Aviation Accident Summaries

Aviation Accident Summary ERA16FA176

Syosset, NY, USA

Aircraft #1

N440H

BEECH V35

Analysis

The instrument-rated pilot was conducting a personal cross-county flight and was operating on an instrument flight rules flight plan. While he was flying in visual conditions between cloud layers at 7,000 ft and heading toward the destination airport, he reported to air traffic control that the airplane had experienced a vacuum pump failure and that he had lost the associated gyroscopic instruments and part of the instrument panel. The pilot continued toward the destination airport because it had the best weather conditions compared to alternate nearby airports; however, after accepting radar vectors for the GPS approach to the airport, he reported that the airplane had entered instrument meteorological conditions (IMC) and that he had lost a "little bit" of control. He then reported that more of the instruments had failed and that he was trying to get back to 7,000 ft. Shortly after, the controller provided the pilot with the weather conditions at a closer airport and asked him if he would like to try to land there; however, no further communications were received from the pilot. Review of radar data revealed that the airplane made several course and altitude deviations as it proceeded northeast until the end of the data. The airplane was found separated in multiple pieces along a 0.4-mile-long debris path. Based on the radar data and debris path, it is likely that the pilot experienced spatial disorientation while maneuvering the airplane in IMC without a full instrument panel, that he subsequently lost airplane control, and that the airplane broke up in flight due to overstress during the ensuing uncontrolled descent. Review of a vacuum pump manufacturer's service letter (SL) revealed that the mandatory replacement time for the make and model vacuum pump was 500 aircraft hours or 6 years from the data of manufacture, whichever came first. Compliance with the SL was not mandatory for 14 Code of Federal Regulations Part 91 operations. The vacuum pump was manufactured in May 1999, which was 17 years before the accident. Additionally, the airplane was not equipped with a backup/standby vacuum pump. Metallurgical examination of the vacuum pump revealed that the rotor had separated radially in numerous locations. Three vanes remained intact, and three vanes separated into numerous pieces. Rotational scoring/rubbing marks were observed on the rotor and pump housing. Additionally, debris was noted in the inlet screen, but the engine had impacted a dirt field. It is likely the rotor's contact with the pump housing caused the failure of the pump rotor and vanes; however, it could not be ruled out that debris ingestion contributed to their failure. The pilot had severe coronary artery disease, and toxicological testing revealed low levels of diphenhydramine, a sedating antihistamine allergy treatment and sleep aid, and zolpidem, a prescription sleep aid. However, there was no evidence that the pilot's heart disease or sedating medications impaired his performance or incapacitated him.

