M20E Fuel Starvation Accident

[kortopates]

Interesting, as in something to learn, by this fuel starvation accident involving an M20E.

http://www.kathrynsreport.com/2018/02/mooney-m20e-chaparral-n7118u-registered.html 

This one happened climbing out from takeoff at only 1000' agl which doesn't say a lot about the pilots pre-flight. But that low, the pilot tried changing tanks but had to put it down. See the very brief report. 

Since these birds have the fuel selector in such a bad place that many pilots use a hand made PVC tool to switch tanks, I wonder if a possible combination of a tight fuel selector and such a practice led to not noticing the handle was becoming loose till it created this real problem. Regardless, Its something this event suggest to be on the look out for; as well as ensuring your on the fullest tank with plenty of gas.

 

[jetdriven]

That setscrew is a critical safety of flight item and it’s also on the mooney annual checklist. 

[RobertGary1]

Lasar told me there have been cases of fuel selectors jamming mid-change ( in the off position). Because of that I removed mine and sent it to them. They offer a full service on the units.

 

-Robert

[jetdriven]

Idk if it’s on the checklist but checking the fuel selector for operation and detents is on the preflight portion of the “checkmate” checklist we have. Regardless, I would always preflight that thing and make sure it’s proper before relying on it to supply fuel from both tanks. Sometimes interior trim screws migrate their way to the little well the fuel selector is contained in and certainly will jam the selector. The pre-1978 fuel selector is very poorly designed and very poorly located. When you absolutely need it right now how fast can you switch tanks? 

Edited February 22, 2018 by jetdriven

[EricJ]

I pull the gascolator ring before startup for both tank selections, i.e., pull it, switch tanks, pull it.   I've not looked super close at it, but mine is safety wired and I feel the safety wire every time I move the selector.

Fortunately for me the selector spot isn't problematic and I can reach and switch it easily.   I'd definitely be a bit anxious about it if I couldn't.    

[RobertGary1]

1 minute ago, EricJ said:

I pull the gascolator ring before startup for both tank selections, i.e., pull it, switch tanks, pull it.   I've not looked super close at it, but mine is safety wired and I feel the safety wire every time I move the selector.

Fortunately for me the selector spot isn't problematic and I can reach and switch it easily.   I'd definitely be a bit anxious about it if I couldn't.    

For me the POH says to do this as part of the preflight checklist. So I've been doing it for 20 some years.

-Robert

[gsxrpilot]

I would expect the fuel selector would be used on every single flight. And they don't just "break" overnight. 

I had a problem with a fuel selector in my M20C once. It was getting more and more difficult to move, but with my PVC tool, I could still move it. Once over Arkansas I needed to switch tanks and couldn't get the selector to move. I struggled with it for a few minutes and then decided to turn around and head for the nearest airport. Once established on a track to the nearest, and I still had more than enough fuel to get there, I kept working it. Eventually it broke lose and I was able to switch tanks. Now with a full tank to work with, I flew on to my destination. But within a couple of days it was on the ramp at KGGG. Don's guys rebuilt the selector and it was smooth as butter after that.

Now with my 252, which has the selector in a much better location, I always verify it's functioning correctly before running a tank dry on long xcountries.

[jaylw314]

3 hours ago, RobertGary1 said:

For me the POH says to do this as part of the preflight checklist. So I've been doing it for 20 some years.

-Robert

+1, running the gascolator drain on one tank, then the other is in my POH.  Is it not on older models?

[Hank]

I like to start the engine then switch tanks. That way I know it draws from both. 

[RobertGary1]

1 minute ago, Hank said:

I like to start the engine then switch tanks. That way I know it draws from both. 

Have you started with the selector in the off position to test that? There can be a fair amount of fuel in the system.

-Robert

[Hank]

Just now, RobertGary1 said:

Have you started with the selector in the off position to test that? There can be a fair amount of fuel in the system.

-Robert

If I land in one tank, I know it works. Then crank on it and switch to the other one while the GPS boots up and finds satellites. Confirm on fullest before reaching Hold Short. 

Found and switched tank once in about 3 seconds, as it cut off when I was distracted and forgot to change just over 3 hours into a trip and ~15 minutes from my destination. 

[jetdriven]

30 minutes ago, Hank said:

I like to start the engine then switch tanks. That way I know it draws from both. 

I like that habit, but I would only switch tanks right after starting it, certainly not within 3-5 minutes of taking off. I have forgotten to take off or land with the fullest tank, I figure it’s a much smaller hazard to do so in cruise than just before a critical phase of flight. 

Edited February 22, 2018 by jetdriven

[jaylw314]

12 minutes ago, jetdriven said:

I like that habit, but I would only switch tanks right after starting it, certainly not within 3-5 minutes of taking off. I have forgotten to take off or land with the fullest tank, I figure it’s a much smaller hazard to do so in cruise than just before a critical phase of flight. 

I guess that depends on how much fuel is in the fuel lines.  If there is 30 seconds of fuel in he fuel lines at idle power, then after startup you'd need to wait 30 seconds before switching tanks to ensure it is actually drawing from the first tank.

 

[carusoam]

Funny observations...

1) There is a lot of fuel in the lines and carb bowl in an M20C...

2) In an old M20C, The detents May not be noticeable anymore... they were there once...

3) As a newbie, you may not know there isn’t a both position between L & R... 

4) That same newbie can get the plane to taxi a hundred yards before it begins to stumble... 

