As the Pentagon waits for Congress to confirm the new Army and Air Force secretaries and the vice chairman of the Joint Chiefs of Staff, another defense official is leaving the building.
Assistant Secretary of Defense for Sustainment Robert McMahon, whose purview includes operating costs for the uber-expensive F-35 and addressing problems in privatized military housing, has submitted his resignation effective as of Nov. 22, said Defense Department spokeswoman Heather Babb.
"Mr. McMahon appreciates the opportunity to have served the department both as a civilian and in uniform," Babb told Task & Purpose.
No further information was provided.
Task & Purpose learned that McMahon submitted his resignation letter to the White House on Sept. 17. Subordinates were told McMahon said it "was the right time" but did not elaborate on his reason for leaving. He had served in the role for less than a year.
All political appointees send their letters of resignation to the White House because they serve at the pleasure of the president, a defense official explained on Thursday.
Prior to serving as the Defense Department's top sustainment official, McMahon served in the Air Force for 34 years, graduating from the U.S. Air Force Academy in 1978, his official biography says. He went on to serve as the military assistant to the assistant secretary of the Air Force for installations, environment and logistics, and commander of Warner Robins Air Logistics Center, Robins Air Force Base, Georgia, before retiring in 2012 as a major general.
In his current position, McMahon is in charge of $170 billion in logistics operations, according his official Defense Department biography. He also oversees the U.S. military's property real estate portfolio, which consists of 28 million acres, more than 500 installations and more than 500,000 buildings with a combined value of more than $1 trillion.
As McMahon leaves, the Pentagon is still struggling to bring the F-35's operating costs under control. In June, McMahon told Air Force Magazine's John Tirpak he still believed the F-35 would eventually cost $25,000 per hour to fly even though other defense officials involved with the program believe the operating costs could be between $34,000 and $36,000 per flight hour.
McMahon's departure also comes amid ongoing efforts to fix widespread problems in privatized military housing. In June, McMahon invited military families to submit their feedback for a proposed "Resident Bill of Rights" through an online survey. Those survey results have not yet been released and the bill of rights is not completed yet.
As of Sept. 26, the Pentagon needed to fill 14 vacant positions.