Wake Turbulence effects as seen from the Tower
My first encounter with wake turblence was one night working the UPS inbound at SDF when Runway 19 and 29 were still in use.
Approach had sequenced and cleared a Metroliner for a visual approach to follow a Heavy UPS DC8 to Runway 29. As the DC8 approached the numbers, the Metroliner was just crossing the marker inbound. I looked out the Tower Cab window just in time to see the Metroliner wingtip lights rotate 360 degrees, and then heard the pilot yell "Jesus Christ... we just did a barrel roll!"
My second encounter was again at SDF. A DAL B737 was on short final to Runway 19 with a Bell Jet Ranger departing from the base of the Tower Cab turning northeast bound VFR. I exchanged traffic with the helicopter and DAL. The helicopter lifted off and banked sharply just east of the area where the DAL B737 was about to touch down. Suddenly the B737 banked sharply to the right... away from the runway... over the parallel taxiway... banked sharply to the left... and then finally landed.
The DAL pilot said, "Son... I want you to know that it was partly my years of experience that allowed me to land this aircraft, but it was mostly luck that we weren't all killed from that helicopter's prop-wash." Apparently the helicopter's prop wash was directed down towards the runway as he banked and then upwards... underneath the left wing of the B737!
In both instances, traffic had been exchanged and the appropriate separation rules had been applied... but wake turbulence and prop wash almost took a life.
These two instances sure made a believer out of me! Scary stuff to see from the Tower Cab.
MEM_ATC