Gear Actuator Failed - Now What?

[ttflyer]

So...  It looks like we've had the worst case scenario happen with our gear actuator.  My partner was flying last week and the gear failed to retract and popped the CB.  Fortunately, the gear was down and locked.  He landed normally.  We just finally got it up and jacks and the landing gear actuator is locked up.  Looks like a No Back Spring failure...

It is an Eaton (Vickers) actuator.

Any suggestions?  Kinda at a loss about what to do next...

[PT20J]

There is an external coil spring attached to the lever on the actuator that holds the emergency gear extension clutch disengaged. I would check that to make sure the emergency extension mechanism is not engaged because that will jam the motor and pop the breaker. If it’s not that, then you’d have to remove and open up the actuator to determine the cause. If it’s a noback spring, you could email Frank Crawford at Mooney to find out the current status. Sometimes you can find a used actuator at salvage yards or eBay. Probably about $10K to buy a used one.

Good luck.

[RoundTwo]

  On 5/31/2024 at 3:56 PM, PT20J said:

There is an external coil spring attached to the lever on the actuator that holds the emergency gear extension clutch disengaged. I would check that to make sure the emergency extension mechanism is not engaged because that will jam the motor and pop the breaker. If it’s not that, then you’d have to remove and open up the actuator to determine the cause. If it’s a noback spring, you could email Frank Crawford at Mooney to find out the current status. Sometimes you can find a used actuator at salvage yards or eBay. Probably about $10K to buy a used one.

Good luck.

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Right now there is an M20J actuator on eBay for $7,500.

[N201MKTurbo]

I would disassemble the actuator and find the root cause before making any decisions.

[jetdriven]

I have a few Eaton actuators and a Dukes actuator as well.

[ttflyer]

Thanks for all the advice and tips!  I found a guy who seems to know his way around these actuators who's willing to look at for us and let us know what he can do...  I think having an expert look at is the first step...

[Matthew P]

  On 6/1/2024 at 4:12 PM, ttflyer said:

Thanks for all the advice and tips!  I found a guy who seems to know his way around these actuators who's willing to look at for us and let us know what he can do...  I think having an expert look at is the first step...

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Can you share his information in the event one of us runs into the same issue?

[LANCECASPER]

  On 5/31/2024 at 3:38 PM, ttflyer said:

So...  It looks like we've had the worst case scenario happen with our gear actuator.  My partner was flying last week and the gear failed to retract and popped the CB.  Fortunately, the gear was down and locked.  He landed normally.  We just finally got it up and jacks and the landing gear actuator is locked up.  Looks like a No Back Spring failure...

It is an Eaton (Vickers) actuator.

Any suggestions?  Kinda at a loss about what to do next...

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Worst case scenario would have been it failing when the gear was up

[shawnd]

Just a FYI - Lasar may have some in stock. They can also diagnose the issue.

https://lasar.com/search?q=gear actuator

 

[ttflyer]

  On 6/22/2024 at 4:24 AM, shawnd said:

Just a FYI - Lasar may have some in stock. They can also diagnose the issue.

https://lasar.com/search?q=gear actuator

 

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Thanks for that!  That is exactly where we sent it.  Good news - The actuator is fine.  Like worked fine on the bench right out of the shipping box.  Fully inspected and everything looked / worked as expected.  So the issue is somewhere else - probably electrical.  We'll get to chase that down when we get the actuator back...

[Matthew P]

If you are looking to sell your dukes actuator, please let me know, not sure if they have the same problem getting the gearset for your actuator or not, if so, may want to hold onto your dukes actuator just in case

[shawnd]

  On 6/23/2024 at 5:19 PM, ttflyer said:

Thanks for that!  That is exactly where we sent it.  Good news - The actuator is fine.  Like worked fine on the bench right out of the shipping box.  Fully inspected and everything looked / worked as expected.  So the issue is somewhere else - probably electrical.  We'll get to chase that down when we get the actuator back...

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That's one expensive fix avoided :-) Good luck with the hunt for the electrical gremlin.

[PT20J]

  On 6/23/2024 at 5:19 PM, ttflyer said:

Thanks for that!  That is exactly where we sent it.  Good news - The actuator is fine.  Like worked fine on the bench right out of the shipping box.  Fully inspected and everything looked / worked as expected.  So the issue is somewhere else - probably electrical.  We'll get to chase that down when we get the actuator back...

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Which breaker popped? If it was the gear actuator breaker, it sure sounds like the emergency gear extension system became engaged. I would check the rigging. It's unlikely to be electrical unless the wiring has a short, but you said that the actuator was "locked up" which would not indicate an electrical problem.

[Yetti]

Could be a relay

[PT20J]

There are two relays: one turns the motor on one way to retract the gear and the other turns the motor on in the opposite direction to lower the gear. If the relay coil is shorted (or the flyback diode) it would pop the Gear Cont CB (not the Gear Act CB) which is why I asked which breaker popped.

[AZOutlaw]

  On 5/31/2024 at 3:56 PM, PT20J said:

There is an external coil spring attached to the lever on the actuator that holds the emergency gear extension clutch disengaged. I would check that to make sure the emergency extension mechanism is not engaged because that will jam the motor and pop the breaker. If it’s not that, then you’d have to remove and open up the actuator to determine the cause. If it’s a noback spring, you could email Frank Crawford at Mooney to find out the current status. Sometimes you can find a used actuator at salvage yards or eBay. Probably about $10K to buy a used one.

