A utva-66 pilot discovered that the fuel starvation occurred when making bank angle turns in excess ...

Narrative:

While circling in the area; engine stopped. Both left and right tanks showed fuel remaining. Engine tank switch was initially selected to left and aircraft was circling to the left. When engine stopped; fuel was selected to both. Engine did not regain power. Engine fuel pressure was observed to be reading almost zero. Selected backup electric fuel pump. Fuel pressure was regained in about 15 seconds and engine regained power. Apparently during the turn; the left tank fuel pickup was no longer in fuel and the engine lost power due to fuel starvation. When both was selected on the fuel tank selector valve; fuel pressure was not regained by use of the normal engine driven fuel pump; but instead the electric pump was required in order to get the engine going again. Tests run later in the day over the airport confirmed that this can happen on either tank; and that both must be selected during any kind of bank over approximately 20 degrees. In later tests; the electric pump was not required to regain power; but the tank was selected to both much faster than when it happened the first time unexpectedly. Cockpit now placarded to read no steep turns without both selected on fuel tank control knob.

Original NASA ASRS Text

Title: A UTVA-66 pilot discovered that the fuel starvation occurred when making bank angle turns in excess of 20 degrees if the tank selector is not on both. The elevated wing fuel pickup became uncovered.

Narrative: While circling in the area; engine stopped. Both left and right tanks showed fuel remaining. Engine tank switch was initially selected to left and aircraft was circling to the left. When engine stopped; fuel was selected to both. Engine did not regain power. Engine fuel pressure was observed to be reading almost zero. Selected backup electric fuel pump. Fuel pressure was regained in about 15 seconds and engine regained power. Apparently during the turn; the left tank fuel pickup was no longer in fuel and the engine lost power due to fuel starvation. When both was selected on the fuel tank selector valve; fuel pressure was not regained by use of the normal engine driven fuel pump; but instead the electric pump was required in order to get the engine going again. Tests run later in the day over the airport confirmed that this can happen on either tank; and that both must be selected during any kind of bank over approximately 20 degrees. In later tests; the electric pump was not required to regain power; but the tank was selected to both much faster than when it happened the first time unexpectedly. Cockpit now placarded to read no steep turns without both selected on fuel tank control knob.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	860173
Time
Date	200911
Local Time Of Day	1201-1800
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Small Aircraft High Wing 1 Eng Fixed Gear
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Flight Plan	None
Component
Aircraft Component	Fuel Distribution System
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Commercial
Experience	Flight Crew Last 90 Days 50 Flight Crew Total 1500 Flight Crew Type 150
Events
Anomaly	Aircraft Equipment Problem Critical

A utva-66 pilot discovered that the fuel starvation occurred when making bank angle turns in excess of 20 degrees if the tank selector is not on both. The elevated wing fuel pickup became uncovered.