Inspection panel come loose during flight?

[SantosDumont]

Anyone ever see an inspection panel work itself loose during flight?

Haven’t been out to the hangar for a month, figured I’d better put the chocks square to the tires (I only backed the plane into the rear chocks putting it away)... and noticed this panel completely off missing all the screws. 

I had topped off the air in the tires last flight and I didn’t notice anything missing then. 

I’m having a hard time thinking about why someone would come in the hangar and remove that particular panel, but I’m having an equally hard time trying to figure out how all 10 screws worked themselves out during a 30 minute flight of 3 touch and gos. 

[Shadrach]

My money is on that panel being aligned but not secured after annual.  I often rotate inspection panels on a single loosened screw when performing maintenance of inspections. Thankfully I've never forgotten one...Be grateful that it's still there. It would be a PITA to deal with replacing.

[toto]

Yep.  The only time I've seen this was after an annual, with finger-tight screws that weren't followed up with a screwdriver.

[MooneyMitch]

Yes, agree with Shadrach......... suspect panel was never fully secured during maintenance.

[SantosDumont]

Weird thing is that its been 100 hours since annual in September. But that was the first real warm day that I went flying.  If they were finger tight that might make sense why they all came out at the same time. 

[MooneyMitch]

48 minutes ago, SantosDumont said:

Weird thing is that its been 100 hours since annual in September. But that was the first real warm day that I went flying.  If they were finger tight that might make sense why they all came out at the same time. 

It’s quite possible all the screws were not installed at all.  Could have been just a couple installed finger tight or less...... then mechanic distraction...... we’re all susceptible. 

[RobertGary1]

2 hours ago, MooneyMitch said:

It’s quite possible all the screws were not installed at all.  Could have been just a couple installed finger tight or less...... then mechanic distraction...... we’re all susceptible. 

Yep. I won’t cast stones but if that panel was secured it would never have gotten away. 
 

-Robert 

[RobertGary1]

I’ve occasionally found 1 or 2 screws have worked out on a panel because the backing broke and it got insufficient love on install but that isn’t close to causing the panel to move out. 
 

-Robert 

[Bartman]

During my ongoing engine rebuild-installation-annual inspection I removed all of the wing panels. Most don’t have to be removed because there is nothing to inspect, but I did it to replace all of the 40+ year old screws. I put most of the panels back on, but left a couple of important ones open each side for my maintainer to inspect. That was months ago and when it came time to start the engine I was going thru my checklist of things that must be completed before first flight. I had made a note of this and dozens of other things so I caught it by my meticulous notes and checklist, not because I remembered to do it. This is an ongoing process and I still have many items to check off the list before first flight, but I could have easily missed it. 

[MooneyMitch]

I did experience a similar panel becoming unsecured many years ago on my F model, after my first annual inspection.

The loose panel did wind up just inside the wing, as did yours.  Most fortunate as well.  

A side comment.......some mechanics tighten the panel screws to where they are most difficult to remove and can destroy the cross head in the process.

I’ve found snugging them firmly is all that’s needed to keep them secured.  Easy to remove without destruction.

[Hank]

1 hour ago, MooneyMitch said:

I’ve found snugging them firmly is all that’s needed to keep them secured.  Easy to remove without destruction.

Since I put teflon washers on these screws, they're a lot easier to get out. It's also my job as part of owner-assist annuals.

[MooneyMitch]

12 minutes ago, Hank said:

Since I put teflon washers on these screws, they're a lot easier to get out. It's also my job as part of owner-assist annuals.

Agree, 100%, teflon washers on the pan head type screws.

[Hank]

1 minute ago, bluehighwayflyer said:

Your Mooney must have round head screws holding all of those panels on, Hank.  The vast majority of Mooneys use flush screws there, making the use of Teflon washers impossible. Just FYI.  

Jim

My inspection panels attack from the outside, too, where the one up above rotated away on the inside.

[47U]

Is. there a sump drain outboard of the main gear door on the F model?  In the wing bay aft of the spar?  Long-range tanks?

tom

 

 

[MooneyMitch]

2 minutes ago, 47U said:

Is. there a sump drain outboard of the main gear door on the F model?  In the wing bay aft of the spar?  Long-range tanks?

tom

 

 

I don’t believe that’s a fuel drain ( I could be wrong.... I was once before ), but I don’t know what that is . 

[ArtVandelay]

I don’t believe that’s a fuel drain ( I could be wrong.... I was once before ), but I don’t know what that is . 

Could be where the old OAT probe was, on my J it’s on the right wing, and there is a gasket, but that does look like a fuel drain.


Tom

[kortopates]

1 hour ago, MooneyMitch said:

I don’t believe that’s a fuel drain ( I could be wrong.... I was once before ), but I don’t know what that is . 

 

4 minutes ago, ArtVandelay said:

Could be where the old OAT probe was, on my J it’s on the right wing, and there is a gasket, but that does look like a fuel drain.


Tom

This sure looks like the outboard sump drain on the Monroy tanks, you can see the two rivets that secure the fitting on the inside.

Also the Mooney OAT is much smaller, on an inspection panel and on the left wing - this looks like the Right wings unless the image is reversed. 

Edited July 6, 2020 by kortopates

[MooneyMitch]

15 minutes ago, kortopates said:

 

This sure looks like the outboard sump drain on the Monroy tanks, you can see the two rivets that secure the fitting on the inside.

Also the Mooney OAT is much smaller, on an inspection panel and on the left wing - this looks like the Right wings unless the image is reversed. 

Yes, I saw the two riverts.  Are the Monroy tanks installed in that area?  How are they secured inside the wing?  Rivets?  If so, do I see non-factory appearing rivets in that area near that fuel drain?  Just curious......

Mr. SantoDumont sir...... does your beauty indeed have tanks in that area?  

[Guest]

I can see one or two screws falling out if they weren’t tightened, but all of them falling out suggests they were never tightened in the first place.

I find that in most cases inspection cover screws are over tightened.  From the J model maintenance manual here are the Torres for 8-32 screws, the most common size in a Mooney.

Clarence

Edited July 6, 2020 by M20Doc

[Hank]

Thanks, Clarence. Tighten our 8-32 screws to 12-15 whats? Inch-pounds? Foot pounds? Newton meters? I'd guess inch pounds, but the whole point of using the chart is to not have to guess . . . .

[MooneyMitch]

Incharoonies!! Although I’ve experienced screws that probably were at foot pounds !  Yikes!!!