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A cpr light transport crew reports that they have doubts about traffic that caused a TCASII RA.
| Attributes | |
| ACN | 256693 |
| Time | |
| Date | 199311 |
| Day | Fri |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | atc facility : dqo |
| State Reference | DE |
| Altitude | msl bound lower : 11000 msl bound upper : 13400 |
| Environment | |
| Flight Conditions | IMC |
| Light | Daylight |
| Aircraft 1 | |
| Operator | general aviation : corporate |
| Make Model Name | Light Transport, Low Wing, 2 Turbojet Eng |
| Flight Phase | cruise other cruise other |
| Route In Use | enroute airway : zdc |
| Flight Plan | IFR |
| Aircraft 2 | |
| Make Model Name | Any Unknown or Unlisted Aircraft Manufacturer |
| Flight Phase | climbout : intermediate altitude cruise other |
| Flight Plan | IFR |
| Person 1 | |
| Affiliation | Other |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| Experience | flight time last 90 days : 100 flight time total : 13000 |
| ASRS Report | 256693 |
| Person 2 | |
| Affiliation | Other |
| Function | flight crew : first officer |
| Qualification | pilot : instrument pilot : atp |
| Experience | flight time last 90 days : 75 flight time total : 9000 flight time type : 760 |
| ASRS Report | 257190 |
| Events | |
| Anomaly | altitude deviation : excursion from assigned altitude conflict : airborne less severe non adherence : clearance 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 |
| Consequence | Other |
| Miss Distance | horizontal : 12000 vertical : 1500 |
| Supplementary | |
| Primary Problem | Aircraft |
| Air Traffic Incident | Pilot Deviation |
Narrative:
While in cruise flight at 11000 ft just no of the dqo VOR (V433) in IMC, ATC advised me that we had traffic below climbing to 10000 ft. ATC further indicated that he was not talking with the aircraft and assumed that this aircraft was going to stop his climb at 10000 ft. A few moments after receiving this transmission we had a TA on our TCASII which showed a target at the 2-3 O'clock position and 1700 ft below our altitude. What seemed to be only a few seconds later, we experienced an RA with instructions to 'climb, climb, climb,' immediately followed by 'increase climb.' the 'increase climb' mode on our TCASII commands a minimum climb speed of 2500-3000 FPM. At approximately 13200-13400 ft the TCASII gave the 'clear of conflict' command at which time I began a descent back to 11000 ft. To this day, I do not know what caused the problem. However, if it was a false signal received by the TCASII or some type of TCASII fault, then fixes to the TCASII system must be completed as soon as possible before major midair collisions occur. Supplemental information from acn 257190: we're climbing at something over 3000 FPM looking at each other, wondering why we're getting such a warning on traffic at such a distance. At 13100 ft we got the 'clear of conflict' command. Our climb peaked at 13400 ft. We advised ATC and went back down to 11000 ft. ATC asked what our TCASII had displayed. We told him that for the duration of the entire incident we had only that 1 target displayed at 3 O'clock. In my opinion the only bad element of the entire situation was created by the TCASII.
Original NASA ASRS Text
Title: A CPR LTT CREW RPTS THAT THEY HAVE DOUBTS ABOUT TFC THAT CAUSED A TCASII RA.
Narrative: WHILE IN CRUISE FLT AT 11000 FT JUST NO OF THE DQO VOR (V433) IN IMC, ATC ADVISED ME THAT WE HAD TFC BELOW CLBING TO 10000 FT. ATC FURTHER INDICATED THAT HE WAS NOT TALKING WITH THE ACFT AND ASSUMED THAT THIS ACFT WAS GOING TO STOP HIS CLB AT 10000 FT. A FEW MOMENTS AFTER RECEIVING THIS XMISSION WE HAD A TA ON OUR TCASII WHICH SHOWED A TARGET AT THE 2-3 O'CLOCK POS AND 1700 FT BELOW OUR ALT. WHAT SEEMED TO BE ONLY A FEW SECONDS LATER, WE EXPERIENCED AN RA WITH INSTRUCTIONS TO 'CLB, CLB, CLB,' IMMEDIATELY FOLLOWED BY 'INCREASE CLB.' THE 'INCREASE CLB' MODE ON OUR TCASII COMMANDS A MINIMUM CLB SPD OF 2500-3000 FPM. AT APPROX 13200-13400 FT THE TCASII GAVE THE 'CLR OF CONFLICT' COMMAND AT WHICH TIME I BEGAN A DSCNT BACK TO 11000 FT. TO THIS DAY, I DO NOT KNOW WHAT CAUSED THE PROB. HOWEVER, IF IT WAS A FALSE SIGNAL RECEIVED BY THE TCASII OR SOME TYPE OF TCASII FAULT, THEN FIXES TO THE TCASII SYS MUST BE COMPLETED ASAP BEFORE MAJOR MIDAIR COLLISIONS OCCUR. SUPPLEMENTAL INFO FROM ACN 257190: WE'RE CLBING AT SOMETHING OVER 3000 FPM LOOKING AT EACH OTHER, WONDERING WHY WE'RE GETTING SUCH A WARNING ON TFC AT SUCH A DISTANCE. AT 13100 FT WE GOT THE 'CLR OF CONFLICT' COMMAND. OUR CLB PEAKED AT 13400 FT. WE ADVISED ATC AND WENT BACK DOWN TO 11000 FT. ATC ASKED WHAT OUR TCASII HAD DISPLAYED. WE TOLD HIM THAT FOR THE DURATION OF THE ENTIRE INCIDENT WE HAD ONLY THAT 1 TARGET DISPLAYED AT 3 O'CLOCK. IN MY OPINION THE ONLY BAD ELEMENT OF THE ENTIRE SIT WAS CREATED BY THE TCASII.
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.