Aviation Accident Summaries

Aviation Accident Summary NYC99FA033

BROOKLYN, CT, USA

Aircraft #1

N6166L

Gulfstream American AA-1

Analysis

The student pilot, formerly commercial-rated, took off, maintained a level flight attitude for about 5 seconds, then put the airplane into a steep climb. A witness then heard the engine 'cut out' and saw the airplane in a steep left bank, rapidly losing altitude. During the descent, the witness heard several backfires. The airplane leveled its wings, but continued a 25-degree descent as it disappeared below a tree line. It crashed into a shallow river, next to which, was a large field. The empennage stuck out of the water at a 40-degree angle, and was buckled on the right side. There was a strong smell of auto gas, though the airplane had no STC for its use. One propeller blade was embedded in the riverbed, with scratches emanating from the leading edge at varying angles. The other propeller blade exhibited S-bending , severe leading edge pitting, and chordwise and lengthwise scratching. Examination of the engine did not disclose evidence of mechanical malfunction. The student pilot's commercial license was permanently revoked in 1996, after he was observed flying during a suspension. He had about 10 hours of flight time since starting to fly again, about a week earlier.

Factual Information

HISTORY OF FLIGHT On December 4, 1998, about 1345 Eastern Standard Time, an American AA-1 Yankee, N6166L, was destroyed when it impacted a river in Brooklyn, Connecticut, shortly after takeoff from Danielson Airport (5B3), Danielson, Connecticut. The student pilot, who was formally a commercial-rated pilot, was fatally injured. Visual meteorological conditions prevailed at the time of the accident. No flight plan was filed for the local flight, which was conducted under 14 CFR Part 91. According to a witness, the airplane took off, maintained a level flight attitude for about 5 seconds, then began a steep climb. The witness estimated the airplane to be about 300 feet in the air, and 1/4 mile past the end of the runway, when he looked away. The witness then heard the engine "cut out," and looked up toward the airplane again. He saw it in a steep left bank, rapidly losing altitude. During the descent, the witness did not hear the engine operate, but did hear several backfires. The airplane appeared to turn to a southwest heading, and level its wings, with a descent angle of 25 degrees. The witness then lost sight of the airplane behind trees, but heard a "loud, abrupt noise" about 2 seconds later. The witness, who was also a pilot, later stated to a Federal Aviation Administration (FAA) Inspector, that he did not see the airplane spin. Another witness, about 300 yards from the impact point, stated to the FAA Inspector that he saw the airplane after the engine noise stopped. It was wings level, just above the trees, in a descent over the Quinebaug River. Just before losing visual contact with the airplane, he saw the right wing and nose drop. The accident occurred during the hours of daylight. The accident site was located at 41 degrees, 49.13 minutes north latitude, and 071 degrees, 54.47 minutes west longitude. PERSONNEL INFORMATION The student pilot's wallet, logbook and license were not recovered. The pilot previously held a commercial pilot certificate, with a single engine land rating. It was suspended in July 1994 due to a "low flying" complaint. The pilot was required to have an FAA recheck flight, but was observed flying with the suspended license. As a result, his license was permanently revoked in February, 1996. The pilot obtained a third class medical/student pilot certificate on April 8, 1997, but didn't begin flying again until November 28, 1998, on an instructional flight with a certified flight instructor. In his interview with the FAA Inspector, the flight instructor stated that he had known the student pilot as a commercial pilot, but didn't know the pilot's license had been revoked, and thought he was giving proficiency instruction instead of student pilot instruction. During the flight, he observed that the pilot was headstrong and not a good listener, tended to avoid using the checklist, tended to roll into a steep turn from downwind to base leg, and rushed everything. However, the pilot also had a good feel for the aircraft, maintained proper airspeed on climbout, was always in trim with the ball centered, reacted properly to windshear, did a good stall recovery, and had good landings. The mechanic who worked on the accident airplane estimated that the pilot had flown about 10 hours between his instructional flight and the accident. He said that on the day before the accident, he asked the pilot if he had ever stalled the airplane with its new engine, and the pilot responded that he had not. AIRCRAFT INFORMATION A review of the aircraft