An air carrier medium large transport missed an altitude on descent on a STAR.

Attributes
ACN	211433
Time
Date	199205
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : ard airport : lga
State Reference	NJ
Altitude	msl bound lower : 26000 msl bound upper : 33000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny artcc : zob
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise other descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 9000 flight time type : 4000
ASRS Report	211433
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : undershoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

En route to new york's lga airport we were giving a crossing restriction to cross somto intersection at FL260. I was the PF and the captain had gone to the forward lav when clearance was issued. I programmed the FMC with the crossing restriction but failed to enter the FL260 altitude in the mode control panel, causing the aircraft not to start down on time missing the altitude by approximately 1000 ft or 4 mi. This problem could have been avoided if, on the captain's return to the cockpit, a briefing would have been conducted of events that had occurred while a pilot was off the flight deck. During the rest of our 4 day trip we practiced this check of briefing each other if one pilot left the flight deck, including any changes in route, altitude, request or general information relayed by ATC, with emphasis on set up of the FMC and mode control panel with the autoplt connected. Possibly another solution to this would be that certain FMC commands that appear in the message pad be followed by an aural warning or chime, especially the command of reset MCP, FMC fail, verify position, or other critical FMC messages. In the case of bright sunlight, the FMC prompts are not really eye catching.

Original NASA ASRS Text

Title: AN ACR MLG MISSED AN ALT ON DSCNT ON A STAR.

Narrative: ENRTE TO NEW YORK'S LGA ARPT WE WERE GIVING A XING RESTRICTION TO CROSS SOMTO INTXN AT FL260. I WAS THE PF AND THE CAPT HAD GONE TO THE FORWARD LAV WHEN CLRNC WAS ISSUED. I PROGRAMMED THE FMC WITH THE XING RESTRICTION BUT FAILED TO ENTER THE FL260 ALT IN THE MODE CTL PANEL, CAUSING THE ACFT NOT TO START DOWN ON TIME MISSING THE ALT BY APPROX 1000 FT OR 4 MI. THIS PROBLEM COULD HAVE BEEN AVOIDED IF, ON THE CAPT'S RETURN TO THE COCKPIT, A BRIEFING WOULD HAVE BEEN CONDUCTED OF EVENTS THAT HAD OCCURRED WHILE A PLT WAS OFF THE FLT DECK. DURING THE REST OF OUR 4 DAY TRIP WE PRACTICED THIS CHK OF BRIEFING EACH OTHER IF ONE PLT LEFT THE FLT DECK, INCLUDING ANY CHANGES IN RTE, ALT, REQUEST OR GENERAL INFO RELAYED BY ATC, WITH EMPHASIS ON SET UP OF THE FMC AND MODE CTL PANEL WITH THE AUTOPLT CONNECTED. POSSIBLY ANOTHER SOLUTION TO THIS WOULD BE THAT CERTAIN FMC COMMANDS THAT APPEAR IN THE MESSAGE PAD BE FOLLOWED BY AN AURAL WARNING OR CHIME, ESPECIALLY THE COMMAND OF RESET MCP, FMC FAIL, VERIFY POS, OR OTHER CRITICAL FMC MESSAGES. IN THE CASE OF BRIGHT SUNLIGHT, THE FMC PROMPTS ARE NOT REALLY EYE CATCHING.

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.