Citing “continuing skepticism” among aviation industry stakeholders in both the U.S. and Europe, the U.S. Government Accountability Office (GAO) has recommended that the FAA provide more information on its efforts to align with Europe on ATC modernization.

In a performance audit report to Congress in November, the federal oversight agency recommended that the FAA disseminate more information about interoperability efforts with Europe in public documents, such as strategic plans and performance reports. In particular, the agency should outline a recently signed memorandum of cooperation (MoC) that established a formal, collaborative structure for the U.S. NextGen and European Sesar ATC modernization programs.

The FAA and European Union signed the MoC on March 3 during a high-level conference in Budapest. The agreement’s first annex covers “cooperative activities and interoperability aspects” of the NextGen and Sesar programs. It calls for the signatories to research the interoperability of avionics, communication protocols and procedures.

Carey Fagan, FAA executive director for international affairs, signed the agreement for the U.S. Pal Volner, state secretary for transport for Hungary, and Siim Kallas, EU vice president and commissioner for transport and mobility, signed on behalf of the EU.

Officials with the Sesar Joint Undertaking (SJU), the public/private organization managing Sesar’s development phase, informed the GAO that moving forward with data communications—or DataComm—represents the program’s “biggest challenge,” because the U.S. and Europe have differing time frames for implementation. The two sides eventually will coalesce on the global Aeronautical Telecommunications Network (ATN) protocol for data communications, but the U.S. plans to leverage existing Future Air Navigation System (FANS)-standard avionics and evolve to ATN.

“SJU would like to see DataComm implemented by 2018, while a senior FAA official responsible for communications believes that it will take until 2023 at the earliest,” the GAO said.