Gear latch issue

[BDPetersen]

I flew my 1st Mooney in March, 1964, between then and 1970 accumulating some 400 hrs of Mooney time. Not so much thereafter until last week when I purchased a beautiful M20C. It has been delightful recapturing a bit of my youth. My manual gear swinging skills came back quickly with one exception, the latch. This one seems inordinately difficult to unlatch, to the point of needing both hands (not a good idea). Getting the thumb button fully depressed and then the collar to slide takes greater effort than I recall. It seems forward pressure may help. (Yes, I was 18 then and 70 now, but . . .)

I am guessing that before getting it up on jacks and exploring, you folks probably have some ideas of what to check out.

In the '60's these were new airframes and I'm sure there are wear issues by now. BTW mine is a 5600 hour plane.

[bonal]

Congratulations on your Mooney and welcome to Mooney space. Ha Ha Carusoam I beat you to the greeting. As with all please post some photos of your new joy. For the latch I think tighter is better and with practice you will recover the technique on breaking it loose. If you can get it up on stands good idea to check and make sure no deformation in the block.

[bonal]

I have a 64 as well and on its first annual we replaced the block. It's very tight to pull down but I think that's by design. Good luck   and have fun flying your 64.

I just assumed it is a 64 what year is it?

Edited October 11, 2015 by bonal

[mike_elliott]

I flew my 1st Mooney in March, 1964, between then and 1970 accumulating some 400 hrs of Mooney time. Not so much thereafter until last week when I purchased a beautiful M20C. It has been delightful recapturing a bit of my youth. My manual gear swinging skills came back quickly with one exception, the latch. This one seems inordinately difficult to unlatch, to the point of needing both hands (not a good idea). Getting the thumb button fully depressed and then the collar to slide takes greater effort than I recall. It seems forward pressure may help. (Yes, I was 18 then and 70 now, but . . .)

I am guessing that before getting it up on jacks and exploring, you folks probably have some ideas of what to check out.

In the '60's these were new airframes and I'm sure there are wear issues by now. BTW mine is a 5600 hour plane.

Welcome! You might have your gear latch block looked at by a pro. If it has never been changed and your new aluminum mistress has 5600 hours on her and is a youthful 50 years old or so, I am sure it could use a little attention. Lasar sells new ones fairly (in aviation terms) inexpensive, and worth not becoming a gear up stat as so many manual gear guys have because of this item.

[Andy95W]

Is there a chance it is just a lubrication issue, or is it really binding on the top of the Johnson bar?  If lubrication is an issue, try silicone spray where metal slides on metal.  If it's binding, you're probably looking at jacking and rigging.  

Let us know how it turns out, good luck, and welcome back to Mooney flying!

[Steve65E-NC]

Knowing the year of your C would help.  My 65E has carpet up the surface under the vertical Jo Bar.  A little extra padding or welting here in the center of the shaft can change the latch force radically.

[Bob_Belville]

Hum, N2482W is supposed to be  1967 Schweizer glider.

http://flightaware.com/resources/registration/N2482W

[BDPetersen]

Oops. Fixed N number. 2582W is a '66 built Dec, 65. 

Gave all latch items some lube during last flight. We'll see. Thanks for the welcomes and interest.

Aviation terminology is fascinating. Wonder how many aircraft have had something called a "Johnson Bar"? Don't think it was used so much for the Mooney gear in the olden days. Kinda like "conventional gear" becoming "tail dragger" I guess. Been at this too long.

[M20F-1968]

The Johnson bar is one item that needs to reliably work.  Without a question, I would contact LASAR and purchase their new downlock block.  They make a PMA part that is identical to the original.  They can fit your thumb lock to the new part, or you can do it yourself.  It is nothing but a "U" shaped pin filed to a sharp edge which fits into the Johnson Bar handle, a spring and the thumb plate which you physically press.  Very simple to clean and adjust.  The $400 or so you pay LASAR for their part is cheap insurance.  Two machine screws hold in the assembly and it can be changed while up on jacks.

John Breda

[carusoam]

Bonal, you beat me by 12 hours!

Welcome aboard, BDP!

The M20C is a wonderful machine.  You are in good company here.

Have you been flying other planes or taking time off from flying before?

Best regards,

-a-

[BDPetersen]

As I think it through, it seems the issue is in getting the thumb button to let go of the slider. (Maybe that's obvious.) My arthritic thumb may not be as strong as it once was, but I don't recall working the latch being at all difficult, rather mastering the swing gracefully was the art. Anxious to research the LASAR latch.

I guess I've been pretty active. Before the M20C, a Citabria 7ECA (which is now reluctantly in search of a new home) (turns out 84kt x-c's required more character than I could muster). Before that an older C310 preceded by an M model Bonanza. Then there's the Stinson my dad flew back from the factory in '47 and I bought from him in the 70's and still have but is down for a restoration. There was a 37.2 year stint with Northwest Airlines that ended 10 years ago. Prior to that a couple years at Purdue flying DC-3's and -6's. And before all that, an Iowa farm boy that got to fly a few Mooneys back from Kerrville and give dual in an M20D, gear down and welded. Still doing the CFI thing when they can catch me

[carusoam]

The thumb button doesn't have much history of being a challenge with J-bars.

