Flight crew of an large transport undershot descent altitude fix due to not setting the proper mode option when programming the FMC. This mistake was not recognized by the crew in sufficient time to make the descent required for the fix crossing as the crew was distraction by communication with flight attendant and company calls.

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Attributes
ACN	415410
Time
Date	199809
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : stw
State Reference	NJ
Altitude	msl bound lower : 23000 msl bound upper : 25000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny artcc : f54
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
Route In Use	enroute airway : j70
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 185 flight time total : 9220 flight time type : 4655
ASRS Report	415410
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : crossing restriction not met altitude deviation : undershoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : anomaly accepted none taken : insufficient time
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

While we were cruising at FL290, ZNY cleared us to cross harty intersection at FL230, 250 KTS. FMS was preprogrammed for harty at FL230. PF placed FL230 in autoplt MCP and then entered 'harty 250 degree radial, 230 KTS' into FMS. I believe that as this information was being entered, the previous 'top of descent' point was reached and the MCP went into an 'altitude hold/speed' confign. As the restrs were then executed, the PF believed the autoplt was in an LNAV/VNAV mode and the aircraft would comply. We were both slightly distraction by calls from flight attendants and company in range and ATIS monitoring. Approximately 4 mi west of harty, captain noticed we had not started down and compliance with the restrs was impossible. We immediately began maximum rate descent and requested radar vectors for separation and distance to comply. Center stated that they needed us below FL250 and that harty was behind us. We leveled at FL230 about 3 mi east of harty. No conflict was noted, and in later query, ZNY stated that 'there was no problem.'

Original NASA ASRS Text

Title: FLC OF AN LGT UNDERSHOT DSCNT ALT FIX DUE TO NOT SETTING THE PROPER MODE OPTION WHEN PROGRAMMING THE FMC. THIS MISTAKE WAS NOT RECOGNIZED BY THE CREW IN SUFFICIENT TIME TO MAKE THE DSCNT REQUIRED FOR THE FIX XING AS THE CREW WAS DISTR BY COM WITH FLT ATTENDANT AND COMPANY CALLS.

Narrative: WHILE WE WERE CRUISING AT FL290, ZNY CLRED US TO CROSS HARTY INTXN AT FL230, 250 KTS. FMS WAS PREPROGRAMMED FOR HARTY AT FL230. PF PLACED FL230 IN AUTOPLT MCP AND THEN ENTERED 'HARTY 250 DEG RADIAL, 230 KTS' INTO FMS. I BELIEVE THAT AS THIS INFO WAS BEING ENTERED, THE PREVIOUS 'TOP OF DSCNT' POINT WAS REACHED AND THE MCP WENT INTO AN 'ALT HOLD/SPD' CONFIGN. AS THE RESTRS WERE THEN EXECUTED, THE PF BELIEVED THE AUTOPLT WAS IN AN LNAV/VNAV MODE AND THE ACFT WOULD COMPLY. WE WERE BOTH SLIGHTLY DISTR BY CALLS FROM FLT ATTENDANTS AND COMPANY IN RANGE AND ATIS MONITORING. APPROX 4 MI W OF HARTY, CAPT NOTICED WE HAD NOT STARTED DOWN AND COMPLIANCE WITH THE RESTRS WAS IMPOSSIBLE. WE IMMEDIATELY BEGAN MAX RATE DSCNT AND REQUESTED RADAR VECTORS FOR SEPARATION AND DISTANCE TO COMPLY. CTR STATED THAT THEY NEEDED US BELOW FL250 AND THAT HARTY WAS BEHIND US. WE LEVELED AT FL230 ABOUT 3 MI E OF HARTY. NO CONFLICT WAS NOTED, AND IN LATER QUERY, ZNY STATED THAT 'THERE WAS NO PROB.'

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.