NTSB Factual Report

HISTORY OF FLIGHT

On June 14, 2015, about 1127 central daylight time, a Grumman American Aviation Corporation AA-5 single-engine airplane, N6552L, was substantially damaged when it impacted terrain shortly after takeoff from Gillespie County Airport (T82), Fredericksburg, Texas. The private pilot sustained serious injuries, and his passenger was fatally injured. The airplane was registered to a private individual and operated by the pilot under the provisions of 14 Code of Federal Regulations (CFR) Part 91 without a flight plan. Day visual meteorological conditions prevailed for the local flight, which was originating at the time of the accident.

On the morning of the accident, the pilot and his aviation mechanic were at the airport to complete an annual inspection of the airplane. Although the pilot was an automotive mechanic, he reported that he did not participate significantly during the annual inspection. He recalled that the mechanic removed several inspection panels to observe the flight control system; verified operation of an avionic device that was installed in the rear fuselage; completed a compression check of each engine cylinder; removed, inspected, and replaced some spark plugs; and drained/replaced the engine oil. Additionally, the pilot recalled that the mechanic collected a fuel sample from at least one drain on the left wing. The pilot stated that the airplane had four fuel drains (two per wing); however, he could not recall if the mechanic had obtained a fuel sample from all four drains during the annual inspection. Additionally, he did not recall if the mechanic had examined the auxiliary electrical fuel pump, drained the pump reservoir, or inspected the pump filter screen. The pilot estimated that the annual inspection took a couple of hours to complete.

After completing the annual inspection, the pilot and his mechanic decided to conduct a local flight in the airport traffic pattern. The pilot stated that he completed his normal preflight inspection of the airplane, which included obtaining fuel samples from all four fuel drains. He did not recall seeing any water or particulate contamination in the fuel samples that he collected. He stated that the left wing tank was nearly full, with about 19 gallons of fuel, and that the right wing tank contained 2 to 4 gallons of fuel. The pilot did not add any fuel to the airplane before the flight. The pilot stated that he did not observe any anomalies with the airplane during his preflight inspection. The pilot completed an engine runup before he taxied from the ramp to runway 14. He stated that the engine developed maximum static rpm during the engine runup and both magnetos were functioning correctly. Additionally, he observed normal fuel and oil pressures and a normal oil temperature.

The pilot did not recall all portions of the accident flight. He remembered that the engine lost power shortly after takeoff from runway 14, and he had a brief memory of the airplane pointing nose-down toward the ground. However, he did not recall any corrective actions that he made following the loss of engine power or the airplane impacting terrain. His next full memory was when he awoke at the hospital during his recovery. The pilot reported that, while he was being treated at the hospital, he had apparently told his wife that the engine had lost power shortly after takeoff and that he had pushed the nose down to regain airspeed.

There were no witnesses to the accident. The wreckage was located by the property owner about 1245.

PERSONNEL INFORMATION

According to Federal Aviation Administration (FAA) records, the 51-year-old pilot held a private pilot certificate with a rating for airplane single-engine land. The pilot's most recent FAA third-class medical certificate was issued on May 22, 2014, with the limitations that he was prohibited from flying at night and by color signal control due to color blindness. A search of FAA records showed no previous accidents, incidents, or enforcement proceedings.

The pilot's flight experience was established using his pilot logbook. The final logbook entry was dated November 15, 2014, at which time he had accumulated 214.1 hours total flight time. The entirety of his logged flight experience was in single-engine airplanes. The pilot had accumulated 34.6 hours in the accident airplane make/model. Although the pilot had flown 33.4 hours during the 12 months before the accident, he had not flown during the 6 months before the accident. The pilot's last flight review, as required by 14 CFR 61.65, was completed on June 13, 2014, in the accident airplane.

AIRCRAFT INFORMATION

The airplane was a 1974 Grumman American Aviation Corporation AA-5, Traveler, serial number AA5-0652. The airplane was a single-engine, low-wing, monoplane of conventional aluminum construction. The airplane was powered by a 150-horsepower, 4-cylinder Lycoming O-320-E2G reciprocating engine, serial number L-38674-27A. The engine provided thrust through a fixed-pitch, two-blade, McCauley IC172/SBTM7359 propeller, serial number E18709. The airplane was equipped with a fixed, tricycle landing gear and could seat the pilot and three passengers. The airplane had a maximum allowable takeoff weight of 2,200 pounds. The FAA issued the airplane a standard category airworthiness certificate on October 8, 1974.

The airplane's recording tachometer meter indicated 7,846.59 hours at the accident site. According to maintenance documentation, the original recording tachometer had been replaced, and the current tachometer indicated 814 hours more than the actual accumulated airframe and engine time. Based on postaccident calculations, the airframe and engine had accumulated a total service time of 7,032.59 hours. The engine had accumulated 492.59 hours since the last major overhaul completed on August 2, 2000. According to the maintenance logbooks, the last documented annual inspection was on May 10, 2014, at 7,010 total airframe hours. The pilot reported that an annual inspection had been completed immediately before the accident flight; however, the maintenance logbooks did not contain an entry for the annual inspection or any work associated with the inspection. A postaccident review of the maintenance records found no history of unresolved airworthiness issues.

