B757 crew had controller concerned whether the aircraft would comply with a crossing restr.

Attributes
ACN	491080
Time
Date	200011
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : orf.airport
State Reference	VA
Altitude	msl single value : 24000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zdc.artcc tower : dfw.tower
Operator	common carrier : air carrier
Make Model Name	B757-200
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : intermediate altitude descent : vacating altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : atp pilot : commercial pilot : flight engineer pilot : multi engine
Experience	flight time last 90 days : 150 flight time total : 12000 flight time type : 306
ASRS Report	491080
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument pilot : multi engine
Events
Anomaly	non adherence : company policies
Independent Detector	other controllera
Resolutory Action	controller : issued alert other
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

Given clearance to cross 80 NM south of norfolk at FL240. FMC programmed properly and aircraft was started down early. Initial monitoring showed aircraft approaching profile descent and all indications normal. Aircraft did not capture descent profile and required manual mode (4000 FPM) descent to make restr. ATC asked for increased descent as we leveled off at assigned altitude indicating they were concerned about the crossing restr. High descent rate probably caused altitude readout lag that showed us higher than we actually were. Cockpit indications showed compliance with crossing restr altitude.

Original NASA ASRS Text

Title: B757 CREW HAD CTLR CONCERNED WHETHER THE ACFT WOULD COMPLY WITH A XING RESTR.

Narrative: GIVEN CLRNC TO CROSS 80 NM S OF NORFOLK AT FL240. FMC PROGRAMMED PROPERLY AND ACFT WAS STARTED DOWN EARLY. INITIAL MONITORING SHOWED ACFT APCHING PROFILE DSCNT AND ALL INDICATIONS NORMAL. ACFT DID NOT CAPTURE DSCNT PROFILE AND REQUIRED MANUAL MODE (4000 FPM) DSCNT TO MAKE RESTR. ATC ASKED FOR INCREASED DSCNT AS WE LEVELED OFF AT ASSIGNED ALT INDICATING THEY WERE CONCERNED ABOUT THE XING RESTR. HIGH DSCNT RATE PROBABLY CAUSED ALT READOUT LAG THAT SHOWED US HIGHER THAN WE ACTUALLY WERE. COCKPIT INDICATIONS SHOWED COMPLIANCE WITH XING RESTR ALT.

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.