 |
37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
|
Air carrier on GS, on localizer is told ATC has low altitude alert. Determines at proper altitude on approach.
| Attributes | |
| ACN | 204498 |
| Time | |
| Date | 199203 |
| Day | Wed |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | airport : sea |
| State Reference | WA |
| Altitude | msl bound lower : 2100 msl bound upper : 2100 |
| Environment | |
| Flight Conditions | VMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | tower : sea |
| Operator | common carrier : air carrier |
| Make Model Name | Large Transport, Low Wing, 3 Turbojet Eng |
| Flight Phase | descent : approach |
| Route In Use | approach : visual enroute : on vectors |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer |
| Experience | flight time last 90 days : 135 flight time total : 12000 flight time type : 3500 |
| ASRS Report | 204498 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : second officer |
| Qualification | pilot : atp pilot : commercial pilot : flight engineer pilot : instrument |
| Experience | flight time last 90 days : 180 flight time total : 4000 flight time type : 600 |
| ASRS Report | 204743 |
| Events | |
| Anomaly | other anomaly other |
| Independent Detector | other controllera |
| Resolutory Action | none taken : unable other |
| Consequence | Other |
| Supplementary | |
| Air Traffic Incident | other |
| Situations | |
| ATC Facility | other physical facility |
Narrative:
We were cleared for a visual approach to follow the aircraft to 34R and told to maintain 3000 ft until established and 180 KIAS to the FAF. On final, on GS and within 1 DOT of the localizer, tower controller said he had a low altitude warning on us and had us at 2100 ft. We immediately checked out altitude, location, etc, and confirmed we were at 2100 ft. We could not determine anything wrong so we continued on the approach and landed normally. I did not call the tower controller after landing to discuss the situation but later I wish I had as over the next 3 days the event surfaced in our conversation as to why there was a warning. After the trip, I discussed it with our safety representative. He discussed the situation with seattle tower personnel and was told they have 3 or 4 erroneous warnings a day for several reasons which I won't elaborate on here. If this ever happens again, I will call tower after landing to determine why the warning occurred, if I made a mistake and missed something, and for the peace of mind in knowing if I erred or not. Supplemental information from acn 204743: suspect software error in approach facility warning system.
Original NASA ASRS Text
Title: ACR ON GS, ON LOC IS TOLD ATC HAS LOW ALT ALERT. DETERMINES AT PROPER ALT ON APCH.
Narrative: WE WERE CLRED FOR A VISUAL APCH TO FOLLOW THE ACFT TO 34R AND TOLD TO MAINTAIN 3000 FT UNTIL ESTABLISHED AND 180 KIAS TO THE FAF. ON FINAL, ON GS AND WITHIN 1 DOT OF THE LOC, TWR CTLR SAID HE HAD A LOW ALT WARNING ON US AND HAD US AT 2100 FT. WE IMMEDIATELY CHKED OUT ALT, LOCATION, ETC, AND CONFIRMED WE WERE AT 2100 FT. WE COULD NOT DETERMINE ANYTHING WRONG SO WE CONTINUED ON THE APCH AND LANDED NORMALLY. I DID NOT CALL THE TWR CTLR AFTER LNDG TO DISCUSS THE SITUATION BUT LATER I WISH I HAD AS OVER THE NEXT 3 DAYS THE EVENT SURFACED IN OUR CONVERSATION AS TO WHY THERE WAS A WARNING. AFTER THE TRIP, I DISCUSSED IT WITH OUR SAFETY REPRESENTATIVE. HE DISCUSSED THE SITUATION WITH SEATTLE TWR PERSONNEL AND WAS TOLD THEY HAVE 3 OR 4 ERRONEOUS WARNINGS A DAY FOR SEVERAL REASONS WHICH I WON'T ELABORATE ON HERE. IF THIS EVER HAPPENS AGAIN, I WILL CALL TWR AFTER LNDG TO DETERMINE WHY THE WARNING OCCURRED, IF I MADE A MISTAKE AND MISSED SOMETHING, AND FOR THE PEACE OF MIND IN KNOWING IF I ERRED OR NOT. SUPPLEMENTAL INFO FROM ACN 204743: SUSPECT SOFTWARE ERROR IN APCH FACILITY WARNING SYS.
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.