Emergency Landing | Baggage Door Blow Off Mid Flight | Model K

[PT20J]

There are only three ways I can see the door coming unlatched:

1. The inside emergency handle is not secured

2. The outside handle is not secured

3. The mechanism is broken or misadjusted.

It might be a good idea to remove the cover and check the inside handle especially after maintenance. Item 16 on the Mooney Inspection Guide is “Inspect cabin & baggage doors for condition, proper operation and sealing.” Who knows if a technician tests the emergency latch operation and then doesn’t secure it properly? 

Locking the baggage door will not protect against an unsecured inside handle, but it will keep the outside handle from opening. It is possible to turn the key to the locked position with the handle open in which case the striker will keep the handle from closing completely. 

The latch mechanism goes over center when closed and it’s hard to see it coming open if properly closed even if unlocked. I think locking is a good idea, though, if for no other reason than it forces you to make sure that the handle is properly closed.

Skip
 

 

[EricJ]

10 hours ago, jetdriven said:

Nobody is kicking  out those Mooney windows, they are a lot stronger than they appear.

Agreed.   Acrylic is tough stuff, and because it flexes it is often harder to get it to break than glass, since it yields and distributes the energy. 

I'm glad that the door was recovered so that the failure mode can be analyzed, whatever it turns out to be.

 

[MooneyMitch]

Possibly I’ve missed this previously, but did the OP say whether they’d locked the baggage door prior to flight? 

[PT20J]

Just now, EricJ said:

Agreed.   Acrylic is tough stuff, and because it flexes it is often harder to get it to break than glass, since it yields and distributes the energy. 

I'm glad that the door was recovered so that the failure mode can be analyzed, whatever it turns out to be.

 

Plus, when it does shatter, it leaves sharp edges 

[shawnd]

2 hours ago, gsxrpilot said:

I installed Medco locks in the baggage door and side door a couple of years ago. For some reason, the baggage door lock will not release the key unless it's in the lock position. So my baggage door is always locked. If it's not, the airplane keys are in the lock and you won't be starting the airplane.

My local school also had this done. Is there a STC for this? Or can any shop swap out the locks?

 

Edit: my instructor also taught me that regardless of whether it locks or not, keep your keys in the lock so you remember to lock it before getting in the aircraft. So when I tow the a/c around, baggage door stays open with keys in it.

[gsxrpilot]

14 minutes ago, shawnd said:

Is there a STC for this? Or can any shop swap out the locks?

Any A&P can do it. I did it myself and then JD took a look and signed it off.

[MoonFlyer68]

Obviously the fact that you are on the ground safe and talking about the incident is the most important thing.  PERIOD

The next thing to look at is why this happened and what can be done to prevent it.  Looking at the pictures I do not feel the door latch mechanism was the fault at all.  I am focusing on the piano hinge.  It looks to me that only about 1/3 of the hinge pin was installed.  In the pictures I see 4 segments of the piano hinge on the door are sheered off and then there is one segment of the hinge that was from the door frame that is broken off and attached to the door still.  If the entire pin was installed then we should see damage and a sheared hinge the entire length.  Why are the other parts of the hinge undamaged unless there was no pin there?  If I am looking the the pictures correctly, I think that the section that may not have been secured was the forward section.  If that is the case, it was only a matter of time before enough air and wind got a hold of that door to rip it off the airplane.

If this is correct, that the hinge pin is our failure point, why did it happen?  Did the pin simply work its way back and out naturally?  Was the door removed during annual and someone was simply fitting it back in place temporarily with a short pin and forgot that it was not properly installed before releasing it?

There are a lot of questions to be answered and I am not an expert but those are my observations from the evidence I am presented.

[Ragsf15e]

14 hours ago, jetdriven said:

Nobody is kicking  out those Mooney windows, they are a lot stronger than they appear.

Also it appears that your emergency latch is missing the cotter pin, and the handle May have opened up, which may have triggered the hatch to open then release. 

 

 

You could be right about kicking out the windows.  Cirrus provides an egress hammer for the windows.  We need to have the reaper try kicking one out next time they take one apart.

[Shadrach]

Does someone have a schematic of the new style latch handy they can post? I can’t envision this being possible with the latch on my 67F regardless of the position of the medico lock. Full disclosure, I have experience initiating takeoff with an unlatched baggage door. It was entirely my fault, nothing failed. The baggage door rotated right before the aircraft. Loads of wind in the cockpit. I knew immediately what had happened because my father did the same thing when I was a kid. Chop the throttle, exit the runway and had to do the walk of shame on the taxiway in front of the tower to secure the baggage door. I see no way that it’s possible for the latch that I’m familiar with to fail. It’s entirely possible for the pilot to fail as I did. Either way, I’m glad this ended well and the pilot kept her cool.

Edited May 31, 2020 by Shadrach

[ArtVandelay]

You could be right about kicking out the windows.  Cirrus provides an egress hammer for the windows.  We need to have the reaper try kicking one out next time they take one apart.

