Air carrier excursion from assigned altitude while making turn onto final approach course.

Attributes
ACN	307026
Time
Date	199506
Day	Sat
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : sea
State Reference	WA
Altitude	msl bound lower : 5000 msl bound upper : 5000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : sea
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	cruise other descent : approach
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : commercial pilot : instrument
Experience	flight time last 90 days : 210 flight time total : 15100 flight time type : 8450
ASRS Report	307026
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 240 flight time total : 9000 flight time type : 2000
ASRS Report	306910
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
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:

Arriving at sea at end of 13 hour back of clock trans- pacific flight (I was flying) being vectored on long downwind east of localizer for ILS runway 16R sea. Given left 90 degree turn to 90 degree intercept angle to ILS runway 16R and cleared for ILS approach to runway 16R told to maintain 5000 ft till eryka 18 DME fix. Immediately after turning to 90 degree intercept heading we knew we would have a large overshoot of the final approach course. The captain was busy making one of many required radio frequency changes as I began turning. Because of large overshoot and about 10 mi visibility, I elected to use visual references to turn final and correct back to course. As I was rolling out on an intercept heading, I realized I had descended 400 ft below assigned altitude before reaching eryka. I immediately corrected back to 5000 ft. So also called altitude as I realized I had descended. Problems: 90 degree intercept angle, other traffic in area to be aware of. High level of fatigue of entire crew. Radio frequency change at critical turn to intercept. My concern about large overshoot and my transition to visual references for help. At nearly 20 DME I had plenty of time to correct back to course. I should not have allowed myself to become distracted although other traffic in the area was a concern.

Original NASA ASRS Text

Title: ACR EXCURSION FROM ASSIGNED ALT WHILE MAKING TURN ONTO FINAL APCH COURSE.

Narrative: ARRIVING AT SEA AT END OF 13 HR BACK OF CLOCK TRANS- PACIFIC FLT (I WAS FLYING) BEING VECTORED ON LONG DOWNWIND E OF LOC FOR ILS RWY 16R SEA. GIVEN L 90 DEG TURN TO 90 DEG INTERCEPT ANGLE TO ILS RWY 16R AND CLRED FOR ILS APCH TO RWY 16R TOLD TO MAINTAIN 5000 FT TILL ERYKA 18 DME FIX. IMMEDIATELY AFTER TURNING TO 90 DEG INTERCEPT HDG WE KNEW WE WOULD HAVE A LARGE OVERSHOOT OF THE FINAL APCH COURSE. THE CAPT WAS BUSY MAKING ONE OF MANY REQUIRED RADIO FREQ CHANGES AS I BEGAN TURNING. BECAUSE OF LARGE OVERSHOOT AND ABOUT 10 MI VISIBILITY, I ELECTED TO USE VISUAL REFS TO TURN FINAL AND CORRECT BACK TO COURSE. AS I WAS ROLLING OUT ON AN INTERCEPT HDG, I REALIZED I HAD DSNDED 400 FT BELOW ASSIGNED ALT BEFORE REACHING ERYKA. I IMMEDIATELY CORRECTED BACK TO 5000 FT. SO ALSO CALLED ALT AS I REALIZED I HAD DSNDED. PROBS: 90 DEG INTERCEPT ANGLE, OTHER TFC IN AREA TO BE AWARE OF. HIGH LEVEL OF FATIGUE OF ENTIRE CREW. RADIO FREQ CHANGE AT CRITICAL TURN TO INTERCEPT. MY CONCERN ABOUT LARGE OVERSHOOT AND MY TRANSITION TO VISUAL REFS FOR HELP. AT NEARLY 20 DME I HAD PLENTY OF TIME TO CORRECT BACK TO COURSE. I SHOULD NOT HAVE ALLOWED MYSELF TO BECOME DISTRACTED ALTHOUGH OTHER TFC IN THE AREA WAS A CONCERN.

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.