Why Not Repair the Existing timers?
  • Parts for the existing timers are obsolete and unavailable at the reasonable costs. The cost to repair existing timers is estimated to be about three times the cost of purchasing new WTT4/WTT5 timers with enhanced features.
Why do the timer sections have red and yellow buttons and displays?
  • The time sections are color-coded to aid in remembering which timer section is in use for what task. The red/green combination was avoided to eliminate any port/starboard association of the timer sections.
The old Timers started a countdown when the button was released not when it was pressed. Why can't the WTT4/WTT5 work the same way?
  • The WTT4/WTT5 timers were developed to support 2 and 3 minute periods before the RECAT was issued. In order to include the common 4 and 5 minute periods of the RECAT, an extended button press is used to extend the 2 minute period to 4 minutes and the 3 minute period to 5 minutes. There is simply no way to include the extended periods of the RECAT and release-to-start operation. 
Why don't the WTT4/WTT5 timers support all 6 periods of the RECAT?
  • The initial timer design was completed before the RECAT was issued. The existing hardware supported two extended periods in a logical and easy-to-use way. Adding all six periods of the RECAT wasn't possible using the existing hardware and the 4½ and 5½ minute periods are seldom used at most facilities. Revised hardware was considered, but this would most likely mean separate controls to set the time period and to initiate a countdown; the single button press select & go was deemed a preferable solution.
Why do the WTT4/WTT5 have different beep patterns depending on the timing interval selected?
  • The beep patterns are different for the red and yellow timer sections so that the user can know which timer section completed without the need to look at the timer. There is no differentiation in beep characteristics depending on the time interval selected.
Why don't the WTT4/WTT5 timers have metal panels?
  • The original lot of 10 timers had aluminum panels manufactured by the FAA Staging Area in Independence, Missouri, and the plan going forward was to continue to use FAA-provided panels.
Unfortunately, obtaining additional panels in a timely fashion proved unreliable. Commercially manufactured aluminum panels in small lots are prohibitively expensive, so an alternative was found. The panels are laser cut from acrylic material; they can be manufactured in small lots at a reasonable cost.