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NTSB Report
February 19, 1988 · Boeing 747-227B · N635US
Chicago, IL
Overview
Report Status
Probable Cause
Event Type
Incident
Date
February 19, 1988
Injury Outcomes
No injuries (297 uninjured)
Location
Chicago, IL
Aircraft
Boeing 747-227B
Tail Number
N635US
Injuries
None
NTSB Number
CHI88IA073
NORTHWEST FLT 3 (BOEING 747, N635US) WAS CLRD TO TAKEOFF ON RWY 14R AT THE SAME TIME AIR WISCONSIN FLT 925 (BAE 146, N602AW) WAS CLRD TO TAKEOFF ON RWY 22L AT THE CHICAGO-O'HARE INTL ARPT. SUBSEQUENTLY, THE TWO ACFT PASSED WITH AN ESTIMATED 3000 TO 4000 FT SEPARATION. THIS OCCURRED AFTER THE TOWER SUPERVISOR HAD NOT ASSURED COORDINATION BETWEEN THE NORTH & SOUTH LOCAL CONTROL POSITIONS. AT THE TIME OF THE OPERATIONAL ERROR, THE TOWER SUPERVISOR WAS ACTING AS BOTH THE SUPERVISOR & THE TOWER CAB COORDINATOR.
NTSB Probable Cause
FAILURE OF THE TOWER CAB SUPERVISOR TO ASSURE THAT COORDINATION BETWEEN THE SOUTH LOCAL CONTROLLER AND NORTH LOCAL CONTROLLER HAD BEEN COMPLETED. A FACTOR IS THE FAILURE OF FAA TOWER MANAGEMENT TO INSURE THERE WERE PERSONNEL MANNING THE CAB COORDINATOR POSITION.
Full Narrative
NORTHWEST FLT 3 (BOEING 747, N635US) WAS CLRD TO TAKEOFF ON RWY 14R AT THE SAME TIME AIR WISCONSIN FLT 925 (BAE 146, N602AW) WAS CLRD TO TAKEOFF ON RWY 22L AT THE CHICAGO-O'HARE INTL ARPT. SUBSEQUENTLY, THE TWO ACFT PASSED WITH AN ESTIMATED 3000 TO 4000 FT SEPARATION. THIS OCCURRED AFTER THE TOWER SUPERVISOR HAD NOT ASSURED COORDINATION BETWEEN THE NORTH & SOUTH LOCAL CONTROL POSITIONS. AT THE TIME OF THE OPERATIONAL ERROR, THE TOWER SUPERVISOR WAS ACTING AS BOTH THE SUPERVISOR & THE TOWER CAB COORDINATOR.
Flight
Event TypeIncident
Event Time12:07 CST
Nearest AirportChicago-O'Hare Intl (0nm N)
Runway14R
Runway Length13000 ft
Runway Width200 ft
Flight Plan FiledIFR
Aircraft FireNo
Aircraft ExplosionNo
Aircraft
AircraftBoeing 747-227B
Tail NumberN635US
Aircraft CategoryAir
Operating RulePart 121
Engines4
Engine TypeTurbofan
Engine DetailsP&W · JT9D · Turbofan · 54750 | Lycoming · ALF-502R · Turbofan · 6970
Seats495
People & Injuries
Injury SummaryNo injuries (297 uninjured)
Fatal0
Serious0
Minor0
Uninjured297
Total297
Crew 1Age 53 · First Class
Crew 2Age 46 · First Class
Conditions
ConditionsVMC
LightDaylight
Wind240° @ 4 kt
Visibility4 sm
CeilingBroken clouds 2300 ft
Temperature / Dew Point39 C / 25 C
Altimeter29.00 inHg
Observation Time18:01
Weather SourceWFAC