The 747 CMCA

The 747 CMCA — Cruise Missile Carrier Aircraft — was a US Air Force study to turn the 747 into a launcher for stand-off weapons, considered while the B-1 Lancer was in development.

The concept

The aircraft would have carried as many as 72 AGM-86 cruise missiles on rotary launchers inside the fuselage, firing them through doors rather than carrying them externally.

The logic is straightforward. A cruise missile flies itself to the target; the aircraft carrying it only has to reach a launch point safely. If that is all you need, a large subsonic aircraft with enormous internal volume and long range is a far cheaper way to carry weapons than a purpose-built bomber — and the 747 already existed, with a production line, an established supply chain and a large pool of trained engineers.

Later thinking has revisited exactly this idea under the label “arsenal plane”.

Why it stayed on paper

The weakness is what happens if the launch point is not safe.

A 747 cannot penetrate defended airspace. It is large, subsonic, unstealthy and unmanoeuvrable, and it depends entirely on launching from far enough away to stay outside the threat. That works against an opponent whose air defences are well mapped and short-ranged, and fails against one whose are not.

The Air Force ultimately preferred an aircraft that could do both — carry stand-off weapons and penetrate defences if required. That is what the B-1 was for, and the CMCA was not pursued.

A recurring proposal

The idea has never entirely gone away. The economics that made it attractive in the 1970s — cheap volume, long range, weapons that guide themselves — still hold, and variations on a large converted airliner carrying stand-off munitions resurface periodically in defence planning.