Aerospatiale ATR-42 N427MQ

Summary

On 22 December 1988 at about 22:29 local time, a Aerospatiale ATR-42 registered N427MQ, operated by Simmons Airlines, was involved in an incident near Mosinee, Wisconsin, United States. 37 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

22 December 1988 at 22:29

Classification

Incident

Location

Mosinee, Wisconsin, United States

Nearest airport

Central Wisconsin (CWA)

Coordinates

44.7791, -89.6798

Aircraft

Aerospatiale ATR-42

Registration

N427MQ

Category

Airplane

Engines

2

Operator

Simmons Airlines

Operating rule

Part 121: Air Carrier

Purpose of flight

Unknown

Phase of flight

Not recorded

Route

Chicago → Unknown

Aircraft damage

Not recorded

Weather

IMC

Light

Night/Dark

NTSB number

CHI89IA034

Nobody was injured.

STALL INDUCED BY THE ACCRETION OF MODERATE TO SEVERE CLEAR ICING.

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

Read the full NTSB narrative

A MISSED APPROACH WAS EXECUTED ON THE FIRST APPROACH, AND THE CREW ELECTED TO FLY THE COMPLETE PROCEDURE TURN FOR THE ILS AT THE CENTRAL WISCONSIN AIRPORT. BOTH THE FIRST AND SECOND APPROACHS WERE FLOWN AT 3000 FEET MSL IN IMC CONDITIONS WITH MODERATE TO HEAVY RAIN. A TEMPERATURE INVERSION EXISTED FROM 5000 FEET TO 3000 FEET MSL WHICH CREATED CONDITIONS CONDUCIVE TO MODERATE TO SEVERE CLEAR ICING. THE AIRCRAFT WAS IN THESE CONDITIONS FOR 11.8 MINUTES. APPROXIMATELY ONE-HALF WAY THROUGH THE PROCEDURE TURN, WHICH WAS FLOWN WITH THE AUTOPILOT ON, THE CAPTAIN REDUCED POWER TO SLOW FOR GEAR EXTENSION. AT 157 KNOTS CLEAN CONFIGURATION THE AIRCRAFT STALLED AND ROLLED 80 DEGREES TO THE LEFT AND 60 DEGREES TO THE RIGHT. THE CREW APPLIED FULL POWER AND EXECUTED STALL RECOVERY PROCEDURES. THE AIRCRAFT WAS RECOVERED WITH AN ALTITUDE LOSS OF 600 FEET. THE CREW DID NOT PERCEIVE ANY ICE ACCRETION, AND THE AIRFRAME DEICE WAS NOT ON UNTIL AFTER THE STALL. THE THIRD APPROACH WAS UNEVENTFUL.

Quoted verbatim from the NTSB record.