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Less than standard separation. Air carrier received a TCASII RA and descends another air carrier in the same holding pattern receives an RA and climbs. Both had been at the same altitude and ARTCC radar controller would not respond to their queries.
| Attributes | |
| ACN | 303415 |
| Time | |
| Date | 199504 |
| Day | Fri |
| Local Time Of Day | 1801 To 2400 |
| Place | |
| Locale Reference | atc facility : fqf |
| State Reference | CO |
| Altitude | msl bound lower : 25000 msl bound upper : 25000 |
| Environment | |
| Flight Conditions | IMC |
| Light | Night |
| Aircraft 1 | |
| Controlling Facilities | artcc : zdv |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Navigation In Use | Other Other |
| Flight Phase | other |
| Route In Use | enroute airway : zdv |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp pilot : flight engineer pilot : cfi |
| Experience | flight time last 90 days : 175 flight time total : 18500 flight time type : 1300 |
| ASRS Report | 303415 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | conflict : airborne less severe non adherence : required legal separation other anomaly other |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified other flight crewa |
| Resolutory Action | flight crew : took evasive action other |
| Consequence | Other |
| Miss Distance | horizontal : 3000 vertical : 200 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Holding at sylvr FL250, received TCASII 'traffic, traffic' followed by RA 'descend, descend.' disengaged autoplt and autothrust and complied with RA. Advised ATC and leveled off at FL240 'clear of conflict.' another air carrier also received an RA and climbed. No explanation from ZDV when questioned by both aircraft. I believe this problem arose because of the amounts of diversions to cos due to den WX and lack of ZDV separating traffic in holding. The performance of this maneuver should be practiced in a simulator session since many things happen in a short period of time. For example, the warnings you receive during an RA are many and noisy, e.g., autoplt disconnect, autothrust disconnect, altitude warning, TCASII commands, etc.
Original NASA ASRS Text
Title: LTSS. ACR RECEIVED A TCASII RA AND DSNDS ANOTHER ACR IN THE SAME HOLDING PATTERN RECEIVES AN RA AND CLBS. BOTH HAD BEEN AT THE SAME ALT AND ARTCC RADAR CTLR WOULD NOT RESPOND TO THEIR QUERIES.
Narrative: HOLDING AT SYLVR FL250, RECEIVED TCASII 'TFC, TFC' FOLLOWED BY RA 'DSND, DSND.' DISENGAGED AUTOPLT AND AUTOTHRUST AND COMPLIED WITH RA. ADVISED ATC AND LEVELED OFF AT FL240 'CLR OF CONFLICT.' ANOTHER ACR ALSO RECEIVED AN RA AND CLBED. NO EXPLANATION FROM ZDV WHEN QUESTIONED BY BOTH ACFT. I BELIEVE THIS PROB AROSE BECAUSE OF THE AMOUNTS OF DIVERSIONS TO COS DUE TO DEN WX AND LACK OF ZDV SEPARATING TFC IN HOLDING. THE PERFORMANCE OF THIS MANEUVER SHOULD BE PRACTICED IN A SIMULATOR SESSION SINCE MANY THINGS HAPPEN IN A SHORT PERIOD OF TIME. FOR EXAMPLE, THE WARNINGS YOU RECEIVE DURING AN RA ARE MANY AND NOISY, E.G., AUTOPLT DISCONNECT, AUTOTHRUST DISCONNECT, ALT WARNING, TCASII COMMANDS, ETC.
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.