Air carrier large transport altitude deviation excursion from clnrc altitude before localizer captur...

Attributes
ACN	102582
Time
Date	198901
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : yyz
State Reference	ON
Altitude	msl bound lower : 3300 msl bound upper : 4000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : yyz
Operator	common carrier : air carrier
Make Model Name	Large Transport, Low Wing, 3 Turbojet Eng
Flight Phase	descent : approach descent other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : second officer
Qualification	pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 250 flight time total : 12000 flight time type : 400
ASRS Report	102582
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 215 flight time total : 5000 flight time type : 1500
ASRS Report	102786
Events
Anomaly	altitude deviation : excursion from assigned altitude non adherence : clearance non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : anomaly accepted
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

First officer was given a vector to intercept localizer 33 at yyz to maintain 4000' until localizer interception. For some reason, he kept descending below 4000 prior to interception. Deviation was caught by crew approximately 2300' MSL at which time he climbed back up to re-intercept glide slope and localizer at approximately 3000'. I (F/east) don't know why he failed to follow the directions of ATC and the approach plate unless his mind was elsewhere. Supplemental information from acn 102786: at 3400' I realized I was low. We were one DOT below and one DOT out on the ILS. We held our altitude for about 15 seconds then continued. Supplemental information from acn 102585:I was switching navaids and approach control frequencys and identifying navaids while first officer descended through assigned ILS intercept altitude.

Original NASA ASRS Text

Title: ACR LGT ALT DEVIATION EXCURSION FROM CLNRC ALT BEFORE LOCALIZER CAPTURE.

Narrative: F/O WAS GIVEN A VECTOR TO INTERCEPT LOC 33 AT YYZ TO MAINTAIN 4000' UNTIL LOC INTERCEPTION. FOR SOME REASON, HE KEPT DSNDING BELOW 4000 PRIOR TO INTERCEPTION. DEVIATION WAS CAUGHT BY CREW APPROX 2300' MSL AT WHICH TIME HE CLIMBED BACK UP TO RE-INTERCEPT GLIDE SLOPE AND LOC AT APPROX 3000'. I (F/E) DON'T KNOW WHY HE FAILED TO FOLLOW THE DIRECTIONS OF ATC AND THE APCH PLATE UNLESS HIS MIND WAS ELSEWHERE. SUPPLEMENTAL INFORMATION FROM ACN 102786: AT 3400' I REALIZED I WAS LOW. WE WERE ONE DOT BELOW AND ONE DOT OUT ON THE ILS. WE HELD OUR ALT FOR ABOUT 15 SECONDS THEN CONTINUED. SUPPLEMENTAL INFORMATION FROM ACN 102585:I WAS SWITCHING NAVAIDS AND APCH CTL FREQS AND IDENTIFYING NAVAIDS WHILE F/O DESCENDED THROUGH ASSIGNED ILS INTERCEPT ALT.

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.

Air carrier large transport altitude deviation excursion from clnrc altitude before localizer capture.