Cessna Stationair/Turbo Stationair 6
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2.5
Situational Awareness; Confusion; Distraction
ATC Issue All Types; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway; Inflight Event / Encounter Weather / Turbulence
Human Factors; Weather
I was working LC1 position in the Tower. The event took place at LC2 position. The surface wind displayed on the CTRD [Certified Tower Radar Display] was showing out of tolerance for CRDA [Converging Runway Display Aid] operations to Runways 18L and [Runway] 27 according to MEM Order 7110.68 'use of CRDA during VFR conditions.' The supervisor; decided to advertise CRDA on the ATIS anyway. Aircraft X was now inbound to RWY 27 with V traffic inbound to RWY 18L. The LC2 Controller told the Supervisor [LC2] was going to break out the arrival to RWY 27 on initial contact; planning to turn Aircraft X south heading 180. The wind was 110 at 11 kts. The Supervisor told [LC2] directly to clear the aircraft to land anyway and said he would take all responsibility for the situation. The LC2 controller complied with the Supervisor's directions and cleared the aircraft to land. In addition; the Supervisor was instructing LC2 to adjust the speeds of aircraft on final to RWY 18L and RWY 27 within the final approach fix - which is not allowed according to the 7110.65w section 5-7-1. Wind of 110 at 11 kts gives the aircraft to RWY 27 a tailwind and then the aircraft to RWY 18L a headwind. These conditions make it unsafe for CRDA operations. After this instance; another arrival was allowed to land RWY 27 in CRDA operations with RWY 18L when the wind was 130 at 10 kts. This aircrafts call sign was Aircraft Y. Again; speeds were adjusted within the final approach fix and the CRDA operation occurred when wind was out of tolerance. MEM Tower should not allow CRDA operations; as per the MEM Order 7110.68; to occur when wind is out of tolerance. RWY 27 should be released to ground control during times when the wind is out of tolerance for CRDA operations.
Memphis Tower Controller reported the incorrect usage of Converging Runway Display Aid procedures.