History of Flight
On April 10, 2011, at about 1815 eastern daylight time, a Cessna 402B, registration N402RC, impacted a house near Biddeford, Maine, after a positioning flight. The airplane, operated under 14 Code of Federal Regulations Part 91, had departed Westchester County Airport (HPN) in White Plains, New York, around 1630. Earlier that day, it had flown from Portland International Airport (PWM) to Nantucket Memorial Airport (ACK), where it took on 115.6 gallons of aviation fuel, then continued to HPN with a passenger. After the passenger disembarked, the pilot departed for PWM but later requested to change destination to Biddeford Municipal Airport (B19).
Radar data showed the airplane overflew the south end of B19 at approximately 1,000 feet above mean sea level (msl), then turned left as if entering a downwind leg for runway 24. About 2 miles from the runway threshold, it turned right 250 degrees, then left toward B19. The last radar return, at 1804:29, showed the aircraft at 400 feet msl and 69 knots ground speed near the accident location.
Personnel Information
The 71-year-old pilot held an Airline Transport Pilot certificate with multiengine land and single-engine land ratings, plus a flight instructor certificate. His most recent FAA second-class medical was issued February 4, 2011, at which he reported 5,010 total flight hours. A resume from August 2010 listed 4,735 hours of civilian flight time and military navigator time, with 120 hours in the accident aircraft make and model. No logbooks were found.
Aircraft Information
The Cessna 402B was manufactured in 1977 and registered to My Plane, LLC on October 18, 2000. It had two Continental Motors TSIO-520 series engines. The most recent annual inspection was August 21, 2010, with 6,624.5 total airframe hours and 4,554.1 Hobbs hours. The engines had 359.0 hours since overhaul. The last maintenance entry was March 21, 2011, showing 4,567.2 Hobbs hours. The Hobbs meter was not recovered.
Meteorological Information
Weather at Sanford Regional Airport (SFM), 16 miles southwest, at 1815 included wind from 150° at 8 knots gusting to 15 knots, variable between 100° and 160°, visibility 10 miles, clear skies, temperature 14°C, dew point -2°C, and altimeter 30.03 inHg.
Airport Information
Biddeford Municipal Airport had a single 3,000-by-75-foot asphalt runway, 06/24. Runway 6 had a 4-box VASI; runway 24 had none. No control tower. Common traffic advisory frequency was used but not recorded. Runway 24 was preferred for calm winds.
Wreckage and Impact Information
The airplane first struck four trees (3.2 to 8.75 inches in diameter) at about 25 feet height, then came to rest on the roof of a single-story residence 1,491 feet northeast of runway 24's threshold. A post-crash fire consumed much of the aircraft. The left wing was thermally damaged; its outboard section lay on the roof. The left engine was inside the house. The right wing and engine were visible above the roofline. The nose, cabin, and empennage were thermally damaged. Flight control components were found.
Examination revealed the right main landing gear was down and locked. The left main and nose gear separated and were inside the house. The left wing leading edge showed impact damage consistent with tree strikes. The left aileron was consumed by fire. Fuel caps were secured. The cockpit fuel selector for the left tank was in the auxiliary position; the wing valve was between main and auxiliary. Fuel strainers and filters had corrosion (approximately 30° coverage). Right wing selector and valve were in the main tank position. The right fuel strainer contained aviation fuel and was free of debris.
Flaps were extended. Flight control continuity was confirmed for rudder, aileron, and elevator. The stall switch was damaged and in the closed circuit position.
Left Engine
The left engine and propeller showed impact and thermal damage. Exhaust, turbocharger, and wastegate were separated. Spark plugs had light gray to dark deposits. Combustion chambers were undamaged. The oil dipstick showed no oil.
Right Engine
The right engine remained partially attached. Oil and fuel lines were attached. The fuel manifold valve had fuel present, screen free of debris. About 2 ounces of fuel dripped from the fuel control inlet screen. Spark plugs had light gray deposits. Compression was obtained from each cylinder. Ignition leads were undamaged; spark was obtained. The oil dipstick showed no oil.
Medical and Pathological Information
Autopsy on April 11, 2011, listed cause of death as smoke inhalation and thermal burns. Toxicology detected 12% carbon monoxide, no cyanide or ethanol, and Quinine in blood.
Additional Information
Engine Examination
Engines were sent to Continental Motors. The left engine could not be run due to thermal damage; disassembly found no preaccident mechanical malfunctions. The right engine was test-run and initially exhibited partial power loss, which could be temporarily corrected by manual primer. After further examination, the throttle and control assembly was found to have incorrect -11 cam instead of -8, and two o-rings had damage (one pinched during installation). After replacing o-rings and correcting the cam, the engine ran smoothly.
Propeller Examination
Both propellers showed impact damage consistent with rotation at low power. No pre-impact failure was found. Blade bending and damage indicated both propellers were at or near low pitch at impact; feather stop mechanisms were undamaged.
O-rings
Two o-rings from the right engine throttle control had damage: one had semicircular cuts (no missing material), the other had missing material consistent with pinching during installation.
Logbook and Manuals
No logbook entry indicated replacement of the throttle control assembly after 2004. The Pilot's Operating Handbook specified flaps down 45° below 140 KIAS, minimum multi-engine approach speed 95 KIAS at 6,200 pounds, and Vmc 82 KIAS. The lowest weight in landing distance charts was 4,300 pounds with 79 KIAS at 50-foot obstacle.
The Pilots Handbook of Aeronautical Knowledge defined Vmc as minimum flight speed for controllable flight with an engine inoperative and remaining engine at takeoff power. The Airplane Flying Handbook stated directional control is not possible if an engine fails below Vmc with takeoff power on the remaining engine. The exact phrasing was used in the source, but no further analysis is added.