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FK10 initiates action to arrest descent to avoid TCASII observed traffic. Previously, ZAU instructions were to expedite descent for traffic. Pilot perceives he would have hit traffic had he continued to follow ATC instructions.
| Attributes | |
| ACN | 429968 |
| Time | |
| Date | 199903 |
| Day | Wed |
| Local Time Of Day | 0601 To 1200 |
| Place | |
| Locale Reference | airport : ord.airport |
| State Reference | IL |
| Altitude | msl single value : 17300 |
| Environment | |
| Light | Daylight |
| Aircraft 1 | |
| Controlling Facilities | artcc : zau.artcc |
| Operator | common carrier : air carrier |
| Make Model Name | Fokker 100 |
| Operating Under FAR Part | Part 121 |
| Flight Phase | descent : approach |
| Flight Plan | IFR |
| Aircraft 2 | |
| Controlling Facilities | artcc : zau.artcc |
| Operator | general aviation : personal |
| Make Model Name | Cessna Single Piston Undifferentiated or Other Model |
| Operating Under FAR Part | Part 91 |
| Flight Phase | cruise : level |
| Person 1 | |
| Affiliation | company : air carrier |
| Function | flight crew : captain oversight : pic |
| Qualification | pilot : atp |
| ASRS Report | 429968 |
| Person 2 | |
| Affiliation | company : air carrier |
| Function | flight crew : first officer |
| Qualification | pilot : multi engine pilot : instrument pilot : commercial |
| Events | |
| Anomaly | conflict : airborne less severe inflight encounter : weather |
| Independent Detector | aircraft equipment : tcas other controllera other flight crewa |
| Resolutory Action | flight crew : took precautionary avoidance action |
| Miss Distance | vertical : 800 |
| Supplementary | |
| Problem Areas | ATC Human Performance Weather |
| Primary Problem | ATC Human Performance |
Narrative:
Descending from FL240 to 14000 ft at 1500 FPM about 60 mi south of ord. Center said expedite descent. Increased rate to 2500 FPM. Center said we (aircraft X) had traffic (aircraft Y) at 16500 ft, 12 O'clock, 5 mi. I looked on TCASII and saw a target 1500 ft low, 5 mi. Just then got a TA from TCASII. I determined if I continued my descent I would hit target. Disconnected autoplt and smoothly leveled aircraft. Descent stopped with TCASII indicating 800 ft of separation. Told center we were leveling. I then initiated a slight climb until I had 1000 ft separation as target had turned orange. I never got an RA from TCASII, but I feel that if I had not reacted when I did and waited for the RA, I would have come very close to hitting this aircraft. We were VMC at the time and the first officer saw the aircraft, a white single engine cessna he thinks pass under us. If we hadn't had the TCASII, I believe we would have hit that aircraft as we would have never seen him in time -- white aircraft against an undercast.
Original NASA ASRS Text
Title: FK10 INITIATES ACTION TO ARREST DSCNT TO AVOID TCASII OBSERVED TFC. PREVIOUSLY, ZAU INSTRUCTIONS WERE TO EXPEDITE DSCNT FOR TFC. PLT PERCEIVES HE WOULD HAVE HIT TFC HAD HE CONTINUED TO FOLLOW ATC INSTRUCTIONS.
Narrative: DSNDING FROM FL240 TO 14000 FT AT 1500 FPM ABOUT 60 MI S OF ORD. CTR SAID EXPEDITE DSCNT. INCREASED RATE TO 2500 FPM. CTR SAID WE (ACFT X) HAD TFC (ACFT Y) AT 16500 FT, 12 O'CLOCK, 5 MI. I LOOKED ON TCASII AND SAW A TARGET 1500 FT LOW, 5 MI. JUST THEN GOT A TA FROM TCASII. I DETERMINED IF I CONTINUED MY DSCNT I WOULD HIT TARGET. DISCONNECTED AUTOPLT AND SMOOTHLY LEVELED ACFT. DSCNT STOPPED WITH TCASII INDICATING 800 FT OF SEPARATION. TOLD CTR WE WERE LEVELING. I THEN INITIATED A SLIGHT CLB UNTIL I HAD 1000 FT SEPARATION AS TARGET HAD TURNED ORANGE. I NEVER GOT AN RA FROM TCASII, BUT I FEEL THAT IF I HAD NOT REACTED WHEN I DID AND WAITED FOR THE RA, I WOULD HAVE COME VERY CLOSE TO HITTING THIS ACFT. WE WERE VMC AT THE TIME AND THE FO SAW THE ACFT, A WHITE SINGLE ENG CESSNA HE THINKS PASS UNDER US. IF WE HADN'T HAD THE TCASII, I BELIEVE WE WOULD HAVE HIT THAT ACFT AS WE WOULD HAVE NEVER SEEN HIM IN TIME -- WHITE ACFT AGAINST AN UNDERCAST.
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.