Good luck.

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I have a 03 Ovation and on 2 occasions ( oth real bumpy runways) my gear would not retract until 5+ min of flight. No breakers popped. Assume up limit switch but could be emergency gear actuator. Upon inspection, it appears the red handle down and locked does not pull the lever forward (on the actuator, under the bottom panel) Am I correct that forward is Unlocked and backwards, with the spring pulling back is locked? 

[jetdriven]

When the handle is stowed, the cable is pulled, and the lever is pulled forward, and the spring is stretched. When you push the little tab forward and the handle pops up, the cable tension relaxes, and then spring, pulls the arm aft to engage the emergency extension Spool with Cable. So you probably need to look at that little piece on the end of the cable that clamps onto the cable just after the lever arm thing is loose or slips yeah it defaults to being engaged. 

[PT20J]

Mine has done that twice. First time it was the gear up relay (verified by tapping on the relay which caused the gear to retract), so I replace both up and down relays. The second time it was the gear up limit switch (verified by exercising the switch multiple times causing the gear to retract) so I replaced that.

If the gear fails to retract because the emergency gear system is engaged, it stalls the motor and trips the gear actuator breaker.

[AZOutlaw]

Thanks jetdriven and PT20J.  It does appear that the cable clamp had slid down the cable and the emergency gear was engaged, even when the handle was down and locked.  When I released the handle, there was 1/2" "slack" between that and the arm it is meant to engage and the cable clamp (pic).  Not sure if that was the issue as no breakers ever popped so it didn't really seem to care that the emergency clutch was activated all the time.

[jetdriven]

Nice cheap fix, you’re gonna be fine

[affricate]

  On 6/5/2024 at 2:42 PM, LANCECASPER said:

Worst case scenario would have been it failing when the gear was up

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Yeah man, I asked Don Maxwell a few months back when I replaced my old noisy Plessey actuator on my Bravo with a brand new Eaton actuator, "About how much more time you think this old Plessey will work?". Don replied, "till it don't". 

Glad your gear was down. 

[PT20J]

  On 7/9/2024 at 12:57 AM, AZOutlaw said:

Thanks jetdriven and PT20J.  It does appear that the cable clamp had slid down the cable and the emergency gear was engaged, even when the handle was down and locked.  When I released the handle, there was 1/2" "slack" between that and the arm it is meant to engage and the cable clamp (pic).  Not sure if that was the issue as no breakers ever popped so it didn't really seem to care that the emergency clutch was activated all the time.

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I hope that is the problem. But it doesn't match your symptoms. If the emergency gear system were engaged, why would it not flip the breaker? And why would it clear after 5 minutes or so? And if the stop on the cable slipped, did it do so all at once or gradually? The cable controls a clutch inside the actuator. It needs to be either fully engaged or fully disengaged. If it is partially engaged and the motor runs, it can chew up the brass clutch. If this were mine, I would put the plane on jacks and re-rig the cable and then thoroughly test the electric retraction/extension and the manual extension to be sure all is well.

[Shadrach]

  On 7/9/2024 at 12:57 AM, AZOutlaw said:

Thanks jetdriven and PT20J.  It does appear that the cable clamp had slid down the cable and the emergency gear was engaged, even when the handle was down and locked.  When I released the handle, there was 1/2" "slack" between that and the arm it is meant to engage and the cable clamp (pic).  Not sure if that was the issue as no breakers ever popped so it didn't really seem to care that the emergency clutch was activated all the time.

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so the long and short of this is that Skip’s analysis was correct and this could’ve been resolved without removing the actuator and sending it to LASAR?

[AZOutlaw]

  On 7/9/2024 at 3:36 AM, PT20J said:

I hope that is the problem. But it doesn't match your symptoms. If the emergency gear system were engaged, why would it not flip the breaker? And why would it clear after 5 minutes or so? And if the stop on the cable slipped, did it do so all at once or gradually? The cable controls a clutch inside the actuator. It needs to be either fully engaged or fully disengaged. If it is partially engaged and the motor runs, it can chew up the brass clutch. If this were mine, I would put the plane on jacks and re-rig the cable and then thoroughly test the electric retraction/extension and the manual extension to be sure all is well.

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I agree completely, it does not match the symptoms.  If there was a prox switch indicating the Emergency gear lever was disengaged, then maybe, but I see no wiring or indication that exists.  We will get it back on the jacks and test it out.  As mentioned, both times it did not retract was due to a big bump on take off.  My home runway has a dip about 1000 feet down and the second was on the worst concrete runway in Iowa.  Not sure what a big jar would do in take off, and why it would then go away.  Thanks for the help!    

[ttflyer]

Just to close out this original thread...

We sent the actuator off to be looked at and got a "there was nothing wrong with it" report back.  Everything including the NBS were checked and completely normal. They completed a service bulletin of some kind and did replace the emergency extension pulley as there were some indications of wear there that weren't up to snuff. 

We put the actuator back in the airplane and it worked normally.  Several flights later - no issues.

We also had our mechanic replace the CB as it had been tripped many times in all this and is 35+ years old...

I'm guessing it was an issue with the emergency extension engagement mechanism.  But our mechanic said he checked that... Who knows.  Anyway, it works now!