Narrative:

During a scheduled flight from acy to phl, I obtained the IFR clearance for our flight which read 'clear to phl via ACY1, as filed, climb, maintain 4000 ft, departure frequency 134.25 and squawk XXXX.' I have only received the ACY1 departure about 4 or maybe 5 times during the last 4 months. Normally the clearance will say: clear to phl, after departure maintain runway heading, radar vectors to victor 184, cedar lakes or woodstown then as filed, climb to 2000 ft, expect 4000 ft in 5 mins, departure frequency 134.25 and squawk YYYY. (Some small variations are normal for the route portion.) on this day, I took off and climbed through 2000 ft and contacted departure control sometime between 2000- 3000 ft. When the controller answered the radio call he questioned our altitude (passing 3300 ft and climbing). We answered him and we were instructed to descend and maintain 3000 ft. The controller asked who cleared us to 4000 ft. I said it was given to us by clearance delivery, as stated earlier. However, I now know and also knew then, that the ACY1 departure requires a climb to 2000 ft and expect filed altitude 10 mins after departure, but somehow, in my mind, we were cleared to 4000 ft unrestr. There was no other conflict, that I know about, or any other deviations at the time, which compromised the safety of this flight. I believed that routine clrncs, in contrast with non-routine, could be somewhat detrimental and could be inadvertently misfollowed. Now, as a direct result of this situation, I fully explain or brief 'all' clrncs to my crew members and query the controller when in doubt.

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Original NASA ASRS Text

Title: ALTDEV ALT OVERSHOT. FLC MISINTERPRETS THE DEP CLRNC AND CLBS BEYOND ITS LEVELOFF ALT.

Narrative: DURING A SCHEDULED FLT FROM ACY TO PHL, I OBTAINED THE IFR CLRNC FOR OUR FLT WHICH READ 'CLR TO PHL VIA ACY1, AS FILED, CLB, MAINTAIN 4000 FT, DEP FREQ 134.25 AND SQUAWK XXXX.' I HAVE ONLY RECEIVED THE ACY1 DEP ABOUT 4 OR MAYBE 5 TIMES DURING THE LAST 4 MONTHS. NORMALLY THE CLRNC WILL SAY: CLR TO PHL, AFTER DEP MAINTAIN RWY HDG, RADAR VECTORS TO VICTOR 184, CEDAR LAKES OR WOODSTOWN THEN AS FILED, CLB TO 2000 FT, EXPECT 4000 FT IN 5 MINS, DEP FREQ 134.25 AND SQUAWK YYYY. (SOME SMALL VARIATIONS ARE NORMAL FOR THE RTE PORTION.) ON THIS DAY, I TOOK OFF AND CLBED THROUGH 2000 FT AND CONTACTED DEP CTL SOMETIME BTWN 2000- 3000 FT. WHEN THE CTLR ANSWERED THE RADIO CALL HE QUESTIONED OUR ALT (PASSING 3300 FT AND CLBING). WE ANSWERED HIM AND WE WERE INSTRUCTED TO DSND AND MAINTAIN 3000 FT. THE CTLR ASKED WHO CLRED US TO 4000 FT. I SAID IT WAS GIVEN TO US BY CLRNC DELIVERY, AS STATED EARLIER. HOWEVER, I NOW KNOW AND ALSO KNEW THEN, THAT THE ACY1 DEP REQUIRES A CLB TO 2000 FT AND EXPECT FILED ALT 10 MINS AFTER DEP, BUT SOMEHOW, IN MY MIND, WE WERE CLRED TO 4000 FT UNRESTR. THERE WAS NO OTHER CONFLICT, THAT I KNOW ABOUT, OR ANY OTHER DEVS AT THE TIME, WHICH COMPROMISED THE SAFETY OF THIS FLT. I BELIEVED THAT ROUTINE CLRNCS, IN CONTRAST WITH NON-ROUTINE, COULD BE SOMEWHAT DETRIMENTAL AND COULD BE INADVERTENTLY MISFOLLOWED. NOW, AS A DIRECT RESULT OF THIS SIT, I FULLY EXPLAIN OR BRIEF 'ALL' CLRNCS TO MY CREW MEMBERS AND QUERY THE CTLR WHEN IN DOUBT.

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.