Crack on horizontal stabilizer

[astaib]

Hello,

I just noticed this “crack” on the horizontal stabilizer during preflight. I assume that it is not new, but I never paid attention to it.

It is like this on both sides (more on right side).

I tried a tap test, but nothing abnormal.

Do you think that it is something to worry or it is only superficial?

Thank you.

[Steve]

Arnaud:

On my aircraft, there is a "mold line" between the top and bottom half of the stabilizer (you can see it on yours). The crack appears to be along that line. I was at the hangar today and looked at mine, and there is no crack. You might take some good photos of the area and email them to Diamond Service Support...

Steve

[astaib]

good idea, I will do so.

[Karl]

We have 17 diamond aircraft all built in Europe and all at least 14 years old. Not a single one shows any cracks or even evidence of a mold line at that location.
I would suggest getting an engineer with composite experience to have a look at it as well as sending the pics to DIA.

[Lance Murray]

I am going to guess it's a body filled seam between top and bottom skins. Not a structural issue. The advice to enlist Diamond is a good call but I think you are ok.

[Steve]

As I mentioned previously, I recalled that my stab has a "mold" or join line at that location. After looking at the IPC, I'm not so sure now:

Horizontal Stabilizer Components.pdf

(177.26 KiB) Downloaded 92 times

The diagram shows a solid trailing edge web in that location (P/N 50), with the top and bottom shells bonded to that. It is similar in configuration to the front and rear spars, and is a single piece from top to bottom, not joined. I will look more closely at mine when I'm next at the hangar, and take some close up photos.

Steve

[Steve]

Arnaud:

Was at the hangar today and inspected that area on my aircraft more carefully. There is definitely a seam in mine, more obvious than in your aircraft:

Horizontal stabilizer bond line

There are even rivets on the top half of mine. None of this is shown in the diagram in the IPC, so perhaps there have been some design changes over the years. But I think you also have a 2001, so maybe back then they were changing designs more quickly...

Steve

[astaib]

Hi Steve,

Thank you for checking on your aircraft! I think you are right that the early birds had design change quickly.

I questionned Diamond and they wrote me that there is no bond line in that area, and they think that it is more a painting crack than a structural. They recommend to sand the surface to see is the crack is only on the painting layer of if it affects the composite.
I will start by looking very closely first before sanding.

Arnaud.

[Boatguy]

I checked my 2018 DA40NG today and there is no seam or crack on either side.

[waynemcc999]

I checked my 2008 XLS and no seam or crack on either side.