Accident Overview
On a solo instrument flight rules (IFR) ferry flight from Quebec City, Quebec, to Peterborough, Ontario, a Beech King Air A100 struck trees while conducting the non-directional beacon (NDB) instrument approach for runway 09 at Peterborough. The pilot subsequently landed the substantially damaged aircraft at the military aerodrome in Trenton, Ontario.
Flight and Weather
The pilot was cleared for the approach when the reported weather at Peterborough was 400 feet overcast with two miles visibility in light drizzle and fog. As the pilot flew the approach, conditions deteriorated to 200 feet overcast and one mile visibility. The minimum descent altitude for the approach was 1,200 feet above sea level (asl), or 575 feet above the touchdown zone elevation (TDZE). After the aircraft struck trees, the pilot advised air traffic control (ATC) and later accepted radar vectors to Trenton, where the weather was 100 feet overcast and one and one-quarter miles visibility in drizzle and fog.
Sequence of Events
The aircraft approached Peterborough from the east. The pilot elected to conduct the NDB RWY 09 approach. While proceeding outbound from the Peterborough beacon and descending to the procedure turn altitude of 2,600 feet asl, the pilot's instrument approach chart fell from his knee pad to the cockpit floor. The chart was part of the Canada Air Pilot (CAP 4) booklet, which was not secured to the knee pad.
Unable to immediately recover the chart, the pilot continued the approach in instrument meteorological conditions (IMC) from memory. The final approach fix crossing altitude was 1,800 feet asl; however, during the procedure turn, the pilot prematurely descended to that altitude. While attempting to retrieve the chart, the aircraft descended below 1,800 feet asl. The pilot then saw tree tops and the aircraft struck them at about 1,100 feet asl.
The pilot immediately applied maximum power, raised the flaps and landing gear, and commenced a climb. He advised ATC that he was on the missed approach and initially requested clearance to Toronto, then elected to proceed to Ottawa. While on radar vectors, he reported the tree strike and a fuel leak. The controller suggested a precision approach radar (PAR) approach at Trenton, which the pilot accepted.
Damage
Inspection after landing revealed damage to the right propeller, engine cowl, right wing leading edge, fuel tanks, right outboard flap, and the underside of the aircraft. Evidence indicated multiple tree impacts on these areas and on the right main and nose landing gear.
Investigation Findings
During the approach, the pilot used the autopilot heading mode but did not engage the altitude hold mode. The pilot held an Airline Transport Pilot Licence with approximately 7,800 total flying hours, including 4,500 hours on twin-engine aircraft. The approach chart fell from the knee pad; the pilot continued the approach from memory and descended below the procedure turn altitude. While attempting to retrieve the chart, the pilot's attention was diverted, and the aircraft descended further until striking trees. The pilot did not monitor the flight instruments during that time.
The Transportation Safety Board determined that the pilot did not adequately monitor the aircraft flight instruments while flying a non-precision approach in IMC. Contributing to the accident was the pilot's decision to continue flying the approach procedure from memory.