Corp light transport descends below assigned altitude and misses crossing restr.

Attributes
ACN	296121
Time
Date	199502
Day	Fri
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : pie
State Reference	FL
Altitude	msl bound lower : 25000 msl bound upper : 27000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zjx
Operator	general aviation : corporate
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 91
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	Other
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 70 flight time total : 14000 flight time type : 20
ASRS Report	296121
Person 2
Affiliation	Other
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : overshoot non adherence : clearance
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared to descend and cross pie at FL270. My captain understood we were cleared to cross srq at FL270. When I questioned our rate of descent, we discussed the crossing restr, and he called jacksonville center for clarification. The reply to his question, 'were we cleared to cross srq or pie at FL270?' was 'cross pie at FL270, descend and maintenance FL240.''contact ZMA.' we both took the FL240 to be a new clearance, nullifying the FL270 at pie. We were passing FL250 when we crossed pie when miami asked us our altitude which we reported as out of 25500 ft for FL240. They said we were to main FL270 till crossing pie. We asked 'what should we do?' controller said 'no problem, main FL240.' in my estimation, and after reviewing the situation with my captain, I think the wording of the clearance to FL240 was confusing and easily misunderstood. If it had said 'cross pie at FL270, then descend and maintain' or 'cross pie at FL270. After crossing pie, descend and maintain' it would have been clear and understood.

Original NASA ASRS Text

Title: CORP LTT DSNDS BELOW ASSIGNED ALT AND MISSES XING RESTR.

Narrative: WE WERE CLRED TO DSND AND CROSS PIE AT FL270. MY CAPT UNDERSTOOD WE WERE CLRED TO CROSS SRQ AT FL270. WHEN I QUESTIONED OUR RATE OF DSCNT, WE DISCUSSED THE XING RESTR, AND HE CALLED JACKSONVILLE CTR FOR CLARIFICATION. THE REPLY TO HIS QUESTION, 'WERE WE CLRED TO CROSS SRQ OR PIE AT FL270?' WAS 'CROSS PIE AT FL270, DSND AND MAINT FL240.''CONTACT ZMA.' WE BOTH TOOK THE FL240 TO BE A NEW CLRNC, NULLIFYING THE FL270 AT PIE. WE WERE PASSING FL250 WHEN WE CROSSED PIE WHEN MIAMI ASKED US OUR ALT WHICH WE RPTED AS OUT OF 25500 FT FOR FL240. THEY SAID WE WERE TO MAIN FL270 TILL XING PIE. WE ASKED 'WHAT SHOULD WE DO?' CTLR SAID 'NO PROB, MAIN FL240.' IN MY ESTIMATION, AND AFTER REVIEWING THE SIT WITH MY CAPT, I THINK THE WORDING OF THE CLRNC TO FL240 WAS CONFUSING AND EASILY MISUNDERSTOOD. IF IT HAD SAID 'CROSS PIE AT FL270, THEN DSND AND MAINTAIN' OR 'CROSS PIE AT FL270. AFTER XING PIE, DSND AND MAINTAIN' IT WOULD HAVE BEEN CLR AND UNDERSTOOD.

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.