An M20 pilot cleared to intercept the final to runway 13L at bfi; experienced an near midair collisi...

Attributes
ACN	953488
Time
Date	201106
Local Time Of Day	1201-1800
Place
Locale Reference	BFI.Airport
State Reference	WA
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	M-20 Series Undifferentiated or Other Model
Operating Under FAR Part	Part 91
Flight Phase	Initial Approach
Route In Use	Visual Approach
Flight Plan	VFR
Aircraft 2
Make Model Name	Cardinal 177/177RG
Flight Phase	Cruise
Person 1
Function	Single Pilot Pilot Flying
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor
Experience	Flight Crew Last 90 Days 200 Flight Crew Total 20000 Flight Crew Type 210
Events
Anomaly	Conflict NMAC
Miss Distance	Horizontal 300 Vertical 0

Narrative:

Approaching final on a three mile left base for runway 13L at bfi at 1;500 ft tower issued traffic/wake turbulence advisory for traffic on final (about 4 NM) for runway 13R. A few seconds later tower called a traffic advisory for us indicating traffic (a cessna cardinal) approaching at 10 o'clock. Traffic was visually spotted almost immediately at an estimated distance of about 500 ft horizontal same altitude approaching from left to right at about 90 degrees to our heading. The aircraft appeared 'stationary' indicating a collision course. I initiated immediate evasive action with a left turn (behind) the approaching aircraft. We passed about 300 ft apart with the aircraft off our right side.I called the tower later and spoke with a controller who said that he witnessed the event. He apologized and explained that the controller had become 'saturated' and simply got behind. The cessna cardinal had apparently been cleared earlier to transit the area - but this information had not been relayed to us when we checked in to the tower. He said that he; in fact; had been in the process of 'plugging in' to assist the controller when the event occurred.

Original NASA ASRS Text

Title: An M20 pilot cleared to intercept the final to Runway 13L at BFI; experienced an NMAC with A C-177 transiting the airport traffic area. Local controllers were distracted and failed to advise of the traffic in a timely fashion.

Narrative: Approaching final on a three mile left base for Runway 13L at BFI at 1;500 FT Tower issued traffic/wake turbulence advisory for traffic on final (about 4 NM) for Runway 13R. A few seconds later tower called a traffic advisory for us indicating traffic (a Cessna Cardinal) approaching at 10 o'clock. Traffic was visually spotted almost immediately at an estimated distance of about 500 FT horizontal same altitude approaching from left to right at about 90 degrees to our heading. The aircraft appeared 'stationary' indicating a collision course. I initiated immediate evasive action with a left turn (behind) the approaching aircraft. We passed about 300 FT apart with the aircraft off our right side.I called the Tower later and spoke with a Controller who said that he witnessed the event. He apologized and explained that the Controller had become 'saturated' and simply got behind. The Cessna Cardinal had apparently been cleared earlier to transit the area - but this information had not been relayed to us when we checked in to the Tower. He said that he; in fact; had been in the process of 'plugging in' to assist the Controller when the event occurred.

Data retrieved from NASA's ASRS site as of April 2012 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.

An M20 pilot cleared to intercept the final to runway 13L at bfi; experienced an near midair collision with a C-177 transiting the airport traffic area. Local controllers were distracted and failed to advise of the traffic in a timely fashion.