Seattle/Tacoma Int. Airport
Aircraft Accident/Incident Report

Seattle, Washington 98188
Saturday, March 2, 2002 6:20 PST

NTSB Narrative Summary Released at Completion of Accident

After completing deicing procedures on a company Boeing 757-200, the driver of the deicing truck maneuvered his truck in a manner that caused the deicing basket boom to impact the trailing edge of the aircraft's left aileron. The boom penetrated the aileron to a depth of almost two feet and damaged its spar. The investigation revealed that while backing out from his position behind the aircraft's left wing, the driver had inadvertently turned his steering wheel in a direction that caused the boom, which is mounted on the back end of the truck, to converge on the trailing edge of the aileron.

NTSB Probable Cause Narrative

The failure of the deicing truck driver to insure that the deicing basket boom remained clear of the aircraft structure as he backed away from the position he had been in while performing deicing procedures.

Event Information

Type of Event Accident
Event Date 3/2/2002
Event Day of the Week Saturday
Time of Event 620
Event Time Zone Pacific Standard Time
Event City Seattle
Event State WASHINGTON
Event Country --
Zipcode of the event site 98188
Event Date Year 2002
Event Date Month 3
MidAir Collision Indicator No
On Ground Collision occurred ? Yes
Event Location Latitude --
Event Location Longitude --
Event Location Airport Seattle/Tacoma Int.
Event Location Nearest Airport ID KSEA
Indicates whether the acc/inc occurred off or on an airport On Airport
Distance from airport in statute miles --
Degrees magnetic from airport --
Airport Elevation 429
Weather Briefing Completeness Unknown
Investigator's weather source Weather Observation Facility
Time of the weather observation 556 Pacific Standard Time
Direction of event from weather observation facility (degrees) --
Weather Observation Facility ID KSEA
Elevation of weather observation facility 429
Distance of event from weather observation facility (units?) --
Time Zone of the weather observation PST
Lighting Conditions Dawn
Lowest Ceiling Height --
Lowest Non-Ceiling Height 20000
Sky/Lowest/Cloud Conditions Few
Sky Condition for Lowest Ceiling None
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) -1
Dew Point at event time (in degress fahrenheit) -1
Wind Direction (degrees magnetic) 130
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 5
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.5
Density Altitude (feet) --
Intensity of Precipitation --
METAR weather report --
Event Highest Injury None
On Ground, Fatal Injuries --
On Ground, Minor Injuries --
On Ground, Serious Injuries --
Injury Total Fatal --
Injury Total Minor --
Injury Total None 90
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 11787
NTSB Notification Source United Airlines
NTSB Notification Date Feb 4 2002 12:00AM
NTSB Notification Time 1400
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Jun 3 2002 12:16PM
User who most recently changed record NTSB\MONR
Basic weather conditions Visual Meteorological Cond
FAA District Office Seattle FSDO

Aircraft Involved

Aircraft #1

Aircraft Registration Number N589UA
NTSB Number SEA02LA049
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 121: Air Carrier
Type of Flight Plan filed IFR
Flight plan Was Activated? No
Damage Substantial
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Boeing
Aircraft Model 757-200
Aircraft Series Identifier --
Aircraft Serial Number 28707
Certified Max Gross Weight 240000
Aircraft Category Airplane
Aircraft Registration Class U.S. Registered/U.S. Soil
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 191
Number of Engines 2
Fixed gear or retractable gear Retractable
Aircraft, Type of Last Inspection Continuous Airworthiness
Date of Last Inspection Sep 11 2001 12:00AM
Airframe hours since last inspection 1668
Airframe Hours 17618
ELT Installed No
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name United Airlines
Aircraft Owner Street Address 1200 Algonquin Rd.
Aircraft Owner City Elk Grove Township
Aircraft Owner State IL
Aircraft Owner Country USA
Aircraft Owner Zipcode 60007
Operator is an individual? No
Operator Name --
Operator Same as Owner? Yes
Operator Is Doing Business As --
Operator Address Same as Owner? Yes
Operator Street Address --
Operator City --
Operator State --
Operator Country --
Operator Zip code --
Operator Code UALA
Owner has at least one certificate --
Other Operator of large aircraft? --
Certified for Part 133 or 137 Operation --
Operator Certificate Number --
Indicates whether an air carrier operation was scheduled or not Scheduled
Indicates Domestic or International Flight Domestic
Operator carrying Pax/Cargo/Mail Passenger Only
Type of Flying (Per_Bus / Primary) --
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code SEA
Departure City Seattle
Departure State WA
Departure Country USA
Departure Time --
Departure Time Zone PST
Destination Same as Local Flt --
Destination Airport Code ORD
Destination City Chigago
Destination State IL
Destination Country USA
Specific Phase of Flight Standing - engine(s) operating
Report sent to ICAO? No
Evacuation occurred No
Date of most recent change to record Mar 18 2002 5:32PM
User who most recently changed record STAM
Since inspection or accident Time of Accident
Event Location Runway Number and Location --
Runway Length --
Runway Width --
Sight Seeing flight No
Air Medical Flight No
Medical Flight --