37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Attributes | |
ACN | 581505 |
Time | |
Date | 200305 |
Day | Tue |
Local Time Of Day | 0601 To 1200 |
Place | |
Locale Reference | airport : sea.airport |
State Reference | WA |
Altitude | msl bound lower : 3000 msl bound upper : 5000 |
Environment | |
Flight Conditions | VMC |
Weather Elements | other |
Light | Dawn |
Aircraft 1 | |
Controlling Facilities | tracon : s46.tracon |
Operator | common carrier : air carrier |
Make Model Name | B737-500 |
Operating Under FAR Part | Part 121 |
Navigation In Use | ils localizer & glide slope : 34l |
Flight Phase | descent : approach |
Route In Use | approach : charted visual arrival : on vectors |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Experience | flight time last 90 days : 160 flight time total : 17500 |
ASRS Report | 581505 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Events | |
Anomaly | altitude deviation : excursion from assigned altitude inflight encounter : weather non adherence : published procedure non adherence : clearance other spatial deviation |
Independent Detector | other controllera |
Resolutory Action | controller : issued advisory flight crew : became reoriented |
Consequence | faa : reviewed incident with flight crew |
Supplementary | |
Problem Areas | Weather Airport Flight Crew Human Performance |
Primary Problem | Flight Crew Human Performance |
Narrative:
We were vectored from the east for the 'mall visual' to runway 34L at seattle. It was early morning with the sun at a low angle and a bit hazy. We were at 5000 ft heading west toward the mall area when the controller asked us to report the mall in sight. I had the ILS to runway 34L set in, and set a point in the LNAV 8 mi out (location of the mall). We had plenty of information to back up our position. Shortly, we saw some roof tops ahead, in the light haze, that we were both sure was the mall. I became fixated on this point so that I could turn final just south of this position. As we approached the area, I was at the recommended 3000 ft. As I got closer, I started a slight descent to follow the GS and began a turn toward the radial. Approach corrected us by saying we should be at 3000 ft till the mall and we needed to turn left. That was the first time we realized that we weren't looking at the mall, but some large white roofed commercial buildings east of the mall. The GS was actually a false GS several degrees east of the actual desired course. We corrected and finished the approach uneventfully. I had more than enough equipment to help me find the correct course guidance. There were aircraft ahead of me that did the approach fine. We both got fixated on the wrong point. The haze impaired visibility as the sun was at a low angle in the sky, but it didn't trigger any alarm because we were so sure we were looking at the right point. The only thing that could have prevented this would have been to rely on my instruments more. However, this was a visual approach and we were believing our eyes. When the visibility is good enough for the mall visual, but less than perfect, there is a large group of buildings east of the mall that is very easy to confuse.
Original NASA ASRS Text
Title: B737 FLT CREW DEVIATES FROM PUBLISHED VISUAL APCH COURSE INTO SEA.
Narrative: WE WERE VECTORED FROM THE E FOR THE 'MALL VISUAL' TO RWY 34L AT SEATTLE. IT WAS EARLY MORNING WITH THE SUN AT A LOW ANGLE AND A BIT HAZY. WE WERE AT 5000 FT HEADING W TOWARD THE MALL AREA WHEN THE CTLR ASKED US TO RPT THE MALL IN SIGHT. I HAD THE ILS TO RWY 34L SET IN, AND SET A POINT IN THE LNAV 8 MI OUT (LOCATION OF THE MALL). WE HAD PLENTY OF INFO TO BACK UP OUR POS. SHORTLY, WE SAW SOME ROOF TOPS AHEAD, IN THE LIGHT HAZE, THAT WE WERE BOTH SURE WAS THE MALL. I BECAME FIXATED ON THIS POINT SO THAT I COULD TURN FINAL JUST S OF THIS POS. AS WE APCHED THE AREA, I WAS AT THE RECOMMENDED 3000 FT. AS I GOT CLOSER, I STARTED A SLIGHT DSCNT TO FOLLOW THE GS AND BEGAN A TURN TOWARD THE RADIAL. APCH CORRECTED US BY SAYING WE SHOULD BE AT 3000 FT TILL THE MALL AND WE NEEDED TO TURN L. THAT WAS THE FIRST TIME WE REALIZED THAT WE WEREN'T LOOKING AT THE MALL, BUT SOME LARGE WHITE ROOFED COMMERCIAL BUILDINGS E OF THE MALL. THE GS WAS ACTUALLY A FALSE GS SEVERAL DEGS E OF THE ACTUAL DESIRED COURSE. WE CORRECTED AND FINISHED THE APCH UNEVENTFULLY. I HAD MORE THAN ENOUGH EQUIP TO HELP ME FIND THE CORRECT COURSE GUIDANCE. THERE WERE ACFT AHEAD OF ME THAT DID THE APCH FINE. WE BOTH GOT FIXATED ON THE WRONG POINT. THE HAZE IMPAIRED VISIBILITY AS THE SUN WAS AT A LOW ANGLE IN THE SKY, BUT IT DIDN'T TRIGGER ANY ALARM BECAUSE WE WERE SO SURE WE WERE LOOKING AT THE RIGHT POINT. THE ONLY THING THAT COULD HAVE PREVENTED THIS WOULD HAVE BEEN TO RELY ON MY INSTS MORE. HOWEVER, THIS WAS A VISUAL APCH AND WE WERE BELIEVING OUR EYES. WHEN THE VISIBILITY IS GOOD ENOUGH FOR THE MALL VISUAL, BUT LESS THAN PERFECT, THERE IS A LARGE GROUP OF BUILDINGS E OF THE MALL THAT IS VERY EASY TO CONFUSE.
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.