Electric gear issue 1965 M20E

[Luxuryairtravel]

Mooniacs, was doing a lil air work this morning and had a few items pop up that I plan on taking to the shop tomorrow. I always like to do my homework on issues so that I do not get the shaft and doing an engine overhaul because my gear wouldn’t come up lol. I know someone who fell for a easy inexpensive fix to overhauling his engine. I degress.. first takeoff positive rate gear up, electric gear, gear handle out and up, no retraction! Recycle no luck, third time gear came up. Went and did some air work cane back abeam touchdown gear down, sound and action perfect. Taxi back for takeoff rotate positive rate gear up nothing... needless to say I did 5 T/O and Landing all with same result if had to cycle gear multiple times before gear cam up. No issues on gear down. Gear up when coming real quiet and slower than normal in my opinion. Squawk switch? What say y’all? Thoughts? BTW I wouldn’t have done so many T/O and Landings if it was vice versus. Usually took 3-4 cycling of the gear handle to get the gear up.

Separate issue was Manifold pressure on last takeoff went to 13 inches on climb out 2500 rpms still climbing strong. Leveled off pulled power to 2400 went to 11 inches, on landing 1800 rpms went to 13 inches. Shut down up to 30 inches. Bad gauge, dirt in line, ??

 

[ShuRugal]

Sounds like a faulty switch or a cracked wire somewhere on the retract side of the circuit.

That said, you're a braver person than me. I wouldn't have left the pattern if the gear were being stubborn about retracting.

[BrianWilkins]

I had this same issue.  When your gear refuses to come up, use something and tap the floor under / just behind the pilot's seat and see if the gear comes up.  There are two switches and two solenoids that wear out over time.  That's where they're located.  I had to replace mine. Another way to troubleshoot is when the gear won't retract, leave it down and put the plane up on. jacks.  Remove the belly pan and tap around those switches and solenoids.  

Good luck!

[Luxuryairtravel]

Just now, BrianWilkins said:

I had this same issue.  When your gear refuses to come up, use something and tap the floor under / just behind the pilot's seat and see if the gear comes up.  There are two switches and two solenoids that wear out over time.  That's where they're located.  I had to replace mine. Another way to troubleshoot is when the gear won't retract, leave it down and put the plane up on. jacks.  Remove the belly pan and tap around those switches and solenoids.  

Good luck!

Curious on cost? 

[BrianWilkins]

Just now, Luxuryairtravel said:

Curious on cost? 

I just looked back at my info on it.  The total for the two switches and two solenoids was $865.  I believe it was about a day's labor for the A&P.

[carusoam]

5 minutes ago, Luxuryairtravel said:

What say y’all? Thoughts?

 

 

Since it could be nothing or something really huge...

Most would be disappointed by having to call it a day...

Most would be more disappointed by it not being a faulty switch, and having it turn into a Bent or broken push/pull tube...

As far as the MP...

Just an instrument issue, or did the MP actually drop that much?

 

Two things that would be better on the ground for problem solving...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Luxuryairtravel]

Just now, BrianWilkins said:

I just looked back at my info on it.  The total for the two switches and two solenoids was $865.  I believe it was about a day's labor for the A&P.

Thank you

[Ragsf15e]

I have had a similar problem every now and then.  Recently i took off the belly panel and lubed/exercised the up limit switch.  Before doing that, I called Dmax.  He was nice enough to talk to me for five minutes and knew the part numbers off the top of his head.  The switches are about $70 each, so $880 makes sense in GA terms.  My problem resolved for now after the lube...

switches:

Dt2ra7
Mcd2711

[Yetti]

Gear up issues are usually bad gear pucks.   It takes a while for the pucks to grow and activate the squat switch.

[Andy95W]

1 hour ago, Yetti said:

Gear up issues are usually bad gear pucks.   It takes a while for the pucks to grow and activate the squat switch.

The 1965 used an airspeed switch, not a squat switch.

But Yetti’s point is still valid- one more possible failure point.

