Amateur/Home Built/Experimental
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial
Flight Crew Last 90 Days 12; Flight Crew Total 927; Flight Crew Type 159
Aircraft Equipment Problem Critical
Air Traffic Control Provided Assistance; Air Traffic Control Separated Traffic; Flight Crew Landed in Emergency Condition; Flight Crew Returned To Departure Airport; General Maintenance Action; General Flight Cancelled / Delayed
Aircraft
Aircraft had not flown in about 3 years. Condition inspection just completed. Tower was informed before taxi that operation was a test flight. On third takeoff on Runway 7; engine began missing badly passing through 700 ft. at 100 kts. Pilot immediately initiated left turn back toward airport while informing tower of engine problem. Turn was inside 2 other aircraft in the traffic pattern and speed allowed altitude gain to 800 ft. which is pattern altitude. Tower cleared aircraft for any runway at about the time the left turn was complete. Pilot pulled power back because engine missing was shaking airplane and at that point the engine quit running. Pilot informed Tower Runway 11 would be the landing runway. Pilot aimed for the end of Runway 11 and arrived there at about 300 ft. at which point pilot initiated a slip to get down to the runway and executed a normal crosswind landing with wind at approximately 10 kts. and 90 degrees to the port side of the aircraft. No other traffic was affected by this event. [Priority handling was not requested.] The engine problem is still being diagnosed; however it is likely a stuck valve due to overheating caused by poor cooling on a rear engine tightly cowled engine installation. The aircraft will not be flown again until the cooling issues are solved and the valves are inspected by an A&P Mechanic. The engine is a Lycoming O-320-E2D with 159 hours since major overhaul by a FAA certified shop that complied with all applicable AD's on the engine. The root problem is aircraft cooling; which problem caused the stuck valve.
Experimental aircraft pilot reported a loss of engine power on takeoff; resulting in a return to land.