Marine One History

CH-46 Sea Knight: Maker and Development

The CH-46 Sea Knight was developed by Vertol Aircraft Corporation, which became Boeing Vertol after its 1960 acquisition by Boeing. Building on Vertol’s successful tandem-rotor designs like the H-21 “Flying Banana,” engineers created the Model 107 (military designation V-107) in the late 1950s to meet the U.S. military’s need for a modern medium-lift transport helicopter. The prototype first flew on April 22, 1958, featuring two powerful General Electric T58 turboshaft engines driving overlapping tandem rotors, a spacious fuselage with a rear loading ramp, and an amphibious hull for water operations. After rigorous testing and competition wins, the improved CH-46A entered service with the U.S. Marine Corps in 1964, quickly proving its value in troop transport, cargo lifting, and medevac roles.

Subsequent variants like the CH-46E and F incorporated upgraded engines, avionics, and structural reinforcements to handle demanding combat environments from Vietnam through the Gulf Wars. Production totaled around 524 aircraft, with the Sea Knight earning the affectionate nickname “Phrog” for its distinctive profile and reliability. It served as a workhorse for over five decades before final retirement in 2015, replaced by the MV-22 Osprey. Its robust tandem-rotor system and versatile design made it a cornerstone of Marine aviation, with select examples even supporting high-profile missions in presidential transport configurations.