M20K 252 Cowl Flap Motor

[David Mazer]

My cowl flap motor went a couple years ago.  I can't really tell you why but the A&P felt that the most likely problems was stripped gears.  For quite some time I tried to find a cowl flap motor.  Mooney said $1,000 but none are available.  We went another route and tried to put in a manual cable system similar to the 231 version but the cowl flaps aren't the same and the original cable and two subsequent attempts have failed.  I don't think the first cable was strong enough to pull the flaps closed even at slow speeds so we tried a button lock cable and then a friction lock cable similar to a throttle cable.  The forces pulling the flaps open over comes all the locking mechanism at cruise over 150 kts or so.  At least with this last, much stronger cable.  The second cable wouldn't even hold it closed at 80 kts.  Improvement but unacceptable.

 

My current A&P thinks we may be better off going back to the motor but I'm worried that we won't be able to find a motor, that it will cost a fortune (this motor is the size of 2 D cell batteries!), and the forces are too much for it and the real reason it went in the first place.

 

Also, my 252 has a Rocket conversion but I don't think that effected the lower cowl and there seems to be a significant difference between the 231 and the 252 cowl flap beyond just manual vs electrical

 

Any suggestions?

[kortopates]

Dave, have you tried:

1) Salvage yards for serviceable replacement

2) Motor repair facility - for example http://www.bigwoodselectric.com/ these folks recently got FAA approval to repair our BendixKing AP servo motors which are similiar to the little cowl motor and their web site says they repair all kinds of servo and dc motors - I'd check with them.

[David Mazer]

I tried all the salvage yards I could find.  I even went from one to the next at SNF one year without any success.  I'll check out bigwood electric to see what they can do.  Thanks.

[FBCK]

Your system is a lot different then my 231 cowl flap system, but I will add this. When I purchased my 231 a couple

 years back I had a hard time openning and closing the flaps, I had to apply way to much presure and it was only a mater of time before something broke.  Took it to a couple of shops that didn't know Mooneys and came out the same.  I was down in Wilmars to have my tank resealed and had them look at it, all was fine on the way home.  Just guessing here but if the "rigging is not properly set it may be taking way to much effort for the motor to move the flaps. I would be surprised if you can have that motor rebuilt, that what I would do, that system is way beter then the manual flaps in my book.

[RJBrown]

231/Rocket cowl flaps are real fiddly. They stay open against the wind because of the way the mechanism goes overcenter. If the adjustment is too far over center they are almost impossible to close at speed. The tab that sets this adjustment is weak and bends. It is a preflight item. Adjusted one way they wont stay open too far the other way you can't close them. I considered milling a replacement out of aluminum for the part that bends but sold the plane before I could. Simple system that works well when in adjustment. PIA when out of adjustment.

[David Mazer]

To those of you kind enough to offer help, I have an update.  First, I give up.  The cowl flap motor is so hard to get off, my A&P is proposing removing the engine to get to it!  That isn't happening.  We have found at least one source for a new motor and another for repair if the shaft hasn't sheared off.  The motors repeatedly fail when oil gets on them and they are almost directly below the oil filter and always get oil on them when the oil filter is changed.  In other words, it will fail again and quickly.

 

The 231 cowl flap mechanism has an over center arrangement while the 252 relies on the motor to carry all the force.  All the cable systems we have so far tried cannot handle the wind force at cruise.

 

In the end, I may have to live with it this way.  We are looking at a mechanical spacer for the push rod but that my be impracticable also.

[goncaloareia]

Hello all!

Our Mooney 252 had a working cowl flap engine actuator until last week, when it went to the avionics shop, the guys removed the lower cowl, putted everything back on when they finish, and now... guess what... the cowl flap motor is malfunctioning....

They removed the motor, and told me that the electric part of the motor is fine, but the shaft assembly and specially the secondary shaft that connects to the gears that multiply the motor force is worn out and also loose. They tried to grip it back in place with no success...

I'm now seeing some 1.300 USD as the lower price I can find for the stupid small motor...

Any ideas of how to repair (if its possible) this motor and its gears/shafts?

Any clues of how easy/cheap it could be to put the cowl flap control manual?

And one last question: we are afraid of flying with the cowl flap motor inop because the cowl flap moves almost freely from open to close, and it closed somewhat when we did a run-up test this morning.

Do you guys know if the cowl flap will open or close in flight?

Thanks for the help and best regards to all.

Goncalo Areia

Lisbon, Portugal

[Murray]

The cowl flap motor is manufactured BY Globe Motors of OHIO and a replacement can be obtained from them for $850. Takes a couple of days to make one up. The cowl flap can be wired open while you are awaiting the part so that you may continue to fly your a/c. Globe's number is 937-228-3171, web www.globe-motors.com. They didn't take credit cards so COD works. It's expensive, I know, but the problem is solved with an exact replacement..

 

Good Luck!

