Washington (CNN) -- Another air traffic controller apparently fell asleep while on duty, a problem that is prompting the government to put an extra staffer on midnight shifts at more than two dozen control towers across the country.
The latest incident occurred Wednesday morning at Reno-Tahoe International Airport in Nevada "when a controller fell asleep while a medical flight carrying an ill patient was trying to land," the Federal Aviation Administration said.
The flight originated in Mammoth Lakes, California, according to the FAA Pacific Division.
"The medical flight pilot was in communication with the Northern California Terminal Radar Approach Control and landed safely. The controller, who was out of communication for approximately 16 minutes, has been suspended while the FAA investigates," the FAA said in a statement.
FAA Administrator Randy Babbitt expressed outrage, saying "we absolutely cannot and will not tolerate sleeping on the job. This type of unprofessional behavior does not meet our high safety standards."
"This is absolutely unacceptable," said U.S. Transportation Secretary Ray LaHood.
It would be the sixth incident this year involving a sleeping controller that the FAA has disclosed. One occurred at Ronald Reagan National Airport in Washington, another at McGhee Tyson Airport in Knoxville, Tennessee, and three incidents involving the same person occurred at Boeing Field/King County International Airport in Seattle.
The FAA said it also suspended two controllers in Lubbock, Texas, for an incident in the early hours of March 29 in which they failed to hand off control of a departing flight to the Fort Worth Air Traffic Control Center, and responded only after several attempts by the same center to hand them control of an arriving flight. The FAA statement did not indicate whether the Lubbock controllers were thought to have been asleep.
Babbitt and LaHood said the FAA will assign an extra air traffic controller on the midnight shift at 27 control towers staffed with only one controller during that time.
The FAA said Babbitt and National Air Traffic Controllers Association President Paul Rinaldi "are launching a nationwide 'Call to Action' on air traffic control safety and professionalism" and will visit air traffic facilities to underscore the need for safety and professionalism.
The move will include "an independent review of the FAA's air traffic control training curriculum and qualifications and the expansion of NATCA's Professional Standards committees."
The FAA is also reviewing staffing and scheduling.
Nevada's senior senator, Harry Reid, said it was "a miracle that everyone is OK. We're glad that they are."
"Last night's near-tragedy reminds us that state-of-the-art structures and the best technology work only as well as the people operating them," Reid said Wednesday on the Senate floor. "If those people fall asleep on the job, they risk the lives of the millions of Americans who fly into and out of our airports every day."
Krys Bart, president of Reno-Tahoe International Airport, said the pilot of the Sierra Life Flight plane -- a Piper Cheyenne twin turboprop -- tried to make contact with the Reno tower at about 2 a.m., but got no response and began to circle the airport. After repeated failed attempts to reach someone in the tower, the pilot evaluated the situation and decided to land.
In his remarks on Capitol Hill, Reid said the pilot "tried to call the tower not once or twice, but seven times. The controller slept through every one of those calls." A federal government source on Wednesday confirmed to CNN the figure of seven attempted calls to the tower.
Bart said it is her understanding that there was only one controller on duty at the time. She added that she is pleased with the FAA's response, and issued a statement to clarify that air traffic control staffing is entirely in the federal agency's domain:
"We have a brand-new, state-of-the-art air traffic control tower, three runways and two instrument landing systems in place to help guide pilots on landing, take-off and ground control," Bart's statement said. "But what the airport has no control over is the staffing levels and personnel in the control tower. ... this is an FAA issue, the Airport Authority does not control what happens in the air traffic control tower."
However, Republican Rep. John L. Mica, who chairs the House Transportation and Infrastructure Committee, said the move to increase tower staffing "misdirects our resources and focus away from congested air traffic control facilities."
"Only in the federal government would you double up on workers, averaging $161,000 per year in salary and benefits, that aren't doing their job," the Florida congressman said.
Mica and other committee leaders plan to meet with FAA officials behind closed doors to discuss what his office described as "a spate of near misses, runway incursions and incidents of sleeping on the job."
CNN's Mike M. Ahlers contributed to this report