Executive/Corporate/Business

A Mitsubishi MU-2 departed Salt Lake City, Utah, and climbed to 16,000 feet MS on an IFR flight to Pocatello, Idaho. While in cruise flight, the MU-2 encountered structural icing conditions. According to radar data, the MU-2 began slowing from a cruise speed of about 190 knots with slight deviations from heading and altitude. The airspeed decreased to about 100 knots, and the flight crew declared an unspecified emergency, then radio contact was lost. The MU-2 began a right turn, then it entered a steep descent and crashed. The pilot of a Beech 1900 (about 12 minutes in trail of the MU-2), stated that he encountered moderate rime icing at 16,000 feet. The Beech pilot activated his deice boots (3 times) and descended to 12,000 feet to exit the icing conditions. The MU-2 flight manual warned that during flight in icing conditions, stall warning devices may not be accurate and should not be relied upon; and to minimize ice accumulation, maintain a minimum cruise speed of 180 knots or exit the icing conditions. An investigation determined that the captain of the MU-2 was aware of deficiencies in the timer for the deice boots, as well as other maintenance deficiencies. The captain's medical certificate was dated 11/17/94; he was providing executive transportation for compensation under an agreement for "contractual flights," under 14 CFR 91. Although icing conditions were forecast in the destination area, no icing was forecast for the en route portion of the flight.

The airplane was circling to land on runway 22 after executing a VOR/DME approach. The airplane impacted the ground approximately one quarter mile northeast of the runway 22 threshold. The wreckage path covered a distance of approximately 350 feet. Control continuity was established. Airframe, engine and navaid examination revealed no abnormalities. The left wing and horizontal stabilizer leading edges had approximately one-eighth inch of rime ice adhering to their leading edges. Two witnesses reported seeing the airplane rolling from the left to the right. The Eagle River AWOS was not available on a VHF radio frequency, due to radio frequency congestion at the O'Hare International Airport, Chicago, Illinois.

The pilot's departure plans were changed, when, instead of flying direct to his originally planned destination, he was asked to pick up a passenger at another airport prior to returning home. He departed for his alternative destination in dark night conditions, leveled off at his cruise altitude and impacted the side of a mountain in level flight about 25 miles from his departure point. Air Traffic Control vectored another aircraft to the vicinity after communications and radar contact were lost. The crew of that aircraft stated that instrument meteorological conditions prevailed at the time in the vicinity of the crash site.

At about 1826 mountain standard time (MST), the aircraft, with the pilot and four passengers on board, departed the Calgary International Airport, Alberta, on a night instrument flight rules (IFR) flight to Hillsboro, Oregon, USA. At about 1946 the aircraft disappeared from the Vancouver Area Control Centre (ACC) radar screen in the vicinity of Castlegar, British Columbia. The Victoria Rescue Coordination Centre (RCC) was notified, and search aircraft were dispatched. Despite bi-national search cooperation and radar fixes of the aircraft's last known position (LKP), a seven-day search failed to locate the missing aircraft. An emergency locator transmitter (ELT) signal was not received. On 14 June 1996, the wreckage was located at latitude 49°14'48"N, longitude 117°03'20"W, at an elevation of approximately 6,700 feet above sea level (asl). The aircraft was destroyed by impact forces and a post-crash fire. The pilot and four passengers were fatally injured.

The pilot obtained a preflight briefing and indicated that he would obtain an IFR clearance after becoming airborne; however, he took off and did not activate a flight plan. Witnesses observed the airplane flying north (away from the destination) about 200 to 300 feet above the ground below a low overcast sky condition. One witness said the airplane was flying very slow; he said he was almost able to keep up with it in his vehicle. The witnesses said they saw the airplane roll rapidly to the right and descend toward the ground. It collided with the ground in an approximate 50 degree pitch down attitude. An on-scene examination did not reveal any airframe or control anomaly that would have resulted in the accident. The engines and propellers were disassembled for inspection. Examination of the engines revealed they were capable of producing power. Examination of the propellers revealed both were operating at low pitch settings. About 25 miles north-northwest at Battle Creek, MI, the 1145 edt weather was, in part: 500 feet overcast, visibility 2 miles with fog, wind from 050 degrees at 10 knots.

