The growing Soviet capability to project military power globally — and to apply that power in several places at one — puts vast new stresses on US mobility. Airlift is obviously the pivotal component for timely initial responses to this global threat. As Lt. Gen. Robert D. Russ, USAF’s Deputy Chief of Staff for Research, Development and Acquisition, put it, “Airlift is the element of force projection that provides the capability to respond rapidly virtually anywhere in the world and with the force that can make the difference between keeping a conflict at a low level or escalation of hostilities to a dangerously high level.” This argument can be extended to reason that airlift can make the difference between victory and defeat.
Yet both forms of airlift, interheater as well as intratheater, are deficient in capacity and in need of modernization. USAF’s new Airlift Master plan, a cohesive roadmap for correcting existing shortfalls and meeting future mobility requirements, is the distillation and capstone of seventeen major mobility studies conducted over the past decade, all of which concluded that airlift requirements far exceed capabilities.
Formulated in close coordination with the other services, the unified and specified commands, the Joint Chiefs of Staff, and the Secretary of Defense, the airlift Mater Plan is anchored primarily in two documents — the long-term Defense Guidance and the Congressionally Mandated Mobility Study (CMMS) of April 1981. As such, it is balanced in relation to the other components of mobility — sealift and propositioning of materiel — and allows for the fact that airlift, although fast and flexible, inherently has a limited capacity and depends on the availability of airfields.
Conversely, the plan allows for the fact that sealift has a large capacity and some flexibility but is slow and seaport-dependent. Prepositioning is dependent on linkups of equipment and personnel to reduce long-range lift requirements and is burdened by the expense of duplicate sets, limited flexibility, and vulnerability. While the individual components of mobility can’t function efficiently by themselves, in combination they are complementary, even synergistic. With the plan’s envisioned ability to deploy rapidly and to sustain fighting units, US forces would be able to meet the central criterion of the Defense Guidance, which is to “contain and reverse the geographic expansion of Soviet control and military presence throughout the world, and increase the costs of Soviet support for and use of proxy, subversive, and terrorist forces.” Possibly even more important, such a force-projection capability would go a long way toward deterring Soviet military adventurism and the accompanying challenge to vital US security interests.
The Airlift Challenge
The present airlift system blends the Military Airlift Command active-duty Air Force, Air Force Reserve, Air National Guard, and Civil Reserve Air Fleet (CRAF) personnel, aircraft, and equipment into a national airlift force. This force at present has the capacity to deliver 32,4000,000 ton-miles of cargo per day over “intertheater” distances. The Defense Authorization Act of 1981 initiated the Congressionally Mandated Mobility Study, a total, long-term look at US mobility requirements. The CMMS gauged the national airlift requirements in relation to a variety of scenarios and time frames, with 1986 serving as the baseline force structure. While it produced a host of findings and hypotheses, CMMS yielded one central conclusion: A combined intertheater airlift capacity of 66,000,000 ton-miles per day (MTM/D) is a “minimum goal.” “Minimum” in this context was defined as constrained by fiscal pressures, thus falling short of the full requirements ensuing from the individual scenarios that served as benchmarks. An ancillary conclusion of the study was that a significant portion of the recommended airlift capacity should be capable of accommodating outsize cargo.
While the Master Plan is governed by the Congressionally Mandated Mobility Study’s minimum goal of sixty-six MTM/D in intertheater lift capacity, the requirements in intratheater mobility could not be pinpointed with the same precision. The Plan is predicated on evidence from a series of preceding studies that the present force of 512 Primary Aircraft Authorized (PAA) C-130s, with a capacity of about 9,2000 ton-miles per day, is inadequate to support intratheater logistical deployment, employment, and resupply requirements. Moreover, the C-130 is intrinsically an intratheater airlifter. Cargo brought into a theater by such intertheater aircraft as the C-5, C-141, or KC-10, therefore, has to be transferred to intratheater aircraft, which causes airfield saturation at the main operating bases and slows down the cargo flow to the users.
The Airlift Master Plan provides for continuing, detailed assessments of mid- and long-term intratheater lift requirements. Until these analyses can be incorporated into the Plan, the present intratheater lift capacity will serve as a temporary baseline even though the Defense Department reported formally to Congress in February 1984 that “we cannot transport heavy, outsize Army equipment to a vast majority of small austere airfields which comprise most of the free world’s runways. Additionally, the productivity of the C-130 is seriously reduced [when] carrying cargo over the long intratheater distances found in Southwest Asia, Africa, and other areas of the Third World.”
