Note: the Controller/Pilot Data Link Communications (CPDLC) program has been cancelled. You may read the US Department of Transportation Inspector General's Audit Report on this program here. Below is an excerpt.

The CPDLC program represented a new way for controllers and pilots to communicate that is analogous to wireless email. CPDLC was planned for use at the en route centers, the facilities that manage high-altitude air traffic. CPDLC was expected to reduce aircraft direct operating costs by reducing delays and improving efficiency by (1) reducing congestion on the voice channels, and (2) reducing misunderstood instructions and read-back errors between controllers and pilots. FAA and industry jointly invested in CPDLC and began using data link on a limited basis in high-altitude airspace managed by the Miami Center in October 2002. CPDLC was expected to play an important role in the Agency’s Operational Evolution Plan for enhancing capacity and reducing delays over the next decade. However, FAA subsequently decided to cancel the current CPDLC program and plans to shut down CPDLC at Miami Center and terminate all the program’s activities by March 2005.

FAA decided to cancel the current CPDLC program for a number of reasons. FAA’s reasons for canceling the CPDLC program included cost growth and schedule delays, caused by such factors as the emergence of unplanned additional integration requirements that posed a risk to the program, and concerns over how quickly airlines would equip with avionics. Although FAA may start another CPDLC program in the future, it is difficult to quantify precisely what can be salvaged from the dollars spent because it is unclear what the next CPDLC effort will resemble in terms of specific technology and related FAA infrastructure. We estimate, however, that $23 million of the $100 million spent on CPDLC may be salvageable for future data link efforts. Finally, we identified a number of lessons learned or processes and controls that FAA should establish to avoid similar outcomes in the future.

One of the reasons FAA canceled CPDLC was because the program encountered cost growth and schedule delays. The original program acquisition cost estimate of $166.7 million to implement CPDLC at 20 sites was no longer valid. FAA’s revised cost estimate indicated it would cost $236.5 million to implement CPDLC at eight sites, less than half the sites originally planned for an additional $69.8 million. Further, the program would be 1.5 years behind schedule. FAA also was concerned about CPDLC’s impact on its operations account, which is already overburdened. 1 For example, FAA’s revised estimate indicated it would cost $345.2 million to operate a reduced CPDLC program effort from fiscal year (FY) 1999 through FY 2017. This estimate included, among other things, $63 million for controller training and overtime and $191 million for CPDLC messaging costs.

CPDLC experienced overruns and delays in part because certain program assumptions were invalid. For example, it was assumed the Display System Replacement (DSR) workstations, which controllers would use to input data link messages, would not require a software change to accommodate CPDLC. This proved wrong, increasing the cost and schedule estimate to accomplish the integration of CPDLC and DSR. This and other delays required FAA to integrate CPDLC with the En Route Automation Modernization (ERAM) architecture (an unplanned requirement), posing additional cost and schedule risk to both programs.