B737 flight crew overshoots leveloff altitude when autoplt is not engaged.

Attributes
ACN	453190
Time
Date	199910
Day	Mon
Local Time Of Day	0601 To 1200
Place
State Reference	CA
Altitude	msl bound lower : 23000 msl bound upper : 23400
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	climbout : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : atp pilot : multi engine pilot : instrument
Experience	flight time last 90 days : 250 flight time total : 2000 flight time type : 400
ASRS Report	453190
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : multi engine pilot : atp
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to assigned altitude
Supplementary
Problem Areas	Environmental Factor Aircraft Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During climb out to FL230, I selected LNAV and vertical speed guidance on the flight director, but forgot to engage the autoplt. The aircraft exceeded FL230 by about 400 ft for about 5-6 seconds. I believe the different autoplt engagement buttons were a factor, as I had not flown a dash 700 in over 1 month. The visibility of the 'engaged' lights are not as obvious as the paddle switches. An additional factor was the 2 jump seat observers. They were quiet, but I was trying to install the sun shade during leveloff (inappropriately). To recover, I hand flew the aircraft back to FL230. ATC did not mention the overshoot.

Original NASA ASRS Text

Title: B737 FLC OVERSHOOTS LEVELOFF ALT WHEN AUTOPLT IS NOT ENGAGED.

Narrative: DURING CLBOUT TO FL230, I SELECTED LNAV AND VERT SPD GUIDANCE ON THE FLT DIRECTOR, BUT FORGOT TO ENGAGE THE AUTOPLT. THE ACFT EXCEEDED FL230 BY ABOUT 400 FT FOR ABOUT 5-6 SECONDS. I BELIEVE THE DIFFERENT AUTOPLT ENGAGEMENT BUTTONS WERE A FACTOR, AS I HAD NOT FLOWN A DASH 700 IN OVER 1 MONTH. THE VISIBILITY OF THE 'ENGAGED' LIGHTS ARE NOT AS OBVIOUS AS THE PADDLE SWITCHES. AN ADDITIONAL FACTOR WAS THE 2 JUMP SEAT OBSERVERS. THEY WERE QUIET, BUT I WAS TRYING TO INSTALL THE SUN SHADE DURING LEVELOFF (INAPPROPRIATELY). TO RECOVER, I HAND FLEW THE ACFT BACK TO FL230. ATC DID NOT MENTION THE OVERSHOOT.

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.