[David Mazer]

Manual operation is extremely hard.  I have tried multiple iterations with limited success.  The replacement motor will work but it is hard to install and easy to break again if the lower cowl is installed incorrectly.  Something very easy to do.  It is likely that it will break again if you allow someone else to deal with the cowl.

 

I have flown with a floppy cowl flap without any real issues except a required reduction in climb speed at about 16,000 ft for a moment or two.  Otherwise, never a problem with temperatures.

 

Good luck.  My odessy has been painful.

[kortopates]

David

I have been trying to understand what improper cowling installation issue led to your cowl flap motor issue. I understood from before your oil draining on the motor during an oil change being an issue but this must be an issue peculiar only to the Rocket conversion since the 252 engine oil filter is located right on center-line and away from the cowl flap motor. With regard to installing the lower cowl, I frequently R&R my lower cowl to work on my 252 and can't imagine what might be happening to brake the cowl flap motor. It seems very basic to disconnect both cowl flap control rod ends at their quick disconnect fittings located on the cowl flap brackets at the same the two lower camlocs are also unlatched. After all the Mooney Maintenance Manual provides detailed instructions with a drawing. Hopefully, your service tech is reviewing the manual if they’re unfamiliar - as they were taught and are required to do so. So I wonder if I am missing something peculiar to the rocket installation yet I’ve understood that the Rocket uses the original 252 cowling. Is it possible to elaborate on what might be going wrong to cause the damage?

Otherwise, so sorry to read your continuing to have so much grief on this issue - it has to be very frustrating. I do believe my cowl flap motor is still original from ’86.

[David Mazer]

It is my understanding that the Rocket lower cowl is the same as a 252.  Only the upper cowl is modified.  The damage to the cowl flap motor occurs when the lower cowl is installed and the cowl flap rods are in the open position and the cowl jams them up, shearing the gears or breaking the shaft.  Personally, I'm taking the word of my IA that is a common cause of the damage.  That makes some sense considering the gears/shaft is a common cause of the failure as opposed to an electrical issue but I can't say that I "know" this is correct from personal experience just from what I'm told by experienced individuals.  I do know that my problems occurred after my lower cowl was removed and re-installed by an avionics shop with limited experience with Mooney 252 cowls but I couldn't say for sure they are the culprits.

[kortopates]

David, I wish we weren't on opposite coasts as I would be happy to help you remove and re-install your cowling to show you the procedure. It takes two people, one on each side to do it properly, such that the front of the cowl doesn't scratch your spinner and the bottom center aluminum bar is oriented to sneak into the very narrow gap between the top of the nose wheel doors and directly below bottom of the airframe - a tight fit. One quickly realizes that they can’t leave the loose cowl flap control rod ends hanging down, as they hang low enough to directly block the lower cowl aluminum bar from passing behind them to narrow slot between the top of the nose wheel door and bottom of the firewall as I was attempting to describe. Its not a problem removing the cowling but the cowing alum bar will jam against them if they remain hanging when you attempt to re-install the lower cowling. This must be what you are describing through your IA. Someone would really have to man-handle the lower cowl trying to force it in before they realizes the hanging control rod ends where blocking it. Honestly there is really no excuse for this. The cowling is not going to go into position until the installer gets under the engine and simply rotates the hanging control rod ends up and out of the way so that they are pointing up and leaning on the firewall and thus totally out of the way. The cowl flap has to fully open to reach in through the opening to disconnect control ends at time of removal as well as to reach back in to re-attach the control rod ends at time of re-installation. But they don’t have to left hanging after they are disconnected.

 

After you’ve gone through this once, you’ll rotate them up out of the way when disconnecting them from the cowling where they will remain till re-installation. It’s that simple and I wish I could show you first hand as I am sure you would conclude it would take some real forcing of the cowling alum bar against the hanging control rod ends to do the damage you’ve gotten. I would encourage you to solicit some help from someone on your field to go through it for yourself. After you see what’s going on, I am certain you’ll feel your IA at least should share in the cost for a new motor if not replace it for you.  Like you say though, its impossible to say failure wasn’t imminent from previous abuse, but removal and re-installation of the cowling shouldn’t have put *any* load on the gearing or motor when done right suggesting any failure should have been while in flight from air loads on it – not re-installation of the cowl.

 

The other point of this is that once you are able to get it properly fixed with a new motor, you should be able to get many years of trouble free service knowing that proper re-installation is not going to damage it.  It’s great to know the motor is available; although quite expensive. Perhaps another local Mooney owner can help you find another Mooney experienced IA in your area.

Good luck!

[LANCECASPER]

The cowl flap motor is manufactured BY Globe Motors of OHIO and a replacement can be obtained from them for $850. Takes a couple of days to make one up. The cowl flap can be wired open while you are awaiting the part so that you may continue to fly your a/c. Globe's number is 937-228-3171, web www.globe-motors.com. They didn't take credit cards so COD works. It's expensive, I know, but the problem is solved with an exact replacement..

