M20J Gear not retracting

[Mikhail]

Hello everybody, my landing gear is not retracting, any tips by what I should start the troubleshooting?

Many thanks guys!

 

[jetdriven]

if its a 1977 or 1978, the rubber donuts get stiff in cold weather and dont expand at liftoff, which wont allow the squat switch to close, allowing power to the gear motor.  If you dont have the red gear bypass button you can install the cold weather kit which will give it to you. If its later than 1978 it could be the airspeed switch

[KSMooniac]

Start with Byron's suggestions, and if those don't solve the problem then move to the limit switches for the gear up/down travel.  They might be sticky or corroded.

[Mikhail]

if its a 1977 or 1978, the rubber donuts get stiff in cold weather and dont expand at liftoff, which wont allow the squat switch to close, allowing power to the gear motor.  If you dont have the red gear bypass button you can install the cold weather kit which will give it to you. If its later than 1978 it could be the airspeed switch

It is 1980 model. does it have a squat switch? Or it is airspeed pressure switch ?

 

I have a red button - try to push it nothing happened . I flown yesterday it was around +7C and today is drop down to -9C so my suspicion was the cold.....I was thinking a kinda Weight On Gear  switch...

 

Thank you will check it tomorrow.

[Mikhail]

If it is a '78 or later, check to ensure that a rear seat passenger did not dislodge the emergency gear pull latch cover on the floor between the front seats.  If this gets unlatched the gear will not operate.  Someone comes on here about once a year with this problem.  Good luck!   

 

Jim

 

 

Jim thank you, the handle between the seat is latched and has not been moved.....

[jetdriven]

You got me, Jim.  The squat switch ran until 24-0237 but the sidewall crank  wasnt changed for the lever type pull thing until 24-0377.  I always assumed they were together.   At any rate, they both were present only in 1977. the 1978  got it together and is a "modern" airplane. Only half of it is obsolete. 

 

Mikhail you should have the pressure switch behind the airspeed indicator. Careful with that thing, people put compressed air to the pitot and blow that thing up, its a smooth 2 grand for another used one. 

 

Seeing as how its so cold out, any number of things may have frozen.

[Mikhail]

 

Mikhail you should have the pressure switch behind the airspeed indicator. Careful with that thing, people put compressed air to the pitot and blow that thing up, its a smooth 2 grand for another used one. 

 

Seeing as how its so cold out, any number of things may have frozen.

Byron, please advise what exactly should I do with airspeed indicator....? The airspeed indicator in flight was working without questioning....

Thank you.

[Marauder]

Byron, please advise what exactly should I do with airspeed indicator....? The airspeed indicator in flight was working without questioning....

Thank you.

On the back of the airspeed indicator there is a device called the airspeed switch. The switch senses the airspeed of the aircraft and will allow gear retraction once the plane reaches a pre-set airspeed. The guys with one can tell you what it is.

The switch should have wires coming off of it that go into the gear system. Byron is suggesting that you could have a problem with that switch, wires running to the switch or something frozen, perhaps moisture in the switch.

[Mikhail]

On the back of the airspeed indicator there is a device called the airspeed switch. The switch senses the airspeed of the aircraft and will allow gear retraction once the plane reaches a pre-set airspeed. The guys with one can tell you what it is.

The switch should have wires coming off of it that go into the gear system. Byron is suggesting that you could have a problem with that switch, wires running to the switch or something frozen, perhaps moisture in the switch.

Got it , thanks.

[Marauder]

Got it , thanks.

You're welcome. What is troubling is that you do have the red override switch and you said it doesn't allow for the gear to retract. This sounds more like an issue with one of the gear position switches.

[Mikhail]

You're welcome. What is troubling is that you do have the red override switch and you said it doesn't allow for the gear to retract. This sounds more like an issue with one of the gear position switches.

So you are recommending start troubleshooting by pressure switch or by jacking the a/c? What do you do on my place?

Thanks.

[jetdriven]

Jack the airplane, put some surgical tubing over the pitot tube, roll it up and clamp it at 80 MPH.  put the gear lever up. if it doesnt move hit the gear bypass button. if that deosnt work, then like others said, look at the limit switches and the actuator, and the airspeed switch.  if the gear handle goes green when u throw the switch the perhaps the up limit switch is stuck closed.  its a simple system. just mess with it on jacks.

[Marauder]

I would get the plane up on jacks in a warm hangar and see if I could get it to retract. If it is cold related that should eliminate it.

The red button is supposed to override the air safety switch. It isn't. So that would make me believe the override switch is not working or you have a problem with the gear somewhere else.

Does the gear unsafe light come on and does the red light on the override switch light?

I have the squat switch and if my gear won't come up because of cold donuts, then the gear unsafe light comes on and the I push the illuminated red light on the override.

