The US Navy is preparing to replace what some have described as “the world’s deadliest aircraft” – E-6 Mercury. Designed as a flying link between the U.S. government and military forces around the world, the E-6 Mercury is tasked with transmitting orders, including missile launch orders, to Ohio-class nuclear-powered patrol submarines. Unlike the current aircraft, which is based on a commercial aircraft, the new aircraft will be based on the C-130J Super Hercules military transport aircraft.

According to Defense News, the Navy is preparing to release a list of requirements for the new aircraft, designated the E-XX. The “E” prefix stands for electronics, a broad category that includes electronic attacks, propaganda distribution, and other roles that include transmission across the electromagnetic spectrum. The service is seeking three test aircraft relatively recently, with nine more contracts by 2025. Twelve new aircraft will replace the 16 E-6s currently in service.

The E-XX is TCAMO’s next-generation aircraft, an acronym for “take responsibility and act”. The aircraft is designed to transmit urgent action messages (EAM) to submarines at sea. Armed with ballistic missiles with nuclear warheads, submarines are tasked with getting lost in the ocean and avoiding detection. In the event of a surprise nuclear attack on the United States, submarines can surface to launch a devastating counterattack. By providing this opportunity, they primarily deter opponents from attacking.

TCAMO aircraft acts as an in-flight message relay service, authenticates and then transmits EAMs between National Command, anyone authorized to issue orders to the US nuclear forces, and submarines at sea. In peacetime, this is the President of the United States, but if the President is killed, incapacitated, or lost during an attack, those powers can be delegated to someone else in the Cabinet or military control. TCAMO aircraft enable the National Command to command nuclear forces even in the midst of a nuclear war.

TCAMO’s 16-man squadron is split into two squadrons, the VQ-3 “Ironmen” and the VQ-4 “Shadows”, all operated by the 1st Strategic Communications Wing based at Tinker AFB, Oklahoma. E-6s also operate from warning facilities at Travis Air Force Base in California and Naval Air Force Base on the Patuxent River in Maryland, where they can fly closer to patrolling ballistic missile submarines.

Usually a TCAMO aircraft is always in the air, and usually up to six aircraft are in the air at the same time. Despite the alarming messages on social media, the number of TCAMO planes in the air does not indicate an imminent nuclear crisis.

The older E-6 Mercury is based on the Boeing 707, one of many military aircraft of the 1960s based on civilian jet aircraft. The Navy wants the new E-XX TCAMO to be based on the C-130J Super Hercules. Lockheed Martin’s participation in the E-XX competition was the EC-130J TCAMO, an aircraft the company developed together with Raytheon and Northrop Grumman. It’s unclear what other defense contractors might be in the game, but one obvious possibility is Boeing.

TCAMO aircraft are among the most important aircraft in the entire US military arsenal, and their work as a vital link in nuclear command and control means that they truly fulfill their exaggeration as “the world’s deadliest aircraft”. No matter how powerful a surprise attack on U.S. soil may be, TCAMO aircraft ensure that any surviving nuclear submarines can and will launch a counterattack. At the same time, airplanes fulfill a larger task: nuclear deterrence and peacekeeping.