Date: 201504
Local time of day: 1801-2400
Location: DEN.Tower, CO
Light: Dusk
Aircraft: Light Transport; Low Wing; 2 Turboprop Eng
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B DEN
ATC / advisory: Tower DEN
Second aircraft: Light Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Government
Reporter function: Local
Reporter qualification: Air Traffic Control Fully Certified
Human factors: Workload; Situational Awareness; Time Pressure; Distraction; Confusion; Communication Breakdown
Anomaly: ATC Issue All Types; Conflict Ground Conflict; Less Severe; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Contributing factors: Procedure
Primary problem: Procedure

Narrative: Working LC2 landing 17R departing 17R/17L; transitioning into a north operation in which we would be landing 35L/35R.  Traffic management had coordinated the last 17R arrival would be Aircraft X but had not advised what the first north arrival(s) would be.  As it turns out; D01 (Denver Approach) was bringing arrivals into both 35L and 35R.  By appearances they were attempting to time the operation so that Aircraft X would be off the runway before opposite direction operation procedures would need to be applied.  I observed Aircraft Y tagged for 35L and another aircraft (flight # not noted) for 35R; south of the airport; slowly maneuvering northbound and kept high.  By my judgment the timing would not work out if the ODO (Opposite Direction Operation) arrivals were cleared for approach; but since they were high my expectation was that they would be getting a holding turn. This did not happen; however.  Aircraft X was not even across the 17R threshold (probably 500-1;000 feet from it) when Aircraft Y checked on over the FAF for Runway 35L; descending out of 8;400 feet MSL.  I advised them to continue and that opposite direction arrival was rolling out; which was Aircraft X's status when the transmission was made.  Aircraft X exited a reverse high-speed (do not remember if it was M6 or M7); and when they were clear of the runway I cleared Aircraft Y to land 35L.  At that time they were approximately three mile final but still at 6;900 feet MSL; significantly above the normal glide path.  They subsequently executed a missed approach on short final (approximately 1/4 mile) due to being too high. It should be noted that during the majority of this event I was in the process of being relieved but that did not interfere with my actions as I kept the frequency and issued instructions; while between myself and the relieving controller we accomplished the coordination and handoff per facility SOP.  Also; I found out after the fact that the Runway 35L ILS and PAPI were not turned on when Aircraft Y was on approach.  The PAPI could have been turned on by myself (but I was not directed to do so) or by supervisor/TMC (as is normal at our facility) but the ILS for 35L could not be turned on until Aircraft X was on the ground or if they had been solicited to allow the change while airborne.  It appears that D01 had not coordinated the first north arrivals with our ODO operations in the Denver approach control airspace were recently suspended at the instruction of D01 due to misapplication of rules/procedures and the need for further training of their controllers.  Despite the suspension of ODO; it appears the final controller did not apply common sense in ensuring that the last 17R arrival would be clear of the runway before transferring communication and control of the first for 35L.  I would recommend that D01 get ODO training as soon as possible if it is ever to be used in the Denver hub.




Synopsis: A Denver Tower Controller reports of an Opposite Direction Operation (ODO) that led to a loss of separation.