Air carrier has altitude deviation as captain off frequency reference possible divert.

Attributes
ACN	255987
Time
Date	199311
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : air
State Reference	PA
Altitude	msl bound lower : 10000 msl bound upper : 11000
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 other
Route In Use	enroute airway : zob
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : commercial pilot : atp pilot : instrument
Experience	flight time last 90 days : 150 flight time total : 26500 flight time type : 11000
ASRS Report	255987
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : flight engineer pilot : instrument
Experience	flight time last 90 days : 210 flight time total : 10000 flight time type : 210
ASRS Report	255986
Events
Anomaly	altitude deviation : undershoot non adherence : clearance
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : became reoriented flight crew : returned to intended course or assigned course
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Air carrier flight en route pit and holding air VOR at 11000 ft. First officer flying aircraft. Captain talking to company dispatch in reference to minimum fuel on board and establishing diversion plan if required when clearance to 10000 received. Captain read back 10000 to ATC and saw first officer select 10000 in altitude alerter and resumed discussion with company dispatch. About 30 seconds later, noticed first officer still at 11000 ft and reminded him of our clearance to 10000. He started down immediately and about that time ATC called to confirm our clearance to 10000. The rest of the time flight was routine and no mention of any conflict from ATC. Once again attempting to cover 2 frequencys at the same time, is the key to the problem along with need of confirming clearance with second crew member.

Original NASA ASRS Text

Title: ACR HAS ALTDEV AS CAPT OFF FREQ REF POSSIBLE DIVERT.

Narrative: ACR FLT ENRTE PIT AND HOLDING AIR VOR AT 11000 FT. FO FLYING ACFT. CAPT TALKING TO COMPANY DISPATCH IN REF TO MINIMUM FUEL ON BOARD AND ESTABLISHING DIVERSION PLAN IF REQUIRED WHEN CLRNC TO 10000 RECEIVED. CAPT READ BACK 10000 TO ATC AND SAW FO SELECT 10000 IN ALT ALERTER AND RESUMED DISCUSSION WITH COMPANY DISPATCH. ABOUT 30 SECONDS LATER, NOTICED FO STILL AT 11000 FT AND REMINDED HIM OF OUR CLRNC TO 10000. HE STARTED DOWN IMMEDIATELY AND ABOUT THAT TIME ATC CALLED TO CONFIRM OUR CLRNC TO 10000. THE REST OF THE TIME FLT WAS ROUTINE AND NO MENTION OF ANY CONFLICT FROM ATC. ONCE AGAIN ATTEMPTING TO COVER 2 FREQS AT THE SAME TIME, IS THE KEY TO THE PROB ALONG WITH NEED OF CONFIRMING CLRNC WITH SECOND CREW MEMBER.

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.