Narrative:

Air carrier X cleared for takeoff behind a light jet transport. To be extra safe and contribute to passenger comfort I climbed the aircraft steeply to avoid any possible wake turbulence. We climbed above the jet's departure path. At 800 ft the first officer saw small aircraft Y, a single engine aircraft, at our 10 O'clock at approximately 1000 ft MSL and approximately 2000 ft horizontal. I saw it then for the first time but determined that there was no conflict between our 2 aircraft and continued the climb. The reason why there was no conflict was because just prior to the first officer pointing out the traffic I had begun reducing our climb angle in order to accelerate to cruise speed. Had I maintained the steep climb our aircraft would have had a horizontal separation of roughly 500 ft at a common altitude. Other contributing factors for the greater separation was the slow speed of small aircraft Y, the small aircraft's landing light which made it easier to spot and the alertness of the first officer. The tower did not advise us in the takeoff clearance or at any other time of this traffic. Supplemental information from acn 197963. After takeoff in our climb from seatt;east runway 16L, we saw small aircraft Y at 10 O'clock and approximately 1000 ft away. We were ready to take evasive action, but small aircraft Y's speed was slow enough that we didn't need to. We first saw traffic when we were approximately 800 ft AGL and he looked to be 900-1000 ft AGL. We notified tower after conflict resolution that we had small aircraft Y traffic in sight at 10 O'clock. Tower said that they thought they had told us about the small aircraft Y traffic, which they had not. The tower apologized. The problem with this oversight, is that had the traffic been faster, a possible midair could have occurred.

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Original NASA ASRS Text

Title: SMA Y HAD LTSS FROM ACR X IN TCA ATA. SYS ERROR.

Narrative: ACR X CLRED FOR TKOF BEHIND A LIGHT JET TRANSPORT. TO BE EXTRA SAFE AND CONTRIBUTE TO PAX COMFORT I CLBED THE ACFT STEEPLY TO AVOID ANY POSSIBLE WAKE TURB. WE CLBED ABOVE THE JET'S DEP PATH. AT 800 FT THE FO SAW SMA Y, A SINGLE ENG ACFT, AT OUR 10 O'CLOCK AT APPROX 1000 FT MSL AND APPROX 2000 FT HORIZ. I SAW IT THEN FOR THE FIRST TIME BUT DETERMINED THAT THERE WAS NO CONFLICT BTWN OUR 2 ACFT AND CONTINUED THE CLB. THE REASON WHY THERE WAS NO CONFLICT WAS BECAUSE JUST PRIOR TO THE FO POINTING OUT THE TFC I HAD BEGUN REDUCING OUR CLB ANGLE IN ORDER TO ACCELERATE TO CRUISE SPD. HAD I MAINTAINED THE STEEP CLB OUR ACFT WOULD HAVE HAD A HORIZ SEPARATION OF ROUGHLY 500 FT AT A COMMON ALT. OTHER CONTRIBUTING FACTORS FOR THE GREATER SEPARATION WAS THE SLOW SPD OF SMA Y, THE SMA'S LNDG LIGHT WHICH MADE IT EASIER TO SPOT AND THE ALERTNESS OF THE FO. THE TWR DID NOT ADVISE US IN THE TKOF CLRNC OR AT ANY OTHER TIME OF THIS TFC. SUPPLEMENTAL INFO FROM ACN 197963. AFTER TKOF IN OUR CLB FROM SEATT;E RWY 16L, WE SAW SMA Y AT 10 O'CLOCK AND APPROX 1000 FT AWAY. WE WERE READY TO TAKE EVASIVE ACTION, BUT SMA Y'S SPD WAS SLOW ENOUGH THAT WE DIDN'T NEED TO. WE FIRST SAW TFC WHEN WE WERE APPROX 800 FT AGL AND HE LOOKED TO BE 900-1000 FT AGL. WE NOTIFIED TWR AFTER CONFLICT RESOLUTION THAT WE HAD SMA Y TFC IN SIGHT AT 10 O'CLOCK. TWR SAID THAT THEY THOUGHT THEY HAD TOLD US ABOUT THE SMA Y TFC, WHICH THEY HAD NOT. THE TWR APOLOGIZED. THE PROBLEM WITH THIS OVERSIGHT, IS THAT HAD THE TFC BEEN FASTER, A POSSIBLE MIDAIR COULD HAVE OCCURRED.

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.