Jump to content

Recommended Posts

Posted

On April 26th my wife and I were traveling to Nassau for a long weekend in the Bahamas. We planned a stop in Daytona Beach for fuel. When we departed Huntsville, AL there was a low pressure to the west pushing a cold front to the east so we had to pass through about 90 miles of light to moderate rain. When we arrived at Daytona Beach the controler took us several miles off shore to enter a right base for 25R. To make sure we had our best glide in case of an engine problem I left the gear up until we started our descent on final. 

As we started to descend on final I put the gear switch down and started my gear checks. Switch down, manual gear indicator in the floor in the green and and gear down light on is my normal procedure. When I looked at the floor indicator I remarked to my wife that the light must have burned out as it was hard to see the green indicator but it was there and I could see it. When I looked at the annunicator gear light it was off. At this point I knew something was wrong but I didn't know what. I am still at a couple thousand feet so I had time to cycle the gear up and back down and had the same indications. I checked the manual gear cover to be sure it was latched and I pulled the manual gear handle to confirm the gear was down. It is now time for a different plan as I knew I wasn't landing without a gear light since I didn't trust that the gear was locked down even though I was confident the gear was down. I thought I probably had a stuck or broken gear down switch.

I have always felt and I teach my complex students that the worse place to diagnose a problem is in the pattern. Close to the ground is no place to deal with the distractions of a gear problem. My call to tower was "Daytona tower, Mooney 49Q has a gear problem and needs to depart the pattern to troubleshoot the issue". He immediately offered an orbit over the speedway and a climb to 1500 feet which I took. In hindsight, maybe not the best spot since I had to stay away from the runways which was a lot more complicated because the autopilot was randomly disconnecting. Lots of distractions during the entire event including the tower asking fuel and souls on board. The tower was great during the entire event but I did have to ask him to standby once since I was feeling overloaded. Flying, troubleshooting and talking was one too many things to do. Things got really quiet after that.

After arriving at the speedway and getting the altitude back where it belonged I started troubleshooting the gear issue. At this point I planned to manually put the gear down since I had tried all the electric troubleshooting I could. When I reached to the circuit breaker panel to pull the electric gear breaker I noticed the gear indicator breaker was popped which explained the lack of lights. I pressed the gear indicator breaker back in and put the gear down which promptly tripped the breaker again. Not good. Next plan is to pull the breaker and manually extend the gear. That worked but I still didn't have a gear light. I reset the gear light breaker and the lights came on. I told the tower that I had a gear down indication and I was ready to land. He sent me on a fairly long downwind since he had two jets to land. I didn't realize until later but the controllers were holding the other planes on the ground to give us the runway.

During the downwind leg I heard someone asking about the alert aircraft and realized they were talking about us. That was a bit sobering. When we turned final we had two fire trucks and an ambulance on our left. They had four trucks at various places on the right of the runway. Lots of airplanes holding on the parallel taxiway since Emery Riddle does a lot of training here. Ok, this is for real. I made a nice slow descent and as gentle touchdown as I could. The gear stayed locked down and after I made the right turnoff on the taxiway I felt fairly confident that the gear wasn't going to collopse. We had one of the alert trucks and a fire truck follow us for a while. The alert truck followed us to the ramp and the airport authority guy took our statement. End of the incident but I still have a broken airplane and reservations in Nassau.

First step is to call Joey Cole and get some advice. He is at lunch and will have to call me back. Daytona Aircraft Services is on the field and were kind enough to put the plane on jacks to check the gear. We performed several gear cycles and no issues were seen. We pulled the gear indicator and confirmed that the gear would lock down even if the gear down indicators wouldn't light. The guys at Daytona Aircraft Services were confident that there were no issues with the gear and that I just had a problem with the gear indicator system. 

When I spoke with Joey and told him the problem his first question was did I fly through a lot of rain. I said that I had flown through about 45 minutes of moderate rain that morning. Joey said that water can cause issues with the gear indicators and that was probably what happened.

