Narrative:

We had done 1 'loop' at benky and were headed southwest when ZAU advised us of traffic about 2000 ft above us at 1 O'clock. We had the traffic on TCASII but not visually. As we turned back nebound to track inbound to benky we got a TA on our TCASII, but we were still at 10000 and he was about 11500. Then we got a descend RA on our TCASII. As the target turned red, it blurred. I took control of the aircraft and, as I looked out I saw the twin small transport in a diving (steep) turn (over 45 degree left turn) at about our 11 O'clock high. To follow the RA and descent would've put ourselves in the path of the small transport, which I thought was out of control. I quickly overpwred the autoplt and began an evasive climbing left turn. We climbed about 300 ft as the twin dove past us. We got the stick shaker at the top of the maneuver. I increased power and gently descended to our cleared altitude of 10000 and airspeed of 210 KTS. We informed ATC, and continued on to ord and landed normally. There were no injuries to either passenger or crew. The center called me on the phone at the jetway and I made a near 'miss' report, at that time. The TCASII was great at alerting us to a situation growing increasingly critical, but the descend RA would have put us in the path of this radically maneuvering aircraft. I also learned from center, while on the phone at ord, that the small transport twin was dropping skydivers--that was the first I'd heard of that! If so, he was dropping them over a published holding fix on a victor airway! V-10 to be exact on the 'bradford 1' arrival into ord. Callback conversation with reporter revealed the following information: reporter said his conversation with ARTCC after landing indicated that the twin was in contact with ATC. He could not answer why jumpers were permitted so close to the airway/holding pattern. He thought the steep descending turn was a spin/spiral at the time but has since learned that jump aircraft often maneuver in this fashion in order to get back on the ground as soon as possible. His evasive maneuver caused him to pass over the jump aircraft. He could not estimate the distance other than 'it was very close.'

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Original NASA ASRS Text

Title: LGT HAS CLOSE NMAC WITH SKYDIVER SMA. EVASIVE ACTION OPPOSITE TCASII RA COMMAND.

Narrative: WE HAD DONE 1 'LOOP' AT BENKY AND WERE HEADED SW WHEN ZAU ADVISED US OF TFC ABOUT 2000 FT ABOVE US AT 1 O'CLOCK. WE HAD THE TFC ON TCASII BUT NOT VISUALLY. AS WE TURNED BACK NEBOUND TO TRACK INBOUND TO BENKY WE GOT A TA ON OUR TCASII, BUT WE WERE STILL AT 10000 AND HE WAS ABOUT 11500. THEN WE GOT A DSND RA ON OUR TCASII. AS THE TARGET TURNED RED, IT BLURRED. I TOOK CTL OF THE ACFT AND, AS I LOOKED OUT I SAW THE TWIN SMT IN A DIVING (STEEP) TURN (OVER 45 DEG L TURN) AT ABOUT OUR 11 O'CLOCK HIGH. TO FOLLOW THE RA AND DSCNT WOULD'VE PUT OURSELVES IN THE PATH OF THE SMT, WHICH I THOUGHT WAS OUT OF CTL. I QUICKLY OVERPWRED THE AUTOPLT AND BEGAN AN EVASIVE CLBING L TURN. WE CLBED ABOUT 300 FT AS THE TWIN DOVE PAST US. WE GOT THE STICK SHAKER AT THE TOP OF THE MANEUVER. I INCREASED PWR AND GENTLY DSNDED TO OUR CLRED ALT OF 10000 AND AIRSPD OF 210 KTS. WE INFORMED ATC, AND CONTINUED ON TO ORD AND LANDED NORMALLY. THERE WERE NO INJURIES TO EITHER PAX OR CREW. THE CTR CALLED ME ON THE PHONE AT THE JETWAY AND I MADE A NEAR 'MISS' RPT, AT THAT TIME. THE TCASII WAS GREAT AT ALERTING US TO A SIT GROWING INCREASINGLY CRITICAL, BUT THE DSND RA WOULD HAVE PUT US IN THE PATH OF THIS RADICALLY MANEUVERING ACFT. I ALSO LEARNED FROM CTR, WHILE ON THE PHONE AT ORD, THAT THE SMT TWIN WAS DROPPING SKYDIVERS--THAT WAS THE FIRST I'D HEARD OF THAT! IF SO, HE WAS DROPPING THEM OVER A PUBLISHED HOLDING FIX ON A VICTOR AIRWAY! V-10 TO BE EXACT ON THE 'BRADFORD 1' ARR INTO ORD. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR SAID HIS CONVERSATION WITH ARTCC AFTER LNDG INDICATED THAT THE TWIN WAS IN CONTACT WITH ATC. HE COULD NOT ANSWER WHY JUMPERS WERE PERMITTED SO CLOSE TO THE AIRWAY/HOLDING PATTERN. HE THOUGHT THE STEEP DSNDING TURN WAS A SPIN/SPIRAL AT THE TIME BUT HAS SINCE LEARNED THAT JUMP ACFT OFTEN MANEUVER IN THIS FASHION IN ORDER TO GET BACK ON THE GND AS SOON AS POSSIBLE. HIS EVASIVE MANEUVER CAUSED HIM TO PASS OVER THE JUMP ACFT. HE COULD NOT ESTIMATE THE DISTANCE OTHER THAN 'IT WAS VERY CLOSE.'

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.