Aviation Accident Summaries

Aviation Accident Summary CEN09FA195

Golden, NM, USA

Aircraft #1

N9646L

GRUMMAN AMERICAN AVN. CORP. AA-1B

Analysis

The non-instrument-rated private pilot and passenger were commuting to work in the dark, following a familiar route of flight. The airplane was not equipped to fly in instrument weather conditions and there was no evidence found indicating the pilot had obtained a weather briefing or filed a flight plan. One witness described light rain falling at the departure airfield 30 minutes before the airplane departed. A second witness, who was driving along the airplane's intended route of flight, saw the airplane depart the airfield and described the weather deteriorating from light rain to snow as she drove towards the accident site. She indicated that heavy snow was falling when she saw the accident site and notified authorities. Ethanol was detected in a postmortem urine specimen (at 0.191 mg/dL), and in two separate postmortem blood specimens from the pilot (at 0.075 and 0.092 mg/dL), consistent with impairment from the effects of alcohol at the time of the accident. No witnesses to the pilot’s behavior the night prior to the accident could be found.

Factual Information

HISTORY OF FLIGHT On March 9, 2009, about 0540 mountain daylight time, a Grumman American Corporation AA-1B airplane, N9646L, was destroyed when it impacted terrain following inadvertent flight into instrument meteorological conditions near Golden, New Mexico. The airplane was owned and operated by the pilot. The private pilot and passenger were fatally injured. The personal flight was being conducted under the provisions of Title 14 Code of Federal Regulations Part 91 without a flight plan. The cross country flight originated at the Sandia Airpark Estates East Airport (1N1), Edgewood, New Mexico, and was en route to Los Alamos Airport (LAM), Los Alamos, New Mexico. Instrument meteorological conditions prevailed at the time of the accident and the accident occurred about one hour and twenty minutes before civil twilight. Witnesses heard the non-instrument rated private pilot and passenger depart 1N1 for LAM about 0530. The pilot and passenger regularly flew between the two locations as passengers in another airplane with another pilot, commuting to work in Los Alamos. The pilot and passenger had only flown together in N9646L once the week prior to the accident due to the other pilot being unavailable to fly. Their regular route of flight generally followed State Route 344 (SR-344) to State Highway 14 (SH-14), then north towards LAM. SR-344 generally runs north from 1N1 about nine miles, and then turns west for about 4.5 miles, crossing a 7,200 foot mean sea level (MSL), north-south running ridgeline 1.6 miles east of SH-14. A witness driving north on SR-344 saw an airplane flying low to the west, then north, in the vicinity of 1N1 about 0530. She described light snow falling as she drove north and the snow became heavy within one half mile east of the ridgeline crossing. As she crossed the ridgeline she spotted a fire burning north of the road and called 911. Emergency responders arrived and identified airplane wreckage in the fire. No evidence was found indicating the pilot had obtained a weather briefing. PERSONNEL INFORMATION The pilot, age 42, held a private pilot certificate with ratings for airplane single-engine land. He was not instrument rated. His last Federal Aviation Administration (FAA) third-class medical was issued August 8, 2007, with no limitations. The last entry in the pilot's logbook was dated December 5, 2008, and indicated 299.6 total hours. The pilot indicated 310 hours total time and 45 hours during the last six months on his last FAA medical application, issued August 8, 2007. AIRCRAFT INFORMATION The 1973-model Grumman American Aviation Corporation AA-1B, serial number AA1B-0146, was a low wing airplane, with a fixed, tricycle landing gear, and was configured for two occupants. The airplane was powered by a direct drive, carbureted, air-cooled, four cylinder engine. The engine was a Lycoming O-320-E2D, serial number L-22848-27A, rated at 150 horsepower, and was driving a Sensenich two-bladed, fixed pitch propeller. The airplane was not equipped to fly in instrument meteorological conditions. The last airframe inspection was an annual type, completed on April 3, 2008. The airframe had accumulated 3,076 hours at the time of inspection. The last engine inspection was an annual type inspection, completed on April 3, 2008. The engine had accumulated approximately 763 hours between the last major