History of Flight
On June 21, 2008, about 1042 eastern daylight time, a Piper PA-28-140, N8776N, was substantially damaged when it impacted a tidal flat near Crockett Point while maneuvering near Knox County Regional Airport (RKD), Rockland, Maine. The certificated private pilot was killed. Visual meteorological conditions were recorded at the airport; however, instrument meteorological conditions were observed in the vicinity and at the accident site. No flight plan was filed for the local personal flight, which was conducted under 14 Code of Federal Regulations Part 91.
The airplane was owned and operated by the Knox County Flying Club. The accident pilot had rented the airplane for a one-and-a-half-hour block starting at 1030, with another member scheduled for 1200. A club member spoke with the pilot before departure, noting she was continuously checking the weather and waiting for the overcast layer to exceed 1,000 feet above ground level to take a flight that would remain in the traffic pattern.
The witness observed the airplane take off and enter a fog bank immediately off the departure end of runway 13 near the water. The engine pitch increased, followed shortly by a thud sound. He and two other ear witnesses called 911 and proceeded to find the accident scene. The airplane was found approximately 200 feet from the shoreline in about 4 feet of water, inverted in the tidal flat. The debris field was about 300 feet long, containing numerous boulders and scattered aircraft pieces. The left wing was separated from the fuselage by a boulder, while the right wing remained attached.
Personnel Information
The pilot held a private pilot certificate with a rating for airplane single engine land and did not possess an instrument rating. Her most recent FAA third-class medical certificate was issued on September 8, 2006. According to her last FAA medical application, she had accumulated 500 total hours of flight experience. Excerpts from her logbook showed 12 hours in the past 12 months, including 1.0 hour in the previous 6 months, flown 2 days prior to the accident flight with a Certificated Flight Instructor as part of the flying club’s insurance requirement. Her last biennial flight review was completed on August 6, 2006.
Aircraft Information
The four-seat, single-engine low-wing monoplane, serial number 28-25600, was issued an airworthiness certificate in February 1969. It was equipped with a Lycoming O-320-E2A engine. Review of maintenance logbooks revealed its most recent annual inspection on December 5, 2007, with a total time in service of 7,293 hours. The last 100-hour inspection was on May 15, 2008, with a total time in service of 7,387.9 hours. At the accident, total time was 7,401.7 hours. The engine was overhauled on March 14, 2006, with a time in service of 4,283.52 hours. The last 100-hour inspection on the engine was on May 15, 2008, with a time in service of 4,792.5 hours; during that inspection, the muffler was inspected with no discrepancies, cylinder compression was checked, and engine oil and filter were replaced; the used oil filter was opened and inspected with no discrepancies. The airplane had a supplemental type certificate allowing automotive gas fuel.
Meteorological Information
Weather reported at RKD at 1035 included winds from 100 degrees at 8 knots, visibility 6 miles, overcast layer at 1,200 feet, temperature 15°C, dew point 13°C, and altimeter setting 30.04 inches of mercury. The 1015 weather reported an overcast layer at 1,000 feet, and the 0955 observation reported an overcast layer at 800 feet. After the accident, the 1055 observation reported a broken layer at 1,200 feet, and the 1115 observation reported a broken layer at 1,000 feet.
The Maine State Police officer who responded within 15 minutes reported a fog bank over the water south of the field, with horizontal visibility estimated at 250 feet.
Wreckage and Impact
The wreckage impacted a tidal flat approximately 3,600 feet from the departure end of the runway on a course of 077 degrees magnetic. It was recovered by a local salvage company and transported to the owner’s hangar at the airport. An FAA inspector examined the wreckage and verified control continuity for all control surfaces. Fuel samples were taken from the airplane and the storage tank; no contaminants were found.
The wreckage was later transported to a secure salvage yard for further examination on July 21, 2008, under an FAA inspector's supervision. The engine was rotated by hand, and good thumb compression was noted on all cylinders. The left-hand magneto sparked on two leads during rotation. The carburetor was disassembled, and floats were intact. The vacuum pump rotated freely by hand and was disassembled; vanes were intact. The attitude indicator was disassembled, and the rotor was removed from the housing, with scoring marks observed on the inside of the housing. No preimpact malfunctions were noted.
Medical and Pathological Information
The Maine Medical Examiners Office in Augusta, Maine, performed an autopsy on June 21, 2008. The reported cause of death was multiple blunt force trauma. Toxicological testing at the FAA’s Bioaeronautical Sciences Research Laboratory was negative for carbon monoxide, cyanide, ethanol, and legal or illegal drugs.
Additional Information
According to the FAA Airplane Flying Handbook (FAA-H-8083-3A, Chapter 16), a VFR pilot is in IMC conditions anytime he or she is unable to maintain airplane attitude control by reference to the natural horizon, regardless of circumstances or prevailing weather. The handbook also stated that the pilot must believe the flight instruments regarding the airplane’s attitude, as the vestibular sense can confuse the pilot. It noted that false sensations often lead to spatial disorientation.
The FAA Airplane Instrument Flying Handbook (FAA-H-8083-15A) defined somatogravic illusion as the misperception of being in a nose-up or nose-down attitude caused by rapid acceleration or deceleration in flight situations lacking visual reference. It stated that acceleration stimulates the otolith organs similarly to tilting the head backwards, creating the illusion of a nose-up attitude, potentially causing the disoriented pilot to push the aircraft into a nose-low or dive attitude.
FAA Advisory Circular 60-4A stated that an aircraft's attitude is generally determined by reference to the natural horizon or other visual references; if neither exists, attitude must be determined by flight instruments. It further noted that tests with qualified instrument pilots indicate it can take up to 35 seconds to establish full control by instruments after loss of visual reference with the surface.