Fuel Exhaustion & Starvation · NTSB CEN10LA050
AUGUSTINE DAVID L SONEX — Burnet, TX
| Date | November 14, 2009 |
| Location | Burnet, TX |
| Aircraft | AUGUSTINE DAVID L SONEX (amateur-built) |
| Purpose of flight | Personal |
| Conditions | Day · Visual Meteorological Cond |
| Phase / occurrence | Enroute-cruise Loss of engine power (partial) |
| Pilot age | 81 |
| Pilot total time | 12,125 hrs · High time |
| Time in type | Unknown |
| Fatalities | 1 |
Probable cause
NTSB findings
- Personnel issues-Task performance-Use of equip/info-Aircraft control-Pilot - C
- Aircraft-Aircraft oper/perf/capability-Performance/control parameters-(general)-Not attained/maintained - C
- Aircraft-Aircraft power plant-Power plant-(general)-Failure - F
- Aircraft-Aircraft systems-Fuel system-Fuel filter-strainer-Capability exceeded - F
- Organizational issues-Development-Design-Equipment design-Manufacturer
What happened
According to several witnesses, the pilot radioed that he was experiencing a loss of engine power and was attempting a forced landing. Witnesses who saw the airplane reported that during the forced landing attempt the nose of airplane dropped and the airplane subsequently impacted terrain in a nose-low attitude. An examination of the flight controls and airframe structure revealed no preaccident anomalies that would have prevented the pilot from maintaining aircraft control. An examination of the engine and fuel system revealed a white substance inside the main fuel tank which had clogged the fuel screen. Laboratory examination of this substance revealed that it was polyurethane. The sealant used to seal the fuel tank contained polyurethane designed to be used to bond the sealant to a metal tank. The airframe builder added this sealant to the accident airplane's plastic (polyethylene) tank when he encountered a leak within the fuel system at the fuel fitting. An examination of the remaining engine and systems revealed no anomalies.