[MBDiagMan]

What year model?  Need to know if it is a squat switch or an airspeed switch.  Did you ever have to rest the gear circuit breaker during all this activity?  That said it’s time for the plane to go on jacks.  In the process make sure the emergency extender is all correct and working correctly.  It can cause the circuit breaker to trip.

Mine has the airspeed switch.  I have it sorted except now I have a problem with the emergency extension mechanism.

The extension is a different circuit than the retraction.

[Yetti]

7 hours ago, Andy95W said:

The 1965 used an airspeed switch, not a squat switch.

But Yetti’s point is still valid- one more possible failure point.

Tru dat.   I think we have found some have squat, some have airspeed,, some have both.   I kind of think my 75 has both.   There is a thread on bad airspeed switch around these parts.

 

[Mooneymite]

10 hours ago, Luxuryairtravel said:

Mooniacs, was doing a lil air work this morning and had a few items pop up that I plan on taking to the shop tomorrow. I always like to do my homework on issues so that I do not get the shaft and doing an engine overhaul because my gear wouldn’t come up lol. I know someone who fell for a easy inexpensive fix to overhauling his engine. I degress.. first takeoff positive rate gear up, electric gear, gear handle out and up, no retraction! Recycle no luck, third time gear came up. Went and did some air work cane back abeam touchdown gear down, sound and action perfect. Taxi back for takeoff rotate positive rate gear up nothing... needless to say I did 5 T/O and Landing all with same result if had to cycle gear multiple times before gear cam up. No issues on gear down. Gear up when coming real quiet and slower than normal in my opinion. Squawk switch? What say y’all? Thoughts? BTW I wouldn’t have done so many T/O and Landings if it was vice versus. Usually took 3-4 cycling of the gear handle to get the gear up.

Separate issue was Manifold pressure on last takeoff went to 13 inches on climb out 2500 rpms still climbing strong. Leveled off pulled power to 2400 went to 11 inches, on landing 1800 rpms went to 13 inches. Shut down up to 30 inches. Bad gauge, dirt in line, ??

 

If the gear won't come up normally, there is (obviously) something wrong.  I think the best course of action would be to leave the gear DOWN and troubleshoot the problem with the plane on jacks.

[Ross Taylor]

Hey @Luxuryairtravel is this a new-to-you E?  One thing I didn't get from reading your symptoms is if this is a new issue that just cropped up or not...and if this is a new bird for you.  And, what's your airspeed when the gear does come up?  If you're raising the gear right after TO and at first positive rate confirmation, your airspeed might well be below the threshold of the airspeed gear safety switch.  Did you try just leaving the gear switch in the up position as you accelerate and see if the gear comes up at, say, 85-90 mph?   I'd try that, first, to see at what speed the safety switch allows the gear to come up.  If it's in need of adjustment, that's pretty easy to do.  This can also be done on the ground, with the plane properly jacked up - put the gear switch in the up position, put a piece of rubber tubing over the pitot tube and roll it slowly towards the pitot tube...as the airspeed indicator slowly reads a higher airspeed, at some point the gear should come up.  This is a two-person job...or one person with a camera set up to film the panel.

[Ragsf15e]

1 hour ago, Mooneymite said:

If the gear won't come up normally, there is (obviously) something wrong.  I think the best course of action would be to leave the gear DOWN and troubleshoot the problem with the plane on jacks.

The problem is the sporadic nature of the failure.  Maybe the OPs would cooperate and fail while it’s up on jacks, but mine has not.  It’s probably had a “delayed retraction” on 4 flights out of the last 100. I don’t even recycle the switch and it has gone up after about 30 seconds.  One time it stayed down 10 minutes while I circled around the airport.  Then it magically came up. That’s when I called Dmax.  I’ve had it on jacks after the first couple times and it works perfectly. Super frustrating.  Mine has an airspeed switch as well.

So to the OP, I do agree if it’s happening relatively regularly, definitely get it up on jacks. This would almost be a best case because you can isolate the issue.

