Jon, may I ask how this display is used, please? What does it actually indicate?
Sorry if my question seems 'off topic' but my wife and I are Private Pilots and so we've visited friends at a couple towers and traffic control centers. The equipment is always very interesting.
Cheerful regards, Mike
Happy to explain but know, i am 10 days out from a total knee replacement and my words may be a little oxicodoney at the moment
These displays are for Wake Turbulence Timers. If a small plane is too close behind a large plane, it can be caught in the wake vortices of the larger plane. The resulting motion can be catestrophic, even spinning the smaller plane around.
In flight and during landing, planes are separated by distance...a number of miles based on relative plane sizes and types of aircraft involved.
For takeoffs, rather than using distance as the separator, the
time between takeoffs is controlled. In most cases, separations of 2 or 3 minutes between takeoffs are used depending on the aircraft type.
How this time interval is monitored depends on the tower and Air Traffic Controller. Controllers may use a stop watch, look at a clock, use a hourglass eagg timer...there is not a lot of standardization. But in a growing number of towers, Wake Turbulence Timers, designed by yours truly, are used. When a plane takes off, the controller presses a button to start a countdown timer of the appropriate interval and receives notice of when the interval has elapsed.
Air traffic safety is enhanced by letting the comtroller focus on the important business at hand and runway throughput can be increased by eliminating wasted time. This timers have undergone a yearlong test program with flying colors and nationwide approval for installation in control towers across the nation is nearly complete...except for one gentleman who thinks a hourglass egg timers are all that Air Traffic Contollers need and are worth. The latest directives provide for more intervals depending on plane types - my timers currently support 4 intervals.
For more information and a glimpse of why it takes the FAA forever to accomplish anything, visit
www.WakeTurbulenceTimers.com