Mooney down at KHEG (north FL)

[EricJ]

6 hours ago, Piloto said:

The engine quit on take off could be due to water displaced toward the fuel tank pickup screen  at the rear of tank. Even if the fuel was drained before flight water may be in the tanks due to the fuel drain adapter hole clogged. To insure of no water remove the drain valve and check for water residue. I switched to the drain valve F-391-72 which has the drain holes just above the adapter to overcome this problem.

I first experience the engine quitting on take off at KFLL. I landed straight ahead on the runway and with the momentum taxi out. At the ramp removed the drain valve and water was pouring out even though I drained the tanks before through the drain valve.

José

That's very similar to the experience that I had.   I didn't have quite enough runway to get stopped and managed to get it turned and roll off onto the taxiway to finish slowing down.   Very exciting.   I do not wish to ever repeat it.

[Hector]

When I first posted about this accident I strongly suspected a fuel issue because the engine appeared to be running great, then it just quit with no roughness or any other signs of trouble. I decided not to post my opinion given that I had just seen the accident and it was pure speculation on my part at that point. I’m just glad the two made it out with nothing but a few scrapes


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[cbarnes403]

Fuel tank vent was obstructed causing fuel starvation.

28-32-00 -FUEL VENTS

The fuel tanks are vented from the outboard upper edge. This vent is routed outboard and is vented overboard through a NACA vent on lower wing surface, To check fuel tank vents:

1. Block entire fuel tank vent by slipping a short length of rubber hose over tube and projecting below

2. Remove fuel tank filler cap; blow gently into rubber hose. Air should be felt coming out of filler port.

3. If Stoppage is found, clear vent prior to flight since fuel starvation could result from vent stoppage,

NOTE

It is important that the fuel tank vent tube protrude only enough to be flush with lower wing skins.

This was removed from the vent

[carusoam]

Great to hear from you Cbarnes!

 

With the various bugs around the country, anyone can get one of these...  There are threads regarding how to avoid bugs in the vents... and how to test if they are clear.

I had one once...

If you encounter a blocked vent, you may be fortunate enough to recognize a simple sign while on the ground...

You may get a slight pressure release when you open the cap to inspect the fuel level. (I didn’t recognize the sign)

If you get a pressure release, this is a very bad sign... Mooneys don’t have pressurized tanks.

Pressurized tanks turn into vacuum tanks, followed by the sheet metal trying to beer can... in flight...

Much depends on size of the tank and how full it is...

Best regards,

-a-

[Guest]

I must be missing something here.  How could installing F391-72 drain valves which have the holes way higher than the drain holes in the F391-53S valve improve safety?  It seems to me you be adding a way to hold even more water closer to the pick up point.

Clarence

[Andy95W]

36 minutes ago, M20Doc said:

I must be missing something here.  How could installing F391-72 drain valves which have the holes way higher than the drain holes in the F391-53S valve improve safety?  It seems to me you be adding a way to hold even more water closer to the pick up point.

Clarence

 

Also, per Service Bulletin (M20-188, I believe), -53S is the one just like Clarence said.

Don't we go through this exact same discussion every couple of years, in between WD-40 discussions?

[ArtVandelay]

I must be missing something here.  How could installing F391-72 drain valves which have the holes way higher than the drain holes in the F391-53S valve improve safety?  It seems to me you be adding a way to hold even more water closer to the pick up point.
Clarence

Reading his post, I believe he is saying that adapter hole (we need a picture of female part) gets clogged, so the fuel is drained not from hole level, but thru the top, which is actually higher. Having a higher hole gets around this. But if this was to happen I would think the fuel would just dribble out and would be noticeable. And you’re correct, it would allow more water to remain if this isn’t the case.
I think the answer is to fix the clogged adapter hole, and not jury rig a way to around it.

[Guest]

36 minutes ago, teejayevans said:

Reading his post, I believe he is saying that adapter hole (we need a picture of female part) gets clogged, so the fuel is drained not from hole level, but thru the top, which is actually higher. Having a higher hole gets around this. But if this was to happen I would think the fuel would just dribble out and would be noticeable. And you’re correct, it would allow more water to remain if this isn’t the case.
I think the answer is to fix the clogged adapter hole, and not jury rig a way to around it.

Here is a picture from SB M20-188.  The blue lines show where the holes in the mounting nut are.  The red line show where the F391-720 drain valve would put the drain hole, allowing for about 3/8” of water and contaminates to be contained in the tank, undrained.  How does this improve safety?

You’re correct, the correct repair is to clear the contaminates from the drain holes in the mounting nut.

Clarence

[mooniac15u]

13 hours ago, cbarnes403 said:

Fuel tank vent was obstructed causing fuel starvation.

28-32-00 -FUEL VENTS

The fuel tanks are vented from the outboard upper edge. This vent is routed outboard and is vented overboard through a NACA vent on lower wing surface, To check fuel tank vents:

1. Block entire fuel tank vent by slipping a short length of rubber hose over tube and projecting below

2. Remove fuel tank filler cap; blow gently into rubber hose. Air should be felt coming out of filler port.

3. If Stoppage is found, clear vent prior to flight since fuel starvation could result from vent stoppage,

NOTE

It is important that the fuel tank vent tube protrude only enough to be flush with lower wing skins.