An hour up on jacks may be a good investment.  The opportunity to clean, lubricate and see all the parts may be very helpful.  The ability to practice the gear movement without air pressure on the gear doors is eye opening. Putting the handle up into the locking block, you actually feel the button locking into place.  The block is a simple piece of aluminum that wears against the chromed handle.  It wears into an egg shaped pattern from it's round origin.  This wear causes a bunch of other ill fitting issues that keep the gear from locking properly.

When you were 30, you may have done this while flying, taking a picture of the down lock block with your IPhone VII.  It is a challenge to feel the lock click while flying. Especially if your right arm is struggling from being tired...

The importance of this button is it is part of the lock that keeps the gear down while landing. If it is not working properly, it may not do it's locking job. 

Many of us do this at annual, or the PPI while it is up on jacks.  Some of us have our own jacks in the hangar.  It is really cool to take the effort to gain the confidence that these little details are all working properly.  Less to be concerned about while actually flying.

I am not a mechanic, just a PP with a few years of 65C ownership.

Hope this helps,

-a-

[MyNameIsNobody]

I flew my 1st Mooney in March, 1964, between then and 1970 accumulating some 400 hrs of Mooney time. Not so much thereafter until last week when I purchased a beautiful M20C. It has been delightful recapturing a bit of my youth. My manual gear swinging skills came back quickly with one exception, the latch. This one seems inordinately difficult to unlatch, to the point of needing both hands (not a good idea). Getting the thumb button fully depressed and then the collar to slide takes greater effort than I recall. It seems forward pressure may help. (Yes, I was 18 then and 70 now, but . . .)

I am guessing that before getting it up on jacks and exploring, you folks probably have some ideas of what to check out.

In the '60's these were new airframes and I'm sure there are wear issues by now. BTW mine is a 5600 hour plane.

The thumb button and J-Bar Chrome sleeve should push/slide seamlessly.  Something is not right.  Get it on jacks and get that sorted.  No way should it require more than light pressure to push and slide.  Yes, the swing is the learning curve...should be.  Probably NOT a big deal.  Good luck.  Let us know.  How much time on the plane?  Mine is fine at 2500ish hours on airframe.

[BDPetersen]

I will have it up on my jacks tomorrow. Looking at the pix accompanying the LASAR latch info, I fully expect mine to look like the old latch they show with a grove worn that is snagging the collar's movement. We'll see. The fix looks easy.

Its a 5600 hr airframe

 

[BigTex]

Something is definitely not right.  Mine almost leaps to the down position.  All I do is guide it into place and give it a tug downward to make sure it's latched.  I don't even think I use the thumb latch in the process. 

If you have to use two hands, don't fly it until it's figured out.

[carusoam]

If it is the original block too, it will probably have the nice oval shape as well. Lasar is great for this kind of support.

Best regards,

-a-

[BDPetersen]

This is a good group. Thanks.

I don't want to create thread creep, but in the same vein, how often do you do gear rigging or is it "on condition". With the C310 it was an annual ritual, but a much more complex system.

[bonal]

Don't know of any specific rigging but the gear and its related parts are checked as part of the annual as well as the pre load tensions. Gear swing and operations checked while it's on the stands including door adjustment. My J bar does not fall out of the block I have to give it a pull down but it's not difficult to get it to get it to release. Hopefully who ever is going to check it for you has experience with this system.

[MyNameIsNobody]

Something is definitely not right.  Mine almost leaps to the down position.  All I do is guide it into place and give it a tug downward to make sure it's latched.  I don't even think I use the thumb latch in the process. 

If you have to use two hands, don't fly it until it's figured out.

+1  mine would bang the receiver if I didn't guide the swing. I too just latch without consciously using thumb detent to lock down gear.   Collar pulled and it swings baby. 

[mike20papa]

I've noticed that if the pre-load is excessive, the latch release button is more difficult to push in, also try greasing the moving/lock pin.  Now, that wouldn't explain the difficulty in sliding the handle down.  That sounds like a lubrication issue. 

[cliffy]

When it goes on the jacks have the gear preloads checked with proper gear tools. Check the sliding of the top of the J bar

Is there heavy carpet on the face of the nose gear well that the J bar is pushed in against? That may provide enough force  in the gear down position to cause a tough to release issue.  

[BDPetersen]

Finally up on jacks. (All projects seem to have a 10x time factor). Only word for latch socket is "gnarly". Or maybe "groovy" would be more appropriate. Pretty good grove worn in aft side of socket. The new LASAR latch will go on tomorrow (or 10x tomorrow ). Will get a good check on preload as well. On jacks with no air load does seem to require a bit of force to achieve down-latch, but air load does facilitate getting gear down, so . . .

Stay tuned.

[BigTex]

Still wouldn't fly it until it's fixed.  Even on jacks you should be able to swing the gear, both up and down, without any effort.

[BDPetersen]

Well, that's the point. It won't fly on jacks and when it comes off jacks it will have new socket and an adjusted preload. The intent is to fix.

[Sabremech]

Here's my down lock block I changed two years ago. The picture doesn't show just how worn it is. I purchased both the down lock and unlock blocks from LASAR.