A climbing B737-700 experiences a track deviation when the FMS drops blh position out of the electronic database. The aircraft was then proceeding direct elp when ATC caught the error.

Home

Browse by month

Random

Latest

About

Contact

Attributes
ACN	428140
Time
Date	199902
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	navaid : blh.vortac
State Reference	CA
Altitude	msl single value : 24000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zla.artcc
Operator	common carrier : air carrier
Make Model Name	B737-600, -700, -800
Operating Under FAR Part	Part 121
Navigation In Use	other other vortac
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 12000 flight time type : 5000
ASRS Report	428140
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 200 flight time total : 10000 flight time type : 4000
ASRS Report	428478
Events
Anomaly	aircraft equipment problem : less severe airspace violation : exit non adherence : clearance non adherence : company policies other spatial deviation
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	controller : issued alert controller : issued new clearance
Consequence	other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

2 problems with electronic data storage for route: 1) on previous day, route was iah-J86-elp direct sso. Electronic data dropped elp and showed J86 figmo direct sso. (Figmo is waypoint just prior to elp.) this one we caught, queried center, and confirmed elp was what they showed. We entered elp -- no problem further on. 2) this problem -- which was a problem -- route was trm J169 blh elp, route loaded ok. In-flight after turn, aircraft made a slight right turn, which was correct. However, blh dropped out without our knowledge and aircraft proceeded toward elp direct. Controller caught the error as we passed approximately 20 NM south of blh. Company has been notified.

Original NASA ASRS Text

Title: A CLBING B737-700 EXPERIENCES A TRACK DEV WHEN THE FMS DROPS BLH POS OUT OF THE ELECTRONIC DATABASE. THE ACFT WAS THEN PROCEEDING DIRECT ELP WHEN ATC CAUGHT THE ERROR.

Narrative: 2 PROBS WITH ELECTRONIC DATA STORAGE FOR RTE: 1) ON PREVIOUS DAY, RTE WAS IAH-J86-ELP DIRECT SSO. ELECTRONIC DATA DROPPED ELP AND SHOWED J86 FIGMO DIRECT SSO. (FIGMO IS WAYPOINT JUST PRIOR TO ELP.) THIS ONE WE CAUGHT, QUERIED CTR, AND CONFIRMED ELP WAS WHAT THEY SHOWED. WE ENTERED ELP -- NO PROB FURTHER ON. 2) THIS PROB -- WHICH WAS A PROB -- RTE WAS TRM J169 BLH ELP, RTE LOADED OK. INFLT AFTER TURN, ACFT MADE A SLIGHT R TURN, WHICH WAS CORRECT. HOWEVER, BLH DROPPED OUT WITHOUT OUR KNOWLEDGE AND ACFT PROCEEDED TOWARD ELP DIRECT. CTLR CAUGHT THE ERROR AS WE PASSED APPROX 20 NM S OF BLH. COMPANY HAS BEEN NOTIFIED.

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.