Congressional Budget Office - March 1997


Annual Savings							Five-Year
Savings from			(Millions of dollars)		Cumulative
the 1997 Plan		1998	1999	2000	2001	2002	Total

Budget Authority	42	131	225	325	433	1,156

Outlays			34	111	201	298	403	1,046

The Air Force owns a large fleet of tanker aircraft to refuel transports, fighters, and bombers while they are airborne. Being able to do so is important for tactical air operations and for deploying forces by air from the United States to other parts of the world. U.S. tanker forces consist of 472 KC-135 aircraft and 54 KC-10 aircraft (both figures reflect primary mission aircraft inventory--those planes available for operational use).

During the past several years, most of the aircraft in the KC-135 fleet have been retrofitted with new CFM-56 engines that increase their fuel-carrying capacity. About two-thirds of the KC-135s have been modernized with this engine. The remainder (designated as KC-135E aircraft) have been retrofitted with less efficient engines for the Air Force Reserve and Air National Guard.

This option would retire 100 E-version aircraft--those with the least efficient engine technology and the smallest capacity for fuel delivery--at a rate of 20 planes per year through 2002. That would still leave the military with more than 420 operational tanker aircraft (including KC-10s). Compared with the Administration's 1997 plan, this approach could save $34 million in outlays in 1998 and over $1.0 billion through 2002.

Historically, the tanker fleet has played an important role in the nuclear deterrence mission by supporting long-range strategic bombers. Today, however, most of the requirements for aerial refueling are derived from regional threats. The tanker fleet provides an "air bridge" for deploying conventional forces, thus reducing the amount of time it takes to place U.S. forces in distant theaters and decreasing the degree to which the United States must rely on foreign bases en route. Tankers can be used to refuel airlift aircraft, as was done to support the C-5 aircraft that carried heavy equipment to Somalia. To a limited extent, KC-135s can also transport cargo during peacetime; in the event of a major regional contingency, 26 would be used in a transport role. Once in theater, tanker aircraft support fighters and bombers, increasing their combat range and endurance. For example, about 300 tanker aircraft supported operations in the Persian Gulf War.

This option could provide enough tanker capacity to meet the requirements of future regional contin-gencies. The combination of planned KC-135 retirements and the changes proposed in this option would amount to about a 15 percent reduction in the Air Force's total capacity for fuel delivery by 2001 compared with its current level. Relative to 1990 levels, those reductions in numbers of tankers are commensurate with the Administration's plans to reduce the number of attack and fighter aircraft by about 40 percent.

Retiring the older KC-135E aircraft would also avoid other problems. The KC-135E has a refurbished engine used formerly by Boeing 707 aircraft in commercial service. Although that engine has greater fuel efficiency than the KC-135's original engine, it gives the aircraft less capacity for fuel delivery and slightly higher operating and support costs than aircraft equipped with the more modern CFM-56 engine. In addition, the older engine does not comply with Federal Aviation Administration Stage III noise standards set for 2000. Since tankers often operate from airfields used for both military and commercial aircraft, the Air Force would probably have to purchase "hush kits" or put new engines in its E-version planes in the near future.

Retiring KC-135E tankers, however, might leave fewer KC-10 aircraft available for airlift tasks. In addition to being an aerial refueling aircraft, the KC-10 can be used as an airlifter; it is especially efficient in delivering bulk cargo. The Air Force plans to dedicate just 15 of its 54 KC-10s to air refueling missions, leaving the remainder free primarily for cargo delivery. Thus, by retiring more of the Air Force's aircraft dedicated to refueling, this option may reduce the number of KC-10s that can be devoted to airlift missions.

Moreover, the Air Force may need to rely more heavily on aerial refueling if the United States loses access to foreign bases that support airlift missions en route. During the Gulf War, three bases (Zaragoza, Torrejon, and Rhein-Main) handled 61 percent of the airlift traffic. Of those bases, one is no longer available, and it is uncertain whether the United States will have the same degree of access to the others in the future. Opponents of this option might argue that a large tanker fleet makes the United States less dependent on obtaining overflight and landing rights.

This option might leave the United States unable to wage a conventional war and a major nuclear war involving strategic bombers at the same time. However, in light of the low probability of major nuclear war and the availability of other platforms for delivering nuclear weapons that do not depend on tankers, the loss of capability is unlikely to be a problem.

Perhaps more important, this option might also limit the United States' ability to achieve the Administration's stated goal of being able to prosecute two major regional conflicts that occur nearly simultaneously. In the Persian Gulf War, the military deployed 46 KC-10 and 262 KC-135 tankers. The refueling aircraft retained under this option would be sufficient for a future deployment of similar size and would also provide capability for a simultaneous, smaller conventional deployment in some other theater or for support of a small nuclear mission that involved bombers. But such a force might not permit the United States to fight two simultaneous wars on the scale of Operation Desert Storm.