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MD11 with zan at FL310 is issued climb clearance; observed conflicting traffic and elected to remain at current altitude.
| Attributes | |
| ACN | 677119 |
| Time | |
| Date | 200511 |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | navaid : sya.ndb |
| State Reference | AK |
| Altitude | msl single value : 31000 |
| Environment | |
| Flight Conditions | VMC |
| Light | Dawn |
| Aircraft 1 | |
| Controlling Facilities | artcc : zan.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zan.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | MD-11 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | cruise : level |
| 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 : 70 flight time total : 12000 flight time type : 6400 |
| ASRS Report | 677119 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument pilot : multi engine pilot : atp pilot : cfi |
| Experience | flight time last 90 days : 100 flight time total : 6500 flight time type : 175 |
| ASRS Report | 677118 |
| Events | |
| Anomaly | conflict : airborne critical |
| Independent Detector | aircraft equipment : tcas other flight crewa other flight crewb |
| Resolutory Action | controller : issued new clearance flight crew : took evasive action |
| Consequence | faa : reviewed incident with flight crew |
| Supplementary | |
| Problem Areas | ATC Human Performance |
| Primary Problem | ATC Human Performance |
Narrative:
In cruise; FL310; eastbound; received clearance from zan to climb and maintain FL330. Because we had been tracking another MD11 (on TCAS and visually; but they were not on frequency) above and slightly offset to the south at FL320; we asked for verification for the climb. We were told again to climb and maintain FL330. Although I initially figured that ATC knew the big picture; as I set FL330 in the altitude window; I expanded the TCAS screen and the MD11 was still there; 1000 ft above and approximately 1 NM south. I disconnected the autoplt and pushed the nose back down to maintain FL310. Simultaneous with my pushover; we received an RA. We were at FL312 at initial pushover and never climbed higher than FL313 during the entire maneuver. I told the pilot monitoring to question; again; the FL330 clearance. There was a momentary pause (confusion) and then we were told to maintain FL310. We slowed to .80 mach to assure more separation and the rest of the flight was uneventful. During subsequent discussion with ATC; they said that they never showed less than 1000 ft vertical separation between aircraft.
Original NASA ASRS Text
Title: MD11 WITH ZAN AT FL310 IS ISSUED CLB CLRNC; OBSERVED CONFLICTING TFC AND ELECTED TO REMAIN AT CURRENT ALT.
Narrative: IN CRUISE; FL310; EBOUND; RECEIVED CLRNC FROM ZAN TO CLB AND MAINTAIN FL330. BECAUSE WE HAD BEEN TRACKING ANOTHER MD11 (ON TCAS AND VISUALLY; BUT THEY WERE NOT ON FREQ) ABOVE AND SLIGHTLY OFFSET TO THE S AT FL320; WE ASKED FOR VERIFICATION FOR THE CLB. WE WERE TOLD AGAIN TO CLB AND MAINTAIN FL330. ALTHOUGH I INITIALLY FIGURED THAT ATC KNEW THE BIG PICTURE; AS I SET FL330 IN THE ALT WINDOW; I EXPANDED THE TCAS SCREEN AND THE MD11 WAS STILL THERE; 1000 FT ABOVE AND APPROX 1 NM S. I DISCONNECTED THE AUTOPLT AND PUSHED THE NOSE BACK DOWN TO MAINTAIN FL310. SIMULTANEOUS WITH MY PUSHOVER; WE RECEIVED AN RA. WE WERE AT FL312 AT INITIAL PUSHOVER AND NEVER CLBED HIGHER THAN FL313 DURING THE ENTIRE MANEUVER. I TOLD THE PLT MONITORING TO QUESTION; AGAIN; THE FL330 CLRNC. THERE WAS A MOMENTARY PAUSE (CONFUSION) AND THEN WE WERE TOLD TO MAINTAIN FL310. WE SLOWED TO .80 MACH TO ASSURE MORE SEPARATION AND THE REST OF THE FLT WAS UNEVENTFUL. DURING SUBSEQUENT DISCUSSION WITH ATC; THEY SAID THAT THEY NEVER SHOWED LESS THAN 1000 FT VERT SEPARATION BTWN ACFT.
Data retrieved from NASA's ASRS site as of January 2009 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.