After climbing to 18,400 feet msl, the pilot reported a turbocharger problem and reversed course. He said he 'may lose the left engine' and that he was unable to maintain altitude. He diverted to an alternate airport. During a right turn onto final approach, the airplane was observed to cross (overshoot) the extended centerline of the runway. It continued in a right turn back toward the centerline, and then entered a left turn to intercept the inbound course. The turn steepened, and then the airplane entered a spin and crashed 1/2 mile short of the runway. A warped flange and evidence of exhaust gas leakage were found on the Inconel exhaust system Wye collector, at the wastegate outlet of the left engine. Neither propeller was in a feather position. There was evidence that the left engine was providing low power during impact. A note on the pilot's clipboard indicated that the (left engine) fuel flow and cylinder head temperature went to zero, and the manifold pressure dropped to 10 inches. The note also indicated that the pilot switched the 'boost pump' to high, the fuel flow went to 260 psi, and manifold pressure increased to 18.5 inches. Calculations showed that the airplane's gross weight (GW) and center-of-gravity (CG) were 7,645 pounds and 158.32 inches. The maximum allowable GW and CG were 7,450 pounds and 158 inches. During impact, the flaps were fully extended. The 'Engine Inoperative Landing' procedure stated, 'Wing Flaps - DOWN when landing is assured.' Most of the pilot's flight time in the Cessna 421 was before 1985; no record was found of recurrent training in the airplane since 1984. Annual and turbocharger inspections were made at 78 and 120 flight hours, respectively, before the accident, but no logbook entries were made concerning maintenance or replacement parts for the exhaust system. All eight occupants were killed.

After deplaning passengers at Thief River Falls after an air taxi flight, the pilot was reportedly anxious to return to his base in Minot to prepare for another trip the following day, and left for the return trip within a few minutes after his arrival at Thief River Falls. There was no record of a weather briefing. Observations of Doppler radar by the University of North Dakota, and a Safety Board meteorological study, show that the airplane had penetrated a thunderstorm when control was lost. The airplane had encountered the center of a microburst, and was located directly under the downdraft.

En route from Miami to Puerto Plata, while cruising at an altitude of 13,000 feet, the pilot informed ATC about the failure of the left engine and was cleared to divert to Nassau. On final approach to Nassau Airport, the aircraft struck a fence and crashed about 300 metres short of runway threshold. All four occupants were rescued and the aircraft was damaged beyond repair.

The pilot was cleared for the localizer runway 11 approach. The airplane impacted in an open field approximately 1 mile northeast of the airport and approximately 600 feet left of the extended centerline of the departure end of the runway. A witness saw the airplane at a low altitude, and stated 'it was foggy,' and he did not see the airplane until it was directly over his head. The witness stated that he saw the airplane for about '3 seconds,' at an altitude of 'between 50 and 100 feet above the ground,' and it did not sound like it was having 'mechanical difficulty.' The airplane turned left (north), and struck the ground with the left wing. The published missed approach called for a climbing 'right turn.' The olney airport automated weather observing system (awos) was operating and current at the time of the accident, but could only be obtained by telephone; hence atc could not provide the pilot with the current awos information. The pilot was provided the Evansville, Indiana (EVV) weather; 1,200 scattered, measured 4,500 overcast, visibility 5 miles, light rain and fog. Evansville was located approximately 20 miles southeast of Olney. The local (awos) weather was; partial obscuration, 100 feet overcast, visibility 3/4 mile.

The crew was completing a short flight from Santo Domingo-Las Américas Airport to Santo Domingo-Herrera Airport located in the city center. On short final, the pilot-in-command mistakenly reduced the engine power too much, causing the aircraft to lose height and to struck the runway surface with an excessive vertical speed. The aircraft landed hard, bounced and came to rest few hundred metres further. All six occupants escaped uninjured and the aircraft was damaged beyond repair.