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Air carrier X climb to occupied altitude had less than standard separation from air carrier Y. TCASII RA evasive action taken, stop climb.
| Attributes | |
| ACN | 305935 |
| Time | |
| Date | 199505 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : lrp |
| State Reference | PA |
| Altitude | msl bound lower : 6500 msl bound upper : 7000 |
| Environment | |
| Flight Conditions | Mixed |
| Light | Daylight |
| Aircraft 1 | |
| Operator | common carrier : air carrier |
| Make Model Name | Commercial Fixed Wing |
| Operating Under FAR Part | Part 121 |
| Flight Phase | climbout : intermediate altitude |
| Route In Use | enroute : direct enroute airway : mdt |
| Flight Plan | IFR |
| Aircraft 2 | |
| Operator | common carrier : air carrier |
| Make Model Name | Jetstream 31 |
| Operating Under FAR Part | Part 135 |
| Navigation In Use | Other |
| Flight Phase | cruise other |
| Route In Use | enroute : direct |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 200 flight time total : 8000 flight time type : 1200 |
| ASRS Report | 305935 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : commercial pilot : instrument |
| Events | |
| Anomaly | altitude deviation : undershoot conflict : airborne less severe non adherence : published procedure non adherence : required legal separation |
| Independent Detector | aircraft equipment other aircraft equipment : unspecified |
| Resolutory Action | flight crew : took evasive action |
| Consequence | Other |
| Miss Distance | horizontal : 1500 vertical : 500 |
| Supplementary | |
| Primary Problem | ATC Human Performance |
| Air Traffic Incident | Operational Error |
Narrative:
Air carrier X cleared to filed altitude of 5000 ft after departing harrisburg international (mdt) en route philadelphia (phl). After leveling at 5000 ft, crew requested and was cleared to 7000 ft. While climbing through 6000 ft we observed TCASII traffic level at 7000 ft, 2 O'clock and converging. We queried harrisburg as to whether they were handling the traffic and got no response. We stopped our climb at 6500 ft, with the traffic in sight. We asked harrisburg approach again regarding the traffic, and they replied, 'thanks, I was trying to coordinate your climb to 7000 ft. Maintain 6000 ft.' TCASII did issue a 'RA' but as per our operations manual, we had air carrier Y in sight (jetstream 31) and were able to maintain separation and thus were not obliged to comply. This seems (on the surface) like a simple 'human error' event. TCASII can be lifesaver, literally. I have come to question the logic in our operations manual regarding noncompliance with RA's when visual separation can be maintained. Specifically, if 2 aircraft are receiving complimentary RA's and 1 does not comply, could a problem be created or worsened? Or does the software anticipate this possibility?
Original NASA ASRS Text
Title: ACR X CLB TO OCCUPIED ALT HAD LTSS FROM ACR Y. TCASII RA EVASIVE ACTION TAKEN, STOP CLB.
Narrative: ACR X CLRED TO FILED ALT OF 5000 FT AFTER DEPARTING HARRISBURG INTL (MDT) ENRTE PHILADELPHIA (PHL). AFTER LEVELING AT 5000 FT, CREW REQUESTED AND WAS CLRED TO 7000 FT. WHILE CLBING THROUGH 6000 FT WE OBSERVED TCASII TFC LEVEL AT 7000 FT, 2 O'CLOCK AND CONVERGING. WE QUERIED HARRISBURG AS TO WHETHER THEY WERE HANDLING THE TFC AND GOT NO RESPONSE. WE STOPPED OUR CLB AT 6500 FT, WITH THE TFC IN SIGHT. WE ASKED HARRISBURG APCH AGAIN REGARDING THE TFC, AND THEY REPLIED, 'THANKS, I WAS TRYING TO COORDINATE YOUR CLB TO 7000 FT. MAINTAIN 6000 FT.' TCASII DID ISSUE A 'RA' BUT AS PER OUR OPS MANUAL, WE HAD ACR Y IN SIGHT (JETSTREAM 31) AND WERE ABLE TO MAINTAIN SEPARATION AND THUS WERE NOT OBLIGED TO COMPLY. THIS SEEMS (ON THE SURFACE) LIKE A SIMPLE 'HUMAN ERROR' EVENT. TCASII CAN BE LIFESAVER, LITERALLY. I HAVE COME TO QUESTION THE LOGIC IN OUR OPS MANUAL REGARDING NONCOMPLIANCE WITH RA'S WHEN VISUAL SEPARATION CAN BE MAINTAINED. SPECIFICALLY, IF 2 ACFT ARE RECEIVING COMPLIMENTARY RA'S AND 1 DOES NOT COMPLY, COULD A PROB BE CREATED OR WORSENED? OR DOES THE SOFTWARE ANTICIPATE THIS POSSIBILITY?
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.