Landing Gear Actuator Breaker

[JP Dice]

On my Mooney M20J, I dropped the gear on downwind today, felt the gear come down, but noticed no gear down indication on annunciator panel or mechanical indicator in floor. I cycled the gear a few times. Each time I could feel the gear retract and extend, but no indications. Turns out the gear actuator breaker had popped. Pushed it in and problem solved. I taxied to maintenance and after some troubleshooting they discovered an odd problem. The A&P noticed when they bumped the gear horn speaker in the ceiling the actuator breaker would pop. Apparently, there is some soft of short circuit. Has anyone ever had such an odd ball problem?

Thanks!

JP Dice
Birmingham, AL

[ArtVandelay]

I assume you mean gear warning CB, if the actuator CB pop, your gear would not have come down. There is also a “gear cont” CB for the actuator relays. Same result.

[JP Dice]

Nope. It was the gear actuator CB. In fact, the gear would come down, but I would not get a gear down indication. When I pushed it back in, I immediately go the gear down indication. It was almost the gear almost extended fully and stopped.

[Hank]

Did you check the floor indicator?

If your gear actuator breaker tripped, they wouldn't go up and down . . . . Lights can fail, but the floor indicator never lies.

[JP Dice]

Yes. See above post. Floor indicator did not show gear down. However, control tower saw gear and I felt them. When I pushed CB back in...I got a light and floor indicator showing gear down. The floor indicator is my primary gear check.

[N201MKTurbo]

You need to put some insulation on the sonalert terminals. When you push up on it, it is shorting on the sheet metal. Mine did the same thing.

[JP Dice]

Bingo!!! I think that is it. I knew someone would have seen this.

[Sandman993]

Floor indicator is mechanical ... kinda important to know that and how it works.

[carusoam]

Welcome aboard, JP...

Sounds like you might have a solution in hand.

If that isn’t it, the gear warning system is in the electrical drawing in the POH.

Be on the look-out for a throttle sensor, a gear-up sensor, and the sonalert That Rich mentioned...

Good luck,

-a-

[JP Dice]

Very aware floor indicator is mechanical. That is why we held off on landing until we resolved the problem. Floor indicator is our primary gear indicator. The point of my post is the sonalert was actually tripping the gear actuator CB and wondered if anyone had experienced such a strange issue.

[ArtVandelay]

Something is not right, what happens when you pull the gear warn cb? Hint, the floor light should go out and annunciator light goes out.

[Bartman]

You wrote that it was the circuit breaker labeled as tha actuator and that you are sure of it. It is unlikely, but Is it possible the gear indicator and gear actuator circuit breakers are labeled incorrectly? This, along with the sonalert shorting at the terminals would explain what you are saying happened. 

If it were my plane this is what I would do. Pull the gear warning circuit breaker in flight and see if the gear works. Then pull the gear actuator CB and see if the gear works. 

[N201MKTurbo]

I believe mine is wired with the horn wired to the actuator breaker too. I assume they did this so you couldn't turn the horn off with the warning breaker. It is an engineering error because the wire to the sonalert is not heavy enough to hold the load of the circuit breaker. But it will blow the breaker with a direct short. It is possible that it was rewired incorrectly at some point by some electrical expert....