“Everybody in government has to be looking at the optics at this time with this economy,” Mr. Ellis said. “Making sure you’re being a good steward of the taxpayer’s money comes with the job. Having been the director of the [Office of Management and Budget] and senior staff for the president, I believe Secretary Panetta should understand that the most.”

Government rules require Mr. Panetta to use military jets for personal travel for security and in order to stay in touch with military commanders and senior-level administration officials.

Mr. Panetta must reimburse the government for personal travel at the cost of an equivalent commercial coach ticket even though the actual cost of the travel is much higher – $3,200 a flight hour, according the Defense Department. Each round trip from Washington to California and back, in an Air Force equivalent of a Gulfstream jet, can add up to more than $30,000.