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Air carrier B757 flight crew turns and climbs to avoid an unknown aircraft climbing up to their altitude. ATC later asks them 'why the turn? You are only allowed a climb or descent.'
| Attributes | |
| ACN | 380340 |
| Time | |
| Date | 199709 |
| Day | Thu |
| Local Time Of Day | 1201 To 1800 |
| Place | |
| Locale Reference | atc facility : sxc airport : sna |
| State Reference | CA |
| Altitude | msl bound lower : 5000 msl bound upper : 5500 |
| Environment | |
| Flight Conditions | VMC |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | tracon : lax |
| Operator | common carrier : air carrier |
| Make Model Name | B757 Undifferentiated or Other Model |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | cruise other |
| Route In Use | arrival other enroute : on vectors |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Operating Under FAR Part | other : unknown |
| Flight Phase | climbout : intermediate altitude |
| Flight Plan | VFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : atp pilot : cfi pilot : flight engineer |
| Experience | flight time last 90 days : 225 flight time total : 15000 flight time type : 1000 |
| ASRS Report | 380340 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time total : 15000 |
| ASRS Report | 380335 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance non adherence : published procedure non adherence : required legal separation other spatial deviation |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified |
| Resolutory Action | flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 5500 vertical : 300 |
| Supplementary | |
| Primary Problem | Flight Crew Human Performance |
| Air Traffic Incident | Pilot Deviation other |
Narrative:
Had traffic on TCASII coming at us climbing out of 4500 ft. Captain requested a heading change from ATC. I could not get a word in due to congestion. Captain started a turn away from target that was climbing through 4800 ft on TCASII. While in the turn we got a climb RA. Followed it and climbed to 5500 ft and conflict over. ATC wanted to know why we turned, captain said he used emergency authority/authorized to avoid conflict and we continued down to 5000 ft and radar vectors to sna. With all the traffic in the los angeles basin separated by 500 ft, we felt a turn before we got the RA was safer. Once the RA occurred we followed it immediately. We never saw the traffic. Supplemental information from acn 380335: ATC said with RA's I can only climb or descend, not turn. I told him I used captain's emergency authority/authorized. He did not say anything and continued radar vectors.
Original NASA ASRS Text
Title: ACR B757 FLC TURNS AND CLBS TO AVOID AN UNKNOWN ACFT CLBING UP TO THEIR ALT. ATC LATER ASKS THEM 'WHY THE TURN? YOU ARE ONLY ALLOWED A CLB OR DSCNT.'
Narrative: HAD TFC ON TCASII COMING AT US CLBING OUT OF 4500 FT. CAPT REQUESTED A HDG CHANGE FROM ATC. I COULD NOT GET A WORD IN DUE TO CONGESTION. CAPT STARTED A TURN AWAY FROM TARGET THAT WAS CLBING THROUGH 4800 FT ON TCASII. WHILE IN THE TURN WE GOT A CLB RA. FOLLOWED IT AND CLBED TO 5500 FT AND CONFLICT OVER. ATC WANTED TO KNOW WHY WE TURNED, CAPT SAID HE USED EMER AUTH TO AVOID CONFLICT AND WE CONTINUED DOWN TO 5000 FT AND RADAR VECTORS TO SNA. WITH ALL THE TFC IN THE LOS ANGELES BASIN SEPARATED BY 500 FT, WE FELT A TURN BEFORE WE GOT THE RA WAS SAFER. ONCE THE RA OCCURRED WE FOLLOWED IT IMMEDIATELY. WE NEVER SAW THE TFC. SUPPLEMENTAL INFO FROM ACN 380335: ATC SAID WITH RA'S I CAN ONLY CLB OR DSND, NOT TURN. I TOLD HIM I USED CAPT'S EMER AUTH. HE DID NOT SAY ANYTHING AND CONTINUED RADAR VECTORS.
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.