Narrative:

Departed seatac runway 34L summa 5 departure with basically a right downwind flight path. Cleared to 9000 ft then 15000 ft. I leveled at 15000 ft and shortly we received a TCASII descend aural instruction. At the same time ZSE controller gave us clearance to a higher altitude (FL330). We told the controller we were in descent because of a TCASII RA. We reached 14500 ft when we received a 'clear of conflict' from our TCASII. I believe there was a problem with the communication between departure control and ZSE. Both aircraft were at 15000 ft level and on 2 different frequencys. Both aircraft were on IFR flight plans. I feel this is a very dangerous situation that has to be looked into. Had the situation been a little different there might have been a mid- air collision. TCASII helped save the day. At no time did the controller ever point out the small jet to us. I also think the controller was unable to clear us to a higher altitude (above 15000 ft) earlier because of another aircraft above us at 16000 ft. This is the first time my TCASII sounded between 2 IFR jet aircraft. Thanks for your time.

Google
 

Original NASA ASRS Text

Title: A DEPARTING ACR MAINTAINING 15000 FT RECEIVES A TCASII RA AND DSNDS TO 14500 FT. TFC WAS A BUSINESS JET ALSO AT 15000 FT THAT PASSED WITHIN 1 MI AND 500 FT. RPTR BELIEVES THAT AN INTERFAC COORD PROB EXISTED BTWN THE CTR AND DEP CTL.

Narrative: DEPARTED SEATAC RWY 34L SUMMA 5 DEP WITH BASICALLY A R DOWNWIND FLT PATH. CLRED TO 9000 FT THEN 15000 FT. I LEVELED AT 15000 FT AND SHORTLY WE RECEIVED A TCASII DSND AURAL INSTRUCTION. AT THE SAME TIME ZSE CTLR GAVE US CLRNC TO A HIGHER ALT (FL330). WE TOLD THE CTLR WE WERE IN DSCNT BECAUSE OF A TCASII RA. WE REACHED 14500 FT WHEN WE RECEIVED A 'CLR OF CONFLICT' FROM OUR TCASII. I BELIEVE THERE WAS A PROB WITH THE COM BTWN DEP CTL AND ZSE. BOTH ACFT WERE AT 15000 FT LEVEL AND ON 2 DIFFERENT FREQS. BOTH ACFT WERE ON IFR FLT PLANS. I FEEL THIS IS A VERY DANGEROUS SIT THAT HAS TO BE LOOKED INTO. HAD THE SIT BEEN A LITTLE DIFFERENT THERE MIGHT HAVE BEEN A MID- AIR COLLISION. TCASII HELPED SAVE THE DAY. AT NO TIME DID THE CTLR EVER POINT OUT THE SMALL JET TO US. I ALSO THINK THE CTLR WAS UNABLE TO CLR US TO A HIGHER ALT (ABOVE 15000 FT) EARLIER BECAUSE OF ANOTHER ACFT ABOVE US AT 16000 FT. THIS IS THE FIRST TIME MY TCASII SOUNDED BTWN 2 IFR JET ACFT. THANKS FOR YOUR TIME.

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.