This report to Congress — which was endorsed specifically by the Secretaries of the Air Force and Army, the Chiefs of Staff of these two services, the Commandant of the Marine Corps, as well as the Secretary of Defense and the Chairman of the Joint Chiefs of Staff — points out that as scheduled improvements in intertheater airlift, sealift, and propositioning increase the amount of cargo delivered to a given theater, “these enhancements, in turn, will require more intratheater movement” to distribute this material.
The Defense Guidance covering the five-year period the FY ’89, therefore, instructs the air Force to increase intratheater lift capacity by fifty percent. Eventually, the plan is to attain a capacity of about 16,000 ton-miles per day. Other details of intratheater airlift modernization will probably be spelled out in the Defense Department’s pending worldwide Intratheater Mobility Study.
The Aging Factor
Because it is oriented toward the long term, the airlift Master Plan allows for attrition and aging of the force and the concomitant requirements of replacement and modernization. By 1990, the Air Force told Congress, the average age of the C-141B fleet will be more than twenty years, and the early C-130 aircraft will be thirty-three years old. Aircraft structural fatigue, coupled with obsolescent technology in avionics, design, and support, can be expected to drive up the operational costs of these aircraft to exorbitant levels over the next twenty years.
The older C-130s already require major modification, including centerwing rehabilitation and new outer wing boxes. In the case of the C-141 fleet, phaseout will probably have to begin in the mid-1990s and be competed shortly after the year 2000 unless major rehabilitation programs are started soon. But even with extensive modification, the useful service life of the 272 C-141s now in the inventory probably can’t be extended beyond 2015, in the view of Air Force experts.
Bases on elaborate, painstaking analytical and tradeoff studies, the Master plan provides two specific sets of force structure recommendations — one geared to the year 1998 and the other keyed to the next century.
In the first instance, the Plan recommends that 180 older PAA C-130s be retired between 1991 and 1998, along with fifty-four PAA C-141Bs. The remaining C-141Bs are to be transferred to the Air Reserve Forces. A total of 180 PAA C-17s (210 total authorized aircraft) is to be acquired by 1998 while 114 PAA C-5s are to be retained and manned by active-duty and ARF personnel. SAC’s sixty KC-10s are to be retained, but their assignment to the airlift or air-refueling mission will remain flexible. While forecasts about CRAF capacities beyond the year 2000 — when the service life of the present fleet becomes marginal and for which the airlines’ replacement plans are not yet formulated — are tenuous at best, the Plan assumes that a minimum of 11.3 MTM/D as well as about 145,000,000 passenger-miles per day will be available for the foreseeable future. The intratheater airlift capability is to be boosted to 16,000 ton-miles per day even though the associated manpower is to increase by only 245 spaces (0.2 percent), mainly because of the greater productivity of the C-17.
Over the longer term, the Plan envisions the replacement of the 180 PAA c-41Bs by the addition of at least forty PAA C-17s, to be operated by either the Air Reserve Forces or the active-duty/Reserve Associate program. In order to maintain the CRF contribution at a constant level, it “may be necessary for the military and civilian sector to jointly develop a new-technology Advanced Civil/Military Aircraft (AMCA),” according to the Master Plan. In addition, there could develop the need to buy additional quantities of C-17s or a new, advanced technology aircraft.
The C-17 Solution
On the basis of a multitude of tradeoff analyses, the Air Force and the Defense Department concluded that the C-17 is essential to modernize and expand both intra- and intertheater airlift in the most effective and economical way. Compared to a force ix involving additional C-5Bs and C-130s, USAF’s recommended force structure revolving around the C-17 costs $17.9 billion less requires 16,500 fewer personnel, and provides “more intratheater capability and military utility.”
Gen. Thomas M. Ryan, Jr., Commander in Chief of the Military Airlift Command, told Air Force Magazine that the C-17 “is a highly survivable solution to a wide range of airlift requirements — including direct delivery of the full range of military equipment over long ranges, to wherever the combatant commanders need it.” He added that the aircraft’s “low operating costs, ease of maintainability, and sharply reduced manpower requirements make it far and away the lowest life-cycle cost solution to the airlift force structure called for in the USAF Airlift Master Plan to meet our national objectives.”
Air Force Chief of Staff Gen. Charles A. Gabriel summed up the key qualities of the C-17 in a memorandum to US Army counterpart in which he said its primary mission is to “help satisfy the wartime inter and intratheater airlift needs of this nation.” The new aircraft, he pointed out, “Will reduce our intratheater airlift shortfall through its capability to operate into small, austere airfields on direct-delivery missions from the CONUS to forward operating areas.”
