Narrative:

On jul/thu/93 I was working both ground control and local control combined. Cpr X called inbound on the ILS runway 10 approach. Cpr X was cleared to land on runway 10. 3 mins earlier small aircraft Y called inbound from the west. Small aircraft Y was instructed to report crossing the fox river straight in for runway 10, small aircraft Y acknowledged his instructions. Small aircraft Y did not report crossing the fox river straight in for runway 10, opting instead to angle in to runway 10 from over the dpa VOR. Small aircraft Y was observed for the first time approximately 2 mi wsw on an angling final for runway 10, I pointed out cpr X who was now on an approximately 2 mi final for runway 10 to small aircraft Y. Small aircraft Y could not see cpr X. I instructed small aircraft Y to turn right, which he did. Cpr X made a right turn a short time later. Cpr X made a 360 turn and landed without further incident. Upon investigation it was determined that small aircraft Y had been talking to ord approach for advisories and that small aircraft Y believed that a VOR runway 10 approach was approved. Small aircraft Y was a training flight practicing IFR flight with an instructor and a student on board. The student was under a hood which restricts any visibility outside of the aircraft. Ord approach claims to have been giving VFR advisories only to small aircraft Y and to have cancelled any radar services before small aircraft Y switched to dpa tower frequency.

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Original NASA ASRS Text

Title: SMA Y NON ADHERENCE TO ATC INSTRUCTION IN ATA HAD NMAC WITH CPR X. SEE AND AVOID. PLTDEV.

Narrative: ON JUL/THU/93 I WAS WORKING BOTH GND CTL AND LCL CTL COMBINED. CPR X CALLED INBOUND ON THE ILS RWY 10 APCH. CPR X WAS CLRED TO LAND ON RWY 10. 3 MINS EARLIER SMA Y CALLED INBOUND FROM THE W. SMA Y WAS INSTRUCTED TO RPT XING THE FOX RIVER STRAIGHT IN FOR RWY 10, SMA Y ACKNOWLEDGED HIS INSTRUCTIONS. SMA Y DID NOT RPT XING THE FOX RIVER STRAIGHT IN FOR RWY 10, OPTING INSTEAD TO ANGLE IN TO RWY 10 FROM OVER THE DPA VOR. SMA Y WAS OBSERVED FOR THE FIRST TIME APPROX 2 MI WSW ON AN ANGLING FINAL FOR RWY 10, I POINTED OUT CPR X WHO WAS NOW ON AN APPROX 2 MI FINAL FOR RWY 10 TO SMA Y. SMA Y COULD NOT SEE CPR X. I INSTRUCTED SMA Y TO TURN R, WHICH HE DID. CPR X MADE A R TURN A SHORT TIME LATER. CPR X MADE A 360 TURN AND LANDED WITHOUT FURTHER INCIDENT. UPON INVESTIGATION IT WAS DETERMINED THAT SMA Y HAD BEEN TALKING TO ORD APCH FOR ADVISORIES AND THAT SMA Y BELIEVED THAT A VOR RWY 10 APCH WAS APPROVED. SMA Y WAS A TRAINING FLT PRACTICING IFR FLT WITH AN INSTRUCTOR AND A STUDENT ON BOARD. THE STUDENT WAS UNDER A HOOD WHICH RESTRICTS ANY VISIBILITY OUTSIDE OF THE ACFT. ORD APCH CLAIMS TO HAVE BEEN GIVING VFR ADVISORIES ONLY TO SMA Y AND TO HAVE CANCELLED ANY RADAR SVCS BEFORE SMA Y SWITCHED TO DPA TWR FREQ.

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.