Aviation Accident Summaries

Aviation Accident Summary ERA10LA113

Oxford, CT, USA

Aircraft #1

N540WF

Foster John Glasair III

Analysis

During a visual approach, at dusk, to a runway with an operating precision approach path indicator (PAPI), the pilot flew well below the approach path and collided with power lines on the final approach leg of the traffic pattern. The pilot had accumulated a total of 7.2 hours of night flight experience and his most recent night flight was more than 4 years prior to the accident. The accident occurred 11 minutes after sunset and 20 minutes before the end of civil twilight. The darker lighting conditions would have required the pilot to rely more on approach aids such as the PAPI lights. Examination of the wreckage and data recovered from an engine instrument system did not reveal any preimpact mechanical malfunctions of the airplane.

Factual Information

On January 13, 2010, at 1656 eastern standard time, an experimental, amateur-built, Foster Glasair III, N540WF, received substantial damage when it collided with a high tension power line, while on final approach to runway 36 at Waterbury-Oxford Airport (OXC), Oxford, Connecticut. The certificated private pilot was killed. Visual meteorological conditions prevailed and a visual flight rules (VFR) flight plan was filed for the personal flight. The airplane was registered to and operated by the private pilot under the provisions of 14 Code of Federal Regulations Part 91. The flight originated from the Montgomery County Airport (GAI) Gaithersburg, Maryland, about 1515. According to information from the Federal Aviation Administration (FAA), OXC air traffic control tower, at 1650, the pilot established radio contact with the tower. The pilot reported his position as 15 miles west of the airport. The tower controller instructed the pilot to report when he was "midfield downwind" for runway 36, which the pilot acknowledged. At 1653, the controller queried the pilot as to his current position. The pilot responded that he was 8 miles west of the airport. At 1654, the controller informed the pilot that he believed he had him in sight and instructed him to proceed to and report a 2-mile left base, which the pilot acknowledged. The controller then provided the pilot with information regarding another airplane in the traffic pattern, on a left downwind leg for runway 36, and informed the pilot that he will be following that airplane. At 1656, the controller cleared the pilot to land and informed him that the airplane ahead was on a short final leg and no traffic factor, which the pilot acknowledged. No further communications were received from the accident airplane. Examination of the accident site by an FAA inspector found that the airplane had impacted a high tension power line about 200 feet below the precision approach path indicator (PAPI) lights for runway 36. After contact with the power line, the airplane traveled approximately 400 feet, before striking the ground near the approach end of the runway. Examination of the wreckage revealed that the landing gear selector switch was in the down position, but bent. Saw-tooth markings were observed on both main landing gear, consistent with wire strike markings. No saw-tooth markings were observed on the nose gear. Both main landing gear tires remained inflated. There were scuff marks observed on the outside of the left main tire, and on the tread of the right main tire. The flap handle was observed between the first and second extended position, and the switch was broken. Examination of the engine found it intact, facing south, with the nose gear assembly attached, but buckled underneath. There was no indication of cylinder failure and the push rods remained intact. The firewall remained attached to the engine. The propeller separated from the engine. There was leading edge damage to the propeller blades, with 1/2-inch gouges near the tips of the blades. At the conclusion of the engine and airframe examination, no evidence of any preimpact mechanical failure or malfunction was found. The pilot, age 50, held a private pilot certificate, with a rating for airplane single-engine land, which was issued on August 21, 2005. His most recent FAA third-class airman medical certificate was issued on December 24, 2008, with no restrictions. A review of the pilot's logbook by the FAA inspector indicated that he had accumulated a total flight experience in all aircraft of 278 hours. Of the total experience, 3.6 hours were in flown during the 90 days preceding the accident. The pilot had accumulated 28.7 hours in the Glasair III and his most recent biannual flight review was recorded on July 9, 2009. Lastly, the pilot had accumulated a total night experience of 7.2 hours and his last night flight was completed on September 11, 2005. The airplane was a two-seat, low-wing, retractable-gear, single-engine airplane, serial number 001, airworthiness date March 1, 2008. It was powered by a Lycoming IO-540-KIA5, 300-horsepower engine. The aircraft logbook was not recovered and no determination could be made of its most recent condition inspection or total hours of operation. A review of recorded weather data from the OXC automated weather observation station, elevation 726 feet, revealed at 1645, conditions were winds calm, visibility 10 statute miles, sky clear, temperature minus 3 degrees Celsius, dew point temperature minus 11 degrees Celsius, and altimeter 30.12 inches of mercury. Sunset was recorded at 1645 with a waning crescent moon; of which, 2 percent of the moon's visible disc was illuminated. The end of civil twilight was recorded at 1716. An autopsy was performed on the pilot on January 14, 2010, by the Office of the Chief Medical Examiner, State of Connecticut, Farmington, Connecticut. Forensic toxicology was performed on specimens from the pilot by the FAA Bioaeronautical Sciences Research Laboratory, Oklahoma City, Oklahoma. The toxicology report indicated that there was no carbon monoxide or cyanide detected in blood, no ethanol detected in vitreous, and no drugs detected in urine. The airplane was equipped with several electronic devices, including a Garmin GPSMAP 496 global positioning system receiver, an Electronic International MVP-50 engine data cockpit display, an altitude encoder, and a CD ignition system. Neither the altitude encoder nor the CD ignition system recorded any data. The Garmin GPSMAP 496 recorded data that was successfully downloaded and plotted. The plotted data revealed the flight path of the airplane, descending below the approach path, while on final approach to runway 36. The Electronic International MVP-50 also provided usable data for the investigation, which included data consistent with continuous engine operation to the impact. Shortly after the accident on January 26, 2010, the FAA performed a flight test of the PAPI glide slope to runway 36. The test results were satisfactory.

Probable Cause and Findings

The pilot's failure to maintain a proper approach path during visual conditions at dusk, which resulted in an in-flight collision with power lines.

 

Source: NTSB Aviation Accident Database

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