History of Flight
On June 9, 2014, at about 1115 Pacific daylight time, an American Aviation AA-1A, registration N9454L, collided with the dry lakebed surface of El Mirage Lake in El Mirage, California. The airplane was co-owned and operated under 14 CFR Part 91. The commercial pilot and a 9-year-old passenger sustained fatal injuries. The airplane was destroyed. The local personal flight departed from the El Mirage Lakebed around 1113. Visual meteorological conditions prevailed, and no flight plan was filed.
Members of the Los Angeles Fire Department had organized an off-duty recreation day at the lakebed. The group included about 12 people, with activities such as camping and flying the accident airplane and powered paragliders. The pilot was a helicopter pilot assigned to the LAFD air operations division.
About 0930, witnesses stated the pilot departed with one of his daughters for a 15-minute sightseeing flight, departing south in light and variable winds. A short time later, he flew his second daughter on a similar flight. For the third flight, the group requested a low pass over the north shore where everyone had assembled.
According to witnesses, the flight departed south, but the wind had increased, creating a left crosswind during takeoff. The airplane approached the group from the northwest at low altitude. After flying over the group, it initiated a climbing right turn to the south, then a right turn to the west. During the turn, the bank angle became excessive. The airplane did not roll level; instead, the nose tucked down and the airplane descended into the ground.
Personnel Information
At the time of the accident, the pilot was assigned to the Air Operations Section of the LAFD as a Fire Helicopter Pilot II. He had been with the division for about 4 years and had completed a 200-hour advanced flight training program, attaining his type rating in the Augusta Westland AW-139 helicopter. He flew 20–30 hours per month in the LAFD AW-139 and Bell 206 and was preparing for his AW139 mission commander check ride.
The pilot held a private pilot certificate with airplane single-engine land rating (March 2002) and a commercial pilot certificate with rotorcraft-helicopter rating (July 2002). He received a certified flight instructor certificate (helicopter) in June 2011 and added his helicopter instrument rating in August 2013.
As of May 2, 2014, his logbook showed about 1,890 total flight hours, with 1,400 in helicopters and most of the remainder in the accident airplane. The co-owner stated the pilot had performed three takeoffs and landings in the airplane the week prior but had not flown it for about a year, having purchased another airplane. His most recent flight review was on May 9, 2013. He held a second-class medical certificate issued December 17, 2013, with a limitation for near vision.
Aircraft Information
The airplane was co-owned since 2002 by the pilot and a fellow LAFD pilot, who held an airframe and powerplant certificate with inspection authorization and had performed most maintenance since 1999. The low-wing, two-seat airplane, serial number AA1A-0254, was manufactured in 1971. Originally fitted with a 110-horsepower Lycoming O-235, it received an overhauled 150-horsepower Lycoming O-320 in June 2012 under supplemental type certificate SA4387NM. The co-owner estimated the pilot had about 10 hours of flight experience in the airplane since the engine upgrade.
An annual inspection completed on July 7, 2013, recorded 2,202.1 total flight hours and 24.1 hours since overhaul. The airplane flew an additional 7 hours in the 11 months before the accident.
Meteorological Information
The closest weather station was at Southern California Logistics Airport, Victorville, about 13 miles east-southeast. At 1115, the report indicated wind from 130 degrees at 7 knots, visibility 10 miles, scattered clouds at 9,500 and 11,000 feet, temperature 37°C, dew point -2°C, altimeter 29.88 inHg. A report 20 minutes later showed wind from 110 degrees at 8 knots; at 1235, wind was from 120 degrees at 10 knots, gusting to 19 knots.
