Narrative:

Flight sjc-rno performing SID from sjc with sac transition. Departure handed us off to ZOA and we were given normal speed and a climb to FL210, then reclred to FL250. The aircraft was very light, and climbing 3500 FPM or better, approximately 320 KTS. At about FL209 we encountered a wingtip vortice and rolled about 20 degree right bank. Judging from the roll we were in trail of another aircraft. Skies were clear, dark and starry, and we were both scanning for traffic and saw none. At about FL214 center advised us to level at FL210. Even with a rapid push over and power reduction we went through FL261 prior to stopping climb and returning to FL210 prior to stopping climb and returning to FL210. About 1 min later I saw us pass directly beneath a slower moving, large aircraft. At the time of the level off center kept asking, 'you are at FL210?' first officer told him we were through FL210 before the call to level was received, and we were descending. Center replied, 'you're at FL210, right?' by that time we were level. No other mention was made. Possibly our climb rate was behind the ARTS tracking capability and the controller assumed we could stop at FL210. I don't know. It was an extremely night and the aircraft in question blended perfectly with the stars and was in fact indistinguishable until immediately above us. Perhaps he was climbing more slowly? I'm positive of clearance to FL250, I think.

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Original NASA ASRS Text

Title: MLG HAS AN APPARENT LESS THAN STANDARD SEPARATION WITH ANOTHER ACFT AFTER BEING GIVEN CLRNC TO STOP CLIMB.

Narrative: FLT SJC-RNO PERFORMING SID FROM SJC WITH SAC TRANSITION. DEP HANDED US OFF TO ZOA AND WE WERE GIVEN NORMAL SPD AND A CLB TO FL210, THEN RECLRED TO FL250. THE ACFT WAS VERY LIGHT, AND CLBING 3500 FPM OR BETTER, APPROX 320 KTS. AT ABOUT FL209 WE ENCOUNTERED A WINGTIP VORTICE AND ROLLED ABOUT 20 DEG RIGHT BANK. JUDGING FROM THE ROLL WE WERE IN TRAIL OF ANOTHER ACFT. SKIES WERE CLR, DARK AND STARRY, AND WE WERE BOTH SCANNING FOR TFC AND SAW NONE. AT ABOUT FL214 CENTER ADVISED US TO LEVEL AT FL210. EVEN WITH A RAPID PUSH OVER AND PWR REDUCTION WE WENT THROUGH FL261 PRIOR TO STOPPING CLB AND RETURNING TO FL210 PRIOR TO STOPPING CLB AND RETURNING TO FL210. ABOUT 1 MIN LATER I SAW US PASS DIRECTLY BENEATH A SLOWER MOVING, LARGE ACFT. AT THE TIME OF THE LEVEL OFF CENTER KEPT ASKING, 'YOU ARE AT FL210?' F/O TOLD HIM WE WERE THROUGH FL210 BEFORE THE CALL TO LEVEL WAS RECEIVED, AND WE WERE DSNDING. CENTER REPLIED, 'YOU'RE AT FL210, RIGHT?' BY THAT TIME WE WERE LEVEL. NO OTHER MENTION WAS MADE. POSSIBLY OUR CLB RATE WAS BEHIND THE ARTS TRACKING CAPABILITY AND THE CTLR ASSUMED WE COULD STOP AT FL210. I DON'T KNOW. IT WAS AN EXTREMELY NIGHT AND THE ACFT IN QUESTION BLENDED PERFECTLY WITH THE STARS AND WAS IN FACT INDISTINGUISHABLE UNTIL IMMEDIATELY ABOVE US. PERHAPS HE WAS CLBING MORE SLOWLY? I'M POSITIVE OF CLRNC TO FL250, I THINK.

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.