 If it’s infrequent, there are at least three switches, two solenoids, an airspeed switch, and all the associated wiring where you could have something failing or loose.

[Mooneymite]

How would the MS community respond to an incident report like this?:

"When the landing gear failed to retract normally after takeoff, pilot elected to cycle the gear switch multiple times.  Upon landing, the gear collapsed.  The pilot evacuated the aircraft without injury."

Edited August 20, 2020 by Mooneymite

[Ragsf15e]

6 minutes ago, Mooneymite said:

How would the MS community respond to an incident report like this?:

"When the landing gear failed to retract normally after takeoff, pilot elected to cycle the gear switch multiple times.  Upon landing, the gear collapsed.  The pilot evacuated the aircraft without injury."

Well if the handle is down, the green light is on, and the floor light shows down but you still have it collapse after landing? 

[Luxuryairtravel]

This is my first Mooney, 19th aircraft, 6th complex, wasn’t cycled immediately with positive rate that’s a call on the jet I fly, just saying. I let the aircraft climb out above 85 and select gear up. I rotate around 70 and pretty quick to 85. It was in the up position for 30 seconds before I tried and cycle the gear and that speed I kept between 90 and 100. Green light down and lock on floor never moved or blinked. 3-4 times green light out 2-3 seconds red light. I am up on emergency gear extension and never once did I feel that it was unsafe. Gear select down, good sound, green light within a second or two and confirmed. I was reaching out to find out if this was an issue on the pre j models with electric gear and what y’all have found. I gather thus it kinda is. So thank you for the feed back and input. 

[Ross Taylor]

Thanks for the additional info, @Luxuryairtravel - this helps. And...it's very possible that your gear airspeed switch may be set closer to 90...not that that's right, but they're not that exact and the diaphragm might change over time.  Knowing at what speed your gear will retract will answer this first troubleshooting question.  Hopefully, that's all the adjustment you'll need. 

[carusoam]

So...

We have a few things to go on...

1) Something isn’t working as designed... leaving the gear down...

2) Squat switches are more popular with older birds...

3) Squat switch problems usually appear with cold weather...

4) air speed switches age...

5) Air speeds switches can get OH’d

6) Either way this is a simple system...

7) Look up what switch you have... clean it, adjust it, get it OH’d...

8) Prove that it is working properly...

9) Fly until the next thing breaks...

10) There is a by-pass system that can be installed...

11) Why do they have a by-pass system? Probably because the airspeed switch and squat switch have aging issues...
 

12) expect it to get worse until it gets fixed... it might be something a simple as a loose wire...

There are many pics around here of squat switches and airspeed switches and where to find them...

PP thoughts only, not a mechanic...

Best regards,

-a-

[Luxuryairtravel]

Update: went into Maintenance and the airspeed switch is set around 93, +/- 2 knots. It’s the old silver switch that can not be adjusted. I understand the new switch which is gold, can be adjusted. So when climbing initially around 90 wasn’t working until I got to 95ish it worked. Manifold pressure gauge system blew out and cleaned and works fine. Expect the gauge is going bad.

Next question(s): the alleged gold pressure  switch I’m looking for vendor, price, part #. I can go through Mx but like to know. Mooney Manifold pressure gauge serviceable or can he purchased? 

Love this site and Blue Skues Mooniacs!!

[carusoam]

Probably best to find used... for a decent price...

Are you familiar with the resources around here?

Best regards,

-a-

[Luxuryairtravel]

No, other than just use the search function 

[Ragsf15e]

You can try @Alan Fox for the airspeed switch.  Prepare yourself, they aren’t cheap.

[carusoam]

We have three resources of pre-flown parts...

@Alan Fox my local NJ-ersian...

@Jerry Pressley an excellent resource for parts in TN...

@SheryLoewen for the most Mooney parts on the left coast... aka Paul, using his wife’s PC.... 

 

PP thoughts only, I have bought and/or sold at least something with these three...
 

Best regards,

-a-