Narrative:

A flight check (flight crew) aircraft was doing approaches to xxr during a very busy period; both arrival runways were stacked with arrivals and departure runways were stacked with departures. I had to hit holes off 15 with arrivals to 9; the aircraft on final were compressing to the point that I could not get any departures out; so a line started forming; I had a good hole to get a few departures out so I did and then out of nowhere flight crew appeared inbound and high doing his approach to xxr; either nobody told me; or I was too busy to hear that he was inbound. I had to vector to get separation but got altitude and switched a B737 to departure; behind him was a Q400; the conflict aircraft. I was told that flight check was going north; I assumed 360; on a missed approach; typically our missed approaches go out at 2;000; so I assumed he was going north and climbing to 2;000 my Q400 was on a 020 heading and I figured no big deal they are separated with diverging headings and altitude so I switched the Q400 to departure. I then cleared another aircraft for take off; which wasn't in conflict at all. I then heard that flight check was put on a 040 heading and climbed to 3;000 which was right in front of that first Q400 and everybody panicked; we had separation laterally because flight crew was VFR. Flight check aircraft have consistently been approved to come in and do their work during some very busy periods. It seems it is very inappropriate to approve flight check requests but time and again it gets approved during very busy periods flight check was in the day before and told he could do his work at xa:00 which is actually one of the busiest periods all week. We have 'no fly days' mids and down time that we can work them but during a push [which] is very task loaded; and presents a very serious safety risk in my opinion; as far as I know these checks had nothing to do with critical NAS components such as ILS.

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Original NASA ASRS Text

Title: Tower Controller described a near separation event between IFR traffic and an FAA Flight Check aircraft; the reporter claiming the flight check operation should have been sceduled a less busy/complex traffic period.

Narrative: A Flight Check (FLC) aircraft was doing approaches to XXR during a very busy period; both arrival runways were stacked with arrivals and departure runways were stacked with departures. I had to hit holes off 15 with arrivals to 9; the aircraft on final were compressing to the point that I could not get any departures out; so a line started forming; I had a good hole to get a few departures out so I did and then out of nowhere FLC appeared inbound and high doing his approach to XXR; either nobody told me; or I was too busy to hear that he was inbound. I had to vector to get separation but got altitude and switched a B737 to departure; behind him was a Q400; the conflict aircraft. I was told that Flight Check was going north; I assumed 360; on a missed approach; typically our missed approaches go out at 2;000; so I assumed he was going north and climbing to 2;000 my Q400 was on a 020 heading and I figured no big deal they are separated with diverging headings and altitude so I switched the Q400 to Departure. I then cleared another aircraft for take off; which wasn't in conflict at all. I then heard that Flight Check was put on a 040 heading and climbed to 3;000 which was right in front of that first Q400 and everybody panicked; we had separation laterally because FLC was VFR. Flight Check aircraft have consistently been approved to come in and do their work during some very busy periods. It seems it is very inappropriate to approve flight check requests but time and again it gets approved during very busy periods Flight Check was in the day before and told he could do his work at XA:00 which is actually one of the busiest periods all week. We have 'no fly days' mids and down time that we can work them but during a push [which] is very task loaded; and presents a very serious safety risk in my opinion; as far as I know these checks had nothing to do with critical NAS components such as ILS.

Data retrieved from NASA's ASRS site as of July 2013 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.