Altitude deviation during descent through WX at ord.

Attributes
ACN	325540
Time
Date	199601
Day	Thu
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : obk
State Reference	IL
Altitude	msl bound lower : 11200 msl bound upper : 12000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zau
Operator	common carrier : air carrier
Make Model Name	B767 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	other personnel other
Qualification	pilot : atp
ASRS Report	325540
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	325539
Events
Anomaly	altitude deviation : overshoot non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

On the pmm 3 arrival into ord, we received a descent clearance from FL200 to 15000 ft. About the time we were approaching FL185, approach control frequency 133.2, told us to stand by for holding instructions at pivot. We subsequently received our holding instruction and a further clearance to descend to 13000 ft. During this time as the international officer I was off frequency obtaining the current ATIS from ord. While I was off frequency we were subsequently given a further clearance to descend to 12000 ft. Passing 13000 ft I questioned the crew as to our cleared altitude and we confirmed with approach that our clearance was to 12000 ft. Shortly after we leveled off we entered the hold at pivot, 12000 ft at XX07Z. Not even 10 seconds later, approach asked us to confirm our altitude. At this time we noted that our altimeters had not been reset from 29.92, local altimeter was 29.10. The altimeters were reset and an immediate climb up to 12000 ft was undertaken. Many distractions to include holding instructions, request for and expedited clearance passing 14000 ft, rapidly changing WX conditions, and a change of runway at chicago contributed to the missing of the altitude reset passing FL180. Supplemental information from acn 325539: very heavy workload on all 3 crew members due to WX in the chicago area.

Original NASA ASRS Text

Title: ALTDEV DURING DSCNT THROUGH WX AT ORD.

Narrative: ON THE PMM 3 ARR INTO ORD, WE RECEIVED A DSCNT CLRNC FROM FL200 TO 15000 FT. ABOUT THE TIME WE WERE APCHING FL185, APCH CTL FREQ 133.2, TOLD US TO STAND BY FOR HOLDING INSTRUCTIONS AT PIVOT. WE SUBSEQUENTLY RECEIVED OUR HOLDING INSTRUCTION AND A FURTHER CLRNC TO DSND TO 13000 FT. DURING THIS TIME AS THE INTL OFFICER I WAS OFF FREQ OBTAINING THE CURRENT ATIS FROM ORD. WHILE I WAS OFF FREQ WE WERE SUBSEQUENTLY GIVEN A FURTHER CLRNC TO DSND TO 12000 FT. PASSING 13000 FT I QUESTIONED THE CREW AS TO OUR CLRED ALT AND WE CONFIRMED WITH APCH THAT OUR CLRNC WAS TO 12000 FT. SHORTLY AFTER WE LEVELED OFF WE ENTERED THE HOLD AT PIVOT, 12000 FT AT XX07Z. NOT EVEN 10 SECONDS LATER, APCH ASKED US TO CONFIRM OUR ALT. AT THIS TIME WE NOTED THAT OUR ALTIMETERS HAD NOT BEEN RESET FROM 29.92, LCL ALTIMETER WAS 29.10. THE ALTIMETERS WERE RESET AND AN IMMEDIATE CLB UP TO 12000 FT WAS UNDERTAKEN. MANY DISTRACTIONS TO INCLUDE HOLDING INSTRUCTIONS, REQUEST FOR AND EXPEDITED CLRNC PASSING 14000 FT, RAPIDLY CHANGING WX CONDITIONS, AND A CHANGE OF RWY AT CHICAGO CONTRIBUTED TO THE MISSING OF THE ALT RESET PASSING FL180. SUPPLEMENTAL INFO FROM ACN 325539: VERY HVY WORKLOAD ON ALL 3 CREW MEMBERS DUE TO WX IN THE CHICAGO AREA.

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.