I have extra thick windows, I tried the hammer designed to break windows (I assume they work on automobile glass) , completely ineffective, this was with the window laying on concrete floor and me giving a full wallop, something you probably couldn’t do confined inside the cabin.

[flyer338]

First, congratulations to OP for excellent handling of an emergency. This was something (to quote S&C Bob) that could have left them upside down in the weeds on fire.

i learned a lot of rom this thread, and I will be locking the baggage door before flight and adding the baggage door hinge condition to my pre-flight check list.

[Ross Taylor]

At the risk of being repetitive, I'll also add my compliments on the handling of this. And I'll also start locking my baggage door, as well. Our 1966 E model does not allow opening from the inside, but I'm not really worried about that. And, yes, I took off with the baggage door unlatched once. It was actually my second take off in our "new" plane. I picked it up in Lynchburg and made a stop a few hours west for fuel. When I put the fuel sample cup back inside the baggage compartment I did not latch it. The door swung upward as I was climbing out, so I kept my speed as low as was safe to do so and went around in the pattern and landed. No harm and no foul, but a definite lesson for me to check the latch every time. Making sure it's locked is not a bad idea...

I'm happy this turned it as it did for you. And thanks for demonstrating the ability of the gear to handle some rough conditions!  

[bradp]

Good job getting a somewhat crippled aircraft down and good job remembering the basic GUMPS check. 
 

Your copilot has about the best attitude imaginable- a little humor trying to avoid a $hitty end to a $hitty day I guess :-)

 

I had a door pop on departure - I don’t have the Medco locks and I don’t have the new style push to release lock nor do I have the emergency release.  Now I’m just careful to check but I don’t want to delete a potential point of egress unless there is a way of bypassing the lock.  You can’t bust the windows. I jumped on my old ones and they’re strong.  Glass shatter hammers just mar them. 

[jetdriven]

5 hours ago, MilitaryAV8R said:

Obviously the fact that you are on the ground safe and talking about the incident is the most important thing.  PERIOD

The next thing to look at is why this happened and what can be done to prevent it.  Looking at the pictures I do not feel the door latch mechanism was the fault at all.  I am focusing on the piano hinge.  It looks to me that only about 1/3 of the hinge pin was installed.  In the pictures I see 4 segments of the piano hinge on the door are sheered off and then there is one segment of the hinge that was from the door frame that is broken off and attached to the door still.  If the entire pin was installed then we should see damage and a sheared hinge the entire length.  Why are the other parts of the hinge undamaged unless there was no pin there?  If I am looking the the pictures correctly, I think that the section that may not have been secured was the forward section.  If that is the case, it was only a matter of time before enough air and wind got a hold of that door to rip it off the airplane.

If this is correct, that the hinge pin is our failure point, why did it happen?  Did the pin simply work its way back and out naturally?  Was the door removed during annual and someone was simply fitting it back in place temporarily with a short pin and forgot that it was not properly installed before releasing it?

There are a lot of questions to be answered and I am not an expert but those are my observations from the evidence I am presented.

Yes, funny you should mention that, but looking at it yes, it looks like only the aft 1/3 of the baggage door had the pin through the both the loops. Question is, was the hinge pin sticking out 8 inches behind the hinge? Also, we cannot discount the fact that the hitch pin is missing from the inside emergency handle and if that handle is tripped.. Perhaps the emergency handle released, and when the baggage door lifted. up, there is basically almost no hinge holding it and that’s what lifted the front of it up and ripped it off. That’s what you said, basically.  Because we have had baggage doors  come open before many times, but having it depart the airplane, that is an unusual circumspect here.  

[David Lloyd]

Years ago I had a new windshield installed in a Bonanza by Jim Klug of Beryl D'Shannon.  Jim said at the time he had installed hundreds of windshields.  He began the process by drilling the frame screws around the 1/4" thick windshield and the told me I may not want to watch.  He took a large ball peen hammer and the third hard whack the windshield cracked. several more hits worked the crack to the frame in each direction and then another crack. He then go some big channel lock pliers in between two edge and started breaking pieces out.  The windshield was out in a couple minutes.  I can't imagine anyone being able to break or kick out a window fastened in place with screws and nuts.

[ArtVandelay]

How is the hinge pin secured, is it like a roll pin or is bent on the ends to prevent it from shifting?

[MATTS875]

Great job on the emergency landing. Proud all are safe. I will definitely start locking my baggage door from this point forward. Thanks for the video

[PMcClure]

Wow, great job getting down safely. I would fly with you any day!

 

 

[PT20J]

I happen to have the interior out of my 1994 M20J and I spent some time looking at the baggage door hinge and lock this afternoon.

This picture shows the door with the exterior handle in the open position:

Here's what it looks like with the exterior handle in the closed position:

Note how far the latching pins protrude in the latched position. There is no way that the door is going to open if the pins are engaged unless perhaps the hinge gives way and allows the door to shift.

