The E-6B Mercury that executes the "Take Charge And Move Out" (TACAMO) mission for America's sprawling nuclear apparatus, basically delivering commands from the National Command Authority that can send nuclear-armed ballistic missiles flying during a nuclear apocalypse, is an incredible aircraft. Not only were they among the last Boeing 707 derivatives ever built, but they are also packed full of EMP hardened systems and highly skilled crews that would literally hold the world as we know it in their hands during a major crisis. Although advanced and highly secure satellite communications and line-of-sight data-links are critical parts of their capability set, a far more cumbersome system is used to talk to ballistic missile submarines hiding deep below the waves. The deployment of this fascinating capability was caught today by a plane tracker that was monitoring an E-6B operating off the coast of New Jersey.

The Very Low Frequency (VLF) communications system can pierce the ocean's surface down to about 60 feet to connect with submarines lurking in the planet's vast undersea environment. A downside to this capability is that data transfer rates are appallingly slow, so only very simple communiques, like Emergency Action Messages, can be transmitted, and huge antenna arrays are required to both send and receive those messages. The E-6B's primary VLF antenna is just over five miles long. It also has a shorter one that is deployed via a trapdoor arrangement in its tail. The VLF antennas are stabilized with a drogue on its trailing end. The idea is to get the antennas as close to vertical as possible for maximum transmission effectiveness. This is done by putting the aircraft into a very steep and tight banking turn at slow speed and above 20,000 feet, not far above the aircraft's stall speed. These turns are repeated, oftentimes for hours at a time, as messages are sent.

USAF E-6B Mercury.

A submarine trails its own long VLF antenna to receive the transmission. If the submarine is too deep to receive the signal, the VLF antenna can be floated to a shallower depth via a buoy while the submarine remains underway at greater depth. This maneuver is precisely what was spotted today by one eagle-eyed aircraft tracker and open-source intelligence enthusiast, @vcdgf555. An E-6B was operating off the northeastern coast of the U.S., hundreds of miles out to sea, and executing a VLF communications deployment maneuver. This track gives us a great visual portrayal of what such a maneuver looks like: