The rare overseas deployment of a US Navy E-6B Mercury nuclear command and control aircraft has drawn international attention after it crossed the Atlantic Ocean and entered European airspace.
Flight tracking data shows the aircraft operating with callsigns WEPT45 and WEPT25. While the E-6B typically operates inside the United States, this flight path indicated the aircraft was approaching the United Kingdom and likely continuing toward Ramstein Air Base in Germany.
A key nuclear command aircraft
The Boeing E-6B Mercury has served for more than 30 years as part of the United States’ Take Charge and Move Out (TACAMO) mission. It is a critical element of the Nuclear Command, Control and Communications (NC3) network, ensuring a survivable link between the US President, Secretary of Defense and US Strategic Command.
The aircraft’s primary role is to maintain contact with Ohio-class ballistic missile submarines, which carry submarine-launched ballistic missiles (SLBMs). These vessels form one of the legs of the US nuclear triad, capable of launching retaliatory strikes even in the event of a catastrophic first strike on the US homeland.
Hardened for nuclear conflict
Often described in the media as a ‘Doomsday plane’, the E-6B is designed to serve as an airborne command post during nuclear war or other catastrophic emergencies. It is hardened against electromagnetic pulses (EMP), fitted with secure, long-range communications equipment, and able to remain airborne for extended periods through aerial refueling.
Such capabilities are intended to guarantee continuity of command and control over US strategic forces even if ground-based command centers are destroyed.
Previous deployment in Europe
The last overseas deployment of the type occurred on June 20, 2024, when an E-6B Mercury operated from Rygge Air Force Base in Norway. That mission coincided with a large-scale US exercise in the Norwegian Sea, involving the guided-missile cruiser USS Normandy (CG 60) and the ballistic missile submarine USS Tennessee (SSBN 734). The Tennessee can carry up to 20 Trident II nuclear missiles, underscoring the strategic weight of the operation.
The purpose of the current E-6B flight into Europe has not been publicly disclosed.
A new generation: the E-130J Phoenix II
The E-6B is set to be replaced by the E-130J Phoenix II, a program led by Northrop Grumman and based on the Lockheed Martin C-130J-30 Super Hercules. The Phoenix II will assume the TACAMO mission, with Northrop Grumman investing more than $1 billion in digital engineering and advanced manufacturing technologies to accelerate its development, testing and sustainment.
The transition aims to modernize the US Navy’s nuclear command and control capability with a more versatile and sustainable platform.
