Baggage door

[PT20J]

After spending some time examining the baggage door mechanism and discussing it with Bob Kromer, here is what I know.

1. The models with the factory-installed internal lever can be opened from the inside when locked.

2. The mechanism operated by either the inside or outside lever has an overcenter spring and will not come unlatched if both levers are properly latched unless the mechanism is defective.

3. The lock only locks the external lever. It is possible to lock the lock with the lever not fully latched (though in this case it will obviously not be flush with the door).

4. Mooney tested the flight characteristics with the door open and found no adverse handling issues.

5. There are at least two cases of the door separating from the aircraft after opening in flight. 

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[kortopates]

3 hours ago, bradp said:

So why have the release handle?

Brad, that was answered in the original thread, by Blue on Top - FAA requirement in the 80's to have a second exit. I haven't tried to find it but assume Part 23. Unlike the earlier models, I believe there was a retrofit kit to add them to earlier J's.

[PT20J]

Just now, kortopates said:

Brad, that was answered in the original thread, by Blue on Top - FAA requirement in the 80's to have a second exit. I haven't tried to find it but assume Part 23. Unlike the earlier models, I believe there was a retrofit kit to add them to earlier J's.

I’m not sure when Mooney added it, but the internal latch was on my ‘78 J.

[kortopates]

4 minutes ago, PT20J said:

There are at least two cases of the door separating from the aircraft after opening in flight.

I know we don't have a definitive count, but the separation incident that Bob recalled the factory repairing had to much earlier than the one we had MAPA PPP. But probably at least 3. 

[donkaye]

Irrespective of the baggage door locking controversy, I don't understand why Mooney put the door opening and closing metal track on the rear of the baggage door.  A twisting moment is easily induced with it placed there.  If it had been placed on the front of the door, while the door could open, having it ripped off with a twisting moment would be a non issue.

[khedrei]

The way I see it is this. If a person needs to leave the inside of the plane be cause the front door is jammed and they are able maneuver themselves to the baggage door they are likely capable of kicking out a window for the same result. As far as someone needing to enter like a fire fighter, they are going to break a window every time. 

I generally dont lock mine. Now that I have a push button start I go keyless. Not even sure where the keys are. In regards to theft...And... I say this only partially joking, we arent as afraid and anal about locks up here as you guys are in the US. Most of the time I dont lock the doors in my house. We dont have the same theft issues up here. 

[flyboy0681]

I took this picture today. Can I assume the mechanism will open the door from the inside even when the outside latch is locked with the key?

[EricJ]

2 hours ago, khedrei said:

The way I see it is this. If a person needs to leave the inside of the plane be cause the front door is jammed and they are able maneuver themselves to the baggage door they are likely capable of kicking out a window for the same result. As far as someone needing to enter like a fire fighter, they are going to break a window every time. 

I suspect that the people who suggest kicking out a polycarb window have never tried something similar.   It can be extremely difficult.  The polycarb flexes and absorbs the energy.    Even if you do manage to break it, it doesn't shatter open like glass, it might just split, which can make it even harder to make an opening to get out.   If you're doing this while injured or dazed or while the airplane is burning, your chances are not going to be good.   The internal latch may have a downside, but from my perspective it's a good thing to have there if you ever do need it.

 

[carusoam]

Keep in mind...

Mooney windows are pmma polymethylmethacrylate... simply called acrylic...

a polymer that has been in wide use since before WW2... Often with the brand name Plexiglas made by a company called Polycast...

Polycarbonate is a highly engineered polymer that became popular in the 80s and improved with time.... getting it to be clear was a challenge... From GE polymers...

 

acrylic shatters pretty easily, it has low impact strength...

poly carbonate’s rise to fame is directly due to the short comings of acrylic...

 

There will be no kicking out of polycarb.... the safety hammer will probably dent the Surface, the hammer will bounce back towards the user...

A good pointy safety hammer... should crack and propagate the cracks in acrylic... It kind of shatters, just not into little pieces like glass...

Note for 0681.... use a screw driver to remove the cover... test the mechanism with the door locked... watch how the springs work... 

then put it all back... any concerns, feel free to hire a mechanic to look over shoulder... take before and after pics... this way you are comfortable with it being all back together properly...

PP thoughts only, not a mechanic...

Best regards,

-a-

[flyboy0681]

49 minutes ago, carusoam said:

Keep in mind...

Mooney windows are pmma polymethylmethacrylate... simply called acrylic...

a polymer that has been in wide use since before WW2... Often with the brand name Polycast...

Polycarbonate is a highly engineered polymer that became popular in the 80s and improved with time.... getting it to be clear was a challenge... From GE polymers...

 

acrylic shatters pretty easily, it has low impact strength...

poly carbonate’s rise to fame is directly due to the short comings of acrylic...

 

There will be no kicking out of polycarb.... the safety hammer will probably dent the Surface, the hammer will bounce back towards the user...

A good pointy safety hammer... should crack and propagate the cracks in acrylic... It kind of shatters, just not into little pieces like glass...

Note for 0681.... use a screw driver to remove the cover... test the mechanism with the door locked... watch how the springs work... 

then put it all back... any concerns, feel free to hire a mechanic to look over shoulder... take before and after pics... this way you are comfortable with it being all back together properly...

PP thoughts only, not a mechanic...

Best regards,

-a-

And all you need is one wayward bird to ruin it.

[carusoam]

Given the option...

Polycarbonate would make a great impact resistant windshield...

