The National Reconnaissance Office (NRO) ran a drill on 9/11 involving a hijacked plane crashing into a building.
Although not everyone uses the word "hijacked", there are articles online that seem to imply this, at least to the casual reader:
On the morning of September 11, 2001, NORAD was running war games involving hijacked airliners while the National Reconnaissance Offices (NRO) was running a drill for the scenario of an errant aircraft crashing into a government building at the exact same time as an identical scenario was perpetrated.
"An identical scenario"? So that must mean the NRO drill involved hijacked aircraft, right? Well, maybe not, as even Mike Ruppert discovered:
...the NRO’s drill was “based on the idea of a Lear Jet or a FedEx plane having a flame-out on takeoff from nearby Dulles airport and crashing into the building.” The NRO is close to the end of one of Dulles’ runways. However, Oborn said, since there was no flying involved, there was no need to coordinate with the military or the FAA.
Page 381, "Crossing the Rubicon"
So this was about a plane crashing into their own offices due to mechanical failure, not hijacking, and there's no indication other agencies were involved. Doesn't look too significant to us, although others have suggested other possible reasons for NRO involvement.
The NRO is, effectively, the “eyes of the world”. With the majority of American spy satellites at its fingertips, it can reasonably be assumed that NRO headquarters was an indispensable resource to NORAD and the Air Force from 8:28 when Flight 77 made its unplanned 180-degree turn over Pennsylvania, until 9:38 when it is said to have struck the Pentagon. The NRO claims as soon as the real world events “began to unfold” the drill was called off and all but the most essential personnel were sent home. (UPI, Aug 22, 2002)
Read that last sentence again.
Why was the NRO sending home personnel during what was likely the biggest military crisis on American soil in recent history? Who were the “most essential” personnel and what did those individuals do as events unfolded?
It seems like we have one or two questionable assumptions here, like the idea that NRO would have been an “indispensable resource” to NORAD. Why? How are spy satellites going to be any more useful at picking up and identifying a particular plane, than radar?
But let’s assume they were. Why shouldn’t the satellites still have been available? Who says they’re controlled from the NRO Headquarters, anyway? From the photos we’ve seen, it just looks like a big office building ( http://ludb.clui.org/ex/i/VA3142/ ).
What’s more, other reports suggest the satellites are actually controlled from Buckley Field in Colorado.
Although precise details of US space-based Sigint satellites launched after 1990 remain obscure, it is apparent from observation of the relevant ground centres that collection systems have expanded rather than contracted. The main stations are at Buckley Field, Denver, Colorado; Pine Gap, Australia; Menwith Hill, England; and Bad Aibling, Germany.
The $1.5 billion satellite is a joint project of the NSA and the National Reconaissance Office (NRO)...
According to John Pike of the Federation of American Scientists, those satellites will likely be controlled from Buckley Field (Aurora, Colorado), an NSA/Reconnaissance downlink base slated to become this hemisphere's largest intelligence base in the 1990s.
The intelligence site Cryptome seems to agree, and has published pictures showing various parts of the Buckley site (note that they don’t mention NRO HQ at all).
Even if the NRO headquarters did play a part, it’s not clear that the drill would have made any difference:
Officials at the Chantilly, Va.-based National Reconnaissance Office had scheduled an exercise that morning in which a small corporate jet crashed into one of the four towers at the agency's headquarters building after experiencing a mechanical failure.
The agency is about four miles from the runways of Washington Dulles International Airport.
Agency chiefs came up with the scenario to test employees' ability to respond to a disaster, said spokesman Art Haubold. To simulate the damage from the plane, some stairwells and exits were to be closed off, forcing employees to find other ways to evacuate the building.
"It was just an incredible coincidence that this happened to involve an aircraft crashing into our facility," Haubold said. "As soon as the real world events began, we canceled the exercise."
As the crash only affected one tower, it’s surely possible that staff elsewhere continued to work as normal. There’s certainly nothing here on the numbers of staff involved, and no reason to believe that satellite feeds wouldn’t have been available as normal.
Note also that, despite this being grandly described as a “war game” at some sites (presumably because it was being run by “John Fulton” and his team, a CIA agent assigned as the “head of the NROs strategic gaming division”), it actually sounds like little more than an extended fire drill.
But wait: the claim is that the NRO staff were sent home “during” the crisis, right? As events unfolded? Might seem suspicious if it were true, but unfortunately there’s no evidence that this happened.
After the Sept. 11 attacks, most of the 3,000 people who work at agency headquarters were sent home, save for some essential personnel, Haubold said.
Staff were sent home after the attacks, not during. And even then, essential personnel remained -- again, no evidence to show satellite use was compromised.