Narrative:

Part 121 scheduled operations B737-300. 320 KIAS descent on ziggy arrival, which is a bit of a slam dunk. Captain flying while I was 'heads down' performing cockpit tasks. As we were approaching dawna intersection, descending through approximately 12600 ft MSL, I spotted something in my peripheral field of vision. I looked up and spotted a high performance sailplane ridge soaring along the northern edge of the san bernardino mountain range. The traffic was on a perpendicular course, right to left, at approximately 12 O'clock position and 1/2 mi. There was slight relative motion which led me to believe that we would pass slightly below and behind the glider. I immediately called out the traffic to the captain who, after 1-2 seconds of evaluation, initiated a hard right, downward bank. His maneuver increased separation to the extent that we passed 400-600 ft below and behind the glider. The maneuver was aggressive enough that 2 flight attendants fell to the galley floor, but did not sustain any injuries. Had we not taken evasive action, the aircraft would probably have passed within 100-200 ft of one another. We reported the incident to ZLA and socal approach, but they could not detect the aircraft on radar. Critique: the incident is one of those 'see and avoid' scenarios where neither party was operating improperly. We had all aircraft lights on and should have been highly visible from a distance of 20+ mi. We could have completed all approach functions earlier as to allow all attention outside below FL180. Finally, the sailplane pilot/club/operators should be aware of the altitude and location of major approach corridors and they should avoid them.

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Original NASA ASRS Text

Title: B737-300 CREW HAD NMAC WITH A SAILPLANE ON THE ZIGGY STAR INTO ONT IN ZLA CLASS E.

Narrative: PART 121 SCHEDULED OPS B737-300. 320 KIAS DSCNT ON ZIGGY ARR, WHICH IS A BIT OF A SLAM DUNK. CAPT FLYING WHILE I WAS 'HEADS DOWN' PERFORMING COCKPIT TASKS. AS WE WERE APCHING DAWNA INTXN, DSNDING THROUGH APPROX 12600 FT MSL, I SPOTTED SOMETHING IN MY PERIPHERAL FIELD OF VISION. I LOOKED UP AND SPOTTED A HIGH PERFORMANCE SAILPLANE RIDGE SOARING ALONG THE NORTHERN EDGE OF THE SAN BERNARDINO MOUNTAIN RANGE. THE TFC WAS ON A PERPENDICULAR COURSE, R TO L, AT APPROX 12 O'CLOCK POS AND 1/2 MI. THERE WAS SLIGHT RELATIVE MOTION WHICH LED ME TO BELIEVE THAT WE WOULD PASS SLIGHTLY BELOW AND BEHIND THE GLIDER. I IMMEDIATELY CALLED OUT THE TFC TO THE CAPT WHO, AFTER 1-2 SECONDS OF EVALUATION, INITIATED A HARD R, DOWNWARD BANK. HIS MANEUVER INCREASED SEPARATION TO THE EXTENT THAT WE PASSED 400-600 FT BELOW AND BEHIND THE GLIDER. THE MANEUVER WAS AGGRESSIVE ENOUGH THAT 2 FLT ATTENDANTS FELL TO THE GALLEY FLOOR, BUT DID NOT SUSTAIN ANY INJURIES. HAD WE NOT TAKEN EVASIVE ACTION, THE ACFT WOULD PROBABLY HAVE PASSED WITHIN 100-200 FT OF ONE ANOTHER. WE RPTED THE INCIDENT TO ZLA AND SOCAL APCH, BUT THEY COULD NOT DETECT THE ACFT ON RADAR. CRITIQUE: THE INCIDENT IS ONE OF THOSE 'SEE AND AVOID' SCENARIOS WHERE NEITHER PARTY WAS OPERATING IMPROPERLY. WE HAD ALL ACFT LIGHTS ON AND SHOULD HAVE BEEN HIGHLY VISIBLE FROM A DISTANCE OF 20+ MI. WE COULD HAVE COMPLETED ALL APCH FUNCTIONS EARLIER AS TO ALLOW ALL ATTN OUTSIDE BELOW FL180. FINALLY, THE SAILPLANE PLT/CLUB/OPERATORS SHOULD BE AWARE OF THE ALT AND LOCATION OF MAJOR APCH CORRIDORS AND THEY SHOULD AVOID THEM.

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.