How many fully equipped soldiers could a Chinook carry in Vietnam?

The Chinook was born out of a debate within the US Army. Part of Army aviation wanted a light tactical transport to inherit the missions of the old Piasecki H-21 and Sikorsky H-34, able to carry about 15 soldiers, the equivalent of a squad. Another faction argued for a much larger aircraft, capable of moving artillery pieces and holding the Pershing missile in its cargo bay. Vertol's first attempt, the YHC-1A, held a maximum of 20 soldiers and was deemed too heavy for assault and too light for general transport.

The production version, the CH-47A, was powered by Lycoming T55 turbines and had a maximum weight of 33,000 lb (15 t). It could carry 33 soldiers, and 349 were built. The 1st Cavalry Division brought its own organic Chinook battalion when it deployed to Vietnam in 1965, and the 147th Medium Helicopter Company arrived on 29 November of that year to support the 1st Infantry Division. Crews quickly learned to mount door guns.

Capacity always depended on seating configuration and each soldier's equipment. In modern versions, the cabin holds 33 to 50 fully equipped soldiers depending on layout, or 24 litters on medevac missions. The CH-47F spec sheet lists 33 to 55 soldiers, or 24 litters with three medical attendants, showing how the same tandem-rotor airframe has kept exploiting its volume for more than six decades.