AOG - RH fuel indicator acting up

[mfdutra]

To correct what I said above, the SC pulled the wing and one wing spar was soaked with TKS. We don't know if that destroyed the fuel probe, but it's likely. I definitely have a TKS leak on the right wing at least. So much for quality control.

[mfdutra]

Today's update:



TKS did indeed destroy the fuel probe. Somehow it made past the o-ring and reached the probe board.

This is the new probe with sealed connectors mentioned in OSB 62-040. Therefore, the service bulletin isn't solving any problem.

We're still investigating the source of the leak and why the leak isn't draining through the wing spar cavity.

[mfdutra]

This is a picture of RH rear wing spar cavity. As you can see, it's full of TKS there. The project of the airplane says there should be a drain in there, exactly for that reason. The factory in Canada drilled the drain in the wrong spot. The other end of the hole they drilled never made into the cavity.

How they ended up with that mistake is shocking to me. We still haven't heard from them on how to fix this issue.

[michael.g.miller]

Make sure you or your shop files an SDR: https://sdrs.faa.gov/

This is how the FAA tracks manufacturing defects and gets them fixed.

[Davestation]

Good forensics. I imagine that the material selected for that o-ring was intended only to be fuel resistant and not glycol resistant?

[mfdutra]

Probably. If you look at the wing design, the fuel tanks are sandwiched between the spars and the TKS is completely separate on the leading edge, in front of the front spar. In theory, TKS should never make to the tanks, especially with enough pressure to damage the electronics, behind another metal plate that exists in front of the probes.