Narrative:

[We] declared emergency on downwind after being cleared to land. Was granted emergency by tower and landed uneventfully. Was doing timed fuel burn measurements of the header tank orbiting at 1;300 ft above runway in right hand orbits. All fuel was flowing from the freshly filled header tank. The main tanks had about 15 gallons. Flight approved by tower. On final orbit; [we] turned to downwind from upwind leg at 1;300 ft started descent into traffic pattern. [We were] cleared to land; number 2 behind a high wing piper on three mile final. I acknowledged and descended to pattern altitude of 850 ft. Before descending to pattern altitude I switched to main fuel tanks. At mid-field downwind; I realized the header tank had run dry and the engine had stopped and the prop had stopped. I had sufficient altitude for a safe landing; but not enough time to restart the engine. My varieze has an electric starter; so can easily be air started with sufficient time and altitude. The piper ahead of me was now about 500 ft AGL and about one mile from the airport. So I declared an emergency so I could land first. The tower immediately cleared me to land and advised the piper to go around. I landed and turned off at the first taxiway so did not delay any arrivals or departures. I restarted the engine and ground control cleared me to taxi to the hangar. After shutdown; I called the tower and advised them of the reason for declaring emergency. They advised this was a routine situation and caused no safety issue. Lesson learned was that the timing tests of the fuel burn from the header tank are not as reliable as earlier tests. I had done the same test the day before; but did orbits at 100 additional RPM. [I] also learned that if the engine stops during a descent with idle power; it is difficult to tell if it is running since the prop is aft. So on a prolonged descent at idle power will occasionally increase throttle to detect a response. [I] also will monitor the egt gauges for loss of temperature.

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Original NASA ASRS Text

Title: Varieze pilot experiences fuel starvation on downwind while doing timed fuel burn measurements of the header tank. An emergency is declared and a dead stick landing ensues.

Narrative: [We] declared emergency on downwind after being cleared to land. Was granted emergency by Tower and landed uneventfully. Was doing timed fuel burn measurements of the header tank orbiting at 1;300 FT above runway in right hand orbits. All fuel was flowing from the freshly filled header tank. The main tanks had about 15 gallons. Flight approved by Tower. On final orbit; [we] turned to downwind from upwind leg at 1;300 FT started descent into traffic pattern. [We were] cleared to land; number 2 behind a high wing piper on three mile final. I acknowledged and descended to pattern altitude of 850 FT. Before descending to pattern altitude I switched to main fuel tanks. At mid-field downwind; I realized the header tank had run dry and the engine had stopped and the prop had stopped. I had sufficient altitude for a safe landing; but not enough time to restart the engine. My Varieze has an electric starter; so can easily be air started with sufficient time and altitude. The Piper ahead of me was now about 500 FT AGL and about one mile from the airport. So I declared an emergency so I could land first. The Tower immediately cleared me to land and advised the Piper to go around. I landed and turned off at the first taxiway so did not delay any arrivals or departures. I restarted the engine and ground control cleared me to taxi to the hangar. After shutdown; I called the Tower and advised them of the reason for declaring emergency. They advised this was a routine situation and caused no safety issue. Lesson learned was that the timing tests of the fuel burn from the header tank are not as reliable as earlier tests. I had done the same test the day before; but did orbits at 100 additional RPM. [I] also learned that if the engine stops during a descent with idle power; it is difficult to tell if it is running since the prop is aft. So on a prolonged descent at idle power will occasionally increase throttle to detect a response. [I] also will monitor the EGT gauges for loss of temperature.

Data retrieved from NASA's ASRS site as of July 2013 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.