BeechTalk - BT

Username Protected · **Posted:** 02 Oct 2013, 03:43

The FAA just issued SAIB CE-13-43R1 on 9/30/2013.
Cirrus has an aluminum low pressure fuel return line passing through their TKS tank in the wing. The TKS fluid is causing this aluminum fuel return line to corrode allowing fuel to enter the TKS tank.
I spoke with a design engineer at Cirrus and asked why the fuel return line is passing through the TKS tank. The answer was "routing". It was easier to run the fuel line through the TKS tank rather than around the TKS tank.
This engineer stated that TKS fluid turns acidic once the shelf life has expired and will corrode aluminum. I understand the shelf life is two years. The expiration date is printed right on the drum.

I plan on putting a piece of aircraft aluminum (2024) in a jar with some TKS fluid and watching it over an extended period of time.

Of course the concern is we want the TKS fluid to melt the ice, not the airframe!
Obviously I am going to make sure our TKS fluid has not expired.

TKS has been around for a long time.
Does anyone on this forum have any real life experience with this issue? Hard facts? Technical knowledge?

Thank You!

Username Protected · **Posted:** 02 Oct 2013, 06:27

Google "TKS corrosion Hawker Citation S550". This is not a new problem.

Username Protected · **Posted:** 02 Oct 2013, 08:18

Actually makes sense.

Why make the panels out of Stainless or Titanium if Aluminum would have been suitable?

Username Protected · **Posted:** 03 Oct 2013, 14:48

Hmmm, TKS becoming acidic after 2 years? Smells fishing to me.

Username Protected · **Posted:** 03 Oct 2013, 15:16

For clarity, SAIB CE-13-43R1 applies to FIKI aircraft only. The older non-hazard system has a small tank in the fuselage. The large tanks for the known icing system are in the wings.

Username Protected · **Posted:** 03 Oct 2013, 15:24

Username Protected wrote:

Actually makes sense.

Why make the panels out of Stainless or Titanium if Aluminum would have been suitable?

I understand the new leading edge is made from those materials, but what protects the rest of the wing/tail? Doesn't the fluid run back, across aluminum? Does the paint provide sufficient protection?

- Martin

Username Protected · **Posted:** 03 Oct 2013, 15:44

One person's experience: I had TKS on my Mooney for 12 1/2 years, and now on my Bo for almost 5 years. Never any sign of corrosion. I've heard the stories, but always second- or third- or....hand.

Username Protected · **Posted:** 03 Oct 2013, 16:49

I will offer to take and haul away any 2 yr old TKS fluid that anyone feels that they don't want to use it because it has turned acidic. It's for the environment you know.

TKS, Cirrus, and Corrosion