Hangar Flying => Hangar Flying => Topic started by: TIM BAILEY on March 20, 2005, 04:47:19 AM
Title: VARI-EZE FUEL SYSTEM ALERT
Post by: TIM BAILEY on March 20, 2005, 04:47:19 AM
Got airborne with 90 mins fuel...after 20 mins smelt fuel an landed. Large puddle of fuel formed under aircraft coming from the hellhole inspection panel between the gear. Main tanks were dry and only half the header tank remaining. The 20 year old plastic tubing was so brittle it fell apart in my hands. This system was installed by a licenced engineer and inspected by a licenced engineer every year for the last 19 years. Get your head inside this area from below (can't see it from the rear seat) and make sure you have the correct tubing securely fitted. :(
Title: Re: VARI-EZE FUEL SYSTEM ALERT
Post by: Dan Patch on March 22, 2005, 02:15:31 PM
The 20 year old plastic tubing was so brittle it fell apart in my hands. This system was installed by a licenced engineer and inspected by a licenced engineer every year for the last 19 years...
You are lucky, I guess, that you made it for 19 years. This (plastic tubing failure) is an old and widespread problem that bit a number of VariEzes not long after folks first started to fly. If I'm not mistaken, it was specifically called out for use in the early plans. By good fortune, many (nearly all?) of the plastic fuel lines that failed did so on the ground, either by being bumped or even spontaneously, rather than in the air. I know that I started flying using some type of 'super' plastic line that was specifically selected by a 'materials expert' in our builder's group who assured us that it was state-of-the art impervious to almost every solvent known to man. I got rid of it after it became seriously discolored - through its thickness - showing that fuel was penetrating into the material. Ultimately, a sample that I still had lying around became so brittle that it would 'shatter'. So much for 'super'!
This is an example of a common, well-known problem being widely recognized by numerous failures, then being corrected (almost entirely), and then drifting out of the EZ-community's 'common knowledge base' as the problem disappeared from the accident/incident list. Thanks for bringing this issue back into main stream awareness again!
Fuel lines are near the top of my annual inspection list, and they get replaced every 5-6 years regardless of how 'good' they look - cheap insurance even at twice the price, as the saying goes! Needless to say, I didn't simply replace the plastic lines with 'new plastic'. Go with real fuel tubing!
Best & blue skies,
Title: fuel tubing
Post by: Sidney on March 23, 2005, 05:46:00 PM
Metal tubing is not perfect either. My LongEZ has the 3003 soft aluminum tube plumbing from the tank selector to the tanks and gascolator. A few years ago, I came out the the ramp, opened the canopy only to hit by a strong smell of gas. Further investigation revealed that one of the SCAT tubes used for cabin heat had been resting on the aluminum fuel line along the left wall of the fuselage. The steel wire in the SCAT tube erroded a small hole in the fuel line due to galvanic response. There was a puddle of fuel in the nose of the airplane. Checking the full length of the fuel lines showed other pitted areas on the aluminum fuel tubes where SCAT tubes where contacting them.
Title: VARI-EZE FUEL SYSTEM ALERT
Post by: Dan Patch on March 23, 2005, 08:42:19 PM
Geez, that's a new one to put in the 'gotcha file' - thanks for the info.