Narrative:

Sfo-ont copilot flying medium large transport. On cajon fix arrival, we were over pmd approximately FL230 with clearance to FL210. Next clearance was to descend to 14,000, which we expected for the majek restriction. Shortly thereafter center cleared us to 'descend to 13,000 at majek (pause) 250 KTS at 14,000.' what I had expected was majek at 14,000 and 250. Something didn't sound right so my response on readback was 'I understand, flight cleared to descend to 13,000, slow to 250 KTS upon reaching 14,000.' center response 'roger'. Airspeed in descent at that time was approximately 300 KTS. At 14,000 the copilot raised the nose to slow, and reduced rate of descent to approximately 500 FPM. About that same time an aircraft behind us was cleared 'cross majek at 14,000, 250 KTS, then descend to 13,000.' we were at approximately 13,700', 250 KTS when the copilot and I both decided that what center wanted was us at 14,000 until majek. He added power and pulled nose up, within seconds we were over majek and legal to go to 13,000. I read your NASA reports all the time and I feel this is a classic case of 'punctuation and hearback'. Upon the original clearance to 13,000, if the pause had come after 'descend to 13,000, pause, at majek, 250 KTS and 14,000', that would have helped solve the problem. A normal sequence of 'majek, 14,000 and 250 KTS' would have helped, or listening to the readback might have helped. The controller was busy, several aircraft on frequency but talking faster doesn't solve the problems. We could have had a serious incident or worse. And I'm sure if the aircraft behind us hadn't been cleared over majek, we would have crossed at 13,000.

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Original NASA ASRS Text

Title: ALT DEVIATION ON STAR. CROSSING RESTRICTION NEARLY VOIDED. CLRNC MISINTERPRETED.

Narrative: SFO-ONT COPLT FLYING MLG. ON CAJON FIX ARRIVAL, WE WERE OVER PMD APPROX FL230 WITH CLRNC TO FL210. NEXT CLRNC WAS TO DSND TO 14,000, WHICH WE EXPECTED FOR THE MAJEK RESTRICTION. SHORTLY THEREAFTER CENTER CLRED US TO 'DSND TO 13,000 AT MAJEK (PAUSE) 250 KTS AT 14,000.' WHAT I HAD EXPECTED WAS MAJEK AT 14,000 AND 250. SOMETHING DIDN'T SOUND RIGHT SO MY RESPONSE ON READBACK WAS 'I UNDERSTAND, FLT CLRED TO DSND TO 13,000, SLOW TO 250 KTS UPON REACHING 14,000.' CENTER RESPONSE 'ROGER'. AIRSPEED IN DSCNT AT THAT TIME WAS APPROX 300 KTS. AT 14,000 THE COPLT RAISED THE NOSE TO SLOW, AND REDUCED RATE OF DSCNT TO APPROX 500 FPM. ABOUT THAT SAME TIME AN ACFT BEHIND US WAS CLRED 'CROSS MAJEK AT 14,000, 250 KTS, THEN DSND TO 13,000.' WE WERE AT APPROX 13,700', 250 KTS WHEN THE COPLT AND I BOTH DECIDED THAT WHAT CENTER WANTED WAS US AT 14,000 UNTIL MAJEK. HE ADDED POWER AND PULLED NOSE UP, WITHIN SECONDS WE WERE OVER MAJEK AND LEGAL TO GO TO 13,000. I READ YOUR NASA REPORTS ALL THE TIME AND I FEEL THIS IS A CLASSIC CASE OF 'PUNCTUATION AND HEARBACK'. UPON THE ORIGINAL CLRNC TO 13,000, IF THE PAUSE HAD COME AFTER 'DSND TO 13,000, PAUSE, AT MAJEK, 250 KTS AND 14,000', THAT WOULD HAVE HELPED SOLVE THE PROBLEM. A NORMAL SEQUENCE OF 'MAJEK, 14,000 AND 250 KTS' WOULD HAVE HELPED, OR LISTENING TO THE READBACK MIGHT HAVE HELPED. THE CTLR WAS BUSY, SEVERAL ACFT ON FREQ BUT TALKING FASTER DOESN'T SOLVE THE PROBLEMS. WE COULD HAVE HAD A SERIOUS INCIDENT OR WORSE. AND I'M SURE IF THE ACFT BEHIND US HADN'T BEEN CLRED OVER MAJEK, WE WOULD HAVE CROSSED AT 13,000.

Data retrieved from NASA's ASRS site as of August 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.