Factual Information

HISTORY OF FLIGHTOn May 3, 2016, at 1542 eastern daylight time, a Beech V35B airplane, N440H, experienced an in-flight breakup near Syosset, New York. The airline transport pilot and two passengers were fatally injured, and the airplane was destroyed. The pilot was operating the airplane as a 14 Code of Federal Regulations (CFR) Part 91 personal flight. Instrument meteorological conditions (IMC) existed near the accident site about the time of the accident, and an instrument flight rules (IFR) flight plan was filed for the planned flight to Robertson Field (4B8), Plainville, Connecticut. The flight originated from Grand Strand Airport, North Myrtle Beach, South Carolina, about 1240. According to air traffic control (ATC) transcripts provided by the Federal Aviation Administration (FAA), about 1522, the pilot checked in with ATC and stated that he was level at 7,000 ft. About 1 minute later, he reported to a controller that the vacuum system had failed and that he had lost the associated gyroscopic instruments and part of the instrument panel, and he asked for the easiest approach to descend to the destination airport. The pilot then stated that the flight was currently operating in visual flight rules (VFR) on top of clouds and that he wanted to continue VFR at 7,000 ft to his destination airport because he did not want to descend into the clouds. The controller asked the pilot if he wanted to declare an emergency, and the pilot stated, "yes," and confirmed that he wanted to proceed to his destination airport because the "weather's…better there." The controller then briefed the next controller along the airplane's flight route. The next controller subsequently confirmed that the pilot was declaring an emergency. At 1529, the pilot requested the weather for the "Hartford-Bradley area"(near his destination) and the controller advised the pilot that the reported weather at Hartford included an overcast ceiling of 1,600 ft and that it looked like Hartford had the best weather conditions compared to alternate nearby airports. The pilot then requested radar vectors for the GPS approach to 4B8, which the controller acknowledged. He then instructed the pilot to proceed direct to Bridgeport, Connecticut, which the pilot acknowledged. The pilot then reported that the flight had entered IMC. At 1538, the pilot reported that he had just lost a "little bit" of control. The controller told him to turn left to 060°, which the pilot acknowledged. At 1539, the pilot reported that more of the instruments had failed and that he was turning to 060° and trying to get back to 7,000 ft. At 1541, the controller provided the pilot with the weather conditions at Republic Airport (FRG), Farmingdale, New York, and asked him if he would like to try to land there; however, no further communications were received from the pilot. Review of radar data revealed that the airplane made several course and altitude deviations as it proceeded northeast over Long Island until the end of the data. PERSONNEL INFORMATIONThe pilot held an airline transport pilot certificate with an airplane multiengine land rating. He also held a commercial pilot certificate with an airplane single-engine land rating. His most recent FAA third-class medical certificate was issued on September 3, 2014. At that time, he reported a total flight experience of 4,000 hours. The pilot's logbook was not recovered. AIRCRAFT INFORMATIONThe six-seat, low-wing, retractable tricycle-gear airplane was manufactured in 1973. It was powered by a 285-horsepower Continental IO-520 engine and was equipped with a three-bladed, constant-speed McCauley propeller. Review of maintenance records revealed that the airplane's most recent annual inspection was completed on February 3, 2016. At that time, the airframe had accumulated 6,166 total hours of operation, and the engine had accumulated 520 hours of operation. The airplane had flown about 20 hours from the time of the last inspection until the accident. The vacuum pump was installed on February 10, 2000, at a tachometer time of 5,813 hours, which was 373 hours of operation before the accident. Review of the vacuum pump manufacturer's Service Letter (SL) 58A revealed that the mandatory replacement time for the make and model vacuum pump was 500 aircraft hours or 6 years from the data of manufacture, whichever came first. Compliance with the SL was mandatory for Part 135 operations, but it was not mandatory for Part 91 operations. The accident vacuum pump was manufactured in May 1999, which was 17 years before the accident. The airplane was not equipped with a backup/standby vacuum pump. METEOROLOGICAL INFORMATIONFRG was located about 8 miles southeast of the accident site. At 1553, the recorded weather at FRG was wind from 040° at 5 knots, visibility 4 miles in mist, broken ceiling at 800 ft, overcast ceiling at 1,200 ft, temperature 11°C, dew point 9°C, and altimeter setting of 29.81 inches of mercury. The pilot had telephoned flight service on the morning of the accident, filed an IFR flight plan, and received a standard weather briefing. The standard briefing included current conditions and a forecast for overcast ceilings with bases between 1,000 and 2,000 ft and multiple cloud layers with tops above 18,000 ft. AIRPORT INFORMATIONThe six-seat, low-wing, retractable tricycle-gear airplane was manufactured in 1973. It was powered by a 285-horsepower Continental IO-520 engine and was equipped with a three-bladed, constant-speed McCauley propeller. Review of maintenance records revealed that the airplane's most recent annual inspection was completed on February 3, 2016. At that time, the airframe had