Some residents of eastern Colorado Springs saw an impromptu air show Monday morning as a pair of fighter jets escorted an airliner into Peterson Air Force Base during a training exercise.
The sight had some worrying that the transport had been hijacked or suffered some other emergency.
"From what I have read, this is the procedure if there is some type of in-flight emergency," said Steve Learning, who spotted the planes over his neighborhood near Barnes and Marksheffel roads just after 10:40 a.m.
The fighters split off just before the airliner safely landed.
The North American Aerospace Defense Command at Peterson said the formation flight was nothing to fret over.
"We did have a military training exercise this morning," said NORAD spokeswoman Army Capt. Ruth Castro.
Since the 9/11 attacks, NORAD has worked to defend the skies from hijacked planes under Operation Noble Eagle. Pilots on the Noble Eagle mission train regularly to meet civilian aircraft mid-air and escort them, or, in a worst-case scenario, shoot them down.
Monday's exercise simulated an airliner in distress and was conducted in conjunction with the Federal Aviation Administration, the command said.
"We had two F-16s from the 140th fighter Wing from the Colorado National Guard," said Castro. "They were conducting a preplanned exercise of the intercept of a C-40B from Andrews Air Force Base."
The C-40B is an Air Force version of the single-aisle Boeing 737 airliner and is used to haul top brass. The F-16s were from Buckley Air Force Base in Aurora.
The exercise comes after a busy weekend for NORAD.
Operation Noble Eagle jets intercepted two small planes that had entered restricted flight areas over the Florida Keys. Such bubbles of airspace are closed off to commercial and civilian traffic to protect events like the Super Bowl, or individuals, including President Barack Obama.
"The first aircraft was out of radio communication initially, but once communication was established it turned around and proceeded out of the restricted area," NORAD said in a Sunday news release. "There was also no communication with the second aircraft, prompting the F-16s to intercept the aircraft and escort it out of the (area)."
NORAD didn't specify the reason the flight restriction was in place, but Obama is vacationing in Florida.
Monday's flight over Colorado Springs was unannounced, which surprised Learning.
"People do notice those things, at least I sure do," he said.