Medium Transport; Low Wing; 2 Turbojet Eng
Air Traffic Control Developmental
Air Traffic Control Time Certified In Pos 1 (yrs) 0.5
Confusion; Distraction; Situational Awareness; Training / Qualification; Communication Breakdown
ATC Issue All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Human Factors; Procedure
Aircraft X [was] on ILS approach following Aircraft Y to runway 26. Dust storm with 3/4 mile visibility and wind approximately 270 at 25G35. I was training on Local combined with Ground/Clearance Delivery and Flight Data; not unusual for time of day and traffic. TRACON switched Aircraft X to Local on about 8 mile final; 4 miles behind Aircraft Y with a 20 knot overtake. I advised Aircraft X that he was number 2 following Aircraft Y and asked that he reduce approach speed as much as practical. Aircraft X continued to compress to 3 miles just inside the final approach fix when I asked my trainer if we are qualified to run 2.5 miles inside of 10 on final. He said that he did not think so; but did not tell me to send Aircraft X around. The Tower Controller in Charge (CIC) began looking up the rule to see if we were able to run reduced separation; but we were not certain; based on the wording; [if] whether we qualified. I advised Aircraft Y to expect to exit at Kilo in order to expedite his runway exit. Separation compressed to approximately 2.5 miles when Aircraft Y crossed the threshold of runway 26. After the event; my trainer discussed that I should have sent the trailing aircraft around. I called the ATM after being relieved; and he said that we are not single site radar and do not qualify for reduced separation. Three miles is required IFR at the runway. I believe that my trainer knew that we needed 3 miles; but when I questioned whether or not we are qualified to compress to 2.5 inside of 10; that he was uncertain and it led to confusion.Next time; I will send the second aircraft around for re-sequence with the TRACON.
LBB Developmental/Front Line Manager (FLM) reports of a loss of separation due to compression on final. The Developmental/FLM asked his instructor if they were capable of running 2.5 miles on final and the instructor replied he didn't think so. After the two aircraft landed the Developmental found out that they needed three miles instead of 2.5.