College Station

While climbing the airplane to cruise altitude after takeoff, the pilot observed an increase in engine oil temperature above the normal range and requested to return to the departure airport. While receiving vectors for an instrument approach, the pilot saw smoke in the cabin and the engine lost total power. Unable to glide to any runway, the pilot selected a field for the forced landing, during which the airplane sustained substantial damage to the wings and fuselage. Postaccident examination revealed that about 2 quarts of oil remained in the engine, and the recovered oil displayed evidence of metal contamination. There was evidence of an oil leak in the engine compartment and along the lower fuselage. There was evidence of a crankcase fracture near the oil dip stick port; however, a laboratory examination determined the fracture to be consistent with overload and likely due to impact-related damage. The engine exhibited no evidence of any loose or disconnected oil lines. The oil filter was removed, and the filter material was found to be saturated with metallic particles. The oil suction screen plug, located on the oil sump, was not secured with safety wire as required per the manufacturer’s maintenance manual. There was no evidence that the plug or required safety wire was damaged by other objects. The oil suction screen plug was found to be loose, with engine oil observed below the oil suction screen plug. The crush washer behind the oil screen plug was intact and exhibited no damage. Laboratory analysis of the metallic debris recovered from the oil suction screen was consistent with connecting rod material as well as steel from fittings, fasteners, and brackets. The metallic debris found in the recovered oil, oil filter, and oil suction screen was likely due to mechanical damage associated with oil starvation. Eleven days before the accident flight, the pilot observed decreased engine manifold pressure and a partial loss of engine power. He diverted to an airport, where he had the turbocharger replaced by an aviation mechanic. In addition to replacing the turbocharger, the mechanic also drained and replaced the engine oil, which included removal and reinstallation of the oil suction screen plug. The loss of engine power was likely due to a loss of oil during the flight that led to oil starvation within the engine. The loose oil suction screen plug, the absence of safety wire on the plug, and the evidence of an oil leak beneath the plug were consistent with the mechanic’s failure to properly secure the oil suction screen plug during recent maintenance.

While conducting a post maintenance test flight in visual flight rules conditions, the private pilot of the multi-engine airplane reported an oil leak to air traffic control. The controller provided vectors for the pilot to enter a right base leg for a landing to the south at the nearest airport, about 7 miles away. The pilot turned toward the airport but indicated that he did not have the airport in sight. Further, while maneuvering toward the airport, the pilot reported that the engine was "dead," and he still did not see the airport. The final radar data point recorded the airplane's position about 3.5 miles west-northwest of the approach end of the runway; the wreckage site was located about 4 miles northeast of the runway, indicating that the pilot flew past the airport rather than turning onto a final approach for landing. The reason that the pilot did not see the runway during the approach to the alternate airport, given that the airplane was operating in visual conditions and the controller was issuing guidance information, could not be determined. Regardless, the pilot did not execute a precautionary landing in a timely manner and lost control of the airplane. Examination of the airplane's left engine revealed that the No. 2 connecting rod was broken. The connecting rod bearings exhibited signs of heat distress and discoloration consistent with a lack of lubrication. The engine's oil pump was intact, and the gears were wet with oil. Based on the available evidence, the engine failure was the result of oil starvation; however, examination could not identify the reason for the starvation.

The aircraft rolled to the right and crashed after a catastrophic (uncontained) failure of the right engine during takeoff for a night flight. The right engine fan rotor disc separated from the hub which damaged the cowling and some disc fragments buried in the fuselage but without damage to the flight controls. The drag created by the loss of thrust and the distorted cowling led to yaw and roll with loss of control of the aircraft. The fan failure propagated from a low grade fatigue crack on the high time fan which was not detected by the visual inspection procedures existing at the time. The manufacturer has since improved the manufacturing and inspection techniques. An AD 86-04-02 was issued on 2/14/86 which deals with fan removal from service according to an operating cycle schedule.

On approach by night while on a cargo flight from College Station, the pilot failed to realize his altitude was insufficient when the twin engine airplane struck trees and crashed few miles from the runway threshold. The pilot and a passenger were killed while a second passenger was seriously injured.