At this point, some people at the FCC and in the White House should start feeling a little … nervous. Yesterday afternoon, the Departments of Defense and Transportation released a joint statement stating that LightSquared is about as bad on navigational equipment as everyone knew it would be:

Today, a government technical group reviewed the findings from last month’s testing of LightSquared’s proposal to provide new broadband service.  The final test report will be sent to the National Telecommunications and Information Agency (NTIA), which advises the President on telecommunications policy, and represents federal agencies to the Federal Communications Commission (FCC).

Preliminary analysis of the test findings found no significant interference with cellular phones. However, the testing did show that LightSquared signals caused harmful interference to the majority of other tested general purpose GPS receivers.  Separate analysis by the Federal Aviation Administration also found interference with a flight safety system designed to warn pilots of approaching terrain.

The findings were presented to the technical steering group which represents the seven federal agencies that make up the Space-Based Positioning Navigation and Timing Executive Committee.  Over the next several weeks, the final analysis of the findings will be completed and a final report will be transmitted from NTIA to the FCC.

One of these is same test whose results leaked last week, showing that LightSquared substantially interfered with 75% of the general-purpose GPS receivers tested; this is the review that LightSquared and its lobbyists apparently thought would significantly change the conclusion of the test.  Oops!   Now the FAA adds even more pressure by concluding that LightSquared interferes with an aviation system that keeps pilots from running into mountains.  Think anyone at the FCC is going to tell airlines not to worry, but just refrain from flying in the dark and in the clouds?  Yeah, me neither.

It’s no great shock that LightSquared doesn’t interfere with other cell phones, since they’re using a part of the spectrum that’s not anywhere close to the frequencies used by other cell phones.  Also, cell phones use signals that are strong enough that the phones don’t have to have extraordinary sensitivity to detect them.  That’s not true of GPS devices, however, which have to have heightened sensitivity to detect and process signals from satellites in orbit, and which don’t transmit signals themselves.  That’s the reason why parking cell-phone traffic and its strong terrestrial-based transmitters next to the GPS band is such an obviously bad idea.

The question isn’t whether the FCC will allow LightSquared to proceed with its commercial roll-out now.  With the DoD and the DoT making a public announcement like this, all of the letters from all of the state legislators in the nation isn’t going to put enough pressure on the FCC to let planes fly into mountains and force millions of people to replace their GPS devices.  No, folks at the FCC and the White House are going to start preparing for the Congressional investigation into their decision to allow LightSquared to pursue this in the first place, along with all of the connections between LightSquared, its parent Harbinger, and the Obama administration — an investigation that Sen. Charles Grassley has been pursuing all along.