 

Good Luck!

I wish this was true. Here's what Globe Motors says:

 

This item is proprietary to Mooney Aviation. You will have to go through them to purchase what you need.  Contact information Below.

 

Main: 830.896.6000

Service Parts: 830-792-2901

 

Sales: sales@mooney.com 

Product/Parts Support: serviceparts@mooney.com

 

Best Regards,

 

Melissa Grazioso

Sales Coordinator

Globe Motors, Inc.

Phone: 937-229-8585

Fax: 937-461-1017

 

If anyone knows of a cowl flap motor (part number 880050-505 or 880050-513). Even if it is just a core that needs to be rebuilt please let me know.

 

Thanks!

[kortopates]

That's bad news to hear that. I just had mine rebuilt by them to the new -513 spec for less than half the cost of buying new and they essentially sent me a new one. So try and locate a core if you lost yours somehow. Keep in mind the shaft holes used to pin it to the attaching lever arm have doubled in size with the -513 spec and you will need to drill out your old lever arm accordingly and use MS16562-33 pins to attach. Good news is that will make your old lever arm like new w/o buying another $350 part.

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[jetdriven]

Try Aeromotors, LLC.  They repair all kinds of small airplane motors, including that famous Dukes fuel pump.

[N601RX]

I worked at Globe for several years.  Instead of calling the sales office in Ohio, call the Dothan,Al branch and asked for the FAA repair station and see if they will overhaul it for you. Send me a PM if you need a contact number.

[FloridaMan]

There's no chance you'd be able to help me find a replacement spinner bulkhead for a "J" model with a hartzell 2-blade prop is there? 

[LANCECASPER]

That's bad news to hear that. I just had mine rebuilt by them to the new -513 spec for less than half the cost of buying new and they essentially sent me a new one. So try and locate a core if you lost yours somehow. Keep in mind the shaft holes used to pin it to the attaching lever arm have doubled in size with the -513 spec and you will need to drill out your old lever arm accordingly and use MS16562-33 pins to attach. Good news is that will make your old lever arm like new w/o buying another $350 part.

Sent from my iPhone using Tapatalk

 

With information from Kortopates I was able to get Globe Motors to rebuild my cowl flap motor. I called Bobbie Eldridge at Globe Motors at the Alabama facility. She couldn't have been any nicer or more helpful. The airplane is at Dugosh having it installed as we speak.

[jetdriven]

IOC globe makes the motor for the century autopilot servos as well. I wonder if that same deal can be bad for that.

[kortopates]

Great, looks like you got a brand new one too!

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[Guest]

To those of you kind enough to offer help, I have an update.  First, I give up.  The cowl flap motor is so hard to get off, my A&P is proposing removing the engine to get to it!  That isn't happening.  We have found at least one source for a new motor and another for repair if the shaft hasn't sheared off.  The motors repeatedly fail when oil gets on them and they are almost directly below the oil filter and always get oil on them when the oil filter is changed.  In other words, it will fail again and quickly.

 

The 231 cowl flap mechanism has an over center arrangement while the 252 relies on the motor to carry all the force.  All the cable systems we have so far tried cannot handle the wind force at cruise.

 

In the end, I may have to live with it this way.  We are looking at a mechanical spacer for the push rod but that my be impracticable also.

Dave,

No offense, but if your A&P can't figure out out to remove the motor without removing the engine or how to do an oil change without baptizing the engine in used oil, look for a new A&P.

Clarence

[David Mazer]

Clarence, really, ever heard of sarcasm or hyperbole?

[jetdriven]

Dave,

No offense, but if your A&P can't figure out out to remove the motor without removing the engine or how to do an oil change without baptizing the engine in used oil, look for a new A&P.

Clarence

Amen brother. It's pretty shocking to see that half or more of the problems are caused by improper or sloppy maintenance procedure.

[LANCECASPER]

With information from Kortopates I was able to get Globe Motors to rebuild my cowl flap motor. I called Bobbie Eldridge at Globe Motors at the Alabama facility. She couldn't have been any nicer or more helpful. The airplane is at Dugosh having it installed as we speak.

 

To follow up, I got the airplane back from Dugosh today. It took 4.5 hours of labor and some miscellaneous hardware, including an uplimit switch (actuator), new roll pins, etc. to get it all put back together, but it is working very well now. Dugosh did a great job on it! David, the mechanic that worked on it, has been there 32 years working on Mooneys. He even researched the lever that links to the cowl flap indicator and found out that there had been an updated improved part from the factory. They were fair on their pricing and good on communication. I know where I'll be going for service.

[Encore Driver]

I've read this thread with interest since I have a question about my cowl flap motor. The motor works but does not hold position. It slowly bleeds off to about half open unless I select full closed or full open. I have to reset it about every 10 minutes in flight to keep the oil temp where I want it. Is this normal for this system or should I have it rebuilt?

Steve