By Barbara Starr

A cheating scandal involving members of the Air Force nuclear command has tripled in size over the past two weeks with more people identified as investigators stepped up their probe.

Air Force Secretary Deborah Lee James said on Thursday that 92 officers from Malmstrom Air Force Base in Montana are now implicated in the scandal over a proficiency test administered last year.

Two weeks ago, officials first alleged 34 officers serving with the 341st Missile Wing were involved - either cheating directly or failing to speak up about others who had done so. It occurred last August and September and involved text messages.

Those swept up in the scandal represent about half of those who took the test. All have been decertified, meaning they cannot carry out their nuclear-related duties.

Despite the scandal, James said she remains "confident" in the "safety, reliability and effectiveness of the nuclear mission." That's because there are multiple safeguards in place.

Nevertheless, James said the situation was "completely unacceptable" and said "we do have systemic problems in the force."

James described, for example, hearing about a drive for perfection that creates a climate of undue stress and fear.

She visited Malmstrom and the Air Force's other intercontinental ballistic missile bases, meeting with leaders and airmen to discuss the issue as part of a review ordered by Defense Secretary Chuck Hagel.

This is the latest incident to rock the Air Force nuclear operations.

Last year, a missile unit at Malmstrom failed a safety and security inspection.

They operate about a third of the 450 Minuteman III nuclear-tipped intercontinental ballistic missiles in the U.S. force, according to the Air Force.

Also last year, another outfit based at Minot, North Dakota, did poorly in an inspection, resulting in the removal of 17 military personnel from their jobs.