Gen. Jim Slife stepped into the role of Air Force vice chief of staff at a Dec. 29 ceremony at Joint Base Anacostia-Bolling in Washington, ending the service’s three-month stretch without Senate-confirmed officers in its top two leadership posts.

Slife’s assignment to the Air Force’s second-highest position is part of a wide-ranging shuffle of the branch’s top brass that began in the fall. His promotion to four-star had sat in limbo since September as part of Alabama Republican Sen. Tommy Tuberville’s lengthy blockade of over 400 military nominees that ended Dec. 19.

“Leaving things better than when you found it … is one of his hallmarks,” Gen. David Allvin, who became the service’s uniformed boss in November, said at Slife’s swearing-in event. “I could not be happier to be able to have this ceremony, put these stars on and get to work with Jim.”

The career special operations pilot replaces Allvin as vice chief of staff following a yearlong stint as deputy chief for operations.

As vice chief, Slife will help drive new policies to organize, train and equip 689,000 uniformed and civilian employees across the active duty Air Force, Air National Guard and Air Force Reserve. Together, he and Allvin will tackle a slew of modern military challenges ranging from lackluster recruiting, to sweeping deployment reforms, to a host of digital-age threats.

Slife will also join the Pentagon’s other No. 2 officers in shaping requirements for major acquisition programs as the Air Force tackles its own multibillion-dollar modernization plan.

“We stand at the precipice of a different strategic environment,” he said at the ceremony. “[Chairman of the Joint Chiefs of Staff Gen. CQ] Brown called on us to accelerate change. [Air Force Secretary Frank] Kendall has empowered us to actually think about … what we need to have to be competitive for the next several decades.”

Slife’s Air Force career began at Auburn University, where he earned his commission through the Reserve Officer Training Corps. He went on to become a decorated pilot with more than 3,100 flight hours on the MH-53 Pave Low search-and-rescue helicopter and the MQ-1 Predator attack drone, among other platforms, according to his official biography.

He also led Air Force Special Operations Command for more than three years and served as the vice commander of U.S. Special Operations Command.

It’s the first time in more than a decade that neither the Air Force chief of staff or its vice chief hail from a fighter background.

While Slife’s proponents have praised him as a strategic thinker who looks to improve airpower overall rather than push parochial interests, others have criticized him for what they see as seeking change at the expense of military readiness.

“He’s not very patient. He’s not willing to look at things and shrug his shoulders,” one retired general said of Slife last May. “I think they’ll probably be, kind of, [Allvin] as the idea guy … and then Slife as the executor.”