This was removed from the vent

 

On 8/28/2018 at 7:24 AM, acpartswhse said:

Was sold to current owner C Barnes who lived in Jacksonville fl. Cause of the engine stoppage was fuel mismanagement.  Owner was selling the plane and prospective buyer took it for test flight and switched fuel off or to empty tank before takeoff according to locals.  

Are we still blaming the pilot for this one?

[Marcopolo]

On 9/5/2018 at 11:02 AM, mooniac15u said:

Are we still blaming the pilot for this one?

  If the pilot did the pre-flight, yes!  If the pilot didn't do the pre-flight, yes!  If the pilot trusted someone else to do the pre-flight, yes!  Not sure who you are expecting the blame to be placed on, but in my opinion it shouldn't be on anyone other than the PIC!  I wish nothing bad on anyone, but sometimes bad is overlooked.

 

Ron

[gsxrpilot]

Should we take a poll to see how many pilots preflight the fuel vents. I've never actually seen anyone walking around their airplane with a length of rubber hose to attach to the vents to verify they're not clogged. I know I never have.

[mooniac15u]

1 hour ago, Marcopolo said:

  If the pilot did the pre-flight, yes!  If the pilot didn't do the pre-flight, yes!  If the pilot trusted someone else to do the pre-flight, yes!  Not sure who you are expecting the blame to be placed on, but in my opinion it shouldn't be on anyone other than the PIC!  I wish nothing bad on anyone, but sometimes bad is overlooked.

 

Ron

The pilot is ultimately responsible for every system on the plane.  I was merely calling out that someone came on here blaming the pilot for fuel mismanagement when it now seems that there was a maintenance issue with the plane.  And the someone making those claims happens to be someone who was, until recently, responsible for the maintenance of that plane.  It is unlikely that the blockage of that vent started in the last few weeks prior to the accident while the plane was stored in a hangar.

Someone handed the keys to a plane with a clogged fuel vent to a pilot.  I would've been unlikely to catch that during preflight.  I think I won't judge that pilot too harshly.

[Mooneymite]

1 hour ago, Marcopolo said:

 Not sure who you are expecting the blame to be placed on, .....

I thought that's why we brought wives along when we fly.....

[Marcopolo]

18 minutes ago, mooniac15u said:

The pilot is ultimately responsible for every system on the plane.  I was merely calling out that someone came on here blaming the pilot for fuel mismanagement when it now seems that there was a maintenance issue with the plane.  And the someone making those claims happens to be someone who was, until recently, responsible for the maintenance of that plane.  It is unlikely that the blockage of that vent started in the last few weeks prior to the accident while the plane was stored in a hangar.

Someone handed the keys to a plane with a clogged fuel vent to a pilot.  I would've been unlikely to catch that during preflight.  I think I won't judge that pilot too harshly.

  Ok,  So I think we are somewhat in agreement.  I was unaware that you were aiming your question at a specific member of the forum, my apologies.  However, I will, as un-harshly as possible, still direct the larger portion of responsibility to the PIC.  The fuel vents are part of the pre-flight inspection process, now if the material that was removed from the vent line was anything other than insect housing building materials I will change my song in a heartbeat and profusely apologize to all involved.

 

  I agree with @gsxrpilot that the fuel vents are rarely inspected on the majority of our planes on a regular basis but that doesn't take the responsibility off of us as PIC and put it on our MX providers.  I would probably be on the same side of his poll as he is, but again, the question was who to blame!  Sorry, I'm stuck to the PIC answer, but glad all involved were able to walk away.

 

Ron

[Alan Fox]

I can tell you that didn't leave Brents shop with clogged vents , Not going to say why , but you would have to run for almost an hour , to build up enough negative pressure to shut down the engine..... 

[Yetti]

Checked my fuel vents in Feb.  At the annual per the IA.   Can also run a piece of safety wire up them.

[carusoam]

Aside from The Who did what to whom....

 

If you encounter a blocked vent, you may be fortunate enough to recognize a simple sign... while still on the ground...

You may get a slight pressure release when you open the cap to inspect the fuel level. Depending on whether the temp is increasing or decreasing some... 

If you get a pressure release, this is a very bad sign... Mooneys don’t have pressurized tanks.

Pressurized tanks turn into vacuum tanks as fuel gets used up, followed by the sheet metal trying to beer can.

 

The time needed for the blockage to occur... about a day.  

I didn’t know NJ had mud/dirt daubers... I also didn’t know dirt daubers Built nests in planes living in hangars....

 

My walk around includes the tank vents looking for tiny feet prints....

 

Important question... what came out of the vent?  All mud/dirt?

 

Got mud daubers in your neighborhood?

 

There are some methods to keep them from returning...  I believe it may be called the safety wire procedure...?

Somebody has covered this before around here somewhere.

Best regards,

-a-

 

[Hank]

5 hours ago, carusoam said:

I didn’t know NJ had mud/dirt daubers... I also didn’t know dirt daubers Built nests in planes living in hangars....

 

They will build a nest wherever they can get to. Used to find them inside my grandfather's workshop, door normally closed.

No idea if they live in Jersey or not. 

[MyNameIsNobody]

Lots of “chain” stuff here to ponder.

[Browncbr1]

I need to get those tobacco pipe screens and zip tie them on there!

[ArtVandelay]

I use homemade covers: small section of rubber hose and red tag, ditto for pitot tube, and yes even when hangared.