History of Flight
On July 5, 2012, about 1324 Pacific daylight time, a TL Ultralight SRO Stingsport, registration N177N, sustained substantial damage when it struck terrain near Piru, California. The aircraft was operated by the pilot under 14 CFR Part 91. The certified flight instructor and commercial pilot receiving instruction were fatally injured. Visual meteorological conditions prevailed, and no flight plan was filed. The local flight originated from Whiteman Airpark (WHP) in Van Nuys, California, at 1300.
Multiple witnesses on Highway 126 near the accident site reported seeing the airplane descending nose-low while spinning counter-clockwise before it dropped below a tree line. According to acquaintances, the flight was intended as a flight review for the pilot.
Personnel Information
It could not be determined which pilot—the 89-year-old commercial pilot and owner in the left seat or the 59-year-old certified flight instructor in the right seat—was manipulating the controls at the time of the accident.
The pilot held a commercial pilot certificate with single-engine land, single-engine sea, and instrument ratings. His most recent third-class medical certificate was issued on November 3, 2005. He reported 3,600 flight hours on his last medical application; his logbook showed 3,999.3 total hours as of May 22, 2012.
The flight instructor held an airline transport pilot certificate with single-engine land, multi-engine land, and instrument ratings, along with a flight instructor certificate for those categories. His most recent second-class medical certificate, issued June 28, 2011, had no limitations. He reported 13,000 total flight hours and 200 hours in the previous six months on his medical application. His logbooks were not found.
Aircraft Information
The light sport, two-seat, low-wing, fixed-gear aircraft (serial number TLUSA 153) was manufactured in 2007. It was powered by a Rotax 912ULS engine (100 horsepower) driving a three-bladed wooden propeller. The airplane was equipped with a Galaxy Rescue Parachute System (GRS).
Logbook review indicated the most recent annual inspection was completed on July 1, 2012, at a Hobbs time of 214.1 hours and tachometer time of 215.9 hours. The aircraft had flown about 1 hour since that inspection.
The Pilot Operating Handbook (POH), Section 4, Normal Procedures, included a pre-taxi checklist item stating, "GRS Safety Pin -- REMOVED and STOWED." A note in the POH advised storing the pin in an easily reachable place, such as the canopy locking lever, to remind the pilot to secure the parachute after landing.
Meteorological Information
Recorded data from the Camarillo Airport (CMA) automated weather station, about 20 miles southwest of the accident site, showed at 1255: wind variable at 4 knots, visibility 10 statute miles, overcast ceiling at 1,600 feet, temperature 18°C, dew point 15°C, and altimeter setting 29.98 inches of mercury. At 1355, CMA reported a broken cloud layer at 1,800 feet.
Wreckage and Impact Information
The airplane came to rest upright in an open field adjacent to an orange orchard, oriented about 294 degrees magnetic. Debris was scattered within 20 feet of the main wreckage. A large ground indentation was found about 1 foot forward of the engine, containing two propeller blades.
The fuselage was mostly intact with impact damage to the forward and lower sections. The GRS handle was displaced from its mount on the cabin roof; the securing pin was removed and found in the wreckage. The handle appeared not to have been actuated. The left wing remained attached, with left aileron and flap attached; the left flap appeared partially extended. The right wing remained attached, with right aileron and flap attached; the right flap appeared partially extended. The empennage was partially separated and displaced 45 degrees to the right, about 1 foot forward of the horizontal stabilizer. The vertical stabilizer, horizontal stabilizer, rudder (partially separated), elevator, and trim tab remained attached. Flight control continuity was verified from cockpit controls to all primary surfaces.
The engine remained attached to its mount. The carburetors were intact and unremarkable upon disassembly. Spark plugs showed normal operation signatures. Rotational continuity and thumb compression were established on all four cylinders. The propeller assembly remained attached to the crankshaft flange; two blades were separated just outboard of the hub, exhibiting slight chordwise scratching. No preexisting mechanical malfunctions were found.
The cabin roof structure, parachute handle, and arming pin were sent to the NTSB Materials Laboratory for examination.
Medical and Pathological Information
FAA medical records indicated the 89-year-old pilot had a history of high blood pressure and coronary artery disease treated with bypass surgery and medications. His medical certificate had not been renewed after expiring on November 30, 2006.
An autopsy performed on July 7, 2012, by the Ventura County Medical Examiner determined the pilot's cause of death as blunt force injuries. A palpable subcutaneous pacemaker was noted but not interrogated; the heart and coronary arteries were not examined due to injury. Toxicology tests by CAMI detected no carbon monoxide or ethanol. Metoprolol, Valsartan, and Ticlopidine were found in blood or urine.
The flight instructor held a second-class medical certificate with no restrictions. His autopsy also listed blunt force injuries as the cause of death. Toxicology tests revealed no carbon monoxide or ethanol, but tetrahydrocannabinol (THC) was detected in the lung (not blood), and THC carboxylic acid was present in blood, urine, and lung. Terazosin was found in blood and urine.
Tests and Research
Two Garmin GPSMAP 396 handheld GPS units were recovered and sent to the NTSB Recorders Laboratory. The data showed the flight departed WHP runway 12, performed two takeoffs and landings in the traffic pattern, then proceeded northwest. The tracks indicated a 360-degree right turn, a 360-degree left turn, and 90-degree turns. About 3 miles south of the accident site, a 45-degree turn to a northerly heading at 4,774 feet msl and 91 knots ground speed was recorded. Over the next 80 seconds, altitude increased to 5,148 feet msl, ground speed decreased to 55 knots, then increased to 95 knots at 5,056 feet msl. The final two data points (19 seconds) showed a decrease to 65 knots at 5,020 feet msl, directly above the accident site, followed by a vertical descent.
Laboratory examination of the roof structure revealed a disbonded area where the parachute arming-handle mounting bracket was adhesively bonded. Higher magnification showed the bracket was loaded in peel, with the crack propagating from the radiused bend toward the square edge. The balance of the faying surfaces were too rough for sufficient adhesive wetting. Traces of roof structure paint were found between the surfaces. The arming pin exhibited permanent bending of approximately 90 degrees relative to the slot cut through its shank, with fretting wear deposits indicating contact with the handle through-holes. Energy-dispersive spectroscopy showed the fretting deposits were primarily oxidized constituents of the handle's aluminum alloy.