1985 — Sep 6, Midwest Express Airlines fl. 105 crash upon departure, Milwaukee, WI — 31
— 31 NTSB. AAR. Midwest Express Airlines…Milwaukee, Wisconsin, Sept 6, 1985. 1987, ii.
— 31 Belcastro and Foster (NASA). Aircraft Loss-of-Control Accident Analysis. 2010, p. 37.
Narrative Information
NTSB Executive Summary: “At 1521 c.d.t. on September 6, 1985, Midwest Express Airlines, Inc., Flight 105, a McDonnell-Douglas DC-9-14 airplane, crashed into an open field at the edge of a wooded area about 1,680 feet southwest of the departure end of runway 19R shortly after taking off from General Billy Mitchell Field, Milwaukee, Wisconsin. The weather was clear with visibility 10 miles. During the initial climb, about 450 feet above ground level (a.g.l.), there was a loud noise and a loss of power associated with an uncontained failure of the 9th to 10th stage high pressure compressor spacer of the right engine. Flight 105 continued to climb to about 700 feet a.g.l, and then rolled to the right until the wings were observed in a near vertical, approximately right 90° banked turn. During the roll, the airplane entered an accelerated stall, control was lost, and the airplane crashed. The aircraft was destroyed by impact forces and postcrash fire. The pilot, the first officer, both flight attendants, and all 27 passengers were fatally injured.
“The Safety Board evaluated the performance characteristics of the DC-9-14 airplane following an abrupt loss of power from the right engine in the takeoff phase of flight and found the airplane to be docile, easily controllable, and requiring no unusual pilot skills or strength. Therefore, the Safety Board examined those factors which might have caused the pilots to lose control, including the possibility that fragments of the right engine separated with sufficient energy and trajectory to cause critical damage to the airplane’s flight control system; the possibility of control system malfunction(s), which could have rendered the airplane uncontrollable; and the possibility of inappropriate flightcrew response to the emergency.
“It was determined that the loss of control was precipitated by improper operation of flight controls, specifically the introduction of incorrect rudder pedal forces about 4 to 5 seconds after the right engine failure, followed by aft control column forces, which allowed the airplane to stall at a high airspeed (accelerated stall). Thus, the Safety Board evaluated flightcrew training of Midwest Express pilots at Republic Airlines, the use and limitations of visual flight simulators used in training, and emergency procedures used by, Midwest Express.
“Additionally, the Safety Board evaluated factors which might have contributed to the right engine failure, including overhaul and inspection practices at AeroThrust Corporation, Federal Aviation Administration (FAA) surveillance at AeroThrust, and FAA and Pratt & Whitney responses to previous removable sleeve spacer failures in JT8D engines.
“The National Transportation Safety Board determines that the probable cause of the accident was the flightcrew’s improper use of flight control in response to the catastrophic failure of the right engine during a critical phase of flight, which led to an accelerated stall and loss of control of the airplane. Contributing to the loss of control was a lack of crew coordination in response to the emergency. The right engine failed from the rupture of the 9th to 10th stage removable sleeve spacer in the high pressure compressor because of the spacer’s vulnerability to cracks.
“During the investigation, the Safety Board issued three recommendations to the FAA related to JT8D removable sleeve compressor spacers. As a result of its investigation, the Safety Board also issued two recommendations on flightcrew training in response to emergencies during the initial climb phase and one recommendation on qualifications for Principal Operations Inspectors. All three recommendations were issued to the FAA.” [p. v.] ….
“The wreckage revealed no evidence of in-flight fire. Evidence indicated that any fire associated with the right engine was contained within the engine. N100ME exploded following impact and was largely consumed by the effects of a postcrash fire.” [p. 21.] ….
“Analysis….General…. Witnesses were consistent in reporting that their attention was attracted to the airplane because of one or more loud noises, described as “bangs,” and similar to “shotgun reports,” which occurred about the same time they saw flames and/or smoke from the right engine. The audible “bang,” associated with an engine failure was confirmed by the CVR. Witnesses did not describe flame emitting from any part of the aircraft other than the right engine. Examination of the airplane confirmed that there was no in-flight fire other than that contained within the right engine. The witnesses estimated that these events occurred about 300 feet a.g.l. It was determined that the right engine actually failed about 450 feet a.g.l.” [p. 44.] ….
“Evaluation of Flightcrew Response….The Safety Board believes that more effective scanning of the flight and engine instruments by the pilots of flight 105 would have enabled them to maintain control of the airplane and to properly evaluate the powerplant anomalies. The failure of the first officer to respond to the captain’s questions and the failure of the captain to maintain control of the airplane suggests that there was a breakdown in instrument scan by both pilots in the critical seconds which followed the right engine failure….” [p. 52.]
“Flight Simulator Training Effectiveness….the Safety Board concludes that infrequent training for an engine failure at low altitude in the initial climb phase of flight could have left the flightcrew ill-prepared to cope with the emergency. Although analyzing abnormal or emergency situations and maintaining control of the airplane by reference to flight instruments are basic elements of airmanship, the Safety Board believes that the FAA and the airline industry should consider the circumstances of this accident with a view toward including scenarios of engine failures after establishment of the takeoff climb in training programs to better prepare pilots for such emergencies. Consideration also should be given to reducing pilot reliance on external visual cures during ‘V1 cut’ training by making greater use of simulated low visibility situations during such training.” [p. 58.] ….
(NTSB. Aircraft Accident Report.. Midwest Express Airlines, Inc., DC-9-14, N100ME, General Billy Mitchell Field, Milwaukee, Wisconsin, September 6, 1985.)D
Belcastro and Foster: “Vehicle stall resulting from engine failure and inappropriate crew response (Pilot Input Incorrect Rudder Command).” (Belcastro, Christine M. and John V. Foster. Aircraft Loss-of-Control Accident Analysis. Hampton, VA: NASA Langley Research Center, 7-14-2010, p. 37.)
Sources
Belcastro, Christine M. and John V. Foster. Aircraft Loss-of-Control Accident Analysis. Hampton, VA: NASA Langley Research Center, 7-14-2010. Accessed 1-27-2017 at: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20100030600.pdf
National Transportation Safety Board. Aircraft Accident Report: Midwest Express Airlines, Inc., DC-9-14, N100ME, General Billy Mitchell Field, Milwaukee, Wisconsin, September 6, 1985 (NTSB/AAR-87/01). Washington, DC: NTSB, 2-3-1987, 106 pages. Accessed 1-27-2017 at: https://www.ntsb.gov/investigations/AccidentReports/Reports/AAR8701.pdf