and engine logbooks revealed that an annual inspection had been completed on November 24, 1998. However, work performed and tachometer/total hours were not logged. In an interview with the FAA Inspector, the mechanic stated that he normally logged those things, but hadn't yet had the time to do so. Additionally, the mechanic stated that the airplane was in "mint" condition. The engine had run very smoothly and there were no known problems of any sort. He felt there was no way the engine could have failed. He said he had a friend who saw the airplane take off, level off, accelerate, do a steep climb, and make a sharp left turn. Then the friend saw the aircraft "shake then, like an accelerated stall, and I don't think [the pilot] recovered from that." The airplane received a supplemental type certificate (STC) to replace the original engine with a Lycoming O-320. The student pilot was known to use automobile gas in the airplane, but it did not have a STC for its use. WRECKAGE AND IMPACT INFORMATION All major components of the airplane were accounted for at the accident scene. The wreckage was located in the middle of the Quinebaug River, about 1,000 feet southwest of the departure end of Danielson Airport Runway 31. A thin tree line ran along the western bank of the river. Behind the tree line was a large, harvested corn field. The depth of the river, where the airplane was found, varied from 2 to 4 feet. The riverbed consisted of rounded pebbles and rocks, with some sand and silt. The airplane's empennage stuck out of the river at approximately a 40-degree angle. It was buckled on the right side where it joined the cabin area, and was canted to the right about 10 degrees. The right wing was separated from the fuselage, while the left wing remained attached. Both wings exhibited some outboard leading edge crushing, and both fiberglass wing tips had separated from the metal wings. The engine was found partially submerged, and the upper left mount was broken away from the airframe. The engine was upright, with one propeller blade embedded in the riverbed. The propeller blade that was found embedded in the riverbed exhibited scratches which emanated from the leading edge of the blade, towards the blade tip, in varying angles of 20 to 70 degrees. The other propeller blade exhibited s-bending, gouges and pitting in the outboard leading edge, chordwise scratches, and additional scratches which paralleled the blade's leading edge. The propeller spinner was dented and scratched in one hemisphere. The orientation matched the damage found on the second propeller blade. Some of the scratches were aligned fore and aft, while others rotated about 1/4 of the way around the spinner. An initial cockpit examination was performed while the airplane was still in the river. There was a strong odor of automobile gas, and a sheen on the water. The fuel gauges indicated between 1/8 and 1/4 full. The carburetor heat knob was in, the throttle was out about 3/4 of an inch, and the mixture and primer knobs were full in. The fuel selector was damaged, and found just inboard of the "left" position. The key-operated magneto switch was not damaged, and found in the "off" position. Engine examination revealed that all rocker boxes were in place, with the number 1 rocker box dented. All spark plugs were tight, except the lower number 1 plug, which was in contact with the number 1 exhaust stack. Drive train continuity was established, and magneto spark was obtained on all leads. Compression was established in all cylinders except number 1. The lower spark plug to that cylinder was removed, and a flex light shined into the cylinder. No damage or discrepancies were found to either the piston or the cylinder walls. The engine driven fuel pump was removed and operated by hand. It was then opened, and no discrepancies were found. METEOROLOGICAL INFORMATION A weather observation made at an airport 14 nautical miles to the west, about 50 minutes earlier, revealed a clear sky, visibility 10 statute miles, and winds from 280 degrees magnetic at 10, gusting to 20 knots. MEDICAL AND PATHOLOGICAL INFORMATION On December 5, 1998, an autopsy was conducted on the student pilot by the State of Connecticut, Office of the Chief Medical Examiner, Farmington, Connecticut. Toxicological testing was performed by the FAA Toxicology and Accident Research Laboratory, Oklahoma City, Oklahoma. Results were negative for carbon monoxide, cyanide, ethanol, and legal and illegal drugs. ADDITIONAL INFORMATION On December 5, 1998, the wreckage was released to the student pilot's son-in-law, in Brooklyn, Connecticut.

Probable Cause and Findings

The student pilot's failure to maintain control of the airplane, resulting in an inadvertent stall/spin.

 

Source: NTSB Aviation Accident Database

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