Large transport flight crew descended below assigned altitude on descent arrival procedure.

Attributes
ACN	311160
Time
Date	199507
Day	Mon
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : atl
State Reference	GA
Altitude	msl bound lower : 12600 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : ztl
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent other
Route In Use	arrival other
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 : 80 flight time total : 3500 flight time type : 300
ASRS Report	311160
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
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:

Descended 300-400 ft below assigned altitude. During descent received clearance to turn and proceed direct to fix on arrival procedure. During turn (aircraft being flown by captain) copilot reprogrammed omega navigation system. Leaning across cockpit to reach control head altitude capture alert/advisory was obscured by copilot's torso. Captain was unable to see altitude alert and failure of autoplt to capture assigned altitude. Solution: location of navigation control head on left side of console can lead to distraction of captain when flying and copilot is reprogramming omega system. Recommend future occurrences that captain transfer control of aircraft to copilot while he (the captain) manages omega control panel.

Original NASA ASRS Text

Title: LGT FLC DSNDED BELOW ASSIGNED ALT ON DSCNT ARR PROC.

Narrative: DSNDED 300-400 FT BELOW ASSIGNED ALT. DURING DSCNT RECEIVED CLRNC TO TURN AND PROCEED DIRECT TO FIX ON ARR PROC. DURING TURN (ACFT BEING FLOWN BY CAPT) COPLT REPROGRAMMED OMEGA NAV SYS. LEANING ACROSS COCKPIT TO REACH CTL HEAD ALT CAPTURE ALERT/ADVISORY WAS OBSCURED BY COPLT'S TORSO. CAPT WAS UNABLE TO SEE ALT ALERT AND FAILURE OF AUTOPLT TO CAPTURE ASSIGNED ALT. SOLUTION: LOCATION OF NAV CTL HEAD ON L SIDE OF CONSOLE CAN LEAD TO DISTR OF CAPT WHEN FLYING AND COPLT IS REPROGRAMMING OMEGA SYS. RECOMMEND FUTURE OCCURRENCES THAT CAPT TRANSFER CTL OF ACFT TO COPLT WHILE HE (THE CAPT) MANAGES OMEGA CTL PANEL.

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.