FLYER Forums

This is one for LAA/homebuilders (mostly):

When I built my aircraft I fitted an Andair FS-15 fuel on/off switch (single fuel tank). Within a few months, the switch became very graunchy and stiff to operate. I spoke to Andair and without going into the various conversations, they replaced it under warranty with an 'upgraded' FS-16. Suffice to say that one of their staff indicated that there had been some problems with the -15.

I now find, after 2 years and 100 hours flying with the -16, that it too, is getting very stiff to operate. I'm beginning to think that turning the fuel off in emergency may become too difficult in the heat of the moment if there's not much time. I spoke to Andair again recently to ask if anyone else has reported problems and the answer was that nobody had. Does anyone else with this kit have any stiffness in Andair fuel switch operation?

I'm not trying to do the firm down (indeed I'd support Blighty's innovation and manufacturing whenever I can)...

Ive been using them for the last 10 years in a couple of RV’s. Never had any problems.

Had one in our Falco for 10 years without issue (other than that I didn’t assemble it properly and filled the belly of the aircraft with fuel........)

Is there an issue with fuel quality? Is the filter upstream or downstream of the switch?

Pure speculation on my part but I wonder if the seals in the valve are being affected by Ethanol in the Mogas you are using?

I wouldn't dream of using Mogas in either of my aeroplanes, whether cleared or not, so ethanol is not involved. It could be fuel quality johnm. There's a finger type filter in the tank upstream; there's an Andair gascolator downstream of the switch. I think it might be worth popping an inline filter upstream. Thanks for that idea.

PB wrote:I'd take it apart and have a look-see if the seals have swelled up.

You don't say if you are operting on Mogas or not, but if you are, they may be other agressive (non-ethanol) components in the fuel that are degrading the seals.

I think you will find he did - in the post immediately before yours

I wouldn't dream of using Mogas in either of my aeroplanes, whether cleared or not, so ethanol is not involved.

johnm wrote:Is there an issue with fuel quality? Is the filter upstream or downstream of the switch?

I'm pleased to report that the problem is now resolved.....Andair advised that the fuel switch seals were contaminated. They replaced the seals and returned the switch FoC, so thank you and well done Andair.

I had been very careful to rinse out the (newly manufactured) fuel tank many, many times and installed an LAS finger bar filter in the tank before fitting same to my homebuild. I've now installed an Andair fuel filter upstream of the switch and don't anticipate any further problems.