Altitude overshot on descent when change in maintain altitude missed by the PF.

Attributes
ACN	83932
Time
Date	198803
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : lga
State Reference	NY
Altitude	msl bound lower : 5000 msl bound upper : 6000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90 tower : hou
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other
Flight Phase	descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 250 flight time total : 3000 flight time type : 250
ASRS Report	83932
Person 2
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance non adherence : far
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Descending into lga with vectors I rang 3 bells (company procedure to signal 10000' to F/a's) just as the senior F/a walked into the cockpit. We were still several miles out so the captain let her stay in the cockpit. I was given a clearance to proceed to the lga VOR and was descending through 5000' to my assigned altitude of 4000'. The captain discontinued his running commentary of the sights to the F/a to state that we were only cleared to 6000'. Apparently the 4000' restriction had been changed to 6000' when I was cleared to the VOR. The autoplt was being used. On all other company aircraft, the PNF sets the altitude alerter (by procedure) on the FMC, it is a very gray area. Approximately 70% of the time when the autoplt is coupled, the PF sets in altitude changes. The other 30%, the pilot on the radio sets it in. For the next 2 days we had the PNF set in all altitude changes. There was some inconvenience, but it worked out well. The F/a should have been asked to leave shortly after coming up to the cockpit. Also, approach control said, 'there was no problem,' and gave us a new vector and altitude of 3000'.

Original NASA ASRS Text

Title: ALT OVERSHOT ON DESCENT WHEN CHANGE IN MAINTAIN ALT MISSED BY THE PF.

Narrative: DSNDING INTO LGA WITH VECTORS I RANG 3 BELLS (COMPANY PROC TO SIGNAL 10000' TO F/A'S) JUST AS THE SENIOR F/A WALKED INTO THE COCKPIT. WE WERE STILL SEVERAL MILES OUT SO THE CAPT LET HER STAY IN THE COCKPIT. I WAS GIVEN A CLRNC TO PROCEED TO THE LGA VOR AND WAS DSNDING THROUGH 5000' TO MY ASSIGNED ALT OF 4000'. THE CAPT DISCONTINUED HIS RUNNING COMMENTARY OF THE SIGHTS TO THE F/A TO STATE THAT WE WERE ONLY CLRED TO 6000'. APPARENTLY THE 4000' RESTRICTION HAD BEEN CHANGED TO 6000' WHEN I WAS CLRED TO THE VOR. THE AUTOPLT WAS BEING USED. ON ALL OTHER COMPANY ACFT, THE PNF SETS THE ALT ALERTER (BY PROC) ON THE FMC, IT IS A VERY GRAY AREA. APPROX 70% OF THE TIME WHEN THE AUTOPLT IS COUPLED, THE PF SETS IN ALT CHANGES. THE OTHER 30%, THE PLT ON THE RADIO SETS IT IN. FOR THE NEXT 2 DAYS WE HAD THE PNF SET IN ALL ALT CHANGES. THERE WAS SOME INCONVENIENCE, BUT IT WORKED OUT WELL. THE F/A SHOULD HAVE BEEN ASKED TO LEAVE SHORTLY AFTER COMING UP TO THE COCKPIT. ALSO, APCH CTL SAID, 'THERE WAS NO PROB,' AND GAVE US A NEW VECTOR AND ALT OF 3000'.

Data retrieved from NASA's ASRS site as of August 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.