Pooldoc

I have a 1975 M20F and will be opening the belly (with an A&P) to inspect/service the switch that indicates the gear position. When I'm down there, I want to replace the bulb that illuminates the background of the gear indicator window in the floor. I want to be ready, so I need to know the bulb specs in order to not lose any flying time. Also, is there an LED substitute so I won't have to replace it again in the near future? Thanks again for your help, Larry

I do have a squat switch. I didn't think there would be any problem pushing the override button on the ground because the selector for the gear was in the down position. Maybe I was a little brave (dumb?). Isn't there a mechanism that lets the plane know the gear is actually down and locked? Does the squat do this as well? 2 functions? Thanks for anymore help you can give.

I have a 1975 F model and believe I have a squat switch and a gear safety bypass switch which I think was added after original manufacture. I also have a manifold pressure indicator switch which turns off the gear warnings over 13" pressure. I don't believe I have an airspeed activated switch. Here is the problem: 2 days ago, at a visiting airport, after being tied down in a heavy cross wind all day, I started up and after idling a while, the gear unsafe light and audible alarm went off. It continued until I pressed the bypass switch. I then taxied and it went off again and I did the same thing and it went off again. After figuring it was just a problem with the warning system and not the gear, I took off. Looking back at it, it was probably a bad decision, not knowing what was really wrong. At the time, I thought the turbulence on the ground might have temporarily disturbed something as well as some moderate turbulence on the way there. The gear retracted normally, I flew for 2 hours, no warning lights, sounds and landed at my home airport with no malfunctions. I then taxied back to my hangar and no warnings occurred. I plan on having it looked at ASAP. I am wondering if it is a gear down position (over center) sensor switch malfunction. I should of let the warning continue and see if it went off during the run up when the manifold pressure was raised. I was wondering if anyone knew what could of caused it. Thanks in advance. Larry

Maybe I should start a new thread, but since there are people tuned in here who have been through this, I'll ask here... I have a 1975 F model and believe I have a squat switch and a gear safety bypass switch which I think was added after original manufacture. I don't believe I have an airspeed activated switch. Here is the problem: 2 days ago, at a visiting airport, after being tied down in a heavy cross wind all day, I started up and after idling a while, the gear unsafe light and audible alarm went off. It continued until I pressed the bypass switch. I then taxied and it went off again and I did the same thing and it went off again. After figuring it was just a problem with the warning system and not the gear, I took off. Looking back at it, it was probably a bad decision, not knowing what was really wrong. At the time, I thought the turbulence on the ground might have temporarily disturbed something as well as some moderate turbulence on the way there. The gear retracted normally, I flew for 2 hours, no warning lights, sounds and landed at my home airport with no malfunctions. I then taxied back to my hangar and no warnings occurred. After reading above, I plan on having it looked at ASAP. I was wondering if anyone knew what could of caused it. Thanks in advance. Larry

I want to thank you guys for all the good advice regarding the fuel dip stick. I made one using Tim's numbers, on a wooden paint stick, for a 32 gallon tank. It is very accurate considering what the fuel flow meter says I used from last fill up. Thanks again. I just made a PVC fuel tank selector valve tool and am working on a cordless drill powered taxi "tool". Larry

Thanks to everyone for your help. I would appreciate those measurements when you get back to your computer, Tim. I already did a little tank experiment when the tank was last filled. I didn't run it dry, but the gauge said empty and looking in the tank , I could see the bottom from directly under the fill cap and the gauge float resting on the bottom. The odd thing was, when filling, it only took 25 gallons. I have 32 gallon tanks. I assume there is approximately 5-7 gallons held on the fuselage side of the fill cap (downhill, near the drain sump), when the bottom of the tank (directly under the fill cap, where the dip stick would measure) is dry. Therefore, when the dip stick reads empty, it can really have 5-7 gallons left. Is this assumption correct? Another question is, when filling it, what is full? I stop about 1/2" below the fuel cap flange. Is this correct to get 32 gallons? Thanks again, Larry

Hi, I'm a new member and new owner of a 1975 M20F. I love the plane and am just getting use to it after my complex checkout. Does anyone know of where I can get a "Dip stick" for directly measuring the amount of fuel in each tank of an M20F? If someone has one, maybe I could just get the measurements and make it with a thin piece of PVC or wood. Thanks, Larry