Gear popping circuit breaker on both extend and retracct

[Ronald Cecchi]

Hello all,

I am a frustrated new owner of a 260c turbo. I purchased the plane in December and have been like a kid who gets water skis for Christmas. I have not been able to fly much due to a horrible winter in upstate New York. Now that I have had a chance to fly it the gear is giving me fits. I am popping the circuit breaker on both extend and retracts. Each time, after the circuit breaker is reset, the cycle completes properly. I am also getting a low bus voltage light, but have still not confirmed when it comes on during this process as I have only had time a weather to fly the plane a few times.

History - the gear was entirely rebuilt a few hears back including the motor and transmission. I flew the plane extensively prior to buying with no gear issues and the prior owner had not issues. The plane was put on jacks and cycled repeated with no issues at all. It was cycled close together to see if gear gear motor temp could be an issue.

Comment - it has been a cold winter and all of the flying has been in very cold weather. The airplane was always slowed down well below the gear operating speed limit. The gear test on jacks was in a 50 degree heated hanger where the plane is currently stored.

I guess I am looking for ideas. Is it temperature related, perhaps caused but grease issues that may be impacted by severe cold? Perhaps a weak circuit breaker, again impacted by the extra demands of cold temps?

Also - is the low bus voltage a cause, effect or unrelated?

Thanks for any ideas. I can't wait to start flying my airplane more, but this gear issue is making it tough!

[William Mattson]

Do you have the new Webco conduits? When I replaced mine last year, the old ones worked really hard and in the cold Minnesota temps they were taxing the motor. I flew last week at -20F and no problems.

Bill

[JIMICS2452]

Probably time to order new conduits from Webco or Piper. Both have long lead times.

[N3322G]

You might also want to have the gear motor and transmission handled by Matt Kurke comanchegear.com Trust him with my plane and therefore my life.

IIRC Piper suggests changing the circuit breaker if it has been popped.

Probably not the way you wanted to start your Comanche ownership - after 44 years, I still find our twin great fun to fly.

I would take the plane to a highly experienced Comanche shop for this work as adjustment after work like this takes patience. After a shop claiming this experience installed the Twin's and I noticed a discrepancy according to the Service manual you can find under Tech Tab on the main page(I am not a mechanic so it had to be blatant), I flew Matt to Texas and he removed and re-installed with the finishing being done by Clifton Aero. Matt may not do this anymore but it was worth it. He found multiple other discrepancies.

Hope this helps.

[James Gardner]

Ronald:
I would second the suggestion to involve ComancheGear in solving your problem. I brought my Twin Comanche from Wisconsin last November, and have popped the gear CB. On jacks, we cycled the gear too many times too quickly, and I burned up the motor. Piper says to wait 10-15 min after cycling once, so be careful. Lesson learned... I am using grease liberally, and not doing touch & goes.

[MULEFLY]

1. Talk to Matt at Comanche Gear
2. Talk to Matt at Comanche Gear
3. Talk to Matt at Comanche Gear

Your gear may have been serviced recently, but that does not mean that it was properly rigged... I'm guessing that "many if not most" servicings are done incorrectly.

Matt has a test stand that can evaluate your gear and tranny assembly... it is not that difficult to pull that assembly and you can send it to him and have him do a thorough evaluation. You may have a Dura tranny that is worn... fairly common.

Matt is the man on this issue.
Jim

[Zach Grant L1011jock]

James,
Not to be argumentative, but could you please provide a reference to your statement that Piper says to wait 10-15 minutes after each gear cycle before cycling again? The only "limit" I know of is that of the electromagnet on the transmission brake (this is not a published limit in any POH but is a duty rating of the particular part). It is rated at 90 seconds of duty every 30 min. So if the average in transit time is 8 sec for the gear, and it takes you 5 minutes per circuit, you can do 5 touch and goes without exceeding that duty cycle on the brake. If all else is good with the system, the motor should be good for many more cycles than that before getting hot. If anyone smells "Hot" electrical smells, from your transmission, check the brake as it is the first thing to go.
-Zach

[md11flyer]

I also did many touch and goes with my ex Pa-30 and out of curiousity, in the summer time,after the last landing took off the gear extension cover and felt the motor, it was warm to touch, but nowhere near hot. In College, way back when, when we used the twin comanche extensively for multi training, the gear would go up and down like a yoyo all day long with no known adverse effects. Of course like everything, the key is proper maintenance which includes new grease every other year or more if used as a trainer.
So for those that have hot motors after a couple of cycles, that indicates binding in the gear somewhere (conduits), or the motor/transmission needs service.
My 2 cents,
Gary

[James Turner]

Hi Ronald,

I had a similar problem with my -180 a few months ago. For me during one retraction cycle the breaker popped with the gear half way up. Before the breaker popped the load was so large that it tripped the alternator off line and caused a low voltage alert (JPI930).

I waited 5mins, reset the breaker and lowered the gear using the manual handle to assist. It took two tries of this procedure to get the gear completely down and locked.

Back in the hanger the gear motor was warm to the touch and there was an electrical smell. Long storey short I had blown the gear motor due to excessive load in the gear system, most likely from stiff conduits. I have since replaced the gear motor and I am waiting on new conduits from Webco.

A good test to perform is to place your aircraft on jacks and perform the manual gear disconnect procedure. Make sure you have someone or something under the aircraft to prevent the gear slamming down BUT, if your gear falls slowly to the mid-extended position like mine does then I think you could strongly suspect that your conduits need replacing.

While I am waiting for my new conduits I have limited gear cycles to one per flight. If I fly circuits then I do it with the gear down. If I fly instrument approaches for practise then I do it with the gear up. I will also continue to assist the gear cycle with the manual handle (old style -180) until I have me new conduits installed. I also watch the load and voltage like a hawk during each gear cycle.

Best of luck.

James.

[Paul Michel Fenouil]

[Paul Michel Fenouil]

[papajoe]

Had similar issues on first flight after purchasing my 260B, did pretty much as other; took to shop, cycled gear etc. but failed again once in the air. In the end good lubrication proved to be the cure, coincidentally also changed battery to address other issues. It does get one's attention when the gear fails to come down.
Joe

[MV Case Jr]

How old are the bungee cords ? In very cold weather they will be stiff and may not work as well as they will in warm weather .

T-6 Driver