The language of the FCOM is intentionally stark and devoid of emotion. It uses a specific syntax: "Condition," "Step," "Action." There are no adjectives. It does not say, "If you see a fire, please consider doing this." It says, "FIRE SWITCH... PULL." This brevity is a safety mechanism. Under the extreme stress of an in-flight emergency, cognitive tunneling narrows a pilot’s vision and distorts perception. The FCOM is designed to bypass the panic, offering a rational, pre-determined path to safety. It is the collective voice of the test pilots and engineers who simulated the disaster a thousand times on the ground so the crew doesn't have to improvise in the air.

The FCOM is the primary reference document for flight crews. It is developed by Boeing and provides the necessary information to operate the airplane within its designed limitations. It is tailored to a specific airline's configuration, including engine type (General Electric GEnx or Rolls-Royce Trent 1000) and customer-specific avionics setups.