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Cold weather "saftey bypass" operation


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It was very cold this weekend and while doing circuits whenever I retracted my gear it started to pop the gear circuit breaker.  I discussed it with the previous owner who told me he had the gear bypass kit installed as shown here.  I understand that it has something to do with the pucks expanding and being hardened in cold temps.  Does anyone have the specs, operators manual or at least some instructions about how/when to use this?

Thanks in advance!
Dave

C-GQOT-193.jpg

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It was very cold this weekend and while doing circuits whenever I retracted my gear it started to pop the gear circuit breaker.  I discussed it with the previous owner who told me he had the gear bypass kit installed as shown here.  I understand that it has something to do with the pucks expanding and being hardened in cold temps.  Does anyone have the specs, operators manual or at least some instructions about how/when to use this?

Thanks in advance!
Dave
C-GQOT-193.jpg


It's to bypass the squat switch. If you raise the handle and the gear will not come up, you push that button and it will bypass the squat switch and it should retract.

Popping the breakers is an entirely different problem. More than likely you have hard Grease or the motor is getting weak.

I'm sure that Clarence can expound upon this further, especially living in the Frozen North as he does!

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The gear bypass switch allows you to raise the gear bypassing the normal anti retraction protections. Either the squat switch on the left gear leg or the airspeed switch.

Tripping of the gear circuit breaker is a sign of impending trouble.  High system friction, weak motor or bad gears in the transmission should all be eliminated. Remember that failure of the transmission gears results in gear up landing as there is no way of disconnecting a failed transmission from the retraction mechanism and lowering the landing gear.

There are a few AD's and S/B's on the subject.

Clarence

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Mine was popping the breaker.  The first step is to replace the breaker.   They get old and weak.   Still popped it with the new breaker.  The actuator is off getting serviced as we speak.  Something is hanging to pull that many amps.

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Clearly not the simple fix you were hoping for, Dr. Quinn...

But now is the time to find out what is causing the over-load challenge.

there are many funny things that happen with various parts of the plane in cold temps.  But, over load of the circuit breaker of the landing gear isn't one of them...

not going up because the donuts are cold,  that happens a lot...  hence the Plan B button that has been installed.

Landing gear can be sensitive to a few things, and easy to break considering the forces that are available.  Often, a back-seater can accidently release the E-handle for the manual operation of the gear.  The manual and powered gear systems are not designed to operate together.  Given the opportunity, One unceremoniously destroys the other.  Often resulting in a gear up landing.

Some people get the Circuit breaker challenge that you described.  Upon checking the manual gear system on the floor, they find the handle has been released from its clip...  you may want to see if your manual gear handle hasn't been released...?

There is an inspection procedure to make sure the brass gear inside hasn't been damaged.  The softness of the brass parts are easy to damage when this happens.

good luck.  This is a PP idea only.  The C's landing gear is a bit different than my O, but the basic challenge might be the same...

Best regards,

-a-

 

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How long has it been since the gear actuator has been out and cleaned and regreased?

What grease was used? (Alaska Airlines, Calif) It makes a difference when cold. 

Check the MM for the requirements.

Did they check the overcenter pressures at the annual? Did they "adjust" any of them?

Your airplane is talking to you, listen up!

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1 hour ago, cliffy said:

How long has it been since the gear actuator has been out and cleaned and regreased?

What grease was used? (Alaska Airlines, Calif) It makes a difference when cold. 

Check the MM for the requirements.

Did they check the overcenter pressures at the annual? Did they "adjust" any of them?

Your airplane is talking to you, listen up!

I'm listening but I don't understand her language just yet!  Don't know any of answers to your queries; I have only had her two months and most of that time it's been either grounded due to weather or in annual waiting for parts.  All I know is my mechanic, and the mechanic who did the pre-purchase a month beforehand were both very satisfied with the gear swings. 

We are going to put her back on the jacks and check her out.  We will be sure to check into some of the items listed here, thanks all of you for help.

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There are service bulletins on when and how to clean and regrease the actuator.  ADs 75-23-04,  73-21-01 are applicable to the landing gear of your airplane. The first one requires a lubrication and check of the gears of the gear actuator (if your airplane has the called for actuator) every 200 hrs. If it hasn't been done the gears my be worn and the grease dry causing problems. Badly worn gears are a BIG deal!

Using the wrong kind of grease can also cause problems with lower temperatures. Some greases freeze at lower temps than others.

The applicable ADs also mandate to check the "gear overcenter" links  for the correct "break open" torque to assure that there is the correct amount of pressure holding the system down and locked. It can be both too little and too much and cause problems. This check requires the use of special tools. It can't be done any other way. Ask your shop if they have the special tools. By saying that the gear was swung numerous times doesn't tell me they did the AD or the over center checks. 

The ADs also mandate a complete lubrication of the gear system along with the rest of the airplane. Look into your log books to see if the ADs have been complied with in the last year. 

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6 minutes ago, cliffy said:

There are service bulletins on when and how to clean and regrease the actuator.  ADs 75-23-04,  73-21-01 are applicable to the landing gear of your airplane. The first one requires a lubrication and check of the gears of the gear actuator (if your airplane has the called for actuator) every 200 hrs. If it hasn't been done the gears my be worn and the grease dry causing problems. Badly worn gears are a BIG deal!

Using the wrong kind of grease can also cause problems with lower temperatures. Some greases freeze at lower temps than others.

The applicable ADs also mandate to check the "gear overcenter" links  for the correct "break open" torque to assure that there is the correct amount of pressure holding the system down and locked. It can be both too little and too much and cause problems. This check requires the use of special tools. It can't be done any other way. Ask your shop if they have the special tools. By saying that the gear was swung numerous times doesn't tell me they did the AD or the over center checks. 

The ADs also mandate a complete lubrication of the gear system along with the rest of the airplane. Look into your log books to see if the ADs have been complied with in the last year. 

I am quite sure he doesn't have the special tools as he said we may have to figure out if I can find some to borrow around here in south central Ontario.  Thanks again!

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I am quite sure he doesn't have the special tools as he said we may have to figure out if I can find some to borrow around here in south central Ontario.  Thanks again!


You may want to take a quick hop over to Clarence's shop (M20doc). He has the tools and the knowledge and he is located somewhere near Toronto.


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Agree with fly it gear down to Clarence. Anyone else who doesn't know that special tools are required probably doesn't know the gear system all that well. Any adjustments made need to be reviewed and can be very detrimental to your aircrafts health and well being. Reference below

https://mooneyspace.com/topic/20619-landing-gear-collapsed-during-taxi/


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2 hours ago, bradp said:

Agree with fly it gear down to Clarence. Anyone else who doesn't know that special tools are required probably doesn't know the gear system all that well. Any adjustments made need to be reviewed and can be very detrimental to your aircrafts health and well being. Reference below

https://mooneyspace.com/topic/20619-landing-gear-collapsed-during-taxi/


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Thanks Brad.  The gear is coming up, it just pops the breaker before it knows that it is.  My mechanic does know the special tools required, just doesn't have them.  Regardless, I had a long chat with extremely helpful and knowledgeable Clarence.  Once we get 'er all figured out I will be sure to post what the problem was.

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