Boeing Field/King County Int. Airport
Aircraft Accident/Incident Report

Seattle, Washington 98134
Thursday, November 16, 2006 14:20 PST

NTSB Narrative Summary Released at Completion of Accident

While on a VFR straight-in approach in a Cessna 172, the flight instructor and her student were advised by the tower that a heavy Boeing 747, which was behind and above the 172, was executing a visual approach to an upwind parallel runway. Although the 747 crew did not have the 172 in sight, the flight instructor in the 172 spotted the 747 soon after being advised of its presence by the tower. The instructor maintained visual contact with the descending 747, and as the 747 neared a point where it would pass the 172, the instructor elected to continue the VFR approach at about the same altitude and on the same course as before. The instructor then watched as the still-descending 747 passed upwind of the 172 at a slightly higher altitude than the 172 was at. When the 747 reached a point about one-quarter mile in front of the 172, the 172 encountered the wake vortices from the 747, and immediately departed controlled flight. Recovery was completed about 150 feet above the terrain. At the time that the 747 passed the 172, the instructor was aware that there was a nine knot wind blowing almost directly across the parallel flight paths of the two aircraft, and although the instructor had requested a low approach at the runway, the instructor did not take evasive action when the 747 passed the 172 while on approach.

NTSB Probable Cause Narrative

The instructor pilot's improper in-flight decision not to take evasive action as a heavy aircraft passed by while on an upwind parallel approach path to an adjacent runway, leading to a wake vortices encounter. Factors include a nearly direct crosswind blowing from the heavy aircraft toward the incident aircraft.

Event Information

Type of Event Incident
Event Date 11/16/2006
Event Day of the Week Thursday
Time of Event 1420
Event Time Zone Pacific Standard Time
Event City Seattle
Event State WASHINGTON
Event Country --
Zipcode of the event site 98134
Event Date Year 2006
Event Date Month 11
MidAir Collision Indicator No
On Ground Collision occurred ? No
Event Location Latitude 473514N
Event Location Longitude 1222000W
Event Location Airport Boeing Field/King County Int.
Event Location Nearest Airport ID KBFI
Indicates whether the acc/inc occurred off or on an airport Off Airport/Airstrip
Distance from airport in statute miles 3
Degrees magnetic from airport --
Airport Elevation 21
Weather Briefing Completeness --
Investigator's weather source Weather Observation Facility
Time of the weather observation 1353 Pacific Standard Time
Direction of event from weather observation facility (degrees) 130
Weather Observation Facility ID KBFI
Elevation of weather observation facility 21
Distance of event from weather observation facility (units?) 3
Time Zone of the weather observation PST
Lighting Conditions Day
Lowest Ceiling Height --
Lowest Non-Ceiling Height 3000
Sky/Lowest/Cloud Conditions Scattered
Sky Condition for Lowest Ceiling --
Visibility Runway Visual Range (Feet) --
Visibility Runway Visual Value (Statute Miles) --
Visibility (Statute Miles) 10
Air Temperature at event time (in degrees celsius) 11
Dew Point at event time (in degress fahrenheit) 1
Wind Direction (degrees magnetic) 210
Variable Wind Indicator Wind direction could be determined
Wind Speed (knots) 9
Wind Velocity Indicator --
Wind Gust Indicator Not Gusting
Wind Gust (knots) --
Altimeter Setting at event time (in. Hg) 30.01
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 2
Injury Total Serious --
Injury Total All --
Investigating Agency NTSB
NTSB Docket Number (internal use) 22790
NTSB Notification Source FAA Regional Operations Center
NTSB Notification Date Nov 16 2006 12:00AM
NTSB Notification Time --
Fiche Number and/or location -used to find docket information DMS
Date of most recent change to record Dec 20 2007 6:59AM
User who most recently changed record NTSB\johb
Basic weather conditions Visual Meteorological Cond
FAA District Office Seattle, WA

Aircraft Involved

Aircraft #1

Aircraft Registration Number N9522S
NTSB Number SEA07IA019
Missing Aircraft Indicator --
Federal Aviation Reg. Part Part 91: General Aviation
Type of Flight Plan filed None
Flight plan Was Activated? --
Damage None
Aircraft Fire None
Aircraft Explosion None
Aircraft Manufacturer's Full Name Cessna
Aircraft Model 172
Aircraft Series Identifier --
Aircraft Serial Number 17280432
Certified Max Gross Weight 2550
Aircraft Category Airplane
Aircraft Registration Class --
Aircraft is a homebuilt? No
Flight Crew Seats --
Cabin Crew Seats --
Passenger Seats --
Total number of seats on the aircraft 4
Number of Engines 1
Fixed gear or retractable gear Fixed
Aircraft, Type of Last Inspection 100 Hour
Date of Last Inspection Oct 1 2006 12:00AM
Airframe hours since last inspection --
Airframe Hours 4077
ELT Installed Yes
ELT Activated No
ELT Aided Location of Event Site No
ELT Type --
Aircraft Owner Name Galvin Flying Service
Aircraft Owner Street Address --
Aircraft Owner City Seattle
Aircraft Owner State WA
Aircraft Owner Country USA
Aircraft Owner Zipcode 98108
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 --
Owner has at least one certificate None
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 --
Indicates Domestic or International Flight --
Operator carrying Pax/Cargo/Mail --
Type of Flying (Per_Bus / Primary) Instructional
Second Pilot on Board Yes
Departure Point Same as Event Yes
Departure Airport Code KBFI
Departure City Seattle
Departure State WA
Departure Country USA
Departure Time 1320
Departure Time Zone PST
Destination Same as Local Flt dest & departure same, accident can occur anywhere
Destination Airport Code KBFI
Destination City --
Destination State --
Destination Country --
Specific Phase of Flight Approach - VFR pattern - final approach
Report sent to ICAO? --
Evacuation occurred --
Date of most recent change to record Nov 30 2007 2:03PM
User who most recently changed record STAM
Since inspection or accident Time of Accident
Event Location Runway Number and Location 13L
Runway Length 3709
Runway Width 100
Sight Seeing flight No
Air Medical Flight No
Medical Flight --