Narrative:

I was looking at the ground to verify my position. I looked up and saw a red and white cessna about 60 ft away and closing, heading sbound, and evasively rolling into a steep bank away from me to the west. I evasively rolled into a diving turn toward the north. If both the other pilot and I had not turned away from each other, we certainly would have collided. Before the occurrence, I had recently made initial contact with boeing tower and had just entered boeing class D airspace. I was never given a TA by boeing tower. I believe that the other aircraft was flying to renton airport, which is likely why boeing tower was not aware of it. I have experienced that VFR traffic between boeing tower and renton tower often conflicts. I would recommend a system that would allow boeing and renton towers to be aware of each other's traffic. If I had received a traffic report, I believe that adequate separation would have been maintained. I would also recommend that if boeing tower's supplemental radar, fed from seatac, had a conflict alert system, it would have notified the controller of the situation.

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Original NASA ASRS Text

Title: A LOW TIME C152 PLT, FLYING IN THE VICINITY OF BFI, WAS LOOKING DOWN AT THE GND WHEN HE FINALLY NOTICED A C172, ONLY 30 FT AWAY, MAKING AN EVASIVE TURN.

Narrative: I WAS LOOKING AT THE GND TO VERIFY MY POS. I LOOKED UP AND SAW A RED AND WHITE CESSNA ABOUT 60 FT AWAY AND CLOSING, HEADING SBOUND, AND EVASIVELY ROLLING INTO A STEEP BANK AWAY FROM ME TO THE W. I EVASIVELY ROLLED INTO A DIVING TURN TOWARD THE N. IF BOTH THE OTHER PLT AND I HAD NOT TURNED AWAY FROM EACH OTHER, WE CERTAINLY WOULD HAVE COLLIDED. BEFORE THE OCCURRENCE, I HAD RECENTLY MADE INITIAL CONTACT WITH BOEING TWR AND HAD JUST ENTERED BOEING CLASS D AIRSPACE. I WAS NEVER GIVEN A TA BY BOEING TWR. I BELIEVE THAT THE OTHER ACFT WAS FLYING TO RENTON ARPT, WHICH IS LIKELY WHY BOEING TWR WAS NOT AWARE OF IT. I HAVE EXPERIENCED THAT VFR TFC BTWN BOEING TWR AND RENTON TWR OFTEN CONFLICTS. I WOULD RECOMMEND A SYS THAT WOULD ALLOW BOEING AND RENTON TWRS TO BE AWARE OF EACH OTHER'S TFC. IF I HAD RECEIVED A TFC RPT, I BELIEVE THAT ADEQUATE SEPARATION WOULD HAVE BEEN MAINTAINED. I WOULD ALSO RECOMMEND THAT IF BOEING TWR'S SUPPLEMENTAL RADAR, FED FROM SEATAC, HAD A CONFLICT ALERT SYS, IT WOULD HAVE NOTIFIED THE CTLR OF THE SIT.

Data retrieved from NASA's ASRS site as of July 2007 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.