Narrative:

Aircraft Y was unexpectedly slow on their approach; and aircraft X; the following aircraft was unexpectedly fast. I issued a speed reduction to aircraft X in what I believed was plenty of time to keep 2.5 miles by the threshold; however; I failed to consider that; being 12 miles from the airport; I am required to keep 3.0 miles spacing; as 2.5 miles is only legal at 10 DME. Apparently; during my speed reduction to aircraft X; I used the words 'speed' and 'knots' the same sentence; which led to a side conversation between 2 supervisors and 2 controllers in my immediate area wherein they all agreed that such phraseology violates the 7110.65; that it generally leads pilots to believe we are incompetent at our jobs; and that such willful non-compliance to published rules is grounds for formal punishment; etc. I allowed this side conversation to distract me from my duty; and cancelled aircraft xs approach clearance later than I otherwise should have; at approx. 2.94 miles; 11 DME from the field. A more timely speed reduction to aircraft X would have helped; as well as a more concerted effort on my part to remain diligent to my work and not allow side conversations to distract me.

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Original NASA ASRS Text

Title: A Controller allowed final approach spacing to decrease to 2.9 miles before breaking the second aircraft out for re-sequencing. Three miles spacing was required.

Narrative: Aircraft Y was unexpectedly slow on their approach; and Aircraft X; the following aircraft was unexpectedly fast. I issued a speed reduction to Aircraft X in what I believed was plenty of time to keep 2.5 miles by the threshold; however; I failed to consider that; being 12 miles from the airport; I am required to keep 3.0 miles spacing; as 2.5 miles is only legal at 10 DME. Apparently; during my speed reduction to Aircraft X; I used the words 'speed' and 'knots' the same sentence; which led to a side conversation between 2 supervisors and 2 controllers in my immediate area wherein they all agreed that such phraseology violates the 7110.65; that it generally leads pilots to believe we are incompetent at our jobs; and that such willful non-compliance to published rules is grounds for formal punishment; etc. I allowed this side conversation to distract me from my duty; and cancelled Aircraft Xs approach clearance later than I otherwise should have; at approx. 2.94 miles; 11 DME from the field. A more timely speed reduction to Aircraft X would have helped; as well as a more concerted effort on my part to remain diligent to my work and not allow side conversations to distract me.

Data retrieved from NASA's ASRS site 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.