EASA AD 2024-0235

[KJH]

I've searched the site but have not seen any prior posts on this EASA AD, which needs to be implemented by the end of Jan 2025.

https://ad.easa.europa.eu/ad/2024-0235

It looks like the door latches of all DA42 rear doors need to be checked and placarded before 31 January 2025.

The owner of the flying school where I'm doing some training mentioned it today, but I found nothing here, so I'm posting. Please delete or relocate if I've missed something.

[Hlflyer]

I'm surprised there haven't been more posts on this subject? Just going through the AD with my AME; still unsure as to the exact fix recommended in the 40 page SB document (SB42-149-M-r0-actions-to-prevent-passenger-door-separation). Our plane was built in 2007, has the "new" latch, which supposedly means that MÄM 42-097 is installed (would include a "gas spring")? However, in my plane there does not seem to be any "snap over" tension, and there does not seem to be any "torsional spring" or "compression gas spring / gas cylinder"? (Possibly this just needs to be serviced / replaced?) My AME will be digging deeper into this issue later this week; will post our findings. Plane is now almost 18 years old, rear door latch has never been an issue. Concerned with the complexity (and potential cost) of complying with this AD!

[Karl]

I'm surprised there haven't been more posts on this subject? Just going through the AD with my AME; still unsure as to the exact fix recommended in the 40 page SB document (SB42-149-M-r0-actions-to-prevent-passenger-door-separation). Our plane was built in 2007, has the "new" latch, which supposedly means that MÄM 42-097 is installed (would include a "gas spring")? However, in my plane there does not seem to be any "snap over" tension, and there does not seem to be any "torsional spring" or "compression gas spring / gas cylinder"? (Possibly this just needs to be serviced / replaced?) My AME will be digging deeper into this issue later this week; will post our findings. Plane is now almost 18 years old, rear door latch has never been an issue. Concerned with the complexity (and potential cost) of complying with this AD!

If there is no snap over tension, then the gas spring needs to be replaced.

[Soareyes]

So far for private owners in the US this is only a recommended MSB, not yet a required AD for the DA42. http://support.diamond-air.at/fileadmin ... ration.pdf

Curious, is there not one for the identical rear door of the DA40?

Inspecting the latch mechanisms is not a bad thing but this AD/MSB deflects from the underlying reason that rear doors sometimes fly away. With delicate top mounted hinges it is a large door that is designed to catch the wind like a sail. You would think that when designing an airplane a front hinged door would be preferable. To be fair, if the door does open in flight it is good the hinges let go and the door can depart safely without further damage. I wonder if that feature was by choice or chance?

I'm skeptical that more placards will increase safety. Plus, they are ugly.

Double check the rear door before start up and before taking the runway. Close the door for your passengers and open it for them after landing. If possible park the plane so that the wind on the ground won't catch it when opened. Hold the door to keep pressure off the hinges if opening it on the ramp in a strong wind. Tell backseat passengers to not touch the door handle basically ever, especially if the door happens to open a little in flight. If the door departs, fly the plane.

[nickname]

It’s a matter of time before it’ll be an FAA AD, and the lead time on the gas spring strut is 4-6 weeks.

[Karl]

So far for private owners in the US this is only a recommended MSB, not yet a required AD for the DA42. http://support.diamond-air.at/fileadmin ... ration.pdf

Curious, is there not one for the identical rear door of the DA40?

Inspecting the latch mechanisms is not a bad thing but this AD/MSB deflects from the underlying reason that rear doors sometimes fly away. With delicate top mounted hinges it is a large door that is designed to catch the wind like a sail. You would think that when designing an airplane a front hinged door would be preferable. To be fair, if the door does open in flight it is good the hinges let go and the door can depart safely without further damage. I wonder if that feature was by choice or chance?

I'm skeptical that more placards will increase safety. Plus, they are ugly.

Double check the rear door before start up and before taking the runway. Close the door for your passengers and open it for them after landing. If possible park the plane so that the wind on the ground won't catch it when opened. Hold the door to keep pressure off the hinges if opening it on the ramp in a strong wind. Tell backseat passengers to not touch the door handle basically ever, especially if the door happens to open a little in flight. If the door departs, fly the plane.

I don't understand why you think it deflects from the cause.
The loss of a door is caused by the latch gas strut and emergency door catch not being maintained in a serviceable condition, hence the inspection.
If the gas strut does not give an over-center force to the latch, it can vibrate open; if the emergency catch is worn or does not engage, you lose the door. Personally, I doubt that the emergency catch would work in flight anyway. There would be so much vibration that it would only be a matter of time before it jumped into an open position.
Hinges are not the cause of the door's loss. They are designed to be broken away if you need to escape when the aircraft is upside down on the ground.

[Soareyes]

I don't understand why you think it deflects from the cause.
The loss of a door is caused by the latch gas strut and emergency door catch not being maintained in a serviceable condition, hence the inspection.
If the gas strut does not give an over-center force to the latch, it can vibrate open; if the emergency catch is worn or does not engage, you lose the door. Personally, I doubt that the emergency catch would work in flight anyway. There would be so much vibration that it would only be a matter of time before it jumped into an open position.
Hinges are not the cause of the door's loss. They are designed to be broken away if you need to escape when the aircraft is upside down on the ground.

Karl, a good point about the importance of the gas strut. You mentioned recently that in your nearly 20 years experience of working on a fleet of Diamonds you have had experience with that. In my 20 years of owning multiple DA40s, now a DA42 and reading about departing doors I've somehow developed the impression that the proximal cause of many lost doors is simply from pilots failing to securely latch the door in the first place. Going with the odds, you know, pilot error.

MSB 42-149 (Dec. 2, 2024) covers instructions for the mechanic to examine the gas spring, door pins, the secondary safety latch and the hinges. It also instructs the pilot to visually check the position of the door handle, physically push and test that the door is secure and to look for "DOOR OPEN" CAS warnings before each flight.

Who has looked at the rear door hinges on a 40 or 42 for the first time and not thought they looked oddly delicate? There are reports of them cracking from time to time and were in fact the subject of their own AD in 2010. https://www.aopa.org/news-and-media/all ... or-bracket

Here is an example of a different plane with top hinges that didn't lose the door when it opened:

Video: https://www.youtube.com/watch?v=ZZy7sfqDzvA

It could be a good thing the DA40/42 doors break off if they open in flight. Depending how the door aligns or not with the slipstream the plane might be uncontrollable otherwise.

Regarding the action of the emergency release, this is a video showing how the handle functions by pulling the pin out of the forward hinge:
https://www.youtube.com/shorts/DmVKA2Se7Qc

[ZAV]

It’s a matter of time before it’ll be an FAA AD, and the lead time on the gas spring strut is 4-6 weeks.

Have already been waiting 4wks for two of these for my DA40.

[Rainair]

It’s a matter of time before it’ll be an FAA AD, and the lead time on the gas spring strut is 4-6 weeks.

AOG orders help, as always with DAI (Sadly)

[dant]

Guess I got in just in time. I ordered this Oct 21 from Premier for my DA40 and had it in hand 2 days later.