Gear Retract Failure

[Diesel 10]

Hi all - I had an unusual gear experience in my '92 M20J MSE that my shop hasn't been able to give any suggestions on. I was departing the other day and was not able to retract the gear.  Each time I attempted, the Gear Act Cct Breaker popped and all indications (including airspeed and climb) were that the gear was still down.  I had a couple of passengers on board so rather than do any further diagnosis, I decided to return to the field (KBFI). I did a low pass so the tower could take a look just to do a visual on the gear and then I landed without event (except for several emergency vehicles waiting to greet me)!

My shop at the field was able to take a look the same day and was not able to recreate the problem.  They put the plane on jack and cycled the gear 5 times.  They removed the belly panel and inspected with further cycles and no problem.

I've since flown the plane a couple of times without problem.  Gear retracts perfectly!

Any thoughts, wisdom or similar experiences?  I'm glad its working but I'm wondering when/if its going to happen again.

Thanks,

Trevor

[kortopates]

One of your rear seat pax knocked the emergency gear extension lever loose. Once its not secure, its in manual mode and electric motor pops the CB trying to turn it when it can't.

Somebody must of re-secured the lever. 

Very common with rear seat pax - checking its security before departure should be on your checklist.

If you tried more than a couple of times you should verify the manual extension still works on jacks. Popping the CB like that repeatedly chews up the brass clutch to the point where it will no longer drive the gear down - you don't want to discover it no longer works when you need it, its happened...

[PTK]

10 hours ago, Diesel 10 said:

I had a couple of passengers on board so rather than do any further diagnosis,

Sometimes passengers in the rear seats may accidentally bump and unlatch the emergency gear extension on the floor. If this happens the gear will not retract.

[jlunseth]

It needs to go on your checklist that the emergency gear extension latch is in place. 

 

[Diesel 10]

Thanks folks.  I definitely manually and visually check the gear extension latch as part of my pre-flight.  This said I had two people in the back (Angel Flight mission) so it is possible one of them unlatched it accidentally.  I remember checking the latch after we landed and didn't see anything odd.  Regardless I will add it to my pre-departure check list if there is anyone in the back!

 

Also good call about the manual extension clutch.  I have an annual coming up and will verify.

[carusoam]

Add it to the passenger conversation too... 

Seat belts, emergency exit, Self destruct latch on the floor... 

Best regards,

-a-

[jlunseth]

8 hours ago, Diesel 10 said:

Thanks folks.  I definitely manually and visually check the gear extension latch as part of my pre-flight.  This said I had two people in the back (Angel Flight mission) so it is possible one of them unlatched it accidentally.  I remember checking the latch after we landed and didn't see anything odd.  Regardless I will add it to my pre-departure check list if there is anyone in the back!

Thank you for stepping forward. Oddly enough, my back seat Angel Flight passenger yesterday asked me what the red thing was between the seats, which made me check it. It was fine. I have learned in flying for Angel Flight Central that I need to have a pre-flight passenger briefing about how things work in the aircraft. That latch. The emergency pin in the baggage hatch. The exits in the aircraft. The need for a sterile cockpit when getting into and out of airports. Silence when ATC calls my number. etc.

[Ibra]

19 hours ago, jlunseth said:

It needs to go on your checklist that the emergency gear extension latch is in place. 

I had a paper one that did not have it, now it has,

I did read whole POH after 2h of flight with gear down, the latch got kicked when we loaded the backseats !

[PT20J]

When the breaker pops it generally means that the motor can't turn. As Paul and others noted, this is usually due to the emergency extension lever being engaged. If that's not it, and you've checked out all the rigging and limit switches, then there is the possibility that something inside the gearbox jammed the motor. If that's the case there is a possibility that it could jam again and perhaps with the gear retracted while also rendering the emergency gear extension mechanism inop. If I couldn't find a cause, I would disassemble and inspect the gearbox just to be sure. Maybe it's a good time to replace the noback spring and replace the grease also.

Skip

[Diesel 10]

1 hour ago, PT20J said:

When the breaker pops it generally means that the motor can't turn. As Paul and others noted, this is usually due to the emergency extension lever being engaged. If that's not it, and you've checked out all the rigging and limit switches, then there is the possibility that something inside the gearbox jammed the motor. If that's the case there is a possibility that it could jam again and perhaps with the gear retracted while also rendering the emergency gear extension mechanism inop. If I couldn't find a cause, I would disassemble and inspect the gearbox just to be sure. Maybe it's a good time to replace the noback spring and replace the grease also.

Skip

Thanks, Skip.  Sounds like a good project to add to the upcoming annual.

[Lance Link]

This happened to me once and it turned out the shop did not line up some contacts when they did the annual.

[steingar]

Johnson bar for the win!

[kortopates]

Johnson bar for the win!

That can’t be the same Johnson bar that unlatched itself?
Sorry but Johnson bars have all their own failures and independent of the gear actuating system the same gear has its issues as well.


Sent from my iPhone using Tapatalk

[steingar]

1 hour ago, kortopates said:

That can’t be the same Johnson bar that unlatched itself?
Sorry but Johnson bars have all their own failures and independent of the gear actuating system the same gear has its issues as well.

When I first started flying the Mooney the bar did unlatch in flight a couple times, but was securely put back in.  Took a Mooney dip to do, but turned out OK.  There have been gear failures from worn uplocks, that I'll admit.  Not many, and an easily preventable failure mode with just a bit of proactive maintenance.

 

[Hank]

3 hours ago, steingar said:

When I first started flying the Mooney the bar did unlatch in flight a couple times, but was securely put back in.  Took a Mooney dip to do, but turned out OK.  There have been gear failures from worn uplocks, that I'll admit.  Not many, and an easily preventable failure mode with just a bit of proactive maintenance.

 

Don't forget the occasions, including last week, when the handle came off the Johnson bar when unlatched to lower the gear and had to be reassembled in the air . . .

[EricJ]

...or the times when the weld at the bottom of the bar failed... 

 

[PT20J]

Back in the ‘80’s I instructed at a club in San Jose, CA that had a manual gear Ranger and it managed to land gear up — twice. (No one I checked out - thankfully). That airplane is still flying last I checked. N78888. 

Skip

[PT20J]

And why do we call it a Johnson bar anyway? And, who’s Johnson?

https://www.wisegeek.com/what-is-a-johnson-bar.htm

[larrynimmo]

21 hours ago, PT20J said:

And why do we call it a Johnson bar anyway? And, who’s Johnson?

https://www.wisegeek.com/what-is-a-johnson-bar.htm

My career is as a refrigeration mechanic....when we want to move something heavy, we use a simple 6 - 7’ lever that has wheels at the ground and about 8” tongue sticking out...and it is called a “Johnson bar”

Edited September 1, 2020 by larrynimmo
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