WASHINGTON (CNN) -- The Federal Aviation Administration on Friday acknowledged that it notified military authorities 69 minutes after losing radio contact with Northwest Flight 188 last month -- about an hour later than it should have.

Under standard procedures, the FAA managers should have reported the incident to the Domestic Events Network -- a government hotline -- five to 10 minutes after losing contact with the flight. The North American Aerospace Defense Command (NORAD) is a participant in the hotline, and frequently scrambles jets to investigate suspicious incidents.

The FAA has taken steps to prevent a repeat of the failure, Administrator Randy Babbitt said Friday.

The lapse was caused because controllers were "keenly focused" on re-establishing contact with the airplane, he said, adding, "No secret, we could've done better."

As it turned out, NORAD prepared to send four jets to intercept the unresponsive plane, but the jets never got off the ground. NORAD opted not to launch them after the FAA re-established contact with the pilots and became convinced the plane had not been hijacked.

The plane landed without incident.

FAA officials said a number of factors led to the delay in notifying the military. One reason is that the the loss of radio contact is "fairly routine," said FAA Chief Operating Officer Henry "Hank" Krakowski.

The FAA loses radio contact with airplanes about seven times a day, he said, typically because pilots get radio frequencies wrong. Those miscommunications are usually rectified in a matter of minutes.

"After about five minutes (without radio contact), we begin to escalate it up," said Babbitt, adding that it notifies the Domestic Events Network no later than 10 minutes into an unusual or suspicious event.

In the case of Northwest Flight 188, the response was not immediately heightened because the plane continued flying on course, continued to broadcast its assigned transponder code, and was flying over a sparsely populated area, officials said.

But concern increased when the plane did not prepare to land as it approached its destination, the Minneapolis-St. Paul airport, the FAA said.

The FAA's problem was exacerbated because the incident occurred during a shift change, and the lack of radio contact with Flight 188 "wasn't specifically told" during some hand-off briefings, he said.

Another problem occurred when the FAA called Northwest Airlines. The FAA had an out-of-date phone number for Northwest, which has merged with Delta, officials said. They got an answering machine that contained the new phone number.

Babbitt called the whole incident "distressing. ... We could have been and should have been more agile."

The answer, he said, rests in better training: "We don't need a new rule. What we need is more adherence to the (existing) rules."

He said the FAA also is improving the amount time it takes for incidents to be reported to top officials, including himself. "It was a little slow to get to a few of us," he said.

Babbitt said he learned of the incident about one hour after it concluded.

The FAA on Friday also revised its timeline of the October 21 flight, which started from San Diego, California. Earlier, the agency said the pilots were without radio contact for 91 minutes, but Friday it reduced that time to 77 minutes, about the length that was originally reported. Difficulty in reconciling "at least 10" audiotapes from different air traffic control sectors led to the different times, Babbitt said.

Six days after the event, the FAA revoked the licenses of Capt. Timothy Bryan Cheney and First Officer Richard Irwin Cole, saying their lack of awareness that they had overflown Minneapolis airport was "completely unacceptable," and "put your passengers and your crew in serious jeopardy."

Both pilots have told the FAA they "lost track of time" while reviewing a new work scheduling system on their laptop computers. After the pilots became aware they had passed their destination, they called the FAA, returned to the airport and landed.

The pilots are appealing their license revocations.