Accident Details
An on-demand air-taxi flight operating under 14 CFR Part 135 was destroyed when it impacted trees and terrain while circling to land during a non-precision instrument approach at night. The airplane came to rest 1.74 nautical miles at a magnetic bearing of 226 degrees from the intended airport. No anomalies were found with respect to the airframe, engines, or systems that could be associated with a pre-impact condition.
Weather and Flight Planning
A weather briefing was obtained, and instrument meteorological conditions were present along the route of flight at the time of the briefing. The airplane obtained weather reports for the two reporting stations closest to the destination prior to executing the approach. These reports listed ceilings of 400 to 500 feet overcast and visibilities of 5 to 7 statute miles. The airport elevation is 669 feet, and the minimum descent altitude for the approach was 1,240 feet. There was no weather reporting station at the destination airport at the time of the accident.
According to the operator's General Operations Manual, the pilot was responsible for the dispatch of the airplane including flight planning and confirming compliance with departure, en-route, arrival, and terminal operations. The manual also stated that for airports without weather reporting, the area forecast and reports from airports in the vicinity must indicate that the weather conditions will be VFR at the estimated time of arrival to allow the aircraft to terminate IFR operations and land under VFR. A note in the manual stated that a visual approach is not approved without weather reporting.
Regulatory Aspects
For 14 CFR Part 135 instrument flight operations conducted at an airport, federal regulations require weather observations at that airport. Additionally, the regulations state that an instrument approach cannot be initiated unless approved weather information is available at the airport where the instrument approach is located and the weather information indicates that the weather conditions are at or above the authorized minimums for the approach procedure.
The commercial pilot held a type rating for the accident airplane. The right-seat occupant was a commercial pilot employed by the operator and did not hold an appropriate type rating for the accident airplane. The pitch trim selector switch was found set to the co-pilot side. The regulations state that 14 CFR Part 135 operators cannot use the services of any person as an airman unless that person is appropriately qualified for the operation for which the person is to be used.
Night Operations
The circling approach was made over primarily unlit land and water. An FAA publication states that during night operations, distance may be deceptive due to limited lighting conditions. The lack of intervening references on the ground and the inability of the pilot to compare the size and location of different ground objects cause this, also applying to the estimation of altitude and speed. Consequently, more dependence must be placed on flight instruments, particularly the altimeter and the airspeed indicator.