5) From inside the plane, it is difficult to know fuel actually drained from both tanks... unless you move the plane, or move the pan...

6) the selector handle should turn smoothly.  If it is stiff, that is a sign of something to put in the schedule...

7) Lasar has a kit to update the worn parts....

Stuff I remember from my first Mooney flight...  that, and the acceleration of 180hp was huge!

Best regards,

-a-

[jetdriven]

42 minutes ago, jaylw314 said:

I guess that depends on how much fuel is in the fuel lines.  If there is 30 seconds of fuel in he fuel lines at idle power, then after startup you'd need to wait 30 seconds before switching tanks to ensure it is actually drawing from the first tank.

 

There also could be a dry fuel line beucause the last flight the tank was ran dry, or water in the tank you just selected. Sampling the fuel for 3-5 minutes maybe if either of those were the case you’d find it before takeoff.  Every day is a little different. 

[RobertGary1]

11 minutes ago, jetdriven said:

There also could be a dry fuel line beucause the last flight the tank was ran dry, or water in the tank you just selected. Sampling the fuel for 3-5 minutes maybe if either of those were the case you’d find it before takeoff.  Every day is a little different. 

3-5 minutes or seconds? I think you'd have a hazmat crew show up if you drained both thanks for 5 minutes at a major airport.

-Robert

[Rookie]

So I've had my J for 18 months and never run a tank out of fuel on cross country. I'm scared the fuel will not get picked up after switching tanks!

[jaylw314]

53 minutes ago, RobertGary1 said:

3-5 minutes or seconds? I think you'd have a hazmat crew show up if you drained both thanks for 5 minutes at a major airport.

-Robert

Hah, that's a funny image!  Realistically, if you pull the fuel drain for 5 minutes, you'd probably get less than a couple gallons out, and a small bucket would be adequate for that.

 

[Hank]

1 hour ago, jetdriven said:

There also could be a dry fuel line beucause the last flight the tank was ran dry, or water in the tank you just selected. Sampling the fuel for 3-5 minutes maybe if either of those were the case you’d find it before takeoff.  Every day is a little different. 

It's often 2-3 minutes for me from e gune start to takeoff. What are you doing for 10 minutes???

[Hank]

Just now, jaylw314 said:

Hah, that's a funny image!  Realistically, if you pull the fuel drain for 5 minutes, you'd probably get less than a couple gallons out, and a small bucket would be adequate for that.

 

Before every flight? Couple gallons per tank is almost 10% reduction in fuel and $20-25. It's also a stupid idea, but don't take it personally--I'm not saying that you are stupid, just the idea of draining a couple gallons per tank as part of preflight . . . .

[EricJ]

FWIW, here's a pic of my safety-wired fuel selector.  Not sure whether that's common practice or not.

 

[jetdriven]

1 hour ago, RobertGary1 said:

3-5 minutes or seconds? I think you'd have a hazmat crew show up if you drained both thanks for 5 minutes at a major airport.

-Robert

By sampling I mean run the engine on that selected tank, such as during  taxi, runup, then then takeoff. 

Edited February 23, 2018 by jetdriven

[jetdriven]

13 minutes ago, Hank said:

Before every flight? Couple gallons per tank is almost 10% reduction in fuel and $20-25. It's also a stupid idea, but don't take it personally--I'm not saying that you are stupid, just the idea of draining a couple gallons per tank as part of preflight . . . .

I’ve actually drained a tank wirh rhe fuel selector pull ring. It drains at the rate of 10 GPH, roughly.  But I wasn’t referring to draining the tank for 3-5 min. 

[gsxrpilot]

1 hour ago, Rookie said:

So I've had my J for 18 months and never run a tank out of fuel on cross country. I'm scared the fuel will not get picked up after switching tanks!

You should really do this once from each tank just to KNOW your total capacity and unusable fuel. But there's no need to do this on a cross country out over the wilderness somewhere. After coming in from a long flight with one of the tanks as close to empty as you'd let it go, don't refill it, rather take off on the fuller tank, and just stay high above your airport or any airport. Switch to the nearly empty tank and stay there until it runs dry and the engine starts to stumble. Then switch tanks back to the fuller one and go land.

Now you know a few things:

1. Running a tank dry is a non-event and the engine will restart immediately. (turbos in the flight levels are a bit different but still a non-event)
2. What your fuel gauge for that tank looks like at the point it will run dry, or how many minutes will go by after the needle has stopped moving before it runs dry.
3. After landing, fuel that tank to full and note the total gallons of USEABLE fuel. 
4. For safety reasons, knowing how your plane typically reacts to running out of fuel is good to know. 

And next time you are on a long cross country and flight plan to arrive at your destination or fuel stop with say, 10 gal remaining, you'll be more comfortable with all 10 gal in one tank rather than a "few" gal in one tank and a "few more" in the other tank.

A couple of personal notes:

1. Never run the tank dry in the pattern at the end of a long cross country. I plan to arrive in the landing pattern already on the tank that I will land with.
2. If I plan to run a tank dry, I'll do it at my cruising altitude.
3. Never let the even surprise you. I'm anticipating the engine stumble and have my hand on the fuel selector.
4. We get the most cross country utility out of our airplanes when we can KNOW exactly how much fuel we have and WHERE it is.

[RobertGary1]

2 hours ago, Hank said:

It's often 2-3 minutes for me from e gune start to takeoff. What are you doing for 10 minutes???

Getting clearance, taxing. I plan for 10-15 from engine start to run up area. 

-Robert