BA31 crew descended below the crossing restr.

Attributes
ACN	442910
Time
Date	199907
Day	Wed
Local Time Of Day	1801 To 2400
Place
Locale Reference	intersection : hyper
State Reference	MD
Altitude	msl bound lower : 8000 msl bound upper : 9000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny.artcc
Operator	common carrier : air carrier
Make Model Name	Jetstream 31
Operating Under FAR Part	Part 135
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : instrument pilot : atp pilot : cfi
Experience	flight time last 90 days : 50 flight time total : 3900 flight time type : 50
ASRS Report	442910
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : multi engine pilot : commercial
Events
Anomaly	non adherence : clearance
Independent Detector	other controllera
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Flight Crew Human Performance FAA ATC Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were at 12000 ft. ZNY gave us a descent clearance to descend and cross hyper intersection at 9000 ft and then robrt at 8000 ft. We proceeded to descend to 8000 ft prior to reaching hyper intersection which is before robrt. The controller then asked a company airplane who was in front of us what altitude he was at (he had received the same clearance). They told him 8000 ft. He then told them that they needed to be at 9000 ft until hyper and then 8000 ft by robrt. He then asked us what altitude we were at. We told him 8000 ft. He then said the same thing to us. I have flown that same route many, many times and have been issued that same clearance many times. Each time we have done the same thing, with no prior problems. I believe it was a misunderstanding between the controller and our flight as well as the other company aircraft ahead of us. Usually when they want you at 9000 ft, they say descend and cross hyper at 9000 ft, expect robrt at 8000 ft. That was never the case here. There were no incidents on this occurrence.

Original NASA ASRS Text

Title: BA31 CREW DSNDED BELOW THE XING RESTR.

Narrative: WE WERE AT 12000 FT. ZNY GAVE US A DSCNT CLRNC TO DSND AND CROSS HYPER INTXN AT 9000 FT AND THEN ROBRT AT 8000 FT. WE PROCEEDED TO DSND TO 8000 FT PRIOR TO REACHING HYPER INTXN WHICH IS BEFORE ROBRT. THE CTLR THEN ASKED A COMPANY AIRPLANE WHO WAS IN FRONT OF US WHAT ALT HE WAS AT (HE HAD RECEIVED THE SAME CLRNC). THEY TOLD HIM 8000 FT. HE THEN TOLD THEM THAT THEY NEEDED TO BE AT 9000 FT UNTIL HYPER AND THEN 8000 FT BY ROBRT. HE THEN ASKED US WHAT ALT WE WERE AT. WE TOLD HIM 8000 FT. HE THEN SAID THE SAME THING TO US. I HAVE FLOWN THAT SAME RTE MANY, MANY TIMES AND HAVE BEEN ISSUED THAT SAME CLRNC MANY TIMES. EACH TIME WE HAVE DONE THE SAME THING, WITH NO PRIOR PROBS. I BELIEVE IT WAS A MISUNDERSTANDING BTWN THE CTLR AND OUR FLT AS WELL AS THE OTHER COMPANY ACFT AHEAD OF US. USUALLY WHEN THEY WANT YOU AT 9000 FT, THEY SAY DSND AND CROSS HYPER AT 9000 FT, EXPECT ROBRT AT 8000 FT. THAT WAS NEVER THE CASE HERE. THERE WERE NO INCIDENTS ON THIS OCCURRENCE.

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.