Narrative:

I was climbing wbound out of 13000 ft MSL for 14000 ft MSL in order to intercept the 360 degree bearing to the drop zone (GPS). I was informed of traffic at my 10-11 O'clock position by pdx approach. The traffic was flying the moxee 3 arrival into pdx. The moxee directly overlies the drop zone. I reported the aircraft in sight and was advised of a horizon F28 in trail of the last traffic by 6 mi. I did not have the F28 in sight and advised pdx I was 2 mins to drop. Pdx stated that the F28 probably would not be a factor. Without the jet in sight I got established on jump run and let the jumpers out at the appropriate spot. I incorrectly assumed the F28 was past me to the north. While descending, I saw the shadow of the F28 pass under me and to my west, then heard pdx approach tell the F28 crew that I was holding my jumpers, but my jumpers were gone and I informed pdx so. The F28 crew reported seeing jumpers pass 1/2 mi off one side of their aircraft. Upon my own questioning of the jumpers involved, I concluded they were closer than 1/2 mi. 1 jumper reported being about 2000-3000 ft above the F28 while in freefall. I believe the event occurred due to a lack of situational awareness on mine and pdx controller's part. Also contributing was a lack of communication (pdx was swamped), and my radio was occasionally scratchy. In the future, if any doubt exists as to an aircraft's position, I will acquire it visually or not drop the jumpers.

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Original NASA ASRS Text

Title: SMT ACFT WITH JUMPERS ON BOARD ARE RELEASED OVER JUMP ZONE, BUT IMPROPER COORD WITH ATC RESULTS IN CLOSE PROX OF ARRIVING ACFT TO JUMPERS.

Narrative: I WAS CLBING WBOUND OUT OF 13000 FT MSL FOR 14000 FT MSL IN ORDER TO INTERCEPT THE 360 DEG BEARING TO THE DROP ZONE (GPS). I WAS INFORMED OF TFC AT MY 10-11 O'CLOCK POS BY PDX APCH. THE TFC WAS FLYING THE MOXEE 3 ARR INTO PDX. THE MOXEE DIRECTLY OVERLIES THE DROP ZONE. I RPTED THE ACFT IN SIGHT AND WAS ADVISED OF A HORIZON F28 IN TRAIL OF THE LAST TFC BY 6 MI. I DID NOT HAVE THE F28 IN SIGHT AND ADVISED PDX I WAS 2 MINS TO DROP. PDX STATED THAT THE F28 PROBABLY WOULD NOT BE A FACTOR. WITHOUT THE JET IN SIGHT I GOT ESTABLISHED ON JUMP RUN AND LET THE JUMPERS OUT AT THE APPROPRIATE SPOT. I INCORRECTLY ASSUMED THE F28 WAS PAST ME TO THE N. WHILE DSNDING, I SAW THE SHADOW OF THE F28 PASS UNDER ME AND TO MY W, THEN HEARD PDX APCH TELL THE F28 CREW THAT I WAS HOLDING MY JUMPERS, BUT MY JUMPERS WERE GONE AND I INFORMED PDX SO. THE F28 CREW RPTED SEEING JUMPERS PASS 1/2 MI OFF ONE SIDE OF THEIR ACFT. UPON MY OWN QUESTIONING OF THE JUMPERS INVOLVED, I CONCLUDED THEY WERE CLOSER THAN 1/2 MI. 1 JUMPER RPTED BEING ABOUT 2000-3000 FT ABOVE THE F28 WHILE IN FREEFALL. I BELIEVE THE EVENT OCCURRED DUE TO A LACK OF SITUATIONAL AWARENESS ON MINE AND PDX CTLR'S PART. ALSO CONTRIBUTING WAS A LACK OF COM (PDX WAS SWAMPED), AND MY RADIO WAS OCCASIONALLY SCRATCHY. IN THE FUTURE, IF ANY DOUBT EXISTS AS TO AN ACFT'S POS, I WILL ACQUIRE IT VISUALLY OR NOT DROP THE JUMPERS.

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.