The "Western White House" -- the term for George W. Bush's Texas ranch and other homes used by Presidents Reagan and Nixon -- is well known. But how about the "Pacific Pentagon?" 

Some Beltway observers and military insiders believe Defense Secretary Leon Panetta's California home could even be called "The Panettagon," due to his frequent trips there.

Panetta has made the cross-continental flight from D.C. to Monterey five weekends since being sworn in at the Pentagon on July 1. 

Panetta's predecessor, Robert Gates, has a home in the Pacific Northwest, which he rarely visited during his five-year tenure spanning three wars. Unlike most defense secretaries, Gates lived on a military installation in Washington, D.C., where he paid rent. 

Some in Washington are questioning whether Panetta is taking a less "hands-on" approach to his new job. Panetta's flights to California were first reported by the Los Angeles Times. 

George Little, a spokesman for Panetta, points out that the secretary informed the White House of his plans to fly home frequently before he agreed to the job. He did the same thing while head of the Central Intelligence Agency. 

"Secretary Panetta has followed government regulations to the letter, works around the clock all week long, and stays in constant touch with the department. If someone thinks he's out of touch because he's away from Washington, they're wrong," Little told Fox News. 

Little also pointed to the secretary's accomplishments while in California. 

"He approved DoD support to states affected by Hurricane Irene, and he was heavily involved in dealing with the Chinook helicopter crash in Afghanistan last month," Little said. "He's been available, too, for last-minute phone calls with the president and his national security team." 

Little says whatever workload Panetta faces, "California is his home and where his family lives." 

Just the same as with any member of Congress, Panetta is made to reimburse the U.S. government for the cost of an equivalent coach fare for every personal flight he takes. But Panetta doesn't fly coach. When he's not flying for business in the Defense Department's customized Boeing E-4B, Panetta travels the country in a government Lear jet at a cost of $3,200 per flight hour. 

At least some Republicans in Washington don't think Panetta will be able to keep up his current travel pace. 

"The late summer in Washington is a poor indication of the workload Secretary Panetta will face," a Republican aide told Fox News. "There won't be a lot of chances for him to slip away during the weekend."