Observation posted by CafeClub (a few slots ago):"... with all the other warning bells and whistles there's nothing on the flight deck that alerts the crew to change frequencies? ... wouldn't be hard to install? ... that's mere data to load ... this be a simple safety remedy?"
The "voice" over VHF COMM is the main problem. The solution [Controller Pilot Data Link Communications Program] would solve several worse problems (blocked calls in busy locations). _OBSERVATIONS ON FAA’S CONTROLLER-PILOT DATA LINK COMMUNICATIONS PROGRAM_, FAA Report Number: AV-2004-101, September 30, 2004
"... FAA decided to cancel the current CPDLC program for a number of reasons.... In late 1998, FAA and industry ... reached a general agreement on the specific technology to transmit messages (Very High Frequency Digital Link Mode-2: VDL-2) and a phased approach for moving forward with CPDLC in the en route environment.... American Airlines agreed to serve as the lead airline and begin equipping aircraft with new avionics for trials ...
According to FAA, CPDLC was expected to reduce aircraft direct operating costs by reducing delays and improving efficiency through decreasing(1) congestion on the voice channels, and
(2) operational errors resulting from misunderstood instructions and read-back errors...."
The USA's "regulator" (FAA) recently blamed the "operator's" human-pilot in this NORDO case. If the USA's air safety system has any integrity remaining, then the USA's "independent Safety Board" will eventually cite the "regulator" for negligence for not developing CPDLC in a timely manor; for not acknowledging the fact that "voice" COMM is out-dated, for still relying on the 1930's method of "voice" COMM for Air Traffic Management.
CPDLC Controller-Pilot Data-Link Communications
Controller-Pilot Datalink (CPDLC)
Avionics Magazine :: Perspectives: Data Link In Europe: An Overview