,000 range.

Owen Bell at Aviation Enterprises (615-865-1802) has a new PMA rear motor for around $1,500 to $2,000 exchange, and an STC that replaces the motor and actuates the cowl flaps mechanically with a cable system.

Both of these gentlemen sometimes have rebuilt used motors.

Ernie

[RRossner]

Yeah we've found them out there for around $3-4K but be careful with Owen Bells rear flap motor. We tried them in the past as well as others and they do not work! In fact we've seen them burn up on the first flight and Owen refuses to replace them.

[Hank]

I had the Owen Bell mechanical conversion kit for the rear cowl flaps installed in my 1965 Skymaster. The system was installed by an experienced A&P and works fine. It did take some work to install properly. The T-handle can be be a little difficult to push in (close the rear cowl flaps) while in flight, sometimes I put on the autopilot and have to use both hands. I went this way because I had replaced the follow up cable twice in the past few years. The locking mechanism failed after a few months and Owen replaced it under warranty. I would recommend this system.

[Richard]

This is going to be my next step. Fortunately, I've found a source that has a few used / functional units. We are negotiating on price right now. They are front motors and require me to take all they have. The asking price is going to be less than $1000 each. I'm seriously thinking about it since Cessna wants either your house or both kidneys for one.

[Ernie Martin]

Richard:

I believe, as stated earlier, that the rear motor is a very different unit and that use of the front motor in the rear is a recipe for trouble. If I'm right, and if most of the failures are in the rear, is having a bunch of front motors a good idea? It would be an asset for Skymaster owners if you acquired such inventory, but I'd hate for you to be burned financially.

Ernie

[Pete Somers]

I have just spent a couple of days just lookiing into the difference in the part numbers and why there is a a difference between the two and I have not found one yet.
A motor is a motor and to control these motors you have micro switches to limit the open and close limits. So any ideas?

Pete

[Ernie Martin]

The rear one has a brake, the front one may not. Gearing and motor torque may be different, in part due to different aerodynamic forces that the device must overcome.

Ernie

[Richard]

The front and rear are both a MIL SPEC 8609- motor, the 24 10,000 rpm motor is still the same, but that is the end of the similarities. (unless you are talking about early 337s and 336s, they have the same motor)

The front one is a 524.6:1 planetary gear motor which gives you 215 oz/in force.

The rear one is a 11??:1 planetary gear motor that gives you almost 500 oz/in of force as well as having an electric brake on the back. It is about 1.5"-2" longer than the front motor.

I've stayed up lots of nights counting all the gear teeth and figuring out the DC motor side.

One thing I have learned is how important that 2 amp inline fuse is to the system. There is enough force from the motors to cause some real damage before it overheats and burns out. The 2 amp fuse is there to protect both your skin and the motor windings.