In an intratheater role, he explained, the C-17 can deliver people, equipment, and supplies to the brigade level and even further forward, if required. Its design will allow delivery of all sizes of cargo into forward operating locations; its maneuverability, speed, climb rates, and redundant systems make it more survivable than any current airlift aircraft.” The C-17’s large payload and small crew size allow “effective risk management by exposing fewer people and aircraft to forward area threats,” according to General Gabriel.
Genesis of an Airlifter
The C-17 program dates back to October 1980 when the Air Force issued a request for proposals (RFP) for what was then called the CX program. Boeing, McDonnell Douglas, and Lockheed responded, with the latter submitting two proposals, one for a new aircraft and the other for an updated C-5. The Air Force subsequently informed relevant elements of Congress that the C-5 would not meet the CX program’s operational requirements. In August 1981, the Air Force selected McDonnell Douglas the winner of the CX competition without entering in to a production commitment at that time. In November of that year, the Chiefs of Staff of the Army and the Air Force, along with the Marine Corps Commandant, informed Congress that they were in accord on the selection of the C-17, and in January 1982 recommended acquisition of forty-four KC-10s and 164 C-17s.
Also in January 1982, the Air Force and the Defense Department, in response to an unsolicited proposal by Lockheed centering on the acquisition of an additional fifty C-5s on a fixed-price basis, announced that the C-5 would go back into production. The reason for this decision was that the C-5 would be ready sooner. After protracted congressional wrangling over whether additional Boeing 747s rather than C-5s should be authorized, the Senate-House Authorization Conference agreed to acquire the additional C-5s, along with three 747s, and to speed up the C-17 program.
Initial development of the C-17 got under way in June 1982. The C-17 program is phased to follow directly behind the C-5B acquisitions, the last of which is scheduled to be delivered in February 1989; the first C-17. R-&D funding of the program in prior years totals about $120 million. The overall cost of the program — R&D as well as acquisition of 210 aircraft — is expected to amount to about $37.5 billion, expressed in then-year dollars.
The rational undergirding USAF’s airlift acquisition strategy, according to General Russ, is “to meet pressing near-term capability shortfalls and provide a long-range solution to correct quantitative and qualitative deficiencies in the total airlift system. The procurement of KC-10, C-5B, and additional CRAF aircraft was the best approach to building intertheater capability quickly, while the Ci-17 offers us the best approach to meet long-range goals.”
The acquisition of the C-5 and the C-17 was not an “either/or decision,” he stressed, adding that “each provides a specific capability and, by complementing each other, helps us meet national force-projection goals better.” While the C-5 will remain “our most efficient carrier of large, heavy payloads over intercontinental distances” with a payload capacity of about 260,000 pounds, the C-17 not only helps to redress quantitative ad qualitative airlift deficiencies but “provides desperately needed force modernization. It adds to our total airlift capability at the lowest life-cycle cost of other alternatives examined to meet the overall shortfall. The C-17 will have significantly lower manpower and operating costs.”
Unique Performance Features
The generic performance requirements for the C-17 were spelled out in the original CX RFP and — according to a report by Secretary Caspar Weinberger to Congress, entitled “Validation of the Requirement, Concepts, and Design or the C-17 Airlift Aircraft,” submitted two months ago — “remain valid today and for the foreseeable future.” These characteristics pivot on intercontinental and in-theater delivery of the full range of Army and Marine Corps equipment; the ability to operate from 3,000-foot runways; ground maneuverability sufficient to permit routine operations through small austere airfields; the capability to airdrop troops and equipment; enhanced survivability; excellent reliability, maintainability, and availability; and low life-cycle cost.
Secretary Weinberger’s detailed validation report pointed out that the C-17, because of its inherent flexibility to perform both the inter- and intratheater missions, “would produce significantly reduced life-cycle cost particularly in manpower, over any multiaircraft solution examined. In addition, any delay in procurement of additional aircraft past the mid-1990s will result in a loss of capability due to the necessary retirement of part of our C-141 and C-130 forces. Such a delay could push the solution to the nation’s airlift shortfall into the twenty-first century. The C-17 provides a timely single aircraft solution to the needs of our airlift system.”
