rank, he or she has no more than 60 days to be appointed or reappointed to a position of equal or greater importance before he or she is expected to retire. Historically, officers leaving four-star positions were allowed to revert to their permanent two-star ranks to mark time in lesser jobs until statutory retirement, but now such officers are expected to retire immediately to avoid obstructing the promotion flow. For example, Vice Admiral Patrick M. Walsh was promoted to admiral and appointed as vice chief of naval operations in 2007. The incumbent vice chief, Admiral Robert F. Willard, was appointed as commander of the U.S. Pacific Fleet. The incumbent Pacific Fleet commander, Admiral Gary Roughead, was appointed as commander of U.S. Fleet Forces Command, whose incumbent commander, Admiral John B. Nathman, received no further appointment and retired at the age of 59, with 37 years of service and three years in grade. Lieutenant General Gary L. North was promoted to general and appointed as commander of Pacific Air Forces in 2009. The incumbent Pacific Air Forces commander, General Carrol Chandler, was appointed as vice chief of staff of the Air Force, while the incumbent vice chief, General William M. Fraser III, was appointed as commander of Air Combat Command, whose incumbent commander, General John D. W. Corley, received no further appointment and retired at the age of 58, with 36 years of service and four years in grade. To retire at four-star grade, an officer must accumulate at least three years of satisfactory active-duty service in that grade, as determined by the secretary of defense. The president and Congress must also receive certification by the secretary of defense that the retiree served satisfactorily in grade. The secretary of defense may reduce this requirement to two years, and the president may waive this requirement altogether, but only if the officer is not being investigated for misconduct. Four-star officers who do not meet the service-in-grade requirement will revert to the next highest grade in which they served satisfactorily for at least six months which is normally the three-star grade. Since three-star ranks are also temporary, if the retiree is also not certified by the secretary of defense or the president to retire as a three-star, the retiree will retire at the last permanent rank he or she satisfactorily held for six months. The retiree may also be subject to congressional approval by