Beech 1900
Air Traffic Control Fully Certified
Communication Breakdown; Situational Awareness
Conflict Airborne Conflict; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance
Human Factors
A Cessna 172 and another 172 were in the traffic pattern. [An airliner] was inbound from the West for a visual approach showing 290 KTS of ground speed. MD was working Local 1 and instructed [the airliner] to make a straight in for Runway XXL and report an 8 mile final. The first 172 was on a 5 mile final for Runway XXL when the second 172 was downwind passing the numbers of Runway XXL. Instead of turning the second 172 into the 5 mile hole; the Controller extended his downwind. I thought the intent was to have the second 172 follow the airliner since he was turning base leg 8 NM North of the airport;. Instead the Controller turned the second 172 to follow the first 172. I told the Controller that wouldn't work since the airliner was still going well over 200 knots. I told the Controller to change the second 172 to Runway XXR and the Controller ended up having to send the first 172 around to have enough room to let the airliner land. The Controller didn't want me to get him/her out because it was too busy; honestly it was self-inflicted volume and complexity. I ended up opening Local 2 and getting Local 1 relieved as he/she was clearly in over his/her head. I don't agree with a check ride for certification consisting of being able to work one session of moderate traffic without an 'A1.' This breeds controllers that can squeak by under idea conditions but can't handle the traffic if any little thing doesn't go their way. Not understanding sequencing; speed control; traffic flow; etc and counting on doing everything rote and having it work out makes for some scary situations and very poor customer service. I asked him/her later what went wrong and she said that the airliner turned a 6 mile final instead of an 8 mile final. I explained that when the trailing aircraft is going nearly 5 miles per minute and the leading aircraft is going less than 2 miles per minute; 2 miles doesn't make any difference at all. I suggested that if traffic existed to take the airliner over the top of the airport and enter them on the downwind in addition to moving pattern traffic to the other runway.
Tower CIC described a go-around event when the Local Controller failed to noted the overtake speed of a much faster aircraft resulting in a go around clearance even after recommendations were provided by the reporter.