 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
ZMP radar controller reports that there is an increasing number of navigation error incidents with aircraft utilizing the VLF omega navigation system. Errors are causing flts to turn off course without flight crew recognizing the situation.
| Attributes | |
| ACN | 343158 |
| Time | |
| Date | 199608 |
| Day | Fri |
| Local Time Of Day | 0001 To 0600 |
| Place | |
| Locale Reference | atc facility : bis |
| State Reference | ND |
| Altitude | msl bound lower : 31000 msl bound upper : 31000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zmp |
| Operator | common carrier : air carrier |
| Make Model Name | MD-80 Series (DC-9-80) Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | government : faa |
| Function | controller : radar |
| Qualification | controller : radar |
| Experience | controller military : 4 controller radar : 15 controller supervisory : 3 |
| ASRS Report | 343158 |
| Person 2 | |
| Affiliation | government : faa |
| Function | oversight : supervisor |
| Qualification | controller : radar |
| Events | |
| Anomaly | non adherence : clearance other anomaly other other spatial deviation |
| Independent Detector | other controllera |
| Resolutory Action | other |
| Consequence | Other |
| Supplementary | |
| Primary Problem | Navigational Facility |
| Air Traffic Incident | other |
| Situations | |
| Navigational Aid | Unspecified |
Narrative:
Due to problems with ground based equipment air carrier X MD80/right aircraft using 'global navigation' are suddenly (and unexpectedly) turning off course. I have personally witnessed this event 4 times in the past 48 hours. Turns have been in excess of 40 degrees (and up to 90 degrees). In each instance observed the PIC was not aware that the aircraft was turning off course. Air carrier X is aware of this problem yet continues to utilize this equipment for route navigation. In the instance tonight the MD80 deviated (at FL310) from a heading of approximately 270 degrees to approximately 350 degrees directly in front of another aircraft wbound at FL330 (wrong altitude for direction of flight). Had the other aircraft been at FL310 the 2 aircraft may have collided.
Original NASA ASRS Text
Title: ZMP RADAR CTLR RPTS THAT THERE IS AN INCREASING NUMBER OF NAV ERROR INCIDENTS WITH ACFT UTILIZING THE VLF OMEGA NAV SYS. ERRORS ARE CAUSING FLTS TO TURN OFF COURSE WITHOUT FLC RECOGNIZING THE SIT.
Narrative: DUE TO PROBS WITH GND BASED EQUIP ACR X MD80/R ACFT USING 'GLOBAL NAV' ARE SUDDENLY (AND UNEXPECTEDLY) TURNING OFF COURSE. I HAVE PERSONALLY WITNESSED THIS EVENT 4 TIMES IN THE PAST 48 HRS. TURNS HAVE BEEN IN EXCESS OF 40 DEGS (AND UP TO 90 DEGS). IN EACH INSTANCE OBSERVED THE PIC WAS NOT AWARE THAT THE ACFT WAS TURNING OFF COURSE. ACR X IS AWARE OF THIS PROB YET CONTINUES TO UTILIZE THIS EQUIP FOR RTE NAV. IN THE INSTANCE TONIGHT THE MD80 DEVIATED (AT FL310) FROM A HDG OF APPROX 270 DEGS TO APPROX 350 DEGS DIRECTLY IN FRONT OF ANOTHER ACFT WBOUND AT FL330 (WRONG ALT FOR DIRECTION OF FLT). HAD THE OTHER ACFT BEEN AT FL310 THE 2 ACFT MAY HAVE COLLIDED.
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.