Brief Description: Testing the Supply Capability of the Fuel System
Testing the Supply Capability of the Fuel System started today. With the aircraft level, fuel was added to the tanks and then the pump flow was measured for one minute. After the minute rate was known, continued pumping of the tank until dry allowed the calculation of the amount of fuel that was unusable in the tank. By subtracting the pumped volume from the known amount that was added to the tank in the beginning, the missing volume value was the amount of unusable fuel left in the tank. The process was repeated twice to verify result.
In the next step of the process of testing, the pumps need to be tested with the aircraft in about a 10 degree nose down attitude. After that test, the process will be again ran with the aircraft in approximately a 25 degree nose high attitude. All of this is to insure adequate fuel flow to the engine in these attitudes. As a Class, too many Experimental Amateur Built Aircraft's first flights experience fuel starvation accidents. Doing these tests will hopefully demonstrate the ability of the fuel system to supply adequat fuel flows to the engine in all of the normal attitudes of flight. To calculate the needed number of ounces of fuel required per minute, the following formula was used: Minimum Fuel Ounces per Minute = Engine Number of Brake Shaft Horspower x 1.25 x 0.36. My needed value is 90 oz./min. So far, this value has been easily met.
