The Air Force's 'Doomsday plane,' where the president can run a nuclear war, needs repairs for wear and tear

US Air Force/Louis Briscese

An E-4B aircraft on the tarmac at Travis Air Force Base, California, September 11, 2017.

• The US Air Force's "Doomsday plane" is undergoing maintenance and upgrades, according to Defense One.
• The Boeing E-4B "Nightwatch" and the Navy's E-6B "Mercury" planes are built to allow the president to direct US forces in the event of a nuclear war.
• It has also served as a mobile Pentagon for defense secretaries, but it's being pulled out of that role to reduce wear on the aircraft.
• Visit Business Insider's home page for more stories.

The E-4B "Nightwatch" plane, which would allow the president to give military orders in the event of a nuclear war and has served as a mobile Pentagon for defense secretaries, is worn out, Defense One's Marcus Weisgerber reports.

The so-called Doomsday plane - which is the Air Force's four E-4Bs and the Navy's E-6B "Mercury" - has been in service since the 1970s, much like Air Force One, and is expected to keep flying through the 2020s. But to preserve the planes, Secretary of Defense Mark Esper has had to use other military aircraft when traveling, including a C-17 Globemaster and a C-32 airliner, both smaller than the E-4B.

"A number of aircraft are in a maintenance status to ensure they remain flyable for this no-fail mission for the next decade," Lt. Col. David Faggard, an Air Force spokesman, told Defense One.

"Upgrades and maintenance include avionics, wiring, communication equipment, and other components to ensure the platform remains viable in a modern world," Faggard said.

US Department of Defense

The E-4B dates to the 1970s, but it needs to have advanced technology to carry out its most important mission - directing US forces in a nuclear war.

The distinctive hump behind the cockpit of the aircraft holds satellite antennae, and the plane's advanced electronics allows the president to order nuclear missile launches from assets on land, in the air, and at sea. It also has no windows except the ones at the cockpit.

The Air Force would not say exactly how many of the aircraft were in for repairs and upgrades, but the number of issues that the E-4B and its Navy counterpart, the E-6B, have faced recently are worrisome.

As Defense One reports, it's sometimes difficult to obtain parts for the aircraft because they're so old. And in 2011, an E-4B carrying then-Defense Secretary Robert Gates broke down on the runway in Belgium.

Just weeks ago, one of the Navy's E-6B Mercury planes was grounded after it hit a bird, causing at least $2 million in damages. In March, another E-6B made an emergency landing in Oklahoma after a fire broke out on board.