Narrative:

Tys approach control had 4 aircraft established on the ILS for runway 23R. 2 aircraft were operating IFR. The other 2 were VFR. All 4 aircraft were conducting practice ILS approachs. The aircraft were spaced about 5 mi apart on the final approach course. In other words, there were 5 mi between each practice approach aircraft on final. Approach control vectored a faster BE58 directly toward the airport and instructed the pilot to cross over the top at midfield and enter a left downwind for runway 23L. Approach control coordinated with local and asked me to see the BE58 and the nearest aircraft on final from the airport and apply visual separation between the 2 aircraft. The BE58 crossed over the airport and turned a left downwind. At this point, I could not see either aircraft out the tower windows. On the BRITE scope, I observed the aircraft pass within 1 1/2 mi of each other. When I determined that the BE58 would not collide with the C172, I cleared the BE58 to land on runway 23L. The runways at tys are too close together for simultaneous operations. There are more military and civilian, practice approachs conducted at mcgee-tyson airport in knoxville annually than any other airport in tennessee. ATC controllers consider the practice approachs to be 'their bread and butter.' controllers regularly allow IFR and VFR. Military and civilian practice approachs to disrupt the flow of other arriving and departing IFR and VFR, aircraft in violation of FAA order 7110.65N, (4-8-1). When controllers feel pressure to expedite the movement of an arriving aircraft that will be, or are delayed, by a practice approach aircraft, they will vector these aircraft to a position in the approach sequence. Attempt to get one aircraft to see another, and to maintain visual separation from it. When the pilots cannot see each other, radar separation is lost. So, the approach controllers will ask tower controllers to see and separate, visually, aircraft in the final approach sequence. This procedure is a gross misapplication of visual separation rules contained in chapter 7 of the FAA order 7110.65.

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Original NASA ASRS Text

Title: TYS CTLR EXPERIENCED OPERROR.

Narrative: TYS APCH CTL HAD 4 ACFT ESTABLISHED ON THE ILS FOR RWY 23R. 2 ACFT WERE OPERATING IFR. THE OTHER 2 WERE VFR. ALL 4 ACFT WERE CONDUCTING PRACTICE ILS APCHS. THE ACFT WERE SPACED ABOUT 5 MI APART ON THE FINAL APCH COURSE. IN OTHER WORDS, THERE WERE 5 MI BTWN EACH PRACTICE APCH ACFT ON FINAL. APCH CTL VECTORED A FASTER BE58 DIRECTLY TOWARD THE ARPT AND INSTRUCTED THE PLT TO CROSS OVER THE TOP AT MIDFIELD AND ENTER A L DOWNWIND FOR RWY 23L. APCH CTL COORDINATED WITH LCL AND ASKED ME TO SEE THE BE58 AND THE NEAREST ACFT ON FINAL FROM THE ARPT AND APPLY VISUAL SEPARATION BTWN THE 2 ACFT. THE BE58 CROSSED OVER THE ARPT AND TURNED A L DOWNWIND. AT THIS POINT, I COULD NOT SEE EITHER ACFT OUT THE TWR WINDOWS. ON THE BRITE SCOPE, I OBSERVED THE ACFT PASS WITHIN 1 1/2 MI OF EACH OTHER. WHEN I DETERMINED THAT THE BE58 WOULD NOT COLLIDE WITH THE C172, I CLRED THE BE58 TO LAND ON RWY 23L. THE RWYS AT TYS ARE TOO CLOSE TOGETHER FOR SIMULTANEOUS OPS. THERE ARE MORE MIL AND CIVILIAN, PRACTICE APCHS CONDUCTED AT MCGEE-TYSON ARPT IN KNOXVILLE ANNUALLY THAN ANY OTHER ARPT IN TENNESSEE. ATC CTLRS CONSIDER THE PRACTICE APCHS TO BE 'THEIR BREAD AND BUTTER.' CTLRS REGULARLY ALLOW IFR AND VFR. MIL AND CIVILIAN PRACTICE APCHS TO DISRUPT THE FLOW OF OTHER ARRIVING AND DEPARTING IFR AND VFR, ACFT IN VIOLATION OF FAA ORDER 7110.65N, (4-8-1). WHEN CTLRS FEEL PRESSURE TO EXPEDITE THE MOVEMENT OF AN ARRIVING ACFT THAT WILL BE, OR ARE DELAYED, BY A PRACTICE APCH ACFT, THEY WILL VECTOR THESE ACFT TO A POS IN THE APCH SEQUENCE. ATTEMPT TO GET ONE ACFT TO SEE ANOTHER, AND TO MAINTAIN VISUAL SEPARATION FROM IT. WHEN THE PLTS CANNOT SEE EACH OTHER, RADAR SEPARATION IS LOST. SO, THE APCH CTLRS WILL ASK TWR CTLRS TO SEE AND SEPARATE, VISUALLY, ACFT IN THE FINAL APCH SEQUENCE. THIS PROC IS A GROSS MISAPPLICATION OF VISUAL SEPARATION RULES CONTAINED IN CHAPTER 7 OF THE FAA ORDER 7110.65.

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.