At this point I felt comfortable that the gear would come down even if the indicators failed to work. We fueled and loaded up to depart for Nassau. When we arrived in Nassau the gear extended and the lights lit with no issues. When we get home I plan to pull the wiring diagram and check for anything that could cause the breaker to trip.

What I did right:
    1) Left the pattern to diagnose the problem
    2) Managed the flight and got all the help I needed
    3) Didn't do anything to make it worse. I was really tempted to cycle the gear instead of getting it on jacks. How much worse would it have been if I had the gear down, put it up and then it wouldn't come down. 
    4) Landed at a field that had a Mooney service center on the field.

What I did wrong:
    1) I should have gotten out the checklist instead of doing everything by memory. I would have caught the popped breaker sooner.
    2) I should have cancelled my IFR clearance sooner. I didn't need it and it made the controller's and my job harder. I definitely busted my assigned altitude due to distraction.

I didn't declare an emergency but I am sure the tower controller did it for me. It will be interesting to see if I hear anything from the FAA about the event.
 

  • Like 18
  • Thanks 1
Posted

Great report Jim. We can all learn something from this. You could not have picked much better of a place to test yourself in. The Daytona approach controllers are amazing considering all the training traffic they deal with along with the big iron. Jakes' crew at Daytona Aircraft services are top drawer wrenches. Glad you worked the problem and saved a prop. Think NASA form since you busted altitude, probably no big deal since your sure the tower declared an emergency, but it doesnt hurt to do this. After all, the whole purpose is to learn and prevent of the NASA system.

 

  • Like 1
Posted

Nice job! I've had a gear motor failure once that required cranking my gear down...fortunately it happened when landing at Willmar for tank work so it was easily handled there. Sounds like you were similarly lucky in ending up a good spot, and you did everything well to get it down safely.

Sent from my LG-US996 using Tapatalk

Posted

I doubt you'll hear anything from the FAA.  I had a similar situation departing out of Austin Bergstrom one evening several years ago.  Retracting the gear popped the breaker and left the "Gear Unsafe" light illuminated.  Putting the handle back down and resetting the breaker would extend the gear no problem (with good indications).  I wasn't going far anyways, so I opted to return and drive and deal with it Monday morning in the daytime.  I by no means asked for any priority/urgency, but I was assigned 35L (normally not used for GA traffic)...and when I made it back to the airport, I saw why.  Like your event, firetrucks or ambulances at each intersection and lots of waiting commercial traffic, but unlike your event, I could have logged a couple of landings.  The entire parade followed me for the VERY long taxi to the other side of the airport back to the FBO.  It made for a huge scene...especially at night.  They wrote my information down asked about the situation, but that was the last I heard of it.  I hadn't really thought too much about it prior to that event, but those services would be nice if you had a less desirable outcome.  Glad your situation ended well though.

Posted

Hi Jim, I just had a similar problem in the same area on April 6th (just a few weeks ago) year except my gear did not go up. I was flying the coast from South Carolina past Daytona Beach to Merritt Island Florida thru rain and low cloud and planed on continuing to Freeport after refueling flight planning. The landing gear extended normally. But on departure from Merritt Island I put my gear switch up and nothing happened!!!! (Green Gear Light Stayed On)

I put the gear switch back to the down position and landed again at Merritt Island. I told my passenger only we were returning to the airport. I canceled my flight plan and decided no more flying for the day.

The cause was the same as yours, a circuit breaker had popped. The same circuit breaker runs my cigarette outlet. I have a splitter with a light that tells me when it is powered.

I reset the breaker and the cigarette lighter powered up again. The next day I tested the gear and continued my flight to the Bahamas, Sun-N-Fun and back to Ontario Canada. I kept a good eye on the power light from the Cigarette lighter. The power light flickered  a few times thru my flight home. I now have a replacement to install.

This breaker is sensitive and running your finger over it to check that it is engaged can be enough to set it off.

I would say that moisture is definitely a factor. And age. 

