For the second time this year, the Marine Corps inspector general from Washington interviewed officials at the western air base headquarters here this week to investigate the possibility of wrongdoing by a top officer.
The target of the inquiry this time is Brig. Gen. Wayne T. Adams, the commander of the Marine Corps' western air bases, who took at least five flights that military officials say raise questions about his mixing personal and business travel.
Several of these flights came just weeks before Adams suspended two of his top aides, chief of staff Col. Joseph E. Underwood and assistant chief of staff Col. James E. Sabow, amid allegations that they improperly used planes. Sabow later killed himself.
"Everyone knows it's housecleaning time," said one official interviewed on the base Monday by Maj. Gen. Hollis Davison, the inspector general, who was traveling from Washington. "You don't have a major general come to town for nothing. People snap to attention."
Davison, in the San Diego-Camp Pendleton area last week for business unrelated to the Adams investigation, made a last-minute stop Monday at El Toro after reports in The Times about Adams' use of base planes. His office opened a formal investigation last week into Adams' activities.
The general returned to Washington on Tuesday.
Using the base law center as his office, Davison interviewed both officers and enlisted personnel about Adams' trips, and he reviewed paperwork on some of the flights in question.
Base sources said that his inquiries at El Toro were not limited to Adams' use of planes, but that he also was seeking information on whether Adams improperly used the Marine Corps' resort lodge at Big Bear for a military inspection and vacation with his fiancee after reportedly "bumping" the reservation of a lower officer for the lodge.
Davison was scheduled to meet with Adams during his work at El Toro, officials said, but it was not known whether that meeting actually took place.
"I really can't comment on this except to say the general's trip was a part of his investigation," said Col. Jim Williams, the Marine Corps' deputy inspector general.
Officials also declined to say whether Davison and his assistants completed their work Monday and Tuesday at the base or whether they would return.
In early January, Davison spent several days at the El Toro base after the Pentagon's fraud "hot line" received a tip alleging that military planes had been used by Underwood for golfing jaunts. That investigation led to Sabow as well, Adams quickly suspended both.
In an interview last week, before his latest trip, Davison would give no timetable for his investigation, promising only that there would be "a thorough review" of the case.
"It takes a careful reviewing of the factual data to make a determination" of whether a flight was taken improperly, Davison said. "Oftentimes, it's a perception rather than anything being wrong. It depends on what the circumstances of the case are."
Adams, en route to a military convention in Virginia last year, flew a side trip to Florida in the midst of a tropical storm and, while there, signed papers to divorce his wife of 26 years.
He also got in flight time in a trip to Washington state, where he met with his fiancee, and last year he ordered a plane to shuttle him between a memorial service at the El Toro base and Big Bear, where he was spending time with his fiancee during a combined vacation and military inspection of Marines' lodgings at the resort.
Regulations for military flights prohibit personal trips and warn against trips in military planes that could be misinterpreted by the public, such as travels back home.
Adams, who oversees the Marine air bases at El Toro, Tustin, Camp Pendleton, and Yuma, Ariz., has maintained that all of his flights were taken in the course of performing official duties and that most were needed to get in the minimum flight time required for him to maintain certification in the C-12 Beechcraft, a turboprop plane.