Wreckage and Impact Information
The accident site was on the western side of the lakebed. The first impact point included 2-inch-deep ground scars continuing 10 feet on a bearing of 320 degrees magnetic, with debris including green wingtip lens fragments and nose landing gear strut. The engine starter ring and alternator belt were nearby. The propeller, nose gear, red wingtip lens shards, and pitot tube were 30 feet further. The main wreckage came to rest about 160 feet beyond the first impact, with the cabin upright (bearing 170 degrees) and crushed from firewall to passenger seat bulkhead. All flight instruments detached. The tail section was intact and undamaged. The engine mount separated, with the engine partially attached via control cables and hoses. Both wings separated from the center spar: the right wing inverted with leading-edge crush at a 45° angle; the left wing leading edge up with crush damage along its length. The stall warning indicator was crushed; the pitot tube detached. Both wing spar fuel tanks were breached, with odor of automotive gasoline. The magneto switch was in the BOTH position; fuel selector in right wing tank; throttle and mixture full forward; flaps retracted. All major components were accounted for, with no bird strike indications.
Additional Information
Video captured the takeoff and accident sequence from about half a mile north. The airplane departed south, began a climbing right turn north, leveled at about 300 ft AGL parallel to the group. It then transitioned east while descending, with engine tone increasing, banking about 25° right as it passed about 50 ft overhead, 80 seconds after takeoff. The turn continued, banking 30° until leveling south. Seven seconds later, a climbing right turn to about 200 ft AGL reached an 80° bank angle as it passed out of view. One second later, it reemerged in a 90° right bank; the nose yawed 20° down while maintaining near-vertical bank. The airplane then rapidly descended, nose dropped further, rolled right, pitched down, and struck the ground in an almost vertical attitude about 18 seconds after the low pass. The engine operated throughout; no smoke or vapor trails were visible.
Weight and balance calculations: The engine STC increased gross weight to 1,579 pounds. Empty weight was 1,130 pounds; pilot and passenger combined about 240 pounds; baggage about 8 pounds. The right fuel tank was full (11 usable gallons); left tank had 3–6 gallons. The airplane was about 100 pounds below max gross weight; center of gravity about 77 inches aft of datum, within the normal category range of 75–80 inches.
Performance data from the AA-1A Owner's Manual: cruise speed 119 mph at 65% power and 8,000 ft; stall speeds (flaps up, max gross weight, forward CG) were 63 mph at 0° bank and 89 mph at 60° bank. Maximum approved positive load factor was 3.8 G's. The FAA Pilot's Handbook describes load factors: 60° bank yields 2 G's, 80° bank yields 5.76 G's; stall speed in an 80° bank would be about 132 mph. Spins were prohibited; spin recovery required brisk application.
Medical and Pathological Information
An autopsy conducted by the San Bernardino County Sheriff's Department reported the cause of death as multiple blunt force injuries. Toxicological tests by the FAA Civil Aerospace Medical Institute and the County of San Diego were negative for all screened drugs and alcohol.
Tests and Research
All flight control cables (elevator, aileron, rudder) were continuous from control surfaces to cockpit attach points. Foot pedals and yoke sustained impact damage. The rudder and elevator moved freely; trim actuator functioned. Both ailerons sustained crush damage and remained partially attached. The flap actuator was fully retracted. Airworthiness Directive 72-06-02 (rudder, aileron, elevator control cables) was complied with; no defects noted. The stall warning indicator was damaged; its working condition could not be assessed.
Engine examination: The lower cowling crushed the inlet air box, exhaust manifold, muffler, and separated the carburetor bowl. The engine-driven fuel pump contained fuel and was free of obstruction; internal diaphragms intact. All fuel fittings were tight. The engine showed no preimpact mechanical malfunction or fire. The two-blade propeller separated from the crankshaft flange; one blade bent 90° midspan opposite rotation, with nicks; the other bent slightly forward. Both magnetos produced sparks; spark plugs showed normal wear. Crankshaft rotated smoothly with thumb compression on all cylinders; mechanical continuity established; rocker arms coated in clear oil. Cylinder combustion chambers, examined via borescope, were undamaged with no foreign object ingestion or detonation. Oil filter and screen were clean. No evidence of preimpact mechanical failure of engine or airframe was noted.