Commuter flight crew descends 1000' low for altitude crossing restriction.

Attributes
ACN	154642
Time
Date	199008
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : orl airport : mco
State Reference	FL
Altitude	msl bound lower : 4000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Small Transport, Low Wing, 2 Turboprop Eng
Flight Phase	descent other
Route In Use	enroute airway : v531
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 250 flight time total : 3900 flight time type : 1400
ASRS Report	154642
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

En route mia to mco nwbnd along V531, given pilot's discretion descent clearance from 9000 to 5000' to cross barin at 5000'. Inadvertently descended to 4000', trying to 'make our crossing altitude.' 15 seconds after level off at 4000' we realized we were low and at the same time we received a call from ZMA questioning our altitude. We notified them we were climbing back up to 5000'. Conditions were day VMC with normal cockpit duties in progress. Aircraft (small transport) had no altitude deviation warning system. Both pilots monitored the descent trying to make the crossing and both pilots misread their altimeters allowing the descent to go 1000' too low.

Original NASA ASRS Text

Title: COMMUTER FLT CREW DESCENDS 1000' LOW FOR ALT CROSSING RESTRICTION.

Narrative: ENRTE MIA TO MCO NWBND ALONG V531, GIVEN PLT'S DISCRETION DSNT CLRNC FROM 9000 TO 5000' TO CROSS BARIN AT 5000'. INADVERTENTLY DSNDED TO 4000', TRYING TO 'MAKE OUR XING ALT.' 15 SECS AFTER LEVEL OFF AT 4000' WE REALIZED WE WERE LOW AND AT THE SAME TIME WE RECEIVED A CALL FROM ZMA QUESTIONING OUR ALT. WE NOTIFIED THEM WE WERE CLBING BACK UP TO 5000'. CONDITIONS WERE DAY VMC WITH NORMAL COCKPIT DUTIES IN PROGRESS. ACFT (SMT) HAD NO ALT DEVIATION WARNING SYS. BOTH PLTS MONITORED THE DSNT TRYING TO MAKE THE XING AND BOTH PLTS MISREAD THEIR ALTIMETERS ALLOWING THE DSNT TO GO 1000' TOO LOW.

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.