New DA40 owner | First Plane | what are common mistakes?

[Steve]

Yes, same parts, although I don't know where Diamond gets theirs from. It shouldn't matter, since it is a standard part, just like a M8 bolt. Your A&P determines that the part is airworthy. Below are a couple of pictures of my new ones:

New elastomer elements in jig to compress prior to install

Installed

Steve

[Rich]

There are two somewhat obscure items glued below each of the wing roots that you wouldn't notice. I had one of each of these disappear from the right wing. They are not listed in the online IPC. The first was the jack point fitting. It's only necessary for putting the plane up on the normal Meyers types of jacks. It comes painted over and looks like just a nub of composite, but it is not. It's an aluminum conical fitting. I discovered mine missing and had to have my local Diamond Service Center dig up the part number and order it from Diamond. They were really cheap, something like $10.00. Supposedly they are glued in place by some kind of unobtainium. But a plain strong glue will work fine. When I replaced it I didn't bother to paint it. When it's missing you see plain fiberglass that looks like this:

N40XE Jack Mount.jpg (8 KiB) Viewed 674 times

The replacement parts look like this:

DA40 Jack Points.jpg (19.17 KiB) Viewed 674 times

You should be aware that when the flaps retract there is a preload of specified amount on the flaps produced by the flexing of the wing root when the flaps retract. The procedure for checking this value is in the AMM. There is a little rubber pad beneath the trailing edge of the wing root against which the flap pushes to avoid the flap composite/paint being gouged by the trailing edge composite itself. The one on my plane disappeared somewhere along the line resulting in some paint scratching on the upper flap surface. There apparently is no standard part number for this, according to Diamond Tech Support. Following their suggestion I replaced the missing piece with a piece of 1/8" thick stiff rubber held in place by double-sided automotive trim tape. If you lower the flaps in your hangar or tie down you can easily detect the presence or absence of this little piece. This is what the original looks like (from my left side wing root):

[Rich]

One other thing related to jacking the airplane. Standard jacks are wide enough that they put a load on the edges of the jack points and even the composite at the edges of the jack points. And they will scratch the paint on the jack points. I used to use rags placed underneath but after losing one of the jack points I decided to try to fine-tune the contact point. I found a great solution - a neoprene washer placed at the top of each jack keeps the force where I want it.

[Rich]

Lycoming originally delivered the engines with an incorrect dipstick. Check that you have part no LW14760. It's stamped right on the upper part of the dipstick shaft. Here's a thread about the service bulletin:
viewtopic.php?f=24&t=5806&p=71356&hilit=dipstick#p71356

[astaib]

Hi Steve,

Thank you for the explanation. Is the 183-59b a wood prop too? What advantages did you noticed by changing it?
Do you have a rough estimation of the cost of the elastomers? Is it a set or several PN has to be ordered?

Thanks!

Arnaud.

Same construction as the 180-17, wood core wrapped with composite. Comparing with speed runs I did prior to the change, the new prop is about 2 knots faster.

For our airplanes, there are two PNs (5 of one and one of the other). They are quite pricey if you order them from DAI. Luckily, they are a standard DIN part. I sourced mine from:

Berger Tools Ltd.

www.berger-tools.co.uk

PNs:

ES-63-50-CR (quan 5)
ES-32-40-CR (quan 1)

Total cost was about 50 British pounds, which is not much more than the cost of one elastomer element from DAI! Even with shipping to me from the UK, total cost was under $150.

Steve

Hi Steve,

Hapy new year first! Enjoy every flight that you will make in 2023.
I have a question regarding the "berger-tools" parts that you named above. I was about ordering them for my plane, when I noticed that the parts from Berger-Tools are not fuel resistant what is not appropriate for us I guess. Additionnaly the DIN of the Diamond Aircraft IPC is DIN 9835 when the DIN on berger-tools is DINISO10069-1.

Do you have an idea of what is the difference?

Thank you.

Arnaud.

[Steve]

Hi Arnaud:

There are three Shore hardness values for the same part made of different materials. The ones in our airplanes are made of rubber (specifically chloroprene rubber), with a Shore hardness of 70. They are black in color.

There are polyurethane versions available with Shore hardness values of 80 and 92 (much harder and less compressible). They are red in color. I never noticed the fuel resistance difference between the rubber and polyurethane versions as stated in the Berger website, since the rubber ones are used by Diamond, and using a version with a different Shore number might predispose to porpoising and a prop strike after a bad landing.

I can assure you that the ones I bought were identical to the factory parts from Austria and have held up well. I wind up changing them out every 7-8 years since by then they have lost about an inch or so of height (prop clearance). On the issue of fuel resistance, other sources state that chloroprene rubber has moderate fuel resistance:

https://www.lavelle.com/materials/chloroprene-rubber-cr

https://cormanufacturing.com/compounds- ... loroprene/

The only way I can see that being an issue is if you had a longstanding big fuel leak in the fuel line or engine-driven fuel pump drenching the rubber donuts. In which case you would have far bigger problems...

Steve

PS: I did fly today for the first time in 2023. 42 Knot headwind, but got the airplane up to 170 Knots groundspeed on the way back...

[Charles]

Don't let the rear door open past the hinge stops. That can happen with strong gusts of wind or uninformed passengers. The area around the hinges is prone to cracking and the repair is non-trivial. I learned that the hard way.

I've installed a piece of Dyneema (non-stretching) rope between the ends of the pneumatic cylinder to limit travel just before the door hits the hinge stops.

[mysands]

Don't let the rear door open past the hinge stops. That can happen with strong gusts of wind or uninformed passengers. The area around the hinges is prone to cracking and the repair is non-trivial. I learned that the hard way.

I've installed a piece of Dyneema (non-stretching) rope between the ends of the pneumatic cylinder to limit travel just before the door hits the hinge stops.

Would you please share a picture?

[astaib]

Hi Arnaud:

There are three Shore hardness values for the same part made of different materials. The ones in our airplanes are made of rubber (specifically chloroprene rubber), with a Shore hardness of 70. They are black in color.

There are polyurethane versions available with Shore hardness values of 80 and 92 (much harder and less compressible). They are red in color. I never noticed the fuel resistance difference between the rubber and polyurethane versions as stated in the Berger website, since the rubber ones are used by Diamond, and using a version with a different Shore number might predispose to porpoising and a prop strike after a bad landing.

I can assure you that the ones I bought were identical to the factory parts from Austria and have held up well. I wind up changing them out every 7-8 years since by then they have lost about an inch or so of height (prop clearance). On the issue of fuel resistance, other sources state that chloroprene rubber has moderate fuel resistance:

https://www.lavelle.com/materials/chloroprene-rubber-cr

https://cormanufacturing.com/compounds- ... loroprene/

The only way I can see that being an issue is if you had a longstanding big fuel leak in the fuel line or engine-driven fuel pump drenching the rubber donuts. In which case you would have far bigger problems...

Steve

PS: I did fly today for the first time in 2023. 42 Knot headwind, but got the airplane up to 170 Knots groundspeed on the way back...

Hi Steve,

Thank you very much, I will order them right now then.

170 GS, whaou! I don't think that I already saw this GS in level flight with my DA40

[Steve]

Arnaud:

While the elastomer elements are off for replacement, it would be a good idea for you, or your mechanic, to inspect the center tube in accordance with this SB:

http://support.diamond-air.at/fileadmin ... r-tube.pdf

I inspected mine a couple of years ago when I last replaced the elastomer elements on mine and it was OK. I can imagine a lot more wear if you land frequently on grass strips.