The central performance feature of the C-17 is its ability to carry a maximum payload of eighty-six tons a distance of 2,940 nautical miles and deliver it directly to forward operating locations. The C-5, by way of a benchmark, can carry a payload of 130 tons up to 1,650 nautical miles, while the C-141B is capable of delivering forty-five tons of cargo over 1,970 nautical miles. These aircraft, however, can’t match the C-17’s “airfield compatibility,” meaning runway length and width standards as well as performance with regard to taxiways, ramp space, obstructions, and weight-bearing capacity.
The Runway Rule
As a rule of thumb, each thousand-foot reduction in runway length required by a given aircraft type doubles the number of airfields at which it can land. It would obviously be desirable to reduce the required length of the runway as much as possible without giving up other essential performance characteristics, such as range and payload. Detailed analyses by the Air Force show that the ability to operate from runways between 3,000 and 4,000 feet in length provides significant operational flexibility and doesn’t tax unduly other performance requirements ad the technology available at this time. Airfields with relatively short runways are usually constrained also in terms of width — on the average, runways in the range of 3,000 to 4,000 feet in length are about ninety feet wide — and are hampered by a limited number of narrow taxiways and cramped parking areas.
For example, in West Germany the typical small, austere airfield has a runway 3,000 to 4,000 feet long and ninety-eight feet wide, taxiways between forty and fifty feet in width, and no more than 50,000 square feet of parking space. In Saudi Arabia, the runways of austere fields range between 3,000 and 5,000 feet in length, are either unpaved or semiprepared, and have neither taxiways nor defined parking areas, according to Secretary Weinberger’s report to Congress. In Korea, many of the paved runways are between 2,500 and 5,000 feet long, lack parallel taxiways or turnaround areas, and are limited to about 110,000 square feet in parking area.
Aircraft operating in these theaters must have the ability to accommodate such constraints. The number of airfields in the free world — excluding those in the US — with runways longer than 5,000 feet and wider than 150 feet is 1,576, while the number of fields with runways more than 3,000 feet in length and ninety feet in width is 9,887, according to the Defense Department’s report to Congress. Even in the NATO nations, there are few airfields that can handle a heavy flow of the large transports currently in MAC’s inventory, mainly because the airfields are too small to accommodate those aircraft’s limited ground maneuverability. Also, runway interdiction and the need to bed down reinforcing fighter and combat support units would exacerbate the problem.
In certain areas of the world, such as the Middle East, Africa, and south America, the limited number of major airfields stretches out of the time required to deliver a force into combat, especially if airlift flow into these few fields must be restricted or if a long overland march is required from the offload base to the area of combat. By way of an example, the Saudi Arabian airfield system consists of ninety-nine airfields with hard-surface runways. Only nineteen of these fields can be considered adequate for C-5 and C-141 operations; almost all of these airfields can accommodate the C-17.
The ability to deliver cargo directly to or near the combat zone is a function of airfield availability and compatibility as well as of a suitable command and control system. Aircraft traits that enhance direct delivery include not only the ability to operate into austere, short-runway fields with minimal ramp space but also the ability to offload without sophisticated ground equipment and to perform with high reliability. The C-17 is optimized for direct delivery by combining intercontinental range, outsize cargo capacity, and the ability to use the same type of airfields as the C-130, according to Secretary Weinberger’s report to Congress. Because of its direct-delivery capability, the C-17 could reduce unit closure time by between seven and fifteen percent when assigned to deployment missions in Southwest Asia. Also, because it reduces transshipment requirements at main operating bases, the C-17 reduces congestion at these vital nodes, lowers the demand for intratheater movement, and hence, cuts the requirement for support personnel and equipment.
There is an additional plus that accrues with the C-17, according to the Defense Department: “The C-17 will comfortably operate in the intratheater role traditionally reserved for the C-130. Although the C-17 has a much greater capacity, it will not replace the C-130 for the sortie-intensive, relatively low-tonnage resupply mission [but will] ease the pressure on the C-130 fleet by augmenting it when the situation justifies the larger capacity, such as for bulk ammunition or fuel supply, or the longer range intratheater missions typical in areas such as Southwest Asia.”
The C-17’s ability to haul large payloads over long distances while retaining the short takeoff and landing (STOL) capabilities and ground maneuverability essential for direct delivery is the result of unique configuration and design features. The advanced technology wing design of the aircraft decreases aerodynamic drag and reduces structural weight, thereby reducing fuel consumption. Also, the greater thickness of the advanced technology airfoil provides a larger internal fuel volume. The use of winglets, proven on commercial aircraft, reduces drag and lowers fuel consumption by approximately four percent. Further, the Pratt & Whitney PW2037 engine chosen for use on the C-17 is the most fuel-efficient engine available. In addition, the aircraft is equipped with a full-time, computer-controlled, energy-performance management system that boosts fuel efficiency. As a result, the C-17’s payload capabilities are optimized in the critical range from 2,400 to 3,200nautical miles where it approaches those of the larger and heavier C-5B.
