Background
An instrument-rated private pilot was conducting a personal cross-country flight in a multiengine airplane under instrument flight rules (IFR). The flight was nearing its destination when air traffic control cleared the pilot for a GPS approach. The pilot requested time to review the approach procedure, which was acknowledged by the controller. After the pilot reported readiness, the controller re-issued clearance for the approach.
Accident Sequence
Radar data showed that during the first approach, the airplane tracked about 0.5 miles right of the final approach course until approximately 1 mile from the runway threshold. The airplane then turned left toward the threshold and descended to about 145 feet above ground level before the pilot executed a missed approach. It is likely that the missed approach was performed because the pilot was unable to align the airplane with the runway before crossing the threshold.
The controller provided radar vectors for a return to the approach course and cleared the airplane a third time for the GPS approach. Radar data indicated that the airplane was established on the final approach course as it passed the initial approach fix. However, before reaching the final approach fix, its airspeed slowed to 111 knots, and it began a left turn with a 25-degree bank angle. About 18 seconds later, while still in the turn, the airplane decelerated to 108 knots and began a rapid descent. The rate of descent exceeded 10,000 feet per minute, and the airplane impacted the ground approximately 9 miles from the destination airport.
Wreckage Examination
Examination of the accident site revealed severe fragmentation and fire damage, with debris scattered over about 450 feet. Postaccident examination did not find evidence of preimpact failures; however, damage to the left engine indicated it was not producing power at the time of impact. The severity of the impact and fire damage precluded determination of why the left engine lost power.
Weather Conditions
Weather conditions at the time were conducive to supercooled liquid water droplets, and the airplane likely encountered moderate or greater icing conditions. Several pilot reports (PIREPs) for icing were reported to air traffic control but were not distributed publicly into the national airspace system. No AIRMET for icing was issued. The pilot had received standard and abbreviated weather briefings, including three PIREPs for icing in the accident area. Given the information provided, the pilot should have known icing conditions were possible.
Aircraft Systems
The airplane was equipped with deicing and anti-icing systems, including wing and empennage deice boots and engine inlet heaters. Due to impact damage to the cockpit, the positions of the ice protection system switches at the time could not be determined.
Performance Considerations
The airplane's airspeed of 108 knots when the steep descent began was above its published stall speed of 77 knots; however, both bank angle and ice accretion increase stall speed. The published minimum control airspeed was 93 knots. It is likely that after passing the initial approach fix, the left engine lost power, the airspeed decayed, and asymmetric thrust resulted in a left turn. As airspeed continued to decrease below either stall speed or minimum control airspeed, the airplane entered an uncontrolled descent.