Narrative:

We were en route to a suburban corporate campus for a passenger pickup. Our route took us overhead 06C (shaumburg airport) from sse to nnw at 1700 ft MSL. We called our intentions at a point 3 NM sse on the CTAF (123.00). No traffic was observed visually or on the TCASII. We crossed midfield and 1 NM north of the airport, called clear but remained on frequency. At the same time a TCASII target appeared 3 mi away at our 11:30. We were able to acquire the traffic visually -- a light cessna single. As the aircraft appeared to be no conflict, we continued on course, and I (PNF) began a descent check in preparation for our landing. When I glanced back outside (now 2 NM nnw of 06C) I observed a red/white cessna sel (probably a C172) initiating a sudden left climbing turn. The aircraft was approximately 50 ft higher and about 100 ft away at our 1 O'clock position. The PF initiated evasive action but the cessna's turn provided clearance sufficient to avoid a collision. At that time we heard over the radio a call of 'did you see him?' followed by 'yeah.' there was no TCASII indication of the aircraft, so I suspect his transponder was not operating. Apparently this aircraft and the one seen earlier were together, although they were not, by any stretch of the imagination, flying in formation. A few seconds later, I keyed the microphone and said 'you guys could be a little bit timelier with your radio calls,' but there was no response. They continued on their way south and did not land at 06C.

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Original NASA ASRS Text

Title: AN SMT HELI HAD NMAC WITH A C172 IN VICINITY OF UNCTLED ARPT. RPTR ACFT HAD BROADCAST ON UNICOM POS, ETC, BUT INTRUDER C172 MADE NO CALL OR ANSWER. BOTH ACFT TOOK EVASIVE ACTION.

Narrative: WE WERE ENRTE TO A SUBURBAN CORPORATE CAMPUS FOR A PAX PICKUP. OUR RTE TOOK US OVERHEAD 06C (SHAUMBURG ARPT) FROM SSE TO NNW AT 1700 FT MSL. WE CALLED OUR INTENTIONS AT A POINT 3 NM SSE ON THE CTAF (123.00). NO TFC WAS OBSERVED VISUALLY OR ON THE TCASII. WE CROSSED MIDFIELD AND 1 NM N OF THE ARPT, CALLED CLR BUT REMAINED ON FREQ. AT THE SAME TIME A TCASII TARGET APPEARED 3 MI AWAY AT OUR 11:30. WE WERE ABLE TO ACQUIRE THE TFC VISUALLY -- A LIGHT CESSNA SINGLE. AS THE ACFT APPEARED TO BE NO CONFLICT, WE CONTINUED ON COURSE, AND I (PNF) BEGAN A DSCNT CHK IN PREPARATION FOR OUR LNDG. WHEN I GLANCED BACK OUTSIDE (NOW 2 NM NNW OF 06C) I OBSERVED A RED/WHITE CESSNA SEL (PROBABLY A C172) INITIATING A SUDDEN L CLBING TURN. THE ACFT WAS APPROX 50 FT HIGHER AND ABOUT 100 FT AWAY AT OUR 1 O'CLOCK POS. THE PF INITIATED EVASIVE ACTION BUT THE CESSNA'S TURN PROVIDED CLRNC SUFFICIENT TO AVOID A COLLISION. AT THAT TIME WE HEARD OVER THE RADIO A CALL OF 'DID YOU SEE HIM?' FOLLOWED BY 'YEAH.' THERE WAS NO TCASII INDICATION OF THE ACFT, SO I SUSPECT HIS XPONDER WAS NOT OPERATING. APPARENTLY THIS ACFT AND THE ONE SEEN EARLIER WERE TOGETHER, ALTHOUGH THEY WERE NOT, BY ANY STRETCH OF THE IMAGINATION, FLYING IN FORMATION. A FEW SECONDS LATER, I KEYED THE MIKE AND SAID 'YOU GUYS COULD BE A LITTLE BIT TIMELIER WITH YOUR RADIO CALLS,' BUT THERE WAS NO RESPONSE. THEY CONTINUED ON THEIR WAY S AND DID NOT LAND AT 06C.

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.