- Date
- June 29, 1990, 09:10 local (14:10 UTC)
- Place
- Chicago, IL
- Injuries
- 65 uninjured
- Damage
- No damage
- Phase of flight
- Enroute
- Aircraft
- N948MLMcdonnell Douglas DC-9-32
- Weather
- Visual (VMC) · Day
- Status
- Completed · report May 10, 1993
- Report
- Approved by Office Director
- Case key
- 14568
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the incident.
On this page
Probable cause
The pilot-in-command's inadequate weather evaluation. Factors in the incident were the weather and artcc's failure to issue a weather advisory.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
A passenger transport experienced severe turbulence during an en route descent to destination. The flight's forecast indicated thunderstorm development in the destination vicinity. The crew heard destination ATIS announce severe turbulence on approach but recalled no ATC advisory stating turbulence was severe. The pilot complied with atc's request to slow for traffic separation, placing the speed below that recommended for turbulence penetration. The airplane was turning to avoid clouds and virga, with speedbrakes extended and autopilot engaged when it entered increasing turbulence. The airplane pitched up 20 degrees and rolled to 45 degrees. The pilot righted the airplane and stopped the descent 500 feet below assigned altitude. Speed brake extension increases roll rate. Autopilot use in severe turbulence is recommended only in the pitch-hold mode.
Aircraft
- Registration
- N948ML
- Reported as
- Mcdonnell Douglas DC-9-32
- Category
- Airplane
- Serial number
- 47169
- Engine
- P&W JT8D-9B, 14,500 lbs thrust, turbo jet
- Damage
- No damage
- Flight
- Part 121
- Registered owner
- Midway Airlines, Inc.
- Airworthiness certificate
- Standard, Transport
- Departed
- DCA · Washington, DC
- Flight plan
- IFR
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 40
- Certificate
- Airline transport
- Airplane ratings
- Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 1, Valid Medical--w/ waivers/lim
- Seat
- Left
- Flight hours
- 15,580 total · 8,000 in this make and model · 8,170 as pilot in command · 220 in the last 90 days · 73 in the last 30 days
Weather
- Conditions
- Visual (VMC) · Day
- Wind
- 280° at 14 knots
- Visibility
- 15 statute miles
- Lowest ceiling
- 9,000 ft overcast
- Temperature
- 70 °F, dew point 66 °F
- Altimeter
- 29.00 inHg
- Observed at
- MDW, 33 nm away