Cowl Flaps

[markejackson02]

I have a very early 201 (serial 24-0048) with manual cowl flaps.  The cowl flaps are either open or closed.  I have tried to push them half way closed but the handle either snaps shut or is all the way open.  Is this the way they are supposed to operate?  I know later versions had the motor with a variety of positions.

Thanks

Mark Jackson

Edited April 18, 2016 by markejackson02
grammar

[Piloto]

Yes that is the way is supposed to work. If you push it slowly while in flight they may set at a mid position. If you are experiencing high CHT while in cruise with cowl flaps closed you may be able to adjust the flaps for a slightly open setting in the closed position. The adjustment is done by adjusting the articulating link to about 1/2" to 1" gap at the rear end of the flap. This gap will substantially bring the CHT down.

José

[cnoe]

Hi Mark. Jose is a great authority on most things Mooney but I can verify that on early J's with manual cowl flaps there is indeed an intermediate setting often referred to as cowl flaps "trailing" which is roughly half-open. Several on the forum agree as evidenced by searching prior threads. There should be a spring on the linkage near the firewall (engine side) that assists with positioning. My POH also refers to this position as shown in the attachment below. In cruise mine have 3 distinct positions and to close them fully requires significant effort from the trailing (half open) position. Jose's suggestion for adjustment when closed is spot on too; they should be slightly open when closed as described in the service manual.

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[PaulB]

I had an issue where I could only get my cowl flaps to be in trail or full open but never closed in cruise. They would close on the ground without any issue. Adjusted the spring and it still did it. Finally found that some of the rivets that attach the bracket to the firewall were loose. Fixed those and now the cowl flaps do whatever I want them to.

[markejackson02]

Interesting.  I will check for the spring.  I had read about the three inch open position but it wasn't working.  Perhaps I am doing it incorrectly, should close it to the three inch position, then close fully.

One the floodwaters in Houston recede, will give it a shot.

[cnoe]

The spring was missing on my J when I bought it and the cowl flaps acted funny. Now after takeoff I go gear up, flaps up, and then push in the cowl flap control about halfway. It has a distinct position where it stops. After climbing and before accelerating I push it the rest of the way in (closed) and it takes a firm push. My belief is that they close more easily if I haven't reached full cruise speed yet. The diagram showing the spring is in my J's parts manual on page 71-10-02 in the powerplant section as shown.

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[jetdriven]

i just push them into trail just before taking off. Cowl flaps locked full open is a lot of stress on the hinges and the cowl. Look at one when its doing a runup sometime.

Edited April 18, 2016 by jetdriven

[markejackson02]

I have tried to rig the cowl flaps to trail 1/2 inch when closed.  I have attached photos.  This still hasn't solved the cooling issues.  Have to open them, fly until things cool off, close them, reopen them, repeat, repeat.

I have adjusted the connecting rods to be as long as I can, but it still seems that they are too far closed.  How do these photos compare to others positions.

(PS I am going to replace the spring to try to be able to use the intermediate position.)

Full open

 

Closed

 

[DonMuncy]

They look to me to be pretty closed when closed. Have you adjusted all the length you can on both top and bottom joint connectors. My hangar elf would not mind cutting longer "all thread" rods to get them open more if needed.

[markejackson02]

They look to me to be pretty closed when closed. Have you adjusted all the length you can on both top and bottom joint connectors. My hangar elf would not mind cutting longer "all thread" rods to get them open more if needed.

I adjusted them so that the top and bottom nuts had at least four turns on them, that was about as loose as I was comfortable with.

Going to see if there are longer rods available.  I note there are three different part numbers in the catalog.

[DonMuncy]

If my memory is correct, they are 1/4 inch 28 tpi. Although the factory rods are threaded on each end, all thread would work just as well and are readily available at better hardware stores (In the aviation section, of course )

[N201MKTurbo]

All thread is kind of weak. Normally you start with a steel rod and put threads on the ends with a threading die.

http://www.metalsdepot.com/catalog_cart_view.php?msg

If you are going to do un-approved modifications, you should at least make it look like it came from the factory that way.