According to the Washington Post's Dan Froomkin, MSNBC had this to say:
Why was it so disturbing that it wasn't deemed necessary for the President to be aware of the situation? Because the Government's reactions that immediately were set in place without his knowledge or consent very nearly resulted in the deaths of two foolish, but innocent Pennsylvanians and could have resulted in many more deaths and injuries on the ground, in residential Washington.
More below the fold...
"McClellan said the president's Secret Service detail was informed about the plane at about 11:59 a.m., when the decision was made to raise the threat level at the White House to 'yellow.'
"Fighter planes were immediately scrambled to intercept the plane, and the threat level at the White House was raised all the way to 'red' before the 'all clear' was given at 12:14 p.m.
"McClellan said Bush was informed about the incident around 12:50 p.m. at the end of his ride. . . .
" 'The president was never in danger and the protocols in place after September 11 were followed,' McClellan said. 'The president has a tremendous amount of trust in his security detail and they were being kept apprised of the situation as it developed.' "
What's so truly disturbing about this failure to notify the President is that by their course of action, it is evident that the snipers aboard the Customs Service S-70 Blackhawk and the DC Air National Guard pilots in their F-16s were cleared to use deadly force if necessary, all without the President's knowledge or consent, when it was readily available.
The Blackhawk stayed abreast the Cessna 150 until the F-16s visually acquired the "target of interest" (TOI), it then departed from formation in order to clear the targeting cone. Were the F-16s unable to arrive on scene in time, the snipers aboard the S-70 would have killed both the pilot and student, if they did not deviate from their course.
As the F-16s began their engagement of the TOI, circling the light plane, which at 90kts, was traveling well below the F-16s' stall speed (~140kts), they were less than 6 minutes from the White House, given that the pilots were unable to communicate with the Cessna, they began dropping flares -- the last non-hostile act in the standard interecept procedure, roughly 90 seconds before the fighters are to drop back and open fire on the non-responsive aircraft.
Generally, this means that the intercepting fighters have already been verbally cleared to use deadly force, if need be, in order to avoid the indecisiveness and command confusion that occurred with the USAF, VA ANG and DC ANG fighters that flew City-CAPs on 9/11.
Although there is now a military chain of command in place, in the event that the President is incommunicado, to clear the destruction of a civilian aircraft suspected to be under terrorist control, the President was clearly not out of communication, if the Secret Service was able to have a back-and-forth conversation with the White House Situation Room.
And BTW, for all the hububb, a fully loaded Cessna 150 (1,600lb Max T/O weight -- 1,000lbs empty) traveling at 100mph still has significantly less kinetic energy than a Ford Expedition traveling at 70mph. In essence, even in the event of a kamikaze-type scenario, the Cessna posed little, if any, threat to the granite and steel construction of the Capitol and the White House.