Landing gear door mechanism broke today.

[skyfarer]

Anybody seen this happen?  I took a short flight and when I landed, I noticed that the right gear door wasn't closed. I flew it back over to my home field where my mechanic was waiting on me to do an oil change, left the gear down for the short hop. The mechanic sent these photos, one is the right (broken) linkage, the other is the left of the same linkage. Looks like a push rod is missing, and the bell crank is bent.  This was the 8th or 9th flight since annual, where they worked on my nose gear but I don't think they did anything at all to my main gear.  I wonder if that push rod popped off on one end, and jammed and that's how the bell crank got bent.

[mgtrevor]

Yes.  In my case, the circular part the bolt passes through broke and left the operating piece dangling.  No bent parts though.

 

[kortopates]

you’ll need to replace the bent bell crank, but before you fly it make sure to identify the cause and rigging. it could be slop in the holes of the rods or any number of things including gotten bent while up on jacks doing retract test. See someone familiar with the Mooney gear.


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[PilotX]

Hmmm. Just saw the same issue today. Headed back in to identify the broken part. Damn. I guess you can fly with it like that because this was after landing.

 

[PilotX]

Looks like a cotter pin sheared. Doesn't line right up so will take some experience to get it to fit back on the clevis. Damn she needs a bath bad.

 

[skyfarer]

So on mine, the two doors were coming together, instead of closing in sequence.  When the two doors hit each other, that bell crank likely bent and the rod end broke off. They adjusted the rigging to get the door timing right. I haven't had any issues since. 

Good luck with yours @PilotX Hope you have it back together and working soon.

[kortopates]

6 hours ago, skyfarer said:

So on mine, the two doors were coming together, instead of closing in sequence.  When the two doors hit each other, that bell crank likely bent and the rod end broke off. They adjusted the rigging to get the door timing right. I haven't had any issues since. 

Good luck with yours @PilotX Hope you have it back together and working soon.

There is no such adjusting of rigging to effect timing of door opening and closing - its all in the mechanical lever arms and spring. Something broke or separated on your allowing the bell crank to get bent. Its actually a very ingenious design. Re-attaching everything properly with unbent parts ensures the inner door operates properly.

[Aerodon]

I know of M20K's that have had the same problem, and have had the gear door stop kit installed to prevent the inner door going over centre.  So I did this when I replaced the gear doors during my Encore upgrade (same gear and doors as later model Mooneys).

I have a spare set of used links if anyone is stuck while waiting for parts.  I would not fly with an inner door unrestrained, and would not install replacement links without going through the complete gear setup process.

 

Aerodon

 

SBM20-254:  

M20M -SIN 27-0107 THRU 27-0147 - (S/N's 27-0115, 27-0123, 27-0127, 27-0131,

27-0137, 27-0142, 27-0144, 27-0150 HAVE HAD INSTRUCTIONS OF SB ACCOMPLISHED).

 

 

 

[Fly Boomer]

18 hours ago, Aerodon said:

I know of M20K's that have had the same problem, and have had the gear door stop kit installed to prevent the inner door going over centre.  So I did this when I replaced the gear doors during my Encore upgrade (same gear and doors as later model Mooneys).

Since you mention Encore upgrade, I assume this is a potential problem for all 252s?  Where can I learn more about this?

[kortopates]

5 hours ago, Fly Boomer said:

Since you mention Encore upgrade, I assume this is a potential problem for all 252s?  Where can I learn more about this?

https://www.mooney.com/wp-content/uploads/2020/12/SBM20-254.pdf

[PilotX]

Seems a simple fix they reattached, ran the gear 5x and voila.