Mamerto Adan is a feature writer who is back in college once again. Science is one of his many interests and his favorite topic.
More than a century ago, we thought that heavier than aircraft cannot fly. Fortunately, we were wrong, and the Wright Brothers took to the air and left the world in awe. Then decades later, the world was introduced to a massive flying vehicle. Boeing unveiled what was the largest winged machine at that time, the 747 (dubbed the Jumbo Jet). This double decked behemoth boasts a wingspan of around 200 feet, and a length reaching 250 feet. People thought that it was too big to fly, but it handled well on its maiden flight, that historic February 9, 1969.
Today, it’s no longer the queen in terms of size. Nevertheless, it remains a well-known bird in civil aviation. The Jumbo Jet is still a competent aircraft. It is a jet airliner, and a cargo plane. It even carried the Space Shuttle upon transport.
And once, it was almost turned into a warplane.
Imagine one of the biggest birds in the sky zooming into battle, and unloading its cargoes of cruise missiles? Sounds far-fetched? Believe it or not it almost came true.
Why Turning the 747 into a Bomber Makes Sense
The Boeing 747 was never really meant for warfare. When it rolled out, carrying passengers and cargoes to and from every airport are what the designers have in mind. For some, turning a 747 into a warplane is like adapting a Ferrari muscle car into a tank.
Yet again, it wasn’t really that far-fetched for proponents.
Do note that the AC-130, the armed variant of the C-130 is basically a cargo plane brisling with large caliber guns. Would it be possible to do the same on larger jets?
For one thing, the mighty 747 is a hardy plane. And seeing its track record and performance in civil aviation, it is also reliable. Being a jet airliner, it could fly at more than 14,000 km, an impressive range that could be extended by aerial refueling. And yes, it couldn’t fly beyond Mach 1, and the designers never made it to be supersonic. Its’ speed could only reach Mach 0.9, though being supersonic was never required for some jet powered warplanes.
But it was the carrying capacity that made it appealing for planners. Inside the fuselage of the 747-8 (the most modern version) is a 6,345 cu ft worth of space. The freighter version (747-8F) could even haul 140 tons of cargo. This means that it could hold a lot of payload, possibly more than any heavy bombers.
The 747 CMCA
Hence during the development of B-1 Lancer strategic bomber, the U.S. Air Force considered arming the Jumbo Jet with air launch cruise missiles. Hence the 747 CMCA “Cruise Missile Carrier Aircraft” was born.
The story started in the 1980s, during the Carter Administration. The U.S. Air Force was trying to retire the venerable B-52 Stratofortress and they are looking for a replacement.
Weaponizing the mighty 747 means doing some changes. The paint job will have an overhaul obviously, and there will be addition of various radios, radars and electronics. But the biggest change will be on the aircraft itself.
The design was based on the 747-200C, the nose loading version. It means that it will have a hinged door on its nose. Inside, nine rotary launchers will occupy the stripped-up passenger cabin. Each launcher would hold eight missiles. Using an overhead handling system, the launchers could be slid back into a launching position at the rear of the aircraft.
The cruise missiles will be ejected on the right-side door of the jet’s tail cone. Launching could be done one at the time, or in rapid succession.
A single 747 CMCA could launch 73 cruise missiles, while the “hump” of the Jumbo Jet could serve a different purpose. In a normal 747, the upper deck is for the first-class passengers. In this case, there is enough room for command and control, not to mention network relay functions.
For a weapon, the modified jet will carry the AGM-86. The range of which is between 500 and 1500 miles depending on the version of the missile. The warhead can reach up to 3000 lbs.
With 72 long range cruise missiles in its bay boasting heavy warheads, the 747 CMCA could unleash massive salvo.
People might point out that the 747 lacked the agility to evade SAMs. But the primary task of modern-day bombers is to loiter in safe air space, away from the dangers of air defense as it unloads its ordinance. In the case of 747 CMCA, it is primarily a cruise missile carrier. It means that it could fly at a distance and let the missiles do the dangerous work of diving into the target.
But we also need to consider that the designers never imagined the 747 to deliver bombs, hence it lacks some qualities that makes a warplane. First is the oscillation during missile launch. The entire fuselage will be exposed to harsh acoustic oscillation (shear oscillation and acoustic resonance). Something that modern bombers are adapted to.
The manner of opening the missile bay could cause considerable amount of turbulence in the weapons bay, considering that the 747 CMCA had a huge one. One must also consider that there will be an increase of radar cross section and drag once the bomb bay door is opened.
Then there is the possibility that those internal mechanism and weapons could affect the aircraft’s weight, and its performance.
The It Was Scrapped
Despite of the shortcomings, the prospect of a loitering weapons platform operating at lower cost would have been attractive. As Tyler Rogoway, the writer of Foxtrot Alpha quoted that, “In retrospect it would seem that choosing not to develop the CMCA was a poor move.”
He also mentioned how such aircraft carrying GPS guided munitions could have been very effective in Afghanistan and Iraq.
But seeing its benefits, why the heck it was abandoned in the first place?
Again, it was conceived during the Carter Administration, when the Soviet was still alive and threatening. Aside from the converted jumbo jet, the early version of the B-1 was also being considered. Proponents stressed that cruise missile jets like the 747 CMCA could perform as the B-1 at lower cost.
But U.S. cruise missiles were not expected to achieve high probabilities of destroying heavily defended targets. And then there is the threat of Soviet long-range interceptors. This is where the B-1 beats the 747 CMCA. In terms of survivability and destroying hard targets, the “Lancer” was preferred.
So, in the end the B-1 was chosen over the modified Jumbo Jet. While the B-52, which was considered for retirement, was given upgrades and still flying up to this day (and won’t be replaced for years to come).
1. Rogoway, Tyler. (July 19, 2014). "Why Boeing's design for a 747 full of cruise missiles makes total sense," Foxtrot Alpha.
2. Pike, John. (March 4, 2016). "Cruise Missile Carrier Aircraft," Global Security.
3. Mills, Jen (January 23, 2016) "These Plans Show Boeing's Proposal to Put Dozens of Missiles in a 747," Metro.