http://www.military.com/daily-news/2015 ... hrogs.html Apr 10, 2015
CAMP PENDLETON, Calif. -- MV-22 Ospreys replaced the Marines' last squadron of CH-46E helicopters Thursday,
officially ending the Sea Knight's 50-year run as the troop and supply transport workhorse of the Corps.
More than 600 CH-46s, affectionately known as "Battle Phrogs," were produced over the years, but on Thursday, just two remained.
One is destined to join dozens of others in the "boneyard," a storage space for retired aircraft, while the other -- a shiny green model that flew missions in Vietnam -- will go to the National Museum of the Marine Corps in Quantico, Va.
The first Ospreys were delivered to the Marine Corps in late 2005, and in 2006, a HMM-263 was redesignated as VMM-263, becoming the service's first Osprey squadron.
The aircraft reached "initial operating capacity" in 2007, and VMM-263 left for the plane's first deployment later that year.
The Marine Corps has been slowly but steadily replacing Phrogs with Ospreys ever since.