[Mikhail]

Does the gear unsafe light come on and does the red light on the override switch light?

 

No,  that light  it doesn't come on.

[ArtVandelay]

At the risk of stating the obvious, you did check the circuit breaker?

[Mikhail]

At the risk of stating the obvious, you did check the circuit breaker?

.... reset it hundred time, thanks...

[Marauder]

No, that light it doesn't come on.

Should be two different lights. I'm not familiar with the 1980 setup, but you should have a gear unsafe or gear in transit light come on either next to the gear switch or on the annunciator and the gear override switch's red light should come on during retraction.

If you have neither or just one something is not fight with the electrical system (switches, limit switches, wiring, etc.) Best to get it up on jacks and figure it out. The last thing you want is a partial retraction and getting it stuck there.

[blaine beaven]

I bought my 78J right before it got cold, but have noticed as it's gotten colder that on occasion during climb out it won't retract gear at 80kts. The red bypass light flashes. I either re-cycle, and it works, I put the nose down to pick up a bit of speed, or I push the bypass switch. Any one of those retracts the gear. I'm assuming moisture in the airspeed switch system.

The other nifty thing that only happened once at -25C at 9500 feet in the dark is the gear extended, uncommanded, in cruise. I had the autopilot on and was noticing a slightly nose high attitude and then saw my airspeed had dropped. No warning lights were on, power was normal. I had time to troubleshoot so checked mixture, mags, fuel then cycled the gear and problem solved. Hasn't happened since, and that was about 15hrs ago.

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[Awqward]

I bought my 78J right before it got cold, but have noticed as it's gotten colder that on occasion during climb out it won't retract gear at 80kts. The red bypass light flashes. I either re-cycle, and it works, I put the nose down to pick up a bit of speed, or I push the bypass switch. Any one of those retracts the gear. I'm assuming moisture in the airspeed switch system.

The other nifty thing that only happened once at -25C at 9500 feet in the dark is the gear extended, uncommanded, in cruise. I had the autopilot on and was noticing a slightly nose high attitude and then saw my airspeed had dropped. No warning lights were on, power was normal. I had time to troubleshoot so checked mixture, mags, fuel then cycled the gear and problem solved. Hasn't happened since, and that was about 15hrs ago.

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Wow...I'm guessing your Gear switch is dodgy.....did you pull the CB to prevent any further uncommanded occurrences?

AQ

[lsearcy]

If it is a '78 or later, check to ensure that a rear seat passenger did not dislodge the emergency gear pull latch cover on the floor between the front seats.  If this gets unlatched the gear will not operate.  Someone comes on here about once a year with this problem.  Good luck!   

 

Jim

 

FWIW, Byron, '78 models use an airspeed safety switch for the gear like later models and don't have squat switches.  At least mine doesn't. 

That was my issue about a year ago.  Rear seat passenger dislodged the red latch.  Relatched and problem solved.

[blaine beaven]

Wow...I'm guessing your Gear switch is dodgy.....did you pull the CB to prevent any further uncommanded occurrences?

AQ

No. It had not happened in the prior 10 hours of flying it. It has not happened since. I'm usually not indicating much above gear speed when I am in cruise. I am hoping it was a one-off gremlin in the machine. All I can do is monitor.

Pulling the CB only works if it was an extension event as opposed to a "relaxing" event. If there is some mechanical linkage issue the CB won't prevent it.

I am also wary of disabling my landing gear system and forgetting I have disabled it during a high workload landing and ending up landing with the gear up. It seems like an unnecessary risk.

Blaine

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[Awqward]

I meant only for that particular flight...immediately after it happened....like you I wouldn't feel comfortable pulling a CB as an ongoing procedure...

Also, as far as I know, the gear in our Mooneys has to be driven down by the electric motor (or the emergency extension drive)...ie it shouldn't "relax" itself down..... Of course the downside to this is that if the emergency gear system fails (because the brass clutch has been unwittingly stripped) there is no way to get the gear down in the event of a primary failure....

[blaine beaven]

Good to know about the gear extension system. The plane (and mooneys) is still new to me. I know some of the hydraulic systems on planes I flew before liked to sag on long flights.

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[Mikhail]

It was still cold outside for SC, around -5C in the morning

 

Jacked the a/c, take of the belly panel visual inspection show nothing.

 

Get in the cockpit turn the master on and pull the GEAR UP. Nothing.

Turned master back off..

 

Just for last desperate action before go any further I slightly tap the gear motor with my screw driver....

 

Get back to the cockpit turn the muster then pull the GEAR UP...   GR SAFETY BY PASS push-button has illuminated...

I push it...

Gear has retracted without any problem!!!! 

 

Thank everybody for tips!

[jetdriven]

Motor brushes perhaps wiring. Be careful with that thing