During the building process of the Zenith CH-601XL, the pilot said he determined the unusable fuel amount in the fuel tanks with them uninstalled in the wings, placed on saw horses in a level attitude, but did not take into account wing dihedral, wing incidence, or pitch attitude.
On the day of the accident, he departed with what he thought was an adequate supply of fuel. When the flight was three or four miles from his destination with the fuel selector positioned to the right tank, the engine quit due to fuel starvation. He repositioned the fuel selector to the left tank, which restored engine power and continued towards the destination airport.
About one minute later the engine quit again. The fuel gauges at that time indicated 1/8 capacity in each tank. He established best glide airspeed and after realizing he was unable to land at the destination airport, he executed a forced landing in a marsh short of the runway near Sumter S.C., resulting in a minor injury.
After touchdown the airplane nosed over and although the emergency locator transmitter (ELT) had activated, the wreckage wasn’t spotted until an airplane that was landing flew over.
During the rescue of the pilot the right wing was cut off but no fuel leakage was reported. Following recovery of the airplane, the left fuel tank which was not breached did not contain any fuel. Additionally, only a teaspoon of fuel was found in the fuel strainer and the carburetor bowl was dry.
Advisory Circular (AC) 90-89A, titled, “Amateur-Built Aircraft and Ultralight Flight Test Handbook” dated May 24, 1995, provides guidance in part for determining unusable fuel amount, and the procedures call for placing the airplane at an angle 5° above the highest anticipated climb angle and to disconnect the fuel line to the carburetor. When the fuel flow stops, the amount remaining in the fuel tank is considered as unusable fuel.
The NTSB determined the probable cause as the total loss of engine power due to fuel exhaustion. Contributing to the fuel exhaustion was the pilot’s failure during the building process to properly determine the unusable quantity of fuel.
NTSB Identification: ERA14CA210
This April 2014 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.
This has nothing to do with build process, Its that little piece of umcompuck that rest between the ears that continues to bring down pilots..better known as, ” el poopie “.
I have seen some modifications done to standard certificated aircraft that are capable of out climbing their fuel flow margins, so a fuel pump is then installed. Never mind the placards or POH supplement limiting high alpha climb outs. Still one needs to figure fuel burn for each engine installed and duration of the planned flight.
Why do so many pilots try to “guess” how much fuel it will take to get from point “A” to point “B” and depart with just that amount? Someone please explain that to me as I don’t understand it? And please don’t say because some planes won’t carry full fuel tanks plus the passengers because the answer to that is, they don’t have a plane that’s large enough. If the tanks are topped off then you know you have enough fuel; that is if you don’t plan to try to fly from New York City to San Diego without making a fuel stop. And from some of the accident reports I read on this site, I guess some pilots would try that too?
BJS, I agree! This fellow was clever enough to build an airplane but not clever enough to put adequate fuel plus a reserve in it. So now he’s in the position of being fortunate enough to escape with a minor injury. The plane, however, is heavily damaged…and a wing cut off?!? Ouch! I wonder what his thoughts are regarding fuel calculations now…
It could be that the calculations for the specific flight were done, including reserve, but having an incorrect unusable fuel number made those calculations useless. So it goes back to being a construction error, rather than a flight planning error.
In any case, I DO like it when these accident reports teach a valuable lesson without someone dying or getting seriously injured. Especially in this case, where it wasn’t a stupid pilot trick but was instead just an honest mistake that happened during the build process.