A controller-pilot datalink communications (CPDLC) training tool available on the Eurocontrol web site shows the difference in man-machine interfacing between old school avionics and the touchscreen smart phones and tablets we've become accustomed to.
While completely functional, the method of interacting with the Rockwell Collins communications management unit (CMU) in the example is not immediately intuitive, at least compared to my iPad. In fact, as a neophyte to Flight Management Systems and CMUs, it took me quite awhile to figure out the method to the madness.
One bit of advice for the uninitiated: Type your response first (by pointing and clicking on the keypad, or typing the numbers/letters on your keyboard), then click the appropriate location on the CMU where you want to place the info.
For CPDLC, the CMU is the brains of the operation, where pilots will respond to secure text messages from ATC and where they will send there own requests, for instance, asking for a rerouting around weather or an altitude change.
Pilots in Europe will be required to use CPDLC texting in airspace above 28,500 ft. starting in 2015.
Several reasons are behind the mandate, which will come to pass in the U.S. a bit later this decade. Over a VHF voice link, non-critical contacts like the ones CPDLC will initially replace can occupy 50% of a controller's time, impacting capacity. Having “canned” text messages will also help to reduce miscommunications and stuck-microphone issues.
Typical CPDLC uplink commands include “climb to,” “descend to” and “fly heading” requests, which pilots respond to by clicking “wilco,” “unable” or “stand-by” buttons. Canned requests for pilots to send to controllers include climbs or descents and weather deviations. Both pilots and controllers can also send free text messages for events not covered by pre-defined messages. If a microphone is stuck in the “transmit” mode, blocking voice communications, controllers can send pilots a text message to investigate the situation.
While new aircraft were required to have the required equipment installed from the factory as of Jan. 1, 2011, the existing fleet was given until Feb. 5, 2015, to equip. Air navigation service providers in Europe are required to have the ground infrastructure in place by early 2013 or 2015, depending on their location, though there are some indications that the February 2013 date is overly optimistic.
For many airlines, 2013 is a “do-or-die” year for scheduling fleet upgrades for the 2015 mandate, in order to overlap the Link 2000+ maintenance work with regularly scheduled C and D heavy maintenance checks rather than to risk taking aircraft out of service unnecessarily.