Is the proposed design of the aeronautical data link system likely to reduce “the miscommunications error rate and controller/flight crew input errors?”

The Operational Safety Assessment (OSA) performed for Controller Pilot Data Link Communications (CPDLC) has resulted in a strategy for operational acceptability for en route radar airspace. This strategy includes: continued use of Very High Frequency (VHF) voice for rapid response messages, use of data link only for “strategic” communication situations, end-to-end integrity functionality, identification of procedural requirements for data link use, and provisions for operations differences due to human factors. This strategy is formulated based on the identification of operational hazards and the understanding of the risk management details in each case. Hazards that drive this strategy include the corruption of a clearance message and the misdirection of a clearance message. The characteristics of the current or baseline air/ground voice communications system in terms of operational effectiveness, availability, and integrity are reviewed and compared with requirements derived for CPDLC Build 1A from operational safety considerations. The comparison is made with the understanding that the operational hazards identified are largely independent of the technology used for communication. We assert that requirements for new capabilities should be considered not in absolute terms but rather relative to the performance of current operational systems. This leads to a rational development of performance requirements and facilitates the fielding of the new technology. We find that current VHF voice communication performance strongly motivates the implementation and use of data communications, and the full understanding of current mitigation strings for the operational hazards associated with miscommunication in Air Traffic Control (ATC). Operational Safety Assessments should, in general, consider the baseline system performance so that operational hazard classifications can be done on a rational basis and that the method consider both hazards introduced and those mitigated by the proposed new capability