Posted
2 hours ago, jcovington said:

What I did right:

Number 1:  You had Jake and the rest of the guys at Daytona Aircraft Service look at your plane.

I just had a total panel redone there and you may have seen my C on the ramp, I am in the process of writing up a review on them for all here to read.

Oh and I never have these issues with my J bar.....

  • Haha 2
Posted

Well done and thanks for sharing Jim.

Another one to add to your list of of what you did right is Aviate - Navigate and Communicate.

Trying to use your autopilot to assist and have it continually disconnect must have put tremendous stress onto you.  

If an incident like this happens again and your wife is with you, consider using her as a resource by reading the appropriate checklist to you.  I have my checklist for the gotcha things on a laminated card in a pocket next to me for easy access without having to fumble through the POH. 

Posted

Nice work Jim! I’d still fill out a NASA report just for the record. Thanks for your thoughts! 

Enjoy your trip!!

-Matt

  • Like 2
Posted

 Very glad it ended well and thanks for the write up. I learned from it. Other than the placard on the instrument panel is the checklist to which you refer in the POH?

Posted

Agree.  I certainly learned from this, and appreciate the detail and time you took to write it up.  Very glad everything worked out in the end that no one (nor your airplane) were injured.

Steve

Posted

Thanks for all the kind comments. I had not thought about the NASA form. I'll get that taken care of.

The thing I found most confusing about the incident was that it was a failure in the gear warning system (which you jbar guys also have) not the gear motor system. When i take my annual flight review we always manually extend the gear by pulling the gear motor breaker. I manually extend the gear and the lights come on. In this case the gear extended like it should but I didn't get the lights. That senario isn't something I had practiced. It will be in the future.

My wife was great during the entire event. She helped when she could and stayed quiet when I needed her to. She watched the manual gear indicator as I cranked the gear down. I could have given her the checklist to read to me but I didn't think of that. I will show her how to do that so she will be ready if needed.

  • Like 1
Posted
14 hours ago, Jim Peace said:

Number 1:  You had Jake and the rest of the guys at Daytona Aircraft Service look at your plane.

I just had a total panel redone there and you may have seen my C on the ramp, I am in the process of writing up a review on them for all here to read.

Oh and I never have these issues with my J bar.....

I did notice a C model parked on the ramp. I was too busy to walk over and look at it. I am sure they did a good job on your panel. I look forward to reading your writeup.

I know you guys are just having fun poking at the electric gear planes but remember the problem was with the indicator not the motor. I haven't flown a C model in a while but I believe it has a gear down indicator light that the jbar turns on. If so, you could still have a similar issue.

Posted
55 minutes ago, jcovington said:

The thing I found most confusing about the incident was that it was a failure in the gear warning system (which you jbar guys also have) not the gear motor system

Except the jbar gear warning system is nothing more than a reed switch in the socket.   If my gear warning malfunctions, it's a simple matter of confirming that the jbar is locked in the gear down position.  If it malfunctions due to rain, I have bigger issues.  :):)

  • Haha 1
Posted
6 minutes ago, neilpilot said:

Except the jbar gear warning system is nothing more than a reed switch in the socket.   If my gear warning malfunctions, it's a simple matter of confirming that the jbar is locked in the gear down position.  If it malfunctions due to rain, I have bigger issues.  :):)

Ha. Good point. The water around your knees would be a dead giveaway somethings not right.

  • Haha 1
Posted
2 hours ago, jcovington said:

The thing I found most confusing about the incident was that it was a failure in the gear warning system (which you jbar guys also have) not the gear motor system.

I don't have the schematics for an M20J handy, but I have late-model M20F schematics which I'm betting are similar.

