Door Opening in flight?

Red Air Rambo · #1 01-21-14, 04:01 PM

Just received this e-mail from a friend........

Hi , well my friend went and looked at the skymaster yesterday at ........, on the demo flight with a so called experienced pilot / mechanic climbing through 10K the boor blew open, he said the upper door took a chunk of the leading edge of the wing out and the lower door damaged the strut along with the door window blowing out, not a good day.

Not sure what caused it but must have to be over pressure and not checking the max pressure gauge. I would imagine the aircraft is junk after that. They confirmed the door was locked and pins engaged.

He's done with P Skymasters. Lucky to be alive, His wife was terrified.

Cheers

Has anyone heard of this happening? My thoughts are that it was not latched properly, possibly not getting the lower door closed correctly due to chain interference?

Red Air Rambo · #2 01-21-14, 07:41 PM

Now they are saying the door window did not blow out. I'm still thinking the bottom was not latched correctly or it would not have opened.

hharney · #3 01-21-14, 09:47 PM

The only way the pressure could have reach too high would be if the safety valve was bad. I agree with you that the door was not latch or was mechanically defective. Too bad that happened to him, but it does make one think about the importance of the latch mechanism and how important it is to make sure the doors are functioning properly

jhickam · #4 01-21-14, 11:45 PM

I had the door open on my 337G a few years ago on climb out at 120 mph and it did not cause any damage. The shop adjusted the linkage so it cams over with more tension and no problems since.

edasmus · #5 01-22-14, 10:38 AM

I have always been worried about that door on my 337G. I could imagine a scenario where much damage occurs after the door departs and starts destroying everything in its path. I think the older style doors on the pre-1973 models are superior.

A few years ago I had my shop completely disassemble the door latching system. I still wasn't satisfied. My IA installed a small locking cable to the airframe which has a quick release pin on the other end. He drilled a small hole in the door handle and as long as the PILOT gets the door physically closed correctly and moves the door handle forward to the latched position, this pin locks into the door handle physically preventing the handle from moving aft and unlatching the door. This is in addition to the Cessna "button" that is supposed to the do the same thing. It would take me one second longer (if that) in an emergency to exit the airplane as a result of this additional lock and nobody is allowed to touch it except me. I always brief passengers and have them unlock it before we start up so they understand how it works but then I always do the final door closing before we fly.

I have a difficult time believing the 1973 and later doors have not experienced this problem many times. It always looked like a week spot to me. I am not familiar with the latches on the P-models but I had always hoped they were better then the latch on my non-P model. Apparently not. Frankly I am surprised there is not an A.D. on the issue.

I would be interested to here more details of the event should they become available.

I am glad everyone was OK.

Ed

jchronic · #6 01-22-14, 02:08 PM

Scary stuff. I'd be more worried about rear prop and empennage damage than the wing getting dented. A door coming off and hitting a critical spot back there could easily be catastrophic within a few seconds. I won't even let clients mount things on my struts.

Happy with my 'D' model.........

Joe

hharney · #7 01-22-14, 09:44 PM

It's just a good reminder for all owners and maintenance personal to do a really good check on doors, latching mech., seals, release's, etc. Especially on the P models.

I have heard stories about the P model doors and damaged latch mechanism that prevents the door from opening. Something about someone stuck on the ramp, really hot day and can't get the door open. There is no other exit???? I am trying to remember, is there a window exit? I don't think so, not sure how the approval allowed that. Even the 340 and 400 series have a window exit.

First trip yesterday in the Navajo that the company I fly for acquired. I sat in the hangar and practiced the door several times just so I would know how to use it. Flew to CAD from Z98, really cold out (like 5 degrees F) and when we landed CAD the door would not open. I didn't know what to do, thought we were going to pop the E window when the owner of the plane finally got it open by using some brute force. Door worked fine the rest of the day. I think it may have been ice but not sure. Anyway, enough said let's check the late model doors close and leave some feedback if anyone finds anything.

edasmus · #8 01-23-14, 01:18 AM

My 1973 337G has a window exit. I believe any 5 seat or more aircraft is required to have two exits. In the pre-1973 337 models, the baggage door counts as the second exit. In the 1973 or later models, no baggage exit existed. This is when the window exits were installed. I am not positive but I believe this was the certification requirement. Comments to verify?

Ed

jhickam · #9 01-23-14, 03:53 AM

I believe all P models are certified for 5 seats due to the only one exit. Any aircraft with 6 or more must have atleast 2 exits from the cabin.

Apelsin Elise · #10 01-23-14, 12:36 PM

Quote:

Originally Posted by Red Air Rambo

on the demo flight with a so called experienced pilot / mechanic climbing through 10K the boor blew open, he said the upper door took a chunk of the leading edge of the wing out and the lower door damaged the strut along with the door window blowing out, not a good day.

Frankly, the whole story sounds just a little bit strange.

On my '79 P337H the door latching mechanism is very robust. Bottom half has two latching points, upper half has four. Both halves latch separately, upper half overlaps the bottom one reinforcing the latching points. It is impossible to latch the upper half if the bottom half is not closed/latched properly. One the upper part, it is impossible to rotate the handle all the way if the upper half latches did not engage properly. It is a well designed and strong system.

In order for both door halves to blow open all 6 latches or 2 separate latching mechanisms need to fail. I am having hard time imagining how this could happen. Even if the cabin pressure was over the limit and the door gave in, only the upper part should open. As soon as the door seal is breached, the pressure differential goes away. Why would the bottom half open then?

I have never heard of a P-Skymaster door opening in flight before.

It will be great if we can get more information about the incident.

What year was the P-Skymaster in question?

Any chance there were some pictures taken?

Red Air Rambo · #11 01-23-14, 04:03 PM

I called the guy selling the plane, turns out the "experienced" pilot did not slide the safety latch forward or lock the safety pins down.

Ernie Martin · #12 01-24-14, 04:56 PM

The upper door has flown open twice on my 337G normally aspirated. Both times pilot error, where I failed to lock the safety pin down.

I share the view of others that the mechanism is robust and open doors are almost certainly pilot error. Locking the pin down is now not only part of my checklist but I always tell whoever is on the copilot seat to remind me before takeoff.

Ernie