Narrative:

During the departure/climb out, we were following another MD88 4-5 mi in trail. We were level at 12000 ft, heading approximately 110 degrees. The lead aircraft was climbing above us on a 130-140 degree heading, drifting to the south of our course. The departure controller was very busy when he issued the lead aircraft a turn to the northeast that they missed and continued on their 130-140 degree heading. Moments later, they received and acknowledged another clearance to turn to the northeast. Because of their new heading and earlier missed call, lateral separation began to narrow between the 2 aircraft (vertical separation ok but I don't know by how much). We were then issued a turn and climb but the call sign was partially blocked and I read back 'call sign blocked, understand cleared heading XXX degrees and 14000 ft.' the controller answered affirmative. The captain said he understood 13000 ft and leveled at 13000 ft. I thought he might just be right since now we were pretty close to the lead M88. I could not clarify this with departure because of frequency congestion. We were then given a frequency change to ZTL. I did not clear up the confused altitude then because the departure controller was very busy, there did not appear to be an immediate threat to our aircraft and I thought ZTL could clear us to 14000 ft and above if in fact the captain was right. The center controller wanted to know, upon check-in, if we had been cleared to 14000 ft. Since we were unsure he had to call on the land line to get us to 14000 ft. We droned on for at least a min in this very uncomfortable confused state. The next time I will clear this up with the controller who issued the clearance, rather than relying on the next guy/gal to fix something they may not have the information or latitude to act on.

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Original NASA ASRS Text

Title: CAPT OF AN MD88 UNDERSHOT ASSIGNED ALT DURING DEP DUE TO A MISUNDERSTANDING OF THE ALT AND SUBSEQUENT ATTEMPTS TO CLARIFY THE CORRECT ALT WITH ATC DUE TO FREQ CONGESTION.

Narrative: DURING THE DEP/CLBOUT, WE WERE FOLLOWING ANOTHER MD88 4-5 MI IN TRAIL. WE WERE LEVEL AT 12000 FT, HDG APPROX 110 DEGS. THE LEAD ACFT WAS CLBING ABOVE US ON A 130-140 DEG HDG, DRIFTING TO THE S OF OUR COURSE. THE DEP CTLR WAS VERY BUSY WHEN HE ISSUED THE LEAD ACFT A TURN TO THE NE THAT THEY MISSED AND CONTINUED ON THEIR 130-140 DEG HDG. MOMENTS LATER, THEY RECEIVED AND ACKNOWLEDGED ANOTHER CLRNC TO TURN TO THE NE. BECAUSE OF THEIR NEW HDG AND EARLIER MISSED CALL, LATERAL SEPARATION BEGAN TO NARROW BTWN THE 2 ACFT (VERT SEPARATION OK BUT I DON'T KNOW BY HOW MUCH). WE WERE THEN ISSUED A TURN AND CLB BUT THE CALL SIGN WAS PARTIALLY BLOCKED AND I READ BACK 'CALL SIGN BLOCKED, UNDERSTAND CLRED HDG XXX DEGS AND 14000 FT.' THE CTLR ANSWERED AFFIRMATIVE. THE CAPT SAID HE UNDERSTOOD 13000 FT AND LEVELED AT 13000 FT. I THOUGHT HE MIGHT JUST BE RIGHT SINCE NOW WE WERE PRETTY CLOSE TO THE LEAD M88. I COULD NOT CLARIFY THIS WITH DEP BECAUSE OF FREQ CONGESTION. WE WERE THEN GIVEN A FREQ CHANGE TO ZTL. I DID NOT CLR UP THE CONFUSED ALT THEN BECAUSE THE DEP CTLR WAS VERY BUSY, THERE DID NOT APPEAR TO BE AN IMMEDIATE THREAT TO OUR ACFT AND I THOUGHT ZTL COULD CLR US TO 14000 FT AND ABOVE IF IN FACT THE CAPT WAS RIGHT. THE CTR CTLR WANTED TO KNOW, UPON CHK-IN, IF WE HAD BEEN CLRED TO 14000 FT. SINCE WE WERE UNSURE HE HAD TO CALL ON THE LAND LINE TO GET US TO 14000 FT. WE DRONED ON FOR AT LEAST A MIN IN THIS VERY UNCOMFORTABLE CONFUSED STATE. THE NEXT TIME I WILL CLR THIS UP WITH THE CTLR WHO ISSUED THE CLRNC, RATHER THAN RELYING ON THE NEXT GUY/GAL TO FIX SOMETHING THEY MAY NOT HAVE THE INFO OR LATITUDE TO ACT ON.

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.