Air carrier X altitude deviation, unauthorized descent from assigned altitude.

Attributes
ACN	302912
Time
Date	199504
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : hpn
State Reference	NY
Altitude	msl bound lower : 2400 msl bound upper : 3000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	tracon : n90
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 6100 flight time type : 1100
ASRS Report	302912
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp pilot : commercial pilot : instrument
Experience	flight time last 90 days : 280 flight time total : 10000 flight time type : 3000
ASRS Report	302620
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Consequence	faa : reviewed incident with flight crew
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier X, pit-hpn. Holding at 3000 ft over hester OM (ILS runway 16). On outbound leg, given RVR 2400 ft by approach, and cleared to intercept localizer 16. We were expecting a lower altitude, and mistook 'RVR 2400' for 'descend to 2400.' some discussion in cockpit, and inbound OM localizer queried ATC. He said he had meant for us to maintain 3000 ft, and that he had said the RVR was 2400 ft. Subsequently, cleared us for the approach, nothing further said. Broke out at minimums and landed.

Original NASA ASRS Text

Title: ACR X ALTDEV, UNAUTH DSCNT FROM ASSIGNED ALT.

Narrative: ACR X, PIT-HPN. HOLDING AT 3000 FT OVER HESTER OM (ILS RWY 16). ON OUTBOUND LEG, GIVEN RVR 2400 FT BY APCH, AND CLRED TO INTERCEPT LOC 16. WE WERE EXPECTING A LOWER ALT, AND MISTOOK 'RVR 2400' FOR 'DSND TO 2400.' SOME DISCUSSION IN COCKPIT, AND INBOUND OM LOC QUERIED ATC. HE SAID HE HAD MEANT FOR US TO MAINTAIN 3000 FT, AND THAT HE HAD SAID THE RVR WAS 2400 FT. SUBSEQUENTLY, CLRED US FOR THE APCH, NOTHING FURTHER SAID. BROKE OUT AT MINIMUMS AND LANDED.

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.