NTSB Factual Report

On September 1, 2015, about 1940 mountain daylight time, an Extra Flugzeugbau GMBH EA 300/L, N4BM, was destroyed when it impacted terrain near the Jerome County Airport (JER), Jerome, Idaho. The airplane was registered to and operated by the pilot under the provisions of Title 14 Code of Federal Regulations Part 91. The private pilot, sole occupant of the airplane, was seriously injured. Visual meteorological conditions prevailed and no flight plan was filed for the personal flight. The local flight originated from JER about 5 minutes prior to the accident.

A witness located at the airport reported that he watched the accident airplane take off and head to the southeast. The witness said that another person who was with him had asked the pilot to return and do a fly by, so they went outside to watch. The witness stated that he observed the accident airplane southeast of the airport, conducting a loop, and estimated that the airplane was about 1,500 feet above ground level as the airplane neared the top of the maneuver. The witness further stated that as he walked away from the building to continue to watch the airplane, he observed it descend out of his line of sight behind a building. He added that as it descended below the building, the airplane appeared to have started to level out, and felt that it should have had enough altitude.

The pilot reported that he didn't recall anything regarding the accident flight other than getting into the airplane and waking up in the hospital 5 days later. The pilot stated that he wanted to go on an easy flight in order to clear his mind since his wife passed away a couple weeks prior, and that he had no intent of performing aerobatics.

Examination of the airplane and accident site by a Federal Aviation Administration inspector revealed that the airplane impacted a corn field about one-half mile southeast of the approach end of runway 27. All major structural components of the airplane were located at the accident site. Wings, engine, and empennage were separated from the fuselage and located within the wreckage debris path. Local law enforcement reported that the debris path was about 375 feet in length. The wreckage was recovered to a secure location for further examination.

Examination of the recovered wreckage revealed that the wings, empennage, and engine were separated from the fuselage. The fuselage was mostly intact. The canopy glass was separated from the canopy structure. The empennage was separated about 30 inches aft of the rear seat. The throttle, mixture, and propeller control cables were pulled /stretched. The acro / center fuel tank remained intact. Air was applied to the fuel filler of the fuel tank, and residual fuel was observed being expelled from the airframe fuel filter housing (gascolator), which was impact damaged.

Flight control continuity was established from the forward and aft control sticks to the left and right wing root, and aft to the separation point of the empennage. Both control sticks remained interconnected. Left and right aileron control continuity was established with various areas of impact damage observed to the control torque tubes (fractures consistent with overload). The rudder cables remained attached to the rudder pedals and exhibited overload signatures (in an area consistent with the separation of the fuselage).

The left and right wings were impact damaged, and were mostly fragmented. The empennage was intact, with the horizontal stabilizers and vertical stabilizers still intact. The forward spars for the left and right elevators and the rudder remained attached to their respective mounts, and the remainder of each flight control surface was fragmented.

The engine was separated from its mounts. Both the left and right magnetos were separated. The oil cooler exhibited impact damage. The accessory housing, rocker box covers, top spark plugs, and propeller assembly were removed. The engine rotated partially by hand using a hand tool. Examination of cylinder number two revealed that the cylinder bore was filled with dirt and metallic debris (portion of the intake elbow). The cylinder was partially removed from the crankcase, and the crankshaft was manually rotated. Thumb compression and suction was obtained on cylinders 1, 3, 4, 5, and 6. Mechanical continuity of cylinder number 2 was established. No internal physical or mechanical damage was observed internally for cylinder 2 when inspected using a lighted borescope.

For further details of the airframe and engine examination, see the NTSB Airframe and Engine Examination Summary report within the public docket for this accident.

No evidence of any preexisting mechanical malfunction was observed that would have precluded normal operation with the airframe or engine.

NTSB Probable Cause

The pilot's failure to maintain clearance from terrain while conducting a low-altitude aerobatic maneuver.