Narrative:

After flying V251 from dnv and vectoring at 4000 ft MSL by ZAU, we were cleared for the ILS runway 10 to laf and instructed to contact laf tower. We began a descent from 4000 ft on the GS. We were alerted to VFR traffic also flying the ILS runway 10 approach. My impression was the traffic was ahead of us and would not present a hazard. We were slightly right of localizer centerline and descending at the marker beacon when the duchess was noticed slightly below and slightly left of our aircraft. I had been diligently scanning for this traffic, but it was blocked from view as we descended. Duchess discontinued approach. 1) control is needed (radar) over training flts at laf. I understand grissom AFB would be willing to provide this, 2) alternately -- VFR aircraft at laf should be educated to consider discontinuing approach when IFR traffic inbound, 3) even though outside of laf class D airspace, tower might provide more information. Consider expanding laf class D airspace to include earle OM? Callback conversation with reporter revealed the following information: the reporter stated she was flying a beech sundowner. She reemphasized there are many similar near midairs on practice approachs at this airport in that it is associated with purdue university which is active in aviation training. There is a professor at the university who has suggested the training be done at grissom AFB. The word is that the AFB has radar and would be delighted to assist in the purdue training.

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Original NASA ASRS Text

Title: RPTR EXPERIENCES NEAR MIDAIR WITH A DUCHESS ON A PRACTICE ILS TO THE SAME RWY.

Narrative: AFTER FLYING V251 FROM DNV AND VECTORING AT 4000 FT MSL BY ZAU, WE WERE CLRED FOR THE ILS RWY 10 TO LAF AND INSTRUCTED TO CONTACT LAF TWR. WE BEGAN A DSCNT FROM 4000 FT ON THE GS. WE WERE ALERTED TO VFR TFC ALSO FLYING THE ILS RWY 10 APCH. MY IMPRESSION WAS THE TFC WAS AHEAD OF US AND WOULD NOT PRESENT A HAZARD. WE WERE SLIGHTLY R OF LOC CTRLINE AND DSNDING AT THE MARKER BEACON WHEN THE DUCHESS WAS NOTICED SLIGHTLY BELOW AND SLIGHTLY L OF OUR ACFT. I HAD BEEN DILIGENTLY SCANNING FOR THIS TFC, BUT IT WAS BLOCKED FROM VIEW AS WE DSNDED. DUCHESS DISCONTINUED APCH. 1) CTL IS NEEDED (RADAR) OVER TRAINING FLTS AT LAF. I UNDERSTAND GRISSOM AFB WOULD BE WILLING TO PROVIDE THIS, 2) ALTERNATELY -- VFR ACFT AT LAF SHOULD BE EDUCATED TO CONSIDER DISCONTINUING APCH WHEN IFR TFC INBOUND, 3) EVEN THOUGH OUTSIDE OF LAF CLASS D AIRSPACE, TWR MIGHT PROVIDE MORE INFO. CONSIDER EXPANDING LAF CLASS D AIRSPACE TO INCLUDE EARLE OM? CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED SHE WAS FLYING A BEECH SUNDOWNER. SHE REEMPHASIZED THERE ARE MANY SIMILAR NEAR MIDAIRS ON PRACTICE APCHS AT THIS ARPT IN THAT IT IS ASSOCIATED WITH PURDUE UNIVERSITY WHICH IS ACTIVE IN AVIATION TRAINING. THERE IS A PROFESSOR AT THE UNIVERSITY WHO HAS SUGGESTED THE TRAINING BE DONE AT GRISSOM AFB. THE WORD IS THAT THE AFB HAS RADAR AND WOULD BE DELIGHTED TO ASSIST IN THE PURDUE TRAINING.

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.