air system setup question??
 

Hey, I'm building a FEJ Rafale. It is the first plane I have had where I have had to plum lines for gear doors and brakes. I installed the 2 air tanks that came with the kit. I am planning on installing one air fill valve and one air gauge for entire system wich includes retracts, gear doors, and brakes. Is this ok to do, or should I install and plum in 2 air fill valves and gauges, one set for each air tank??? Not sure how is best to approach setup for air systems. Any suggestions would be appreciated. Thanks Jon

RE: air system setup question??
 

Jonboy, install them seperate. if one should fail the other will still operate. use two fill valves and 2 gages.......


mark

RE: air system setup question??
 

personally, i like to install my gear and door systems seperate from the brakes. that way if the brake system develops a leak, you can still get the gear down. I believe others also like to keep the doors and gear seperate as the gear can open the doors when commanded down. its all personal preference.

RE: air system setup question??
 

Make all the air lines and stuff removable.
Darryl

RE: air system setup question??
 

Jonboy,
Separate lines definitely. Specially if you are using Jet Tronic valves, the break valve bleeds a lot of air on the off cycle and you loose alot of pressure if you use your breaks while taxiing. Also, I like using a 4 way junction, and route, tank /Gauge/Filler valve and supply line all in one junction. Also you may want to use an orifice on the up or down line for the main retracts to slow it down abit. I would also use quick disconnects with check valve on fuselage side at the junction to the wings. (so that you can check the system for leaks without the wings being plugged in) only for the gears not break line. and try to keep the lines going to each mains same length as much as you can to limit delay between gears.

good luck
jason

RE: air system setup question??
 

I would put two more air tanks in the plane that way when you land you still might have some air.

RE: air system setup question??
 

Jonboy

I agree with the rest go for separate systems.

I installed 3 separate tanks on my FEJ Rafale each as separate systems with 3 fill valves. This does at least mean if the doors or brakes leak you can at least get the U/C down. Personally I would not put the gauges in the plane, they are just something else to leak. The pump will have a pressure gauge. Do spend plenty of time thorougly testing the door rams under water especially with them fully extended and applying pressure from side to side. I could not get mine to work reliably leak free and fitted UP cylinders which were perfect. My retracts were fine, but others have had leaks again, check with them out of the plane.

John

RE: air system setup question??
 

I guess I continue to be the oddball. Two seperate systems presumes you will have a leak only in the brake line. Ya, and you guys never landed with the gear in the up position :eek:

I use one air system on all my airplanes with one fill. I install the tam's unit for loss of air situation and I am done. Since I have had the tam's unit installed, I have never landed gear up (except one time when there was a mechanical bind on the nose gear, but that does not count ;) )

I have suffered loss of air, and the Tam's unit threw the gear out while I was inverted at full speed.

I came around and incredibly had enough air to stop the airplane. THANK YOU TAM!

RE: air system setup question??
 

Looks like Sean' s system but two tanks with the TAM's fail safe on the gear/doors side covers all things ;)

marcs

RE: air system setup question??
 

Sean, you always will be :D, but in this case you're not alone. I use one airsystem (which sometimes includes multiple tanks), with one fill valve and one gauge to feed brakes, retracts, gear doors and speed brake)

RE: air system setup question??
 

KEEP IT SIMPLE, every component is subject to leak, so first reduce their amount.

I prefer Spring Air like single action retracts, 1 fill valve, no gauge, but install only water tested components in the planes, and an amazingly high percentage of them fail the test, some are easy to fix, some back to manufacturer. Most of them where Brakes, Spring Air button and level actuator, Fill valves, and small cylinders.

If you remain on dual action, the TAMJETS Failsafe is a very very usefull thing. Just use some restrictors to help that a single line leaking or unplugged cannot be fast enough to empty your tanks before gear is locked down, this at least for the brakes like , which are the most likely to give.

Important point is to get axial loads only on the valves, and lube regularely every moving part and seal.

I prefer mechanical valves and servos cause operable by hand and then keep positions.

And if you do not want to risk any leaks, use a dolly, or fly foamies !!

Daniel Rossier

PS: Sean, you are not alone in this way of doing !!!