Others have been critical of the program as well. PASS, for instance, has in the past voiced concern over safety and efficiency issues related to FTI.

PASS spokeswoman Kori Blalock Keller said the FAA needs to hold Harris accountable for the problems. "If they are going to provide service, we need to make sure they are reliable and they are quick" to respond to outages, she said. Although several FAA technicians were on hand in Salt Lake City today, they couldn't do much to help out because the FTI system is managed by Harris, she said.

According to Keller, the incident will likely prompt Congress to ask the FAA Inspector General for another review of the system. The National Air Traffic Controllers Association (NACTA) has also expressed frustration over FTI. After the failure in Memphis, the organization blasted the network as "unreliable [and] lacking suitable backup" and called it a source of "great frustration and deep concern" for FAA technicians and air traffic controllers. Bill Curtis chief scientist at CAST Software and co-author of the Capability Maturity Model used in software development today, said the outage highlights the havoc that can be created when something goes wrong in large, highly interconnected systems such as the FAA air traffic control system.

"It's not just one system, but a system of systems," he said. "If one of them starts behaving in a funny way, it starts propagating out and causes problems in other systems," said Curtis.