The E-6 command and control plane could order a launch in response to a nuclear attack. Key point: The airborne command post helps to ensure deterrence by showcasing how the President could still give orders from the air. Here is how the Cold War-era role is still kept today. In a military that operates Raptor stealth fighters, A-10 tank busters, B-52 bombers and Harrier jump jets, the U.S. Navy’s placid-looking E-6 Mercury, based on the 707 airliner, seems particularly inoffensive. But don’t be deceived by appearances. Though the Mercury doesn’t carry any weapons of its own, it may be in a sense the deadliest aircraft operated by the Pentagon, as its job is to command the launch of land-based and sea-based nuclear ballistic missiles.