But, it is definitely try before you buy kind of thing... optical clarity may be challenging....

We had THE @Canopyman around here that was really familiar with the issues...
Unfortunately, he flew west in a less than timely fashion...

The Polycast company made sheets of acrylic in all thicknesses...  I toured one of their facilities in Hackensack NJ.... they claimed the F14’s canopy starts out as a flat sheet, that they Reaction cast between two pieces of glass for a mold...

The forming process adds to all the different light bending problems...

Best regards,

-a-

[khedrei]

I have heard of a wingtip touching a window in a hangar and it shattering. Perhaps this was not an accurate report. 

I might be wrong in assuming it would be easy to kick it out. I didnt actually think it would be easy to break the window itself but that it wouldnt be overly difficult to kick it out. Meaning it would bust off at the seams holding it to the airframe and likely come out in one piece. No? The ones on the Piper doors seem to crack all the time around the little vent windows.  Like I said, I could be wrong. 

[PT20J]

2 hours ago, carusoam said:

Mooney windows are pmma polymethylmethacrylate... simply called acrylic...

Trade names are Plexiglas, Lucite and, for the Brits, Perspex.

[tomatl]

56 minutes ago, flyboy0681 said:

And all you need is one wayward bird to ruin it.

Just for fun: Assume you are hit by a small, 1 pound, waterfowl while flying at 120 knots. If the total momentum is transferred while the plane travels into the bird (assume 8 inches), the force on the windshield is about 8.5 kN, or equivalent to almost 2000 lbs. This is an order of magnitude more than what you can achieve pushing with your feet (at least for me).

[PT20J]

4 hours ago, flyboy0681 said:

I took this picture today. Can I assume the mechanism will open the door from the inside even when the outside latch is locked with the key?

I answered your question above, but yes, it can be opened from inside when the door is locked. This appears to be a retrofit and there are a couple of installation errors. First, the placard is upside down. It is meant to be right side up when viewed from inside the baggage compartment with the door closed. Also, the cover screw holes should be notched to the edges so that the cover is easily removed by ripping it off without tools in an emergency.

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[Hank]

Below is the baggage door on my C. I don't see this latch vibrating open during flight. The second photo is with the latch closed--two pins are extended into the frame.

Like Jim, I don't lock mine before flight, and I don't worry about it opening any time that I don't want it to. 

[tomatl]

Below is the baggage door on my C. I don't see this latch vibrating open during flight. The second photo is with the latch closed--two pins are extended into the frame.
Like Jim, I don't lock mine before flight, and I don't worry about it opening any time that I don't want it to. 

I have not looked at the design of this latch but I assume that is similar to the "over center leverage" of the door or the cowl flaps. On both of these I had malfunction due to bad adjustment by a mechanic. Based on these experiences, I don't assume the baggage door will always latch properly. My baggage door opens from the inside, which is good enough for me. Locking it is on my preflight checklist, and it stays there unless someone has a really strong argument against it.


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[flyboy0681]

1 hour ago, PT20J said:

I answered your question above, but yes, it can be opened from inside when the door is locked. This appears to be a retrofit and there are a couple of installation errors. First, the placard is upside down. It is meant to be right side up when viewed from inside the baggage compartment with the door closed. Also, the cover screw holes should be notched to the edges so that the cover is easily removed by ripping it off without tools in an emergency.

Skip

 

I never knew any of this. Was it was done in the field after delivery in 1983 as a kit? Most interesting.

 

[EricJ]

53 minutes ago, tomatl said:

I have not looked at the design of this latch but I assume that is similar to the "over center leverage" of the door or the cowl flaps. On both of these I had malfunction due to bad adjustment by a mechanic. Based on these experiences, I don't assume the baggage door will always latch properly. My baggage door opens from the inside, which is good enough for me. Locking it is on my preflight checklist, and it stays there unless someone has a really strong argument against it.
 

It is not an over-center system, just a simple mechanical system with the lever, and the lock turns a cam that interferes and prevents movement in the latch position.   I took this to show how I added an interior pull, but you can see the interior portion of the actuating lever in the upper right, which just moves one of the pin arms, which moves a bellcrank that moves the other in the opposite direction.

This is shown in the open position, and the lock cam is behind the end of the "other" rod which still has black paint on it.   When that rod is pushed out to the latched position the lock can turn the cam to prevent the rod from moving back.

This is an older construction, which is similar across the C, E, F, G, and very early J (like mine) models.    The newer ones are a little different to accommodate the factory  interior latch and so it can be opened from inside when locked.

 

Edited June 14, 2020 by EricJ

[tomatl]

Smart fix!

[PT20J]

1 hour ago, flyboy0681 said:

I never knew any of this. Was it was done in the field after delivery in 1983 as a kit? Most interesting.

 

According to the IPC, the M20Js starting with S/N 24-0378 had the inside lever mechanism. So, yours is probably original and more likely someone just replaced some parts. I notice that the color of the cover appears different than the color of the door panel. It could be that the cover is a Plane Plastics part which has to be trimmed and drilled.

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[Guest]

Good luck kicking out the side windows on most of these airplanes.  They are bonded and in older models bonded and screwed to the aluminum skin.  In my experience unless the window has some form of defect such as deep crazing or cracks emanating from the screw holes or the pilot’s foul weather window they don’t break easily.

Many Pipers had very thin side windows of only 0.080”, these are the exception most are now 0.125” to 0.250.

Clarence

[bradp]

When I took out my old windows I jumped on them.  They didn’t break.