EC135 Sliding Door Adjustment
 

I've been around 12-13 different 135s, old and new, and their sliding doors have always rolled nicely and pushed into the airframe opening and latched like butter. Unfortunately, the aircraft I fly daily is the opposite. We have tried many times over the years to adjust the sliding door and it never get anywhere near what it should be. All parts have been replaced including upper middle rails, rollers, you name it. You can get it to roll nicely but the issue is when it makes the turn in the track and tried to get into the opening it fights hard. You have to push hard to jam it in and then the handle is hard to drive the pin into the upper opening. The adjustment of the bracket the holds the middle track attachment to the door that gives both a forward/aft adjustment along with up and down is what gets us. We have tried everything from loosening all the hardware, pushing the door into the opening, trying to center it and then tightening it down but it's never right. Is there a trick that we are missing? The manual just says to adjust till smooth with a 5mm gap. I'm sure at the factory they have a jig that allows it to get put perfectly in place. I swear I would fly the person who assembles the doors from the factory to my place just to fix this for once. Any tips?

Maybe treat these two items as separate issues. First, remove the lower guide assy and with the door handle/latches open slide the door closed. If the upper roller arm is preventing the door from moving flush with the opening it maybe bent. The goal is to get the door in the opening flush to the airframe... even if you need remove the upper guide arm. But use caution and have help as if you let the door drop with only the center track connected you'll have more problems. Once you can get the door flush and latched, work your way back and see what part is causing the problem.

If you get the door flush, but the door handle will not latch easily then that should signal you have two separate problems. However, usually once we would get the door to seat flush in the opening the latch issue was no longer a problem. But if it is check to make sure there is no axial play with the handle shaft as if there is this is a sign the internal teflon spacers are missing and it can bind the latch linkage. As you mentioned these doors usually work great but when they don't they can be a pain. Good luck.

Is the airframe straight? Has there ever been any heavy landings or damage?

Is it both sliding doors or just one? Was a door seal changed at some point? Does the door seal have air holes in it so that it properly collapses when compressed?

Was just the left door for a long time, one pilot who has been here since aircraft was new said it was always a little odd but never as bad as is now or has been for the last few years. The right door is now just as bad after the mechanic tried to make an adjustment to fix a grinding noise but loosened up the wrong bit and of course couldn't get it back where it was. Based on that I'm sure it's just an alignment and adjustment problem, the issue is we cannot seem to find the right technique. It feels like the door is too far forward or back and it tries to push itself when it enters the curved part of the track as it goes into the airframe opening. The primary adjust problem area are the two bolts under the cover on the middle roller that bolts to the middle of the door. The manual gives no help other than "adjust the door till it works with a 5mm gap" If I could watch how them put these on the aircraft on the assembly line just once I'm sure everything would make sense but that's obviously impossible being in the USA. Gaskets are ok and still original, its a binding on the curved part of the track that the door just wants to pop back out.

Apart from the obvious it is pretty critical that the forward upper cart is in good shape. You cant just fit it and expect it to work. When it is all bolted in place but still loose so you can move it slightly on the fasteners there is quite a range to get it in the sweet spot. Don't just bolt it all up as it sits. Goes without saying that if the rollers are worn undersize or the track is worn (hard to see without torch and mirror) you will be pushing it uphill so to speak. The roller axles need lubrication pretty regularly and normally the vertical axis one does most of the work. If you here grinding you can tilt the cart within it's attachments when it is still loose as there is no pressure on the vertical roller and it's dragging on the track. There are peel shims under the brackets for the two forward rollers but I doubt they need adjusting.

Also check the gap to the forward door. Any change with the front door open or closed? Also check that the forward upper cart is not too far forward and hitting the end of the channel.

When the door is in the correct closed position have you tried backing off the fasteners to remove preload then re-torque? FWD upper and MID aft.

If you watch the upper part of the door inflight it is interesting! Check that you have steel bracket arms because alloy ones do crack.

It takes a bit to get them smooth but they should just be able to be closed with one finger as you say.

You could always go to the Airbus plant in Mississippi where they build the UH-72 which is basically an off the shelf H145. The 145 has the same door and fuselage door frame as a EC135. Regardless, the method I posted above has worked fixing 135 door issues to include swapping doors between airframes. As mentioned above, the upper guide arm plays a big roll in how that door opens/closes. At one time we had people use that guide as a handhold and we were always having to tweak the doors to shut good.

I'm surprised to hear this - SA/AS/EC/AH are well know for sturdy door mountings, and they never fall off.....

135 door is similar but I think the 145 door is about ~ 180 mm longer with 2 handles on the inside?

You might be right. I might be thinking of the crew doors and the only the hardware for the cabin doors. I do remember most of the 135/145 cabin door latch/guide part numbers are the same. Thanks.

Dear Surfandturf and all members,
Likewise we are encountered same issue, Similar phenomenon/symptom we are encountered,
We kindly suggest if that possible we can join a webinar to further discuss this issue,
Here is my e-mail: (deleted by SP), Appreciate if you can sharing your e-mail in order to settle this issue,
Thanks a lot,

I have reluctantly approved your post, but only in order to make the point that taking this discussion off the forum deprives PPRuNers of any salient points and further input, plus a reference in the future.

I have removed your email line to dissuade such a move.

Get a hold of your local tech rep. If they don't come up with an answer to your satisfaction ask them to elevate it to Donauworth. Guys there will jump over backwards to help in my experience. You can do it online as an AH customer and more than likely they will know any tips and tricks.

That's absolutely a good way to settle it, Indeed we get the solution from AH,
However we wanna figure out what's root cause lead to this situation?
Long-term hoist operation? or issue remain since delivery?
Actually we compare initial adjustment after delivery, Exact position It's almost same,
Only difference is door will become hard to lock in place after period of operation,
Did you try to add an belt-handle at inner side of sliding door to facilitate this situation? or grind off tip of dowel pin to become sharper in order to easy alignment?