Two years ago, the U.S. Air Force revised the maintenance contract, with the aircraft's manufacturer, for its 21 B-2 bombers. A key element of the new contract was an availability (percentage of aircraft available for combat) guarantee. The B-2 has been notoriously difficult, and expensive, to maintain. The availability percentage guarantee has not been revealed. For a long time, the B-2 has been known as a "Hanger Queen" (an aircraft that spends too much time in the hanger for maintenance or repairs). The air force was desperate to change this. In the past, the air force has admitted that B-2 availability is usually less than 50 percent. Three years ago, only about seven of the U.S. Air Force's 21 B-2 bombers were ready to go at any time. In response, a combination of robots, sprayers and quality control were introduced in an attempt to double the readiness rate.
Five years ago, the U.S. Air Force introduced the use of robots to reduce the maintenance efforts required to keep their B-2 bombers flying. The B-2 uses a stealth (anti-radar) system that depends a lot on a smooth outer skin. That, in turn, required that the usual access panels and such on the B-2, be covered with tape and special paste to make it all smooth. And after every flight, a lot of this tape and paste has to be touched up, either because of the result of flying, or because access panels had to be opened. All this takes at lot of time, being one of the main reasons the B-2 required 25 man hours of maintenance for each hour in the air. Since most B-2 missions have been 30 or more hours each, well, do the math. The readiness rate of the B-2 fleet (of 21 aircraft) was then about 35 percent, which was less than half the rate of most other aircraft. This meant, that whenever there is a crises that requires the attention of B-2s, there were not many of these bombers ready to fly.
The main base for B-2s is in Missouri, and over a thousand maintenance personnel were assigned to take care of 19 aircraft there. That was where a team of four robots was installed, to apply the liquid coating to B-2s, thus cutting maintenance hours in half. But there were quality control problems with the liquid coating, often forcing maintenance crews to go back to tape and paste. Now the quality control problems are thought to be solved, but the readiness rate of B-2s rarely got over 50 percent.
B-2s still requires special, climate controlled hangars. There are some portable B-2 hangers, that can be flown to distant bases, thus keeping the bombers in the air less, and reducing the amount of maintenance needed. B-2 quality hangers have been built at Guam, in the Pacific, and Diego Garcia in the Indian ocean Still, the cost to operate the B-2 is over three times that of the B-52.
If stealth is not an issue (as when there is not much enemy opposition), than it's a lot cheaper to send a B-52. This is exactly what the air force does most of the time. But in a war with a nation possessing modern (or even semi-modern) air defenses, the B-2s can be very valuable. Costing over two billion dollars each to buy, and very expensive to operate, the B-2s provide that extra edge. No other nation has anything like the B-2s, although many are working on ways to defeat it's stealth and knock them down. Still, when equipped with over a hundred of the new SDB (250 pound, GPS guided Small Diameter Bomb), the B-2 would be a formidable one-plane air force.
The latest attempt to improve B-2 readiness is PBL (Performance Based Logistics). This is yet another new commercial concept being adopted by the military. Think of it as outsourcing on steroids. Put simply, PBL is buying a complete support program for a major piece of equipment (ship, aircraft) over its entire lifetime. The fixed (with adjustments for inflation and some other uncontrollable elements) price also comes with minimum availability and performance requirements for the supported equipment. The U.S. Department of Defense has nearly $100 billion a years worth of such work.
Another example of how this all works is a PBL deal by the Royal Air Force, to have its fleet of fifty C-130 transports maintained over the next 24 years. Total cost of the contract, $2.86 billion (about $120 million a year, or about $2.4 million a year per aircraft). The deal is expected to save the RAF about $12 million a year, and be one less headache for RAF commanders.
PBL deals don't replace the maintenance done by the crew, in the course of regular operations. But the cost of major repairs, periodic refurbishment and the like, is typically done at centralized maintenance facility. The military PBL deals also make provision for war related damage, which is taken care of by surcharges. It's unclear if PBL has worked any magic on B-2 availability.