The airplane fuel system consisted of two fuel tanks located immediately outboard of each wing root fairing, two smaller sump tanks located within each wing root fairing, an engine-driven mechanical fuel pump, an auxiliary electric fuel pump, a selector valve, and fuel gauges. The total fuel capacity of each fuel tank was 19 gallons, with ½ gallon of unusable fuel in each tank. Fuel from the fuel tanks was piped to the sumps before being directed to the selector valve and fuel pumps. The mechanical fuel pump transferred fuel from the tanks to the carburetor during normal operations. The auxiliary electric fuel pump supplemented the engine-driven pump and was used to provide fuel pressure redundancy during low altitude operations, such as during takeoff and landing. The auxiliary electric fuel pump incorporated a screen filter that could be removed for inspection and cleaning. The airplane was not equipped with a gascolator or a fuel drain in the engine compartment, because the fuel system was sloped downward toward the sumps located within each wing root fairing. As such, the sumps were the lowest point in the fuel system. The fuel system was equipped with four drains; one in each fuel tank, and one in each sump tank. According to the Grumman AA5 Owner's Manual, a fuel sample should be collected from all four drains during preflight to check for fuel contamination. According to the Grumman AA5 Maintenance Manual, during an annual inspection, the auxiliary electric fuel pump should be disassembled and its filter inspected/cleaned, the fuel tanks and sumps inspected, and the engine carburetor bowl drained.

METEOROLOGICAL INFORMATION

At 1115, the T82 automated surface observing system reported wind from 170° at 7 knots; broken ceilings at 2,100 ft above ground level (agl) and 2,700 ft agl; 10 miles surface visibility; temperature 26°C; dew point 21°C; and an altimeter setting of 29.93 inches of mercury.

AIRPORT INFORMATION

The Gillespie County Airport, located about 3 miles southwest of Fredericksburg, Texas, was served by a single asphalt runway, runway 14/32, that measured 5,001 ft by 75 ft. The airport elevation was 1,695 ft mean sea level.

WRECKAGE AND IMPACT INFORMATION

The wreckage was located in an open pasture, with no trees or obstructions in the general vicinity of the accident site. The accident site was located along the extended centerline for runway 14, about ¼ mile from the departure threshold. The aircraft wreckage was oriented on a 350° magnetic heading. The airplane impacted in a nose-down attitude, and there was no appreciable wreckage propagation from the point of impact. The main wreckage consisted of the entire airframe, including all structural components and flight control surfaces. Flight control continuity was established from the cockpit controls to the rudder and elevator surfaces. Flight control continuity for the right aileron was confirmed; however, the left aileron torque tube separated, consistent with impact damage. The wing flaps appeared to be fully retracted. The fuel system was compromised due to impact damage. A first responder reported that the cockpit fuel selector was initially found in the RIGHT position and that during rescue efforts he turned the fuel selector to the OFF position. Fluid was present in both supply lines leading to the fuel selector assembly. The outflow line from the fuel selector was fragmented. Fluid collected from the right tank supply line was consistent in color and odor to 100 low-lead aviation fuel. No water or particulate contamination was in the sample collected from the right tank supply line. The fluid collected from the left tank supply line contained a mixture of fuel and water. The auxiliary electric fuel pump contained a mixture of fuel and water. The fuel pump filter screen was corroded and was partially obstructed by particulate contamination.

The engine remained partially attached to the firewall by its mounts and control cables. Mechanical continuity was confirmed from the engine components to their respective cockpit controls. Internal engine and valve train continuity was confirmed as the engine crankshaft was rotated. Compression and suction were noted on all cylinders in conjunction with crankshaft rotation. The spark plugs were removed and exhibited features consistent with normal engine operation. Both magnetos provided spark on all leads when rotated. There were no obstructions between the air filter housing and the carburetor. The carburetor fuel bowl contained a trace amount of a fluid that was brown/tan in color, had an odor consistent with aviation fuel, and tested positive for water contamination. Several water droplets were observed to drain from the number 2 engine cylinder when the lower spark plug was removed. The propeller remained attached to the engine crankshaft flange. The propeller blades exhibited aft bending, chordwise scratches, and polishing. The postaccident engine examination revealed no evidence of a mechanical failure that would have precluded normal operation.

Two handheld GPS devices were recovered from the wreckage. The first device, a Garmin GPSMap 396, exhibited minor damage but remained functional. A review of the device established that it had recorded an external power interruption at 1119:38 and 1127:12 on the day of the accident. Review of the device settings established that it was not configured to record historical position/track data. The second GPS device, a Garmin GPSMap 296, was damaged beyond repair and was not examined further.

ADDITIONAL DATA/INFORMATION

According to National Transportation Safety Board (NTSB) Safety Alert No. SA-019, Prevent Aerodynamic Stalls at Low Altitude, many aerodynamic stalls occur in visual meteorological conditions when a pilot becomes momentarily distracted from the primary task of flying, such as while maneuvering in the airport traffic pattern, during an emergency, or when fixating on ground objects. The safety alert further states that reducing angle-of-attack by lowering the airplane's nose at the first indication of a stall is the most important immediate response for stall avoidance and stall recovery.

NTSB Probable Cause

The pilot's failure to maintain adequate airspeed following a partial loss of engine power during initial climb, which resulted in the airplane exceeding its critical angle of attack and experiencing an aerodynamic stall. Also causal was the mechanic's inadequate inspection of the airplane fuel system, which resulted in the partial loss of engine power due to fuel contamination.