A tornado just took out this nuclear apocalypse-proof Air Force jet

When the US Air Force took delivery of its four E-4B Nightwatch 'doomsday' jets, they made sure the small fleet was capable of surviving a nuclear holocaust, its occupants safe and sound within its protective cocoons as they carried out their mission of directing the US military in the aftermath of the end of the world.

As it turns out, the Nightwatch may be able to survive a nuclear blast in the air, but the forces of nature are a different matter altogether.

On June 16, a pair of E-4Bs, currently known as "Advanced Airborne Command Posts," found themselves sitting in the path of a tornado while parked at Offutt AFB in Nebraska. Though both aircraft were pulled into hangars, their tailplanes still sat somewhat exposed and suffered the wrath of the tornado, taking enough damage to keep them grounded and inoperable.

A number of RC-135 reconnaissance aircraft, also parked at Offutt at the time, were affected by the storm but were quickly repaired and returned to service.

The extent of the damage is unclear, though it's probable that these two aircraft will be out of service for the time being as the Air Force and Boeing both evaluate and determine a course of action to repair them. The two remaining Nightwatches were away from Offutt at the time — one undergoing an overhaul, while the other is currently operational.

The tailplane of the Nightwatch does house one of its mission systems — a 5-mile long antenna which can be spooled out the rear of the aircraft while in-flight. This antenna allows the battle staff aboard the E-4B to communicate with the US Navy's ballistic missile submarines while they're underway. It's definitely likely that this part of the aircraft, known as the Trailing Wire Antenna, sustained some damage during the storm.

The E-4B, formerly known as the National Airborne Operations Center, entered service with the Air Force in the 1970s, replacing older EC-135J "Looking Glass" aircraft, as "doomsday planes" — command posts that allow members of the US National Command Authority to stay in touch with the military during a catastrophic event. Each Nightwatch is equipped with an advanced communications suite that facilitates this, allowing it to virtually contact anything connected to a phone line in the entire world.

Today, Nightawtch serves as the Secretary of Defense's official transport, ferrying him across the world on state-sponsored trips to foster good relationships with American military partners. Because of its communications abilities, the E-4B allows the SECDEF to remain constantly up-to-date on US military activity no matter where he is, even while flying.

The Air Force recently tendered a $73 million contract to support the E-4B's expansive communications systems over the next seven years, though it's possible that the service could potentially consider retiring all Nightwatch jets in the coming years in favor replacing them with newer aircraft with lower operating costs. The current hourly operating figure for a single E-4B is estimated to be at least $159,529 per hour.

Above the heavy financial burdens of flying these converted Boeing 747s, the small fleet is getting harder to support due to its age. The Air Force projects that by 2039, all E-4Bs will have maxed out their lifetime flying hours, necessitating a follow-on aircraft to carry out the same mission on behalf of the Air Force and NCA.

In May, the Air Force announced it would spearhead a joint program with the Navy to seek a replacement for the E-4B and the Navy's E-6 Mercury. The E-6 is a continuation of the Looking Glass program, and shares a similar role with the Nightwatch fleet, though its mission is more popularly known as TACAMO, short for "Take Charge And Move Out."

This project will see the Air Force and Navy unite their airborne command post assets under a fleet of identical nuclear-proof aircraft with next-generation communication and sensor systems. There's no word just yet on whether or not America's upcoming fleet of doomsday aircraft will be tornado-proof as well, however.