Speedbrakes Doing Their Own Thing

[TGreen]

Speedbrakes deployed on their own in flight today. Was able to retract the first time. Then they deployed again and would not retract until I landed and turned off the master. Turned the master back on and then they functioned normally. We had a lot of rain last week. Could that have been the cause?

[LANCECASPER]

2 hours ago, TGreen said:

Speedbrakes deployed on their own in flight today. Was able to retract the first time. Then they deployed again and would not retract until I landed and turned off the master. Turned the master back on and then they functioned normally. We had a lot of rain last week. Could that have been the cause?

Pull the breaker and they'll drop like a rock.

[StevenL757]

2 hours ago, TGreen said:

Speedbrakes deployed on their own in flight today. Was able to retract the first time. Then they deployed again and would not retract until I landed and turned off the master. Turned the master back on and then they functioned normally. We had a lot of rain last week. Could that have been the cause?

Personally, I’d double-check the wiring and security of the cannon plugs up inside the speed brake inspection panels on the bottom of the wing.  If they both look secure and all pins are seated properly, your issue is likely elsewhere in the electrical system.  I doubt you’d have two bad speed brakes.

[dkkim73]

What model are they? The newer ones have a central box that controls their deployment together. That could provide another source of failure or bad connection. Or the yoke switch if flaky. 

[LANCECASPER]

1 minute ago, dkkim73 said:

What model are they? The newer ones have a central box that controls their deployment together. That could provide another source of failure or bad connection. Or the yoke switch if flaky. 

My bet would be the yoke switch

[ArtVandelay]

What model are they? The newer ones have a central box that controls their deployment together. That could provide another source of failure or bad connection. Or the yoke switch if flaky. 

The older ones have a 4 way relay that acts as the control box, but I would check the switch first in this case.

[geoffb]

18 hours ago, LANCECASPER said:

My bet would be the yoke switch

agree, suspect you have a short to ground somewhere between the switch and the relay 

[PeterRus]

21 hours ago, dkkim73 said:

What model are they? The newer ones have a central box that controls their deployment together.

Judging by the M20R'06 (from the tail #) they are newer ones. 

[Coachella Bravo]

Recently, my speed breaks, would intermittently only deploy on one side.  Made for some interesting descents.  Had to IRAN with Precise Flight.  Work like a champ now.

Not cheap, but "Quality is not Expensive,    Its Priceless"

;-)

[IvanP]

I like the simplicity of the older vacuum driven speedbrakes. Simple actuator and couple of cables and springs. Of course, the main drawback is the need for vacuum pump and the inability to find replacement parts.