Bus

"Officially, it's an Airborne Mobile Command Station, but we call it the Bus."

- Leo Fitz to Skye

The "Bus" (formally known as the CXD 23 Airborne Mobile Command Station officially designated as "S.H.I.E.L.D. 6-1-6".) is a specialized Boeing C-17 Globemaster III owned and modified by S.H.I.E.L.D. It serves as a flying command center for Agent Phil Coulson and his team. It is piloted by Melinda May.

Capabilities and Design
The "Bus" is a specialized Boeing C-17 Globemaster III modified to serve as an  'Airborne Mobile Command Station' for Agent Coulson's personal S.H.I.E.L.D. team. In addition to the common features of the Boeing C-17, the Bus appears to have an additional pair of engines and half-length wings located at the tail section of the fuselage, below the conventional, elevated tail section. This gives the Bus greater aerodynamic and flight capabilities, making it better able to transport the team for great distances to points of interest in a prompt amount of time. Additionally, the six engines are able to pivot up on each wing, allowing them to be angled at the ground, giving the Bus Vertical Take-Off and Landing (VTOL) capabilities.

While the majority of a conventional C-17's interior is open cargo space, the Bus has been modified to suit the needs of Coulson's S.H.I.E.L.D. team including a passenger area, an interrogation room, and a private forensics and research lab to accommodate Agents Leo Fitz and Jemma Simmons. The Bus retains a small cargo area at the rear of the plane where the team's SUV is stored along with Coulson's personal car, Lola.