Mitsubishi MU-2 Marquise

During the takeoff roll at São Paulo-Congonhas Airport, the crew encountered an engine failure and decided to abort. The airplane was stopped on the main runway and all five occupants escaped uninjured. However, debris punctured a fuel tank and the aircraft caught fire and was severely damaged by fire and later written off.

The airplane departed runway 1L and radar data indicated the airplane maintained about a 110 knot ground speed for 37 seconds as it climbed to 1,400 feet msl (642 feet agl) with a 008 degree heading. The last radar 14 seconds later indicated the airplane's heading was 342 degrees and had a 130 knot ground speed. The winds were 290/11. Witnesses reported seeing the airplane flying low and slow, and then it made a turn like a "barrel roll" to the left before impacting the ground. Examination of the engines and airframe revealed no pre-existent anomalies. The left and right propellers exhibited leading edge damage and chordwise abrasions. The pilot had a total of about 1,175 flight hours with about 250 hours in the type and model aircraft. The copilot had 4,094 total hours, but had 10 hours of turbine time and no flight time in the type and model of aircraft. The pilot had indicated he was practicing simulated single engine failures. The gear was fully retracted. The trim settings were set for a right engine out situation. The flap selector was set to "UP" flaps, but the flaps were found in transit at approximately 2 degrees of flaps. The Airplane Flight Manual indicated that during "Engine Failure in Takeoff-Gear Fully Retracted" stated that the required airspeed before selecting flaps to 5 degrees was 140 KCAS. The Pilot's Operating Handbook stated the flaps take approximately 31 seconds to retract from 20 to 0 flaps, or 21 seconds to retract from 5 to 0 flaps.

The pilot said that after climbing about 500 feet after takeoff, at 120 knots with the gear retracted, the left engine lost power. He feathered the propeller, lowered the nose to the horizon, and began a shallow left turn back to the airport. He left the flaps at 20° and noted a descent of 200 feet to 300 feet per minute in the turn. After clearing trees, the pilot extended the landing gear, banked the aircraft to the right to align it with the runway and lowered flaps to 40°. After touchdown, he applied single engine reversing. The aircraft went off right side of runway and into a ditch, collapsing the right main and nose gear. Examination of the engine revealed the torque sensor housing had failed, resulting in loss of drive to the fuel pump. Metallurgical exam of the housing arm of the torque sensor revealed it had failed from fatigue. On 9/14/79, a service bulletin (SB) was issued for replacement of the torque sensor housing with an improved housing. The manufacturer overhauled the engine on 12/1979, but SB was not complied with. SB indicated a history of resonant vibration causing cracks in the housing arm of original torque sensor and gear assemblies, and that the housing should be replaced, no later than during next part exposure. Investigation revealed pilot did not comply with engine failure procedures and airspeeds. Flight manual cautioned not to use 40° of flaps during single engine landings.

The right engine lost power after an uncontained engine failure during the initial takeoff climb. The airplane would not climb and the pilot was forced to land. The pilot selected a street for a forced landing area. The pilot landed gear up while maneuvering to avoid hitting street light poles and automobiles. After touchdown, the airplane slid into a block wall. A fire erupted as a result of a post impact fuel leak in the left wing. The airplane's engines were examined at the manufacturer's facilities. The right engine exhibited evidence of an uncontained separation of the second stage turbine rotor disk. Examination of the disk fragments revealed a low cycle fatigue fracture mode. The fatigue initiated from multiple areas at and adjacent to the inside diameter bore surface near the aft side of the disk. According to the engine manufacturer, the multiple indication areas were associated with uninspectable size porosity and the primary carbides in the cast material. There were no material or casting defects detected on any of the fractures through the wheel.

The pilot was engaged in a local military mission at Tyndall AFB. On approach to runway 13L, conflicting traffic forced the pilot to initiate a go-around procedure. During the second approach, the pilot failed to follow the approach checklist and failed to lower the undercarriage. The aircraft landed on its belly and came to rest on the runway. The pilot escaped uninjured.

The pilot reported that loss of power occurred in both engines after he entered the traffic pattern for a full stop landing. The airplane collided with trees during an emergency landing in a cotton field near the airport. Subsequent review of the aircraft maintenance logs disclosed that Mitsubishi MU-2 Service Bulletin (SB) 130A had not been accomplished on this airplane. According to the manufacturer, an inadvertent failure or the improper installation of a filler cap after refueling may cause an air pressure differential between the center and outboard portions of the main integral fuel tank. Air leakage from the filler cap may result in failure of the fuel transfer system to move fuel from the outboard tank section to the center tank section. To eliminate this possible malfunction, the operator was to remove vent check valves from the bulkhead between the tanks in accordance with SB 130A. The operator's maintenance policies required that, company jet and turbo propeller aircraft be maintained under a maintenance program in accordance with FAR Parts 135.415, 135.417, 135.423, 135.443, and a corporate flight management approved aircraft inspection program (AAIP). The maintenance inspection program also included compliance with manufacturers' service bulletins and service letters.

The flight was on the ILS approach to runway 6, broke out of the clouds at 500 feet, and then re-entered the clouds. The airplane had not yet touched down when it drifted to right of the runway centerline and struck a snow bank located in the grass to the right of the runway, between the runway and the taxiway. The pilot stated he was just starting the missed approach when the accident occurred, and '...that there was no indication of a malfunction of the aircraft.' The reported ceiling was, 100 sky obscured, and the visibility was 1/4 mile, wind 040 degrees, 6 knots.

The flight departed on a maintenance test flight with known wind gusts to 27 knots. Before takeoff the pilot performed an NTS check to each engine with no discrepancies noted. During flight the pilot performed an NTS check to the left engine. Two attempts to restart the left engine were unsuccessful. Each time the propeller came out of the feathered position and started to rotate but there was no fuel flow or ignition. The flight returned to land and while on short final to runway 29 with the wind from 250 degrees at 20 knots, a witness observed the airplane pitch nose up then down then heard the sound of power applied to the right engine. The airplane than rolled to the left, pitched nose down, impacted the ground coming to rest nearly inverted with the wing section separated. Postaccident examination of the left engine and accessories revealed no evidence of preimpact failure or malfunction. The left engine fuel shutoff valve was found in the 'closed' position and no fuel was found aft of the fuel shutoff valve. The pilot stated that he has no recollection of the accident. The left and right engines had just been installed following 'hot section' work to both, and both were then started the day after installation with no discrepancies noted by company maintenance personnel.

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.

A witness stated he observed the airplane on climbout from runway 32. The airplane started a right turn estimated at about 30 to 45° angle of bank. The airplane stopped climbing and began descending. Subsequently, it collided with a tree line, while in a right bank, and then it impacted the ground. Weather conditions at the time of accident were described by the witness as very dark, with no ambient light or visible horizon. Examination of the airframe, flight control system, engine assembly, and propeller assembly revealed no evidence of a precrash failure or malfunction. The autopilot was found in the off position, and the autopilot circuit breakers were not tripped. The pilot and passenger were seriously injured and had no memory of the flight. A radio transcript revealed that after taking off, the flight had made one radio transmission to request an ifr clearance.