Light Sport Aircraft
Flight Crew Instrument; Flight Crew Commercial
Flight Crew Last 90 Days 31; Flight Crew Total 765; Flight Crew Type 250
Situational Awareness; Training / Qualification
Aircraft Equipment Problem Critical; Inflight Event / Encounter Fuel Issue
Aircraft Aircraft Damaged; Flight Crew Inflight Shutdown; Flight Crew Landed in Emergency Condition; General Maintenance Action
Aircraft
En route my next destination flight time about 2.5 hours; cruising 2;800 MSL; 92% power; EGT and CHT's normal; no traffic; clear conditions. Without warning engine sputtered and stopped; restart attempts unsuccessful. [I made a] precautionary landing in hay field; no personal injuries; no property damage; except aircraft's landing gear damaged. On the ground inspection revealed empty fuel tank and dry gas filter. Airplane had been topped off before departure with sufficient fuel for 4 hours plus 45' reserve. Suspected problem was an en route fuel leak. Before departure; minor repairs to lexan panel done; and also the prop pitch was reduced by 1 degree. Test flew for 0.2 hours and engine performed well. Aircraft was then parked on the ramp in front of the FBO; preflighted; suitcase and camera bag loaded and secured; and 1 quart oil added. There were no fuel leaks either on the plane or on the ramp; and another pilot sitting near the plane; observing me; would have noticed any dripping fuel. TT on HKS 700e engine (and airframe) 274 hours; a thorough annual was completed on May 2012; pilot BFR on April 2012. Jan. 2012; carburetors rebuilt and synchronized; May 2012; cylinder heads cleaned and new gaskets. In numerous previous tests; fuel consumption typically was 3.0 GPH (or less) at 90% power; and ranged between 3.1 and 3.3 GPH at 95% power; and 3.5 GPH at 97%; including taxi; takeoff; and climbout.
The Reporter stated that the final maintenance inspection report is not out yet but he suspects that a loose connection at the fuel filter allowed fuel to leak while in flight.
A Challenger LSA HKS 700e engine quit in flight forcing an off field landing which resulted in minor landing gear damage. The aircraft was airborne 2.5 hours with takeoff fuel for 4.5 hours; so a fuel filter fitting leak is suspected.