McDonnell Douglas DC-9-32 N948ML

Summary

On 29 June 1990 at about 14:10 local time, a McDonnell Douglas DC-9-32 registered N948ML was involved in an incident near Chicago, Illinois, United States. 65 people were on board and nobody was injured. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 June 1990 at 14:10

Classification

Incident

Location

Chicago, Illinois, United States

Coordinates

41.7793, -87.7709

Aircraft

McDonnell Douglas DC-9-32

Registration

N948ML

Category

Airplane

Engines

2

Operator

Not recorded

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Washington → Unknown

Aircraft damage

Not recorded

Weather

VMC

Light

Day

NTSB number

CHI90IA166

Nobody was injured.

THE PILOT-IN-COMMAND'S INADEQUATE WEATHER EVALUATION. FACTORS IN THE INCIDENT WERE THE WEATHER AND ARTCC'S FAILURE TO ISSUE A WEATHER ADVISORY.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

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.

Quoted verbatim from the NTSB record.