History of Flight
On March 9, 2009, about 0540 mountain daylight time, a Grumman American Corporation AA-1B airplane, N9646L, was destroyed when it struck terrain after unintentionally entering instrument meteorological conditions (IMC) near Golden, New Mexico. The private pilot and passenger sustained fatal injuries. The personal flight, conducted under 14 CFR Part 91 without a flight plan, originated at Sandia Airpark Estates East Airport (1N1) in Edgewood, New Mexico, and was destined for Los Alamos Airport (LAM) in Los Alamos, New Mexico. Instrument conditions prevailed at the accident time, which occurred about one hour and twenty minutes before civil twilight.
Witnesses reported hearing the non-instrument-rated pilot and passenger depart 1N1 for LAM around 0530. The duo regularly commuted between the two locations as passengers in another aircraft with another pilot. They had flown together in N9646L only once the week prior, as the usual pilot was unavailable. Their typical route followed State Route 344 (SR-344) to State Highway 14 (SH-14), then north toward LAM. SR-344 runs north from 1N1 for about nine miles, then west for about 4.5 miles, crossing a 7,200-foot mean sea level (MSL) ridgeline 1.6 miles east of SH-14.
A driver northbound on SR-344 observed an airplane flying low to the west, then north, near 1N1 around 0530. She noted light snowfall that intensified within half a mile east of the ridgeline crossing. Upon crossing the ridgeline, she saw a fire north of the road and called 911. Emergency responders arrived and identified airplane wreckage amid the fire. No evidence indicated the pilot obtained a weather briefing.
Personnel Information
The 42-year-old pilot held a private pilot certificate with airplane single-engine land rating but was not instrument rated. His most recent FAA third-class medical was issued on August 8, 2007, with no limitations. The last logbook entry, dated December 8, 2008, recorded 299.6 total hours. On his last medical application (August 8, 2007), he reported 310 total hours and 45 hours in the preceding six months.
Aircraft Information
The 1973 Grumman American Aviation Corporation AA-1B, serial number AA1B-0146, was a low-wing airplane with fixed tricycle landing gear and two seats. It was powered by a Lycoming O-320-E2D engine (serial L-22848-27A) rated at 150 horsepower, driving a Sensenich two-bladed fixed-pitch propeller. The aircraft was not equipped for IMC flight. The last annual airframe inspection occurred on April 3, 2008, at 3,076 hours airframe time. The engine had its last annual inspection on the same date, with about 763 hours since major overhaul.
Meteorological Information
Weather radar data near the accident site was limited due to mountainous terrain blocking radar signals. Returns showed weak echoes with cloud tops near 28,000 feet MSL over the location, with light to moderate precipitation north and very light precipitation south. Sunrise at Albuquerque, New Mexico (26 miles southwest), was at 0725, with civil twilight at 0700. Daylight saving time had changed on March 8, 2009.
At 0533, Albuquerque (ABQ) reported: ceiling 2,900 feet overcast, visibility 10 miles, light rain, temperature 43°F, dew point 37°F, winds 310° at 9 knots, altimeter 29.97 inHg, mountains obscured northeast through southeast. At 0453, Santa Fe (SAF) reported: ceiling 4,800 feet overcast, visibility 10 miles, 43°F/25°F, winds 280° at 11 knots, altimeter 29.95 inHg. At 0553, SAF observed: ceiling 2,400 feet overcast, visibility 10 miles, light rain, 36°F/32°F, winds 300° at 6 knots, altimeter 29.97 inHg. At 0550, Los Alamos (LAM) reported: 2,000 feet broken, 3,100 feet overcast, calm winds, 10 miles visibility.
A witness at 1N1 heard rain between 0500 and 0530. Responding law enforcement reported heavy snow and rain between the accident site and Sandia Mountain to the west.
Wreckage and Impact
The airplane struck a west-facing slope of a north-south ridgeline at 7,074 feet MSL, about 600 feet north of SR-344. The terrain had moderate slope with pinion trees and small boulders. The debris field spanned about 100 feet on a 105-degree magnetic heading. Broken trees near impact indicated a 35-degree nose-low and 30-40 degree right bank attitude. The wreckage was mostly burned. Flight control cable continuity was verified from cockpit to aileron, elevator, and rudder surfaces. One propeller blade had multiple leading-edge gouges (up to 0.5 inches deep) and chordwise scratches; the second blade was bent aft. No evidence of catastrophic engine failure was found.
Medical and Pathological Information
An autopsy on March 10, 2009, by the New Mexico Office of the Medical Investigator attributed the pilot's cause of death to multiple blunt force trauma. The autopsy noted 160 ml of clear urine in the bladder. Toxicological testing revealed 0.092 mg/100 ml ethanol in subclavian blood. FAA testing detected ethanol in blood (75 mg/dl), urine (191 mg/dl), and muscle (83 mg/dl). The serotonin metabolite ratio (5-HTOL/5-HIAA) in urine was 17.29 pmol/nmol, indicating ethanol ingestion. No witnesses could testify to the pilot's behavior the night before the accident.