Boeing E-4
Description
Role	Airborne command post
Crew	Up to 114
Dimensions
Length	231 ft 4 in	70.5 m
Wingspan	195 ft 8 in	59.7 m
Height	63 ft 5 in	19.3 m
Wing area	5,500 ft&sup2	511 m²
Weights
Empty	410,000 lb	186 tonnes
Loaded	820,000 lb	372,000 kg
Powerplant
Engines	Four General Electric CF6-50E2 turbofans
Thrust	52,500 lbf each	234 kN each
Performance
Maximum speed	602 mph	969 km/h
Ferry range	7,100 mi	11,426 km
Service ceiling	45,000 ft	13,700 m
Rate of climb

The E-4B, also known as NAOC (National Airborne Operations Center), is a Boeing 747 aircraft refitted to serve as a command post for the United States armed forces during a nuclear war. For this reason, E-4Bs are sometimes referred as "the doomsday planes." Four are currently operated by the United States Air Force, and are assigned to the 55th Wing at Offutt Air Force Base, Nebraska. Maintenance and crews are provided by Air Combat Command, while operations are coordinated by Strategic Command .

The NAOC fleet was originally deployed in 1974, when it was known as NEACP (National Emergency Airborne Command Post). It was originally stationed at Andrews Air Force Base in Maryland, alongside Air Force One, so that the President and Secretary of Defense could access it quickly in the event of an emergency. Later, the aircraft were moved to the Midwest, where they would be safer from attack but still accessible by helicopter. One E-4B is kept on full alert at all times, and one remains relatively close to Air Force One so that the President can access it quickly from anywhere in the world.

In 1994, NEACP's name was changed to NAOC, and it took on a new responsibility: ferrying Federal Emergency Management Agency crews to natural disaster sites and serving as a temporary command post on the ground until facilities could be built on site.

The E-4B, which replaced the older E-4A in 1980, is specially modified to weather nuclear warfare conditions. Its computers and communications systems are shielded from electromagnetic pulse, and its air conditioning system is specially modified to block radiation.

External links

• USAF fact sheet
• FAS profile
• Boeing profile