A lire sur http://en.wikipedia.org/wiki/Marine_One

On 7 May 2014 the Navy awarded Sikorsky Aircraft a $1.24 billion contract to build six presidential helicopters. A 21 helicopter fleet is anticipated by 2023

Marine One is transported via C-17 or C-5 military transport planes (as is the president’s limousine) wherever the President travels, within the U.S. as well as overseas.^[17] At a presidential inauguration, the Marines offer the outgoing President a final flight from the Capitol to Joint Base Andrews Naval Air Facility.