accumulated 6,166 total hours of operation, and the engine had accumulated 520 hours of operation. The airplane had flown about 20 hours from the time of the last inspection until the accident. The vacuum pump was installed on February 10, 2000, at a tachometer time of 5,813 hours, which was 373 hours of operation before the accident. Review of the vacuum pump manufacturer's Service Letter (SL) 58A revealed that the mandatory replacement time for the make and model vacuum pump was 500 aircraft hours or 6 years from the data of manufacture, whichever came first. Compliance with the SL was mandatory for Part 135 operations, but it was not mandatory for Part 91 operations. The accident vacuum pump was manufactured in May 1999, which was 17 years before the accident. The airplane was not equipped with a backup/standby vacuum pump. WRECKAGE AND IMPACT INFORMATIONThe wreckage impacted a populated area consisting of residences, fields, and wooded terrain. A debris path extended about 0.4 mile on a magnetic heading of about 010°. The outboard section of the right ruddervator, remaining right ruddervator, and sections of the interior overhead panel were located at the beginning of the debris path. The fuselage, outboard section of the left wing, left ruddervator, and right wing were located about 400 ft farther along the debris path. The inboard left wing was located about another 400 ft farther along the debris path, and the engine and instrument panel were located at the end of the debris path. The outboard left wing had separated near the aileron/flap junction and exhibited paint transfer marks, consistent with right ruddervator contact. The left aileron had separated and fractured into two sections. The left inboard wing remained attached to the carry-through spar, and the spar caps displayed deformation damage in an upward direction. The left flap remained attached to the inboard left wing section. The right wing had separated near the root, and about 8 gallons of fuel remained in the right wing. The right flap and an approximate 15-inch-long section of inboard right aileron remained attached to the right wing. The right ruddervator had separated, and the left ruddervator remained attached to the tailcone. Measurement of the elevator trim jackscrew corresponded to an approximate 10°-tab-up (nose-down) trim setting. Due to multiple separations and cabin fragmentation, flight control continuity could not be verified; however, all recovered flight control cables exhibited broomstraw separation, consistent with overstress. The propeller had separated from the engine at the crankcase, and the engine came to rest inverted and was buried in a 3-ft-deep crater. One propeller blade had separated from the hub, but the other two propeller blades remained attached. All three propeller blades exhibited scoring and bending. The crankshaft could not be rotated due to front engine case damage, but borescope inspection of all six cylinders revealed no evidence of any preimpact mechanical malfunctions. Both magnetos sustained impact damage and could not be tested. The top and bottom spark plugs were removed from the six cylinders, and their electrodes were intact and light gray. The engine-driven fuel pump remained attached, and its drive coupling was intact. When the drive coupling was rotated by hand, the engine-driven fuel pump shaft rotated. The fuel metering unit and manifold valve exhibited impact damage. The vacuum pump remained attached to the engine and was removed for metallurgical examination. The examination revealed that the pump housing was jammed and would not rotate. The opposite end of the coupling rotated freely. Disassembly of the pump housing revealed that that the rotor had separated radially in numerous locations. Three vanes remained intact, and three vanes had separated into numerous pieces. Rotational scoring/rubbing marks were observed on the rotor and pump housing. Additionally, debris was noted in the inlet screen; the engine had impacted a dirt field. A panel-mounted GPS was removed from the instrument panel, and examination of the unit revealed that it did not store track data. MEDICAL AND PATHOLOGICAL INFORMATIONThe Nassau County Medical Examiner's Office, East Meadow, New York conducted an autopsy on the pilot. The autopsy report noted the cause of death as "multiple blunt impact injuries." The autopsy identified significant coronary artery disease. The FAA's Bioaeronautical Science Research Laboratory, Oklahoma City, Oklahoma performed toxicological testing on the pilot's specimens. The toxicology testing detected diphenhydramine in his urine, 0.03 (ug/ml. ug/g) diphenhydramine in his blood, ibuprofen in his urine, 0.007 (ug/ml, ug/g) zolpidem in his urine, and 0.007 (ug/ml, ug/g) zolpidem in his blood. Diphenhydramine is a sedating antihistamine used to treat allergy symptoms and as a sleep aid and carries the following Federal Drug Administration warning: "may impair mental and/or physical ability required for the performance of potentially hazardous tasks (e.g., driving, operating heavy machinery)." Zolpidem is a prescription sleep aid and carries a warning about sedation and changes in judgment or behavior.

Probable Cause and Findings

The pilot's loss of airplane control while operating in instrument meteorological conditions with only a partial instrument panel due to a failure of the airplane's vacuum pump. Contributing to the accident were the pilot's spatial disorientation and the operation of the vacuum pump beyond the 6-year time limit recommended by the vacuum pump manufacturer.

 

Source: NTSB Aviation Accident Database

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