From Halopedia, the Halo wiki
The G77S Pelican Gunship is a modified variant of the D77-TC Pelican dropship traditionally employed by the UNSC. The G77S is an impromptu modification of the standard D77 variant, cooked up by the engineers of the UNSC Spirit of Fire to compete with the Banished on Installation 00.
As an unofficial modification of the standard D77 airframe, the G77S shares most of its design with the standard D77. The gunship modifications include two top-mounted ANVIL-II missile pods, four M41 Vulcan rotary cannons mounted onto the fuselage and four payload hardpoints to complement the standard nose-mounted 70mm M370 autocannon.
G77S Pelicans were heavily employed as close air support by Captain James Cutter during the Second Ark Conflict. During the conflict, they were often employed in groups of four to circle a target area and strafe it with overlapping fields of machine gun and missile fire.
Halo Wars 2
In Halo Wars 2, the G77S gunship can be used by players playing as Captain Cutter, by calling in the Close Air Support leader power. Four Pelicans will descend orbit to temporarily saturate the target area with fire before departing.
List of appearances