Light Aircraft Association

Hi

Is it a good idea to mount the gascolator in the cockpit?

In our aircraft (a Spitfire Mk26b) the fuel tank is just behind the instrument panel and mounting a gascolator on the engine side of the firewall would be difficult to get it lower than the bottom of the tank. The air intake scoop for the oil cooler is in the way too. However there is plenty of room under the pilot's seat for it.

The benefits as far as I see it are that the gascolator would be away from the heat of the engine bay (reducing the chance of vapour lock etc), is in the lowest point of the fuel system next to the fuel shut-off valve and is readily accesible for routine maintenance.

I believe it is common practice in Vans RV's to put the gascolator in the cockpit.

Can't say I've come across the fitment of a gascolator in an RV cockpit.
I'm not convinced it would be the lowest point in the system.
Given there are 2 wing mounted fuel tanks (on most RVs) positioning it would be interesting.
Testing / servicing it would spill lots of fuel in a passenger area - not nice!

In my experience gascolators are one of the most common places for a fuel leak through a perished O ring in the Curtis valve or round the main bowl seal. RV's tend to have proper aircraft grade aluminium fuel lines and fittings that are generally leak proof, so that's all I'd want in the cockpit.

You may be thinking of the fuel pump being on the people side of the firewall on RVs. It's typically under the pilot's footwell floor, if I remember the RV-6/7 plans correctly, but earlier ones may have it on the side, like mine does.

I wouldn't. I looked to buy a Pulsar that had one inside the cockpit. The last I saw of it the owner and his mate were bailing out fuel from the cockpit next the the runway hold..............

Phil

I have the gascolator in the tunnel on my RV-10. I have repeated a mod used by Roger Hopkinson on the first -10. Basically, it was accepted that the gascolator was never going to be lower that the wing drains. We have fitted the Andair unit with the screw on bowl and deleted the fuel filter and the drain on the gascolator. Basically, the requirement to fit a gascolator has been met but it is being used as a fuel filter.

It doesn't seem to make a lot of sense to fit one on the firewall on a low-wing aircraft where it is higher than the wing drains.

Paul, the mk26B has a fuselage tank and lowest point will be above the gascolator IIRC. I saw the aircraft on Sat and it looks as if a firewall position has been agreed by the group, but they are still concerned about heat build-up within the cowl causing issues. With cool fuel flowing through it I think it should be OK.

Is the tunnel in the RV10 sealed from the rest of the passenger compartment?

Not sealed as such, but fully enclosed. All the fuel system components and lines to the engine are in the tunnel.

Sorry Paul got your name wrong there, now corrected.

IIRC as a four seater the RV10 is required to be more in line with CS-VLA than other permit aircraft, or is it CS-23? Both require isolation of fuel systems from the cabin so that any breakage or failure would not cause a hazard.

The standard VANS design has the fuel lines, selector, pump, filter and fuel flow sensor all in the tunnel. All the mod does is substitute a gascolator for the filter. The logic for this was that the wing drains trap any water and the gascolator has it's own filter screen. It makes maintenance easier and safer as, to clean the filter, you can unscrew the bowl instead of having to undo fuel couplings to get at the filter. All this has been approved by LAA Eng.

I guess the answer is that the tunnel IS considered isolated from the cabin - as much as, say, running everything under the floor. Let's face it, you have to get the fuel from the tanks to the engine somehow and this has to involve running pipes etc by, through or under the pax compartment.

Having said that, I am considering putting in some sort of small access hole so as to be able to discharge a fire extinguisher into the tunnel.

Sorry Mark - seem to have hi-jacked your thread somewhat

paul330 wrote:I have the gascolator in the tunnel on my RV-10.

I stand corrected!