Investigation Summary
The accident began as the aircraft climbed through 450 feet when the right engine's 9th-stage high-pressure compressor removable sleeve spacer failed due to metal fatigue. This caused an uncontained engine failure, characterized by loud bangs and visible flames. Captain Martin initially responded correctly by applying right rudder to counter the yaw. However, he became confused by the nature of the emergency and repeatedly asked First Officer Weiss for assistance. Weiss, despite being a senior captain acting as a first officer, did not respond to the captain's queries, instead focusing on radio communications with Air Traffic Control. This breakdown in Crew Resource Management (CRM) was exacerbated by an unwritten 'silent cockpit' rule at Midwest Express, which discouraged non-essential communication below 800 feet. During this silence, the pilots allowed the nose to pitch up, causing the airspeed to decay. The aircraft entered a stall and rolled sharply to the right. The NTSB also noted that the left engine may have suffered a power loss due to the ingestion of debris from the right engine or atmospheric disturbances caused by the stall, but the primary cause was the crew's failure to maintain control of the aircraft during a survivable mechanical emergency.
Final Conclusions
The National Transportation Safety Board determined that the probable cause was the flight crew's improper control of the airplane following an uncontained failure of the right engine. This failure to maintain control resulted from a lack of coordination between the pilots and a failure to monitor flight instruments. Contributing to the accident was the uncontained failure of the right engine and the FAA's inadequate oversight of Midwest Express Airlines' pilot training program.
Photographic Evidence (1)
Video Analysis
The Crash of Midwest Express Flight 105 | Mini Air Crash Investigation — A detailed look at the 1985 crash in Milwaukee where a mechanical failure led to a fatal breakdown in cockpit coordination.
If playback is blocked, the owner has disabled embedding — use the link above.
Airframe & Maintenance
Crew Experience
Captain
Danny Watkin Martin. Had 500 hours as captain on type.
First Officer
William Roger Weiss. A senior captain acting as First Officer; had 1,140 hours as captain on type.
Systems & Failure Modes
Pratt & Whitney JT8D-7 Engine
The DC-9 was equipped with two JT8D engines; the right engine suffered an uncontained failure of the 9th-stage compressor spacer.
Stick Shaker
A mechanical device that vibrates the control yoke to provide a tactile warning to the crew that the aircraft is approaching a stall.
Crew Resource Management (CRM)
The effective use of all available resources, including hardware and personnel, which failed in this instance due to a lack of communication between the two captains.
Interesting Facts
- 01The right engine failure was caused by metal fatigue in a removable sleeve spacer.
- 02Both pilots were experienced aviators but had relatively low time (approx. 1,100–1,600 hours) on the DC-9 type.
- 03The aircraft reached a 90-degree bank angle before crashing.
- 04The NTSB concluded the aircraft was controllable despite the engine failure.
- 051985 was one of the deadliest years in aviation history, with Flight 105 being the eighth major accident that year.
- 06The airline utilized an unwritten 'silent cockpit' rule that prohibited non-essential communication below 800 feet, which hindered emergency coordination.
- 07The 31 souls on board included 27 passengers and 4 crew members; one passenger was a Kimberly-Clark employee riding in the cockpit jump seat.
Safety Actions & Advisories
FAA Oversight Review
The NTSB recommended improvements in FAA oversight regarding the quality and standardization of airline pilot training programs.