Gear down light

[flyboy0681]

Yesterday while preparing for landing the gear light did not illuminate. I immediately checked the bellcrank sight between the seats and it was full green and the white bar was where it should have been. My next step was to press the annunciator test button and the light came on.

I cycled the gear again and the light remained off. Flying in the right seat with me was my friend who flies 767's for American. While we were strategizing on what to do next, the light finally came on by itself (about 2 minutes after dropping the handle) and I proceeded to make a normal landing. The red "gear unsafe" light was off during the entire episode

When arriving back home the light came on normally.

I'm thinking a stuck micro-switch and would like to hear other opinions. Our A&P has been summoned to check the system out. Also, does the floor window actually mean the gear is locked into place?

[Magnum]

There are two gear down lights: One in the annunciator panel, and one behind the sight between the seats. Were both not working? Then I'd suggest a problem with the gear down switch, it is a changeover switch. It opened for the gear unsafe warning (and stopped the gear motor), but didn't close for the gear down light.

[N1026F]

Pick the least expensive fix and diagnostic first. After the same thing happened to me, I replaced the micro-switch ($300.00+) then found out it was the breaker switch to the warning light--much cheaper.

[flyboy0681]

There are two gear down lights: One in the annunciator panel, and one behind the sight between the seats.

Even during the best of times I can barely make out whether the light down on the floor is on, except at night. But yesterday the sun was shining right into the cabin and I couldn't make it out.

[David Mazer]

I was told in transition training, lo those many years ago, that the gear indicator between the seats was a mechanical linkage and as reliable an indicator as one could have but I don't know if it assures that the gear is locked. As a result I only look at the one between the seats during my pre-landing checks.

[David Mazer]

Even during the best of times I can barely make out whether the light down on the floor is on, except at night. But yesterday the sun was shining right into the cabin and I couldn't make it out.

That isn't right. My on the floor indicator light is always visible. You should deal with that issue also.

[Magnum]

That isn't right. My on the floor indicator light is always visible. You should deal with that issue also.

I *think* there was a wrong part number in the parts catalogue for some Mooneys. IMHO it was a 24V bulb for a 12V system, but I am not quite sure. With the wrong bulb installed you can't see the light. Even in bright daylight I can see if it is on or not.

Edit: Unfortunately the search function doesn't seem to work with old posts, I think there was a discussion about this some years ago.

[Magnum]

Pick the least expensive fix and diagnostic first. After the same thing happened to me, I replaced the micro-switch ($300.00+) then found out it was the breaker switch to the warning light--much cheaper.

A good point, the gear down AND the gear unsafe warning light go to this breaker. So if the breaker is popped, you don't get any warning. OTOH the light came on later in this case.

[Magnum]

I was told in transition training, lo those many years ago, that the gear indicator between the seats was a mechanical linkage and as reliable an indicator as one could have but I don't know if it assures that the gear is locked. As a result I only look at the one between the seats during my pre-landing checks.

The best way to make sure it is REALLY down. We had a gear up landing of a Mooney at my field some years ago. The pilot said that he put the gear switch down and that the gear down light was on. We put it on jacks, cycled the gear for more than 50 times. Everything worked fine and we thought it was an excuse for forgetting to put it down. We cycled it again, gear switch on down position, green light came on and the gear stayed up. The gear down micro switch didn't work and the pilots reputation was restored. What he didn't know was that there is the mechanical indication on the floor. The bulb was burned and he never looked down.

[flyboy0681]

That isn't right. My on the floor indicator light is always visible. You should deal with that issue also.

Your point is an interesting one Dave. Here is what my POH say's about the Gear Position Indicator: "The illuminated gear-down position indicator at the back of the fuel selector trim pan aft of center console has two marks that align when the gear is down and illuminates when the green gear down light is on"

But what you said is also valid because I've seen the entire unit illuminated at night.

[gwcolwell]

Similar experience with 1974 M20F. Micro switch in lh landing gear was at fault. Switch contacts burned causing ntermittent contact when gear down.

[mulro767]

Even during the best of times I can barely make out whether the light down on the floor is on, except at night. But yesterday the sun was shining right into the cabin and I couldn't make it out.

Mine was the same way before my last annual. They cleaned out the plastic cover and replaced the light. It is 10x brighter now and just a quick glance even in the brightest daylight confirms the gear down.

[flyboy0681]

As a follow up to this thread, I flew yesterday and made a note to check the floor sight light once I had the time. When the gear was up and the sight showed the barber pole, the light was most definitely out. The only time it illuminates is when the gear is down and showing green.

That said, when the light is on could it be construed that the gear is actually locked? In other words, is it an alternate indicator to the annunciator panel?

[Hank]

Unless the gear was reworked for your later models, the mechanical indicator is a primary indicator, the little green light on the panel is just a convenience. I always double-check the floor indicator on final just to be sure.

FYI, my floor indicator is Red when the gear is up, Green when it is down, and is barber-pole only in transition. It is never difficult to see during the day, but the backlight only comes on when I turn on the panel lights. The mechanical indictor is more difficult to spoof than a millivolt electrical current.

[Magnum]

As a follow up to this thread, I flew yesterday and made a note to check the floor sight light once I had the time. When the gear was up and the sight showed the barber pole, the light was most definitely out. The only time it illuminates is when the gear is down and showing green.

That said, when the light is on could it be construed that the gear is actually locked? In other words, is it an alternate indicator to the annunciator panel?

In my J the light illuminates together with the gear down light in the annunciator panel.

[kortopates]

After reading this thread some time ago there are two things that stood out:

- This is a great example of why Transistion training by a Mooney specific instructor can be so valuable - many folks apparently didn't learn in their transition training that the Floor mounted visual Indicator is the Primary indicator for verifying the gear is down and should be checked before every landing - Hank above has it eactly right. Its great to use the annunciator when you first put the gear down, but we all need to check the floor indicator no laterthan short final before landing.

- Secondly, from some of quotations from folks POH its evident you all didn't get the POH update that was first issued in 09-2001 in service bulletin M20-279 and now superceded by the latest M20-282-A. In it, on page 7, is a POH insert for all electric gear POHs that makes the above warning to check the Floor visual gear position indicator prior to ALL landings. If you don't have it , you can get for your POH at: http://www.mooney.com/images/pdfs/sb-pdf/sbm20-282-a.pdf

[xftrplt]

Deleted

[tyrefoote]

What was your resolultion? I'm having the same issue

[flyboy0681]

This incident was the one and only time it occurred. The light has been working ever since.

[Marauder]

Just a note on the floor indicator. In my 75 F, I actually had that indicator fail. It is a plexiglass piece that is mechanically linked to the gear. It gets pushed and pulled in a slot underneath the window you see in the cockpit. My failure was just the opposite. I had a gear down indication light, but the floor indicator showed the gear up. Big pucker factor on that landing since it was late in the day and to a remote airport destination.