Air carrier medium large transport overshot altitude on descent.

Attributes
ACN	90987
Time
Date	198807
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : sna
State Reference	CA
Altitude	msl bound lower : 6700 msl bound upper : 7000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Flight Phase	descent other
Route In Use	arrival other enroute airway : sna
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : cfi pilot : atp pilot : flight engineer
Experience	flight time last 90 days : 120 flight time total : 8000 flight time type : 100
ASRS Report	90987
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer
Events
Anomaly	altitude deviation : overshoot non adherence : clearance
Independent Detector	other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

New first officer flying. He had approximately 40 hours in type, with company 3 months. Captain 100 hours in type, been a captain 3 months. First officer apparently failed to arm altitude that was set in altitude alert/autoplt preselect window. Captain failed to notice this due to scanning outside for VFR traffic called to our attention. Aircraft descent arrested 300' low (6700'). First officer disconnected autoplt and climbed back to assigned 7000'. Controller made no mention of deviation. I will be more observant next time since I'm responsible, but I wish that setting altitude in window also armed it! I've seen other pilots (and myself) miss the additional arming button step! It's a human factors set up.

Original NASA ASRS Text

Title: ACR MLG OVERSHOT ALT ON DESCENT.

Narrative: NEW F/O FLYING. HE HAD APPROX 40 HRS IN TYPE, WITH COMPANY 3 MONTHS. CAPT 100 HRS IN TYPE, BEEN A CAPT 3 MONTHS. F/O APPARENTLY FAILED TO ARM ALT THAT WAS SET IN ALT ALERT/AUTOPLT PRESELECT WINDOW. CAPT FAILED TO NOTICE THIS DUE TO SCANNING OUTSIDE FOR VFR TFC CALLED TO OUR ATTN. ACFT DSCNT ARRESTED 300' LOW (6700'). F/O DISCONNECTED AUTOPLT AND CLBED BACK TO ASSIGNED 7000'. CTLR MADE NO MENTION OF DEVIATION. I WILL BE MORE OBSERVANT NEXT TIME SINCE I'M RESPONSIBLE, BUT I WISH THAT SETTING ALT IN WINDOW ALSO ARMED IT! I'VE SEEN OTHER PLTS (AND MYSELF) MISS THE ADDITIONAL ARMING BUTTON STEP! IT'S A HUMAN FACTORS SET UP.

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.