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|
Attributes | |
ACN | 465416 |
Time | |
Date | 200003 |
Day | Mon |
Local Time Of Day | 1801 To 2400 |
Place | |
Locale Reference | intersection : wason |
State Reference | AZ |
Altitude | msl single value : 6000 |
Environment | |
Flight Conditions | IMC |
Weather Elements | Rain Turbulence |
Aircraft 1 | |
Controlling Facilities | tracon : u90.tracon |
Operator | common carrier : air carrier |
Make Model Name | Medium Large Transport, Low Wing, 2 Turbojet Eng |
Operating Under FAR Part | Part 121 |
Flight Phase | descent : approach |
Route In Use | approach : instrument precision |
Flight Plan | IFR |
Aircraft 2 | |
Controlling Facilities | tracon : u90.tracon |
Make Model Name | Cessna Single Piston Undifferentiated or Other Model |
Operating Under FAR Part | Part 91 |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : flight engineer pilot : atp |
Experience | flight time last 90 days : 210 flight time total : 11500 flight time type : 2500 |
ASRS Report | 465416 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : commercial pilot : instrument pilot : multi engine |
Events | |
Anomaly | altitude deviation : excursion from assigned altitude |
Independent Detector | aircraft equipment : gpws other controllera |
Resolutory Action | controller : separated traffic flight crew : took evasive action flight crew : returned to assigned altitude |
Supplementary | |
Problem Areas | Environmental Factor Flight Crew Human Performance ATC Human Performance |
Primary Problem | Environmental Factor |
Narrative:
We were on the intercept heading for ILS runway 11L tus just about to intercept final. We got a 'terrain, pull up!' warning and initiated a pull-up. We did have traffic on TCASII about 1-2 mi left of us at 7200 ft. I advised ATC of the climb for terrain. He said 'maintain 6000 ft for traffic.' at this point, we were already correcting back to 6000 ft. We had climbed to about 7000 ft. I was watching the traffic -- the symbol never turned yellow and we leveled at 6000 ft by wason intersection. ATC said 'I was afraid that would happen -- you guys get that terrain warning there and I had traffic above you. Something needs to be done.' I replied that we have to follow terrain warnings when it's IMC and night and can't visually verify the terrain. He said 'yes, but I don't want you climbing into my cessna.' we had not experienced this terrain warning at this point before and were not aware of the false warnings there. Since he was familiar with the problem, it would have been good to let us know and be sure cessna wasn't so close. We knew that 6000 ft would clear terrain after wason intersection but since we couldn't see it with rain and turbulence, we had to follow the warning. Perhaps the egpws is too sensitive on this particular approach as we were not descending but level at 6000 ft. Highest peak is at 4687 ft.
Original NASA ASRS Text
Title: MLG ACR ON ILS APCH TO RWY 11 RECEIVES A EGPWS ALERT WHILE DSNDING TO 6000 FT AND EXECUTES AN ESCAPE MANEUVER.
Narrative: WE WERE ON THE INTERCEPT HDG FOR ILS RWY 11L TUS JUST ABOUT TO INTERCEPT FINAL. WE GOT A 'TERRAIN, PULL UP!' WARNING AND INITIATED A PULL-UP. WE DID HAVE TFC ON TCASII ABOUT 1-2 MI L OF US AT 7200 FT. I ADVISED ATC OF THE CLB FOR TERRAIN. HE SAID 'MAINTAIN 6000 FT FOR TFC.' AT THIS POINT, WE WERE ALREADY CORRECTING BACK TO 6000 FT. WE HAD CLBED TO ABOUT 7000 FT. I WAS WATCHING THE TFC -- THE SYMBOL NEVER TURNED YELLOW AND WE LEVELED AT 6000 FT BY WASON INTXN. ATC SAID 'I WAS AFRAID THAT WOULD HAPPEN -- YOU GUYS GET THAT TERRAIN WARNING THERE AND I HAD TFC ABOVE YOU. SOMETHING NEEDS TO BE DONE.' I REPLIED THAT WE HAVE TO FOLLOW TERRAIN WARNINGS WHEN IT'S IMC AND NIGHT AND CAN'T VISUALLY VERIFY THE TERRAIN. HE SAID 'YES, BUT I DON'T WANT YOU CLBING INTO MY CESSNA.' WE HAD NOT EXPERIENCED THIS TERRAIN WARNING AT THIS POINT BEFORE AND WERE NOT AWARE OF THE FALSE WARNINGS THERE. SINCE HE WAS FAMILIAR WITH THE PROB, IT WOULD HAVE BEEN GOOD TO LET US KNOW AND BE SURE CESSNA WASN'T SO CLOSE. WE KNEW THAT 6000 FT WOULD CLR TERRAIN AFTER WASON INTXN BUT SINCE WE COULDN'T SEE IT WITH RAIN AND TURB, WE HAD TO FOLLOW THE WARNING. PERHAPS THE EGPWS IS TOO SENSITIVE ON THIS PARTICULAR APCH AS WE WERE NOT DSNDING BUT LEVEL AT 6000 FT. HIGHEST PEAK IS AT 4687 FT.
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.