Here's the portion of the schematic showing the gear motor, the limit switches in the belly, and the light that controls the floor indicator lamp.  Note that one side of the limit-down DPDT switch controls the relays that shut off the gear motor, the other side goes to the floor lamp. The schematic happens to show the switches in the gear-down position, i.e. power applied to the lamp and power removed from the gear motor.

mooneygear.thumb.png.b603bf425c9bb3c763007830a8aeb412.png

 

That ring terminal splicing off the floor lamp indicator goes to the annunciator light on the instrument panel.  In other words, the same connection powers both the "Gear Position" floor lamp and the "Gear Down" instrument panel light.  If you trace that wire in the schematic, it leads to the panel annunciator lights themselves:

gear2.png.b47f3fde8e303e5cb80b67fa12cba1a6.png

Notice the annunciator lights have one common (ground) terminal, but two terminals for power (applying voltage to either one will light the lamp).  The "2" terminals on the right side connect to the push-to-test switch.  The "1" terminals on the left side connect to the limit switches in the belly... and also the floor lamp indicator in the case of the gear down indicator, as explained above.  In particular, when the down-limit switch moves to the "Gear Down" position, power is applied to the "1" terminal of the Gear Down indicator above.

So, couple of things to understand about failure modes.  First, if the gear indicator breaker trips, it affects both the panel annunciator and the floor lamp.  These two gear down lights are not on independent circuits, they're only "redundant" in the case of a burned out bulb.  The good news is, the mechanical lubber line on the floor indicator is still a good indication of gear down regardless of any lights.

Second, the terminals on the instrument panel indicators have to be physically close together since there are three of them - maybe 1/4" to 1/8" apart.  If you get a drop of moisture on the back of the indicator - perhaps streaming in through imperfectly sealed access panels just outside the windshield when flying in rain - it can form a short between the terminals.  If moisture forms a short between terminal "1" and terminal "C" of the gear down indicator, this can create an electrical short between power and ground - but not until the gear reaches the down position and the limit switch in the belly closes to apply power to terminal "1".  If you put the gear back up, power is not applied to terminal "1" and the breaker can be reset.  If you put the gear back down, the breaker will pop again when the down limit switch in the belly closes.  Sounds like this may be what happened to you.

Hope that helps.

  • Like 5
Posted

Nice work, Vance!

I just shared your post to another MSer needing help with his M20F gear indicator light...

You get a two-fer award! :)

Best regards,

-a-

  • Like 2
Posted
2 hours ago, Vance Harral said:

If you put the gear back up, power is not applied to terminal "1" and the breaker can be reset.  If you put the gear back down, the breaker will pop again when the down limit switch in the belly closes.  Sounds like this may be what happened to you.

Hope that helps.

Vance

Very nice analysis. Thanks for doing that research. That sounds exactly like what happened. When I get home I'll compare your drawings to the J schematics. I suspect you are right they are similar if not identical.

Jim

Posted

I had nearly the same thing happen but mine was on take off.  I hit the switch to raise the gear and nothing.  I continued out of the patter and area so I could evaluate.  After several checks determined it was the breaker.  Like you attempted to reset and it kept popping.  Then during one check I realized my manual gear release knob was already in the release position.  I then pushed the release knob back to position and "whala" I had normal gear operation again.  What I realized is that somehow my head phone cords had gotten wrapped up with the release knob and that it released when I pulled on my head phone cord.  I remained out of the area for a bit cycled the gear and aborted my scheduled trip (It was VFR and a beautiful day so less distracting than your day).  I returned to my home airport asked ATC if I could go missed and they could confirm all gear was in position as I had a circuit breaker trip but had resolved the issue.  Did the fly by and they confirmed all appeared from their vantage point to be normal.  I did not declare emergency and they did not either so I did not have the fan fair on landing as you did.  Once on the ground all inspections revealed normal and the last annual all normal.  But, as you know an odd feeling thinking is my gear going to actually remain locked once I touch the runway.

Posted

The fear that comes with electric gear operation while the manual system has been partially deployed.... is a destroyed spline shaft that keeps both the manual and electric gear systems from operating...

Use caution when stuff gets wrapped around that handle... or skipping that line item in the check list...

PP thoughts only,

-a-

 

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.