Here's a shot with the interior emergency handle pulled open:

I labeled two springs, A and B. Spring A creates an over center force to hold the mechanism either open or closed. In addition, Spring B acts to hold the pins in the latched position and did so (albeit less forcefully) even when I removed spring A. 

I noticed that to open the door with either the inside or outside latch, the lever has to be pulled forcefully over center. Even if the hitch pin was removed from the inner lever, I don't think the door could open unless something pulled on the lever with enough force to compress spring A and move the mechanism over center.

The piano hinge is riveted to the tailcone skin and the door. It is recessed slightly so that the tailcone skin retains the hinge pin. 

The design seems very secure. I don't see how it could open unless something was broken or it wasn't latched. But, in cases where it is not latched, I would expect that it would open on takeoff as others have reported. In this case, there was a delay. 

Skip

[kortopates]

Mooney side windows and door windows are only 1/8" thick. Windshields are 50% thicker as installed and many have gone to thicker .25". I  haven't had to break a side window yet but I doubts its going to be impossible to break out 1/8" side window when there is nothing on the other side of the window to support it.

The steel piano hinge wire securing the baggage door to the airframe is not going anywhere - in facts it a real bitch to move it out at all. its recessed in a cutoff of the fuselage skin where the other 1/2 the piano hinge is riveted to the skin. The soft aluminium piano hinge is what fails when the baggage door is slammed up by the air, first braking the hold open arm and then bending the baggage door it self, as shown in the the pictures above. That is a major load on the piano hinge but at cruise speed, that piano hinge breaks from the huge lifting force. Another way to look at it, is that there is no tearing load on the hinge till after the door becomes unlatched at the bottom and the bottom is secured by two pins through 2 steel strikers. The door is going no where until its unlatched at the bottom. Opening up at the bottom is what causes the huge lifting load on the door to slam back against the roof and tear off the hinge.

Its possible the door could have become unlatched from the inside, if the cover was missing and perhaps the pin magically fell out, but there is a much greater chance the baggage door lock just wasn't  fully secured - locking it guarantees its is.   When they're totally unlatched they typically pop open before you rotate or right away afterwards while still slow enough not to depart. Not opening till in cruise is a much bigger mystery on the state of the latch and how it unlatched in flight. But it had to unlatch if it wasn't fully latched at takeoff.  But at 150+ kts that piano hinge won't keep it attached either.

Edited June 1, 2020 by kortopates

[MoonFlyer68]

1 hour ago, PT20J said:

I happen to have the interior out of my 1994 M20J and I spent some time looking at the baggage door hinge and lock this afternoon.

This picture shows the door with the exterior handle in the open position:

Here's what it looks like with the exterior handle in the closed position:

Note how far the latching pins protrude in the latched position. There is no way that the door is going to open if the pins are engaged unless perhaps the hinge gives way and allows the door to shift.

Here's a shot with the interior emergency handle pulled open:

I labeled two springs, A and B. Spring A creates an over center force to hold the mechanism either open or closed. In addition, Spring B acts to hold the pins in the latched position and did so (albeit less forcefully) even when I removed spring A. 

I noticed that to open the door with either the inside or outside latch, the lever has to be pulled forcefully over center. Even if the hitch pin was removed from the inner lever, I don't think the door could open unless something pulled on the lever with enough force to compress spring A and move the mechanism over center.

The piano hinge is riveted to the tailcone skin and the door. It is recessed slightly so that the tailcone skin retains the hinge pin. 

The design seems very secure. I don't see how it could open unless something was broken or it wasn't latched. But, in cases where it is not latched, I would expect that it would open on takeoff as others have reported. In this case, there was a delay. 

Skip

That J model door is very impressive compared to what I have on my 68 F.

 

[carusoam]

The post modern doors got the emergency release parts added to them...

An upgrade that is available to the earlier versions...

Best regards,

-a-

[kortopates]

Its probably worth mentioning while we're on this topic that there are few Mooney SB on the emergency baggage door latch that applies to J's and K's to prevent the door from opening in flight and where Mooney's answer to some causes of doors opening in flight years ago and may still be applicable to some Mooneys out there. 

sbm20-239a Baggage Inside Latch Modification.pdf sim20-63 Engagement of Baggage Door Mechanism.pdf sim20-82 Baggage door inside latch mod.pdf

[MoonFlyer68]

4 minutes ago, carusoam said:

The post modern doors got the emergency release parts added to them...

An upgrade that is available to the earlier versions...

Best regards,

-a-

IS this a parts kit that gets added to my current door or would it involve acquiring a later model door and attaching it to my older model airplane?

[carusoam]

AV8R,

Check the links Paul just dropped above you...

You should be able to find a parts kit that updates what you have...

A small dollar amount... not a whole new door measured in AMUs amount...

Best regards,

-a-