U2 drained US air traffic control of its memory

Last week’s terrifying incident where the Los Angeles Air Traffic control shut down when an U2 spy plane flew overhead was the result of a memory problem and it could have happened anywhere in the US.

In fact those looking into the incident claim that the same vulnerability could have been used by an attacker in a deliberate shut-down.

The error blanked out a broad swath of the southwestern United States, from the West Coast to western Arizona and from southern Nevada to the Mexico border.

It cost the US more than $2.4 billion to build the Air Traffic Control system, which was  made by Lockheed Martin. Apparently the system had a lack of altitude information in the U-2’s flight plan and caused a memory overload. The FAA spokeswoman Laura Brown said the computer had to examine a large number of air routes to “de-conflict the aircraft with lower-altitude flights and the system just did not have the RAM for it.

The FAA later set the system to require altitudes for every flight plan and added memory to the system, which should prevent such problems in the future, Brown said.

When the system went out, air traffic controllers working in the regional centre switched to a back-up system so they could see the planes on their screens and reverted to pen and paper for communications to other control centres.

Apparently the ERAM system failed because it limits how much data each plane can send it, according to the sources. Most planes have simple flight plans, so they do not exceed that limit. But the U2 had a complex flight plan that put it close to the system’s limit, the sources said.

For example the flight plan showed the plane going in and out of the Los Angeles control area multiple times, not a simple point-to-point route like most flights, they said. The conflict generated error messages and caused the system to begin cycling through restarts.

What is worrying is that the same gear is used in other airports so it could happen there at any time. The problem could also, with some difficultly, be created by a hacker.

Security experts said that from the description by insiders, the failure appeared to have been made possible by the sort of routine programming mistake that should have been identified in testing before it was deployed. The FAA said that a fix was being rolled out.