overhaul and the time of the inspection. METEOROLOGICAL INFORMATION Weather radar data for the accident location was limited due to mountainous terrain located between the accident site and the weather radar facilities. Radar data was poor from about ten miles north to ten miles south of the accident location. There was an area of weak returns with cloud tops near 28,000 feet MSL depicted over the accident location. Radar returns depicted areas of light to moderate precipitation north of the accident location and very light precipitation to the south. Sunrise at Albuquerque, New Mexico, located about 26 miles southwest of the accident site, was at 0725. Civil twilight began at 0700. Daylight savings time changed on March 8, 2009. Weather at Albuquerque, New Mexico (ABQ), at 0533 was reported ceiling 2,900 feet overcast, visibility 10 miles, light rain, temperature 43 degrees Fahrenheit (F), dew point 37 degrees F, winds 310 degrees at 9 miles per hour, altimeter setting 29.97 inches of Mercury (Hg), mountains obscured northeast thru southeast. Weather at Santa Fe, New Mexico (SAF), at 0453 was reported ceiling 4,800 feet overcast, visibility 10 miles, temperature 43 degrees F, dew point 25 degrees F, winds 280 degrees at 11 miles per hour, altimeter setting 29.95 inches of Hg. At 0553, SAF weather was reported ceiling 2,400 feet overcast, visibility 10 miles, light rain, temperature 36 degrees F, dew point 32 degrees F, winds 300 degrees at 6 miles per hour, altimeter setting 29.97 inches of Hg. Weather at LAM at 0550 was reported 2,000 feet broken, 3,100 feet overcast, calm winds, and 10 miles visibility. A witness living at 1N1 described hearing rain falling between 0500 and 0530. Responding law enforcement officers reported heavy snow and rain falling between the accident site and Sandia Mountain to the west. WRECKAGE AND IMPACT INFORMATION The airplane impacted the west facing slope of a north-south running ridgeline at 7,074 feet MSL, about 600 feet north of SR-344. The slope was moderate terrain covered in pinion trees and small boulders. The wreckage debris field was about 100 feet long and aligned on a 105 degree magnetic heading. Broken trees and branches near the impact point were consistent with impact from the airplane in a 35 degree nose low and 30 to 40 degree right bank attitude. Examination of the airplane revealed the airplane mostly burned. Flight control cable continuity was verified from the cockpit controls to each aileron, elevator and rudder control surface. One propeller blade had multiple leading edge gouges, up to one half inch deep, and chord wise scratches. The second blade was bent aft. No evidence of catastrophic engine failure was found. MEDICAL AND PATHOLOGICAL INFORMATION The Office of the Medical Investigator, State of New Mexico, located in Albuquerque, New Mexico, performed an autopsy on the pilot on March 10, 2009. The cause of death was attributed to multiple blunt force trauma. The autopsy report noted, in part, that “The urinary bladder contains 160 ml of clear urine; the mucosa is gray-tan and smooth.” Toxicological testing performed in conjunction with the autopsy noted 0.092mg/100ml of ethanol in subclavian blood. The FAA, Toxicology Accident Research Laboratory, located in Oklahoma City, Oklahoma, conducted toxicological testing on the pilot. The pilot tested negative for carbon monoxide and Cyanide. The pilot tested positive for ethanol in his blood, urine and muscle in the following amounts: - 75 (mg/dl, mg/hg) ethanol detected in blood. - 191 (mg/dl, mg/hg) ethanol detected in urine. - 83 (mg/dl, mg/hg) ethanol detected in muscle. The FAA, Toxicology Accident Research Laboratory, provided the following clinical report with the toxicological testing results. " Postmortem vitreous glucose levels above 125 mg/dL are considered abnormal and postmortem urine levels above 100 mg/dL are considered abnormal.” “Hemoglobin A1C blood levels above 6% are considered abnormal.” “A 5-HTOL/5-HIAA ratio value < 15 pmol/nmol is not consistent with ethanol ingestion, while a ratio value > 15 pmol/nmol is indicative of ethanol ingestion." - 17.29 (pmol/nmol) serotonin metabolite ratio detected in urine. There were no witnesses located that could testify to the pilots behavior the night prior to the accident.

Probable Cause and Findings

The pilot's continued visual flight into instrument meteorological conditions. Contributing to the accident were the pilot's recent usage of alcohol and his subsequent impairment.

 

Source: NTSB Aviation Accident Database

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