The C-17’s STOL features, proven in 800 flight-test hours on the YC-15 prototype aircraft, stem in part from externally blown flaps. The engine exhaust flows over and through the flaps to generate additional lift. The high, forward position of the engines increases and spreads the exhaust flow over the flap and, at the same time, increases ground clearance. This feature also helps in obstacle avoidance and reduces the risk of foreign object damage. The C-17 uses direct-lift control spoilers, mounted on the upper wing surfaces, to improve low-speed handling. This combination of externally blown flaps and direct-lift control spoilers permits approach speeds as low as 115 knots with a maximum payload and sufficient fuel for a 500 nautical mile return flight.
The C-17 incorporates a head-up display and a high-impact landing gear that, along with its high low-speed maneuverability, enable the pilot to touch down with high precision. The C-17’s design is also tailored for efficient ground operations at small, austere airfields, with the physical dimensions of the aircraft — 165-foot wingspan and 175.2-foot length — permitting simultaneous operation of two C-17s on a 250-foot by 300-foot ramp or single aircraft operations on ramps as small as 135 feet by 125 feet. Further, the aircraft’s thrust-reversing system facilitates backup during ground operations and enables the C-17 to turn around on a ninety-foot-wide runway. While the Air Force expects to operate the C-17 mainly from paved runways, the aircraft can operate with a full payload from unpaved, semiprepared, compacted surfaces, such as sandy clay or gravel. The engine exhaust flow, when reversed, is deflected upward to cut down on dust ad debris that might interfere with ground personnel and equipment.
The C-17’s cargo compartment accommodates outsize cargo and makes possible side-by-side double-row loading of the oversize pieces that make up the bulk of the Army equipment. Two five-ton trucks, for instance, can be carried side by side to make efficient use of the cargo space. A large cargo ramp and door allow straight-in loading of all equipment.
Survivability is obviously a cardinal requirement for an airlift aircraft meant to operate as close as tactically practical to the forward edge of the battle area. The C-17 is optimized for high survivability. Exposure to threats is reduced intrinsically by its high maneuverability and the flexibility of being able to choose from a large number of airfields. Also, the C-17 can use in-flight thrust reversal for rapid, straight-in descent or small-radius, spiral approaches to avoid enemy weapons in the vicinity of airfields. Conversely, the ability to accelerate rapidly and climb out with powered lift in small-diameter spirals reduces exposure on takeoff. Rapid onload and offload on the ground or LAPES (low-altitude parachute extraction system) airdrops also help reduce the time the aircraft needs to spend in combat areas. Lastly, the C-17’s low noise and smoke levels make it difficult for ground-based threats to detect the aircraft.
In terms of self-protection features, the C-17 incorporates provisions for radar warning systems, electronic countermeasures pods, cockpit electronic countermeasure control, and infrared missile protection. The design also stresses redundancy and separation of subsystem components, shielding, and fail-safe critical components to cut the C-17’s vulnerability.
The C-17’s crew is protected by armor and provided with a redundant oxygen supply. The aircraft can sustain flight with two of its four widely separated engines out of commission. The engine cases are designed for blade containment. The aircraft’s electrical system is both redundant and shielded. These and other design features, the Air Force reported to Congress, make the C-17 a highly survivable airlifter in the Army’s Airland Battle environment.
The C-17 takes advantage of technologies pioneered and proven in modern commercial aircraft to simplify maintenance, streamline logistics support, bolster reliability, and allow for high utilization rates. The aircraft’s avionics incorporate the latest advances in digital computer hardware and software, such as the systems in use on the DC-9-80, Boeing 757, and Boeing 767 commercial airliners. Before its first flight on the C017, the Pratt & Whitney PW2037 engine will be proven in more than three and a half million hours of commercial service o the Boeing 757.
Unique Warranty Provisions
The C-17 contract contains unique warranty provisions concerning reliability, availability, and maintainability, all of which are better than the performance levels of the three airlift aircraft now in MAC’s inventory. Should the C-17 fail to meet any of the warranted performance levels, the contractor must provide corrective action at no increase in contract price. At the same time, the contract provides for incentive payments to the contractor if the aircraft exceeds the specified goals. The contract further requires the contractor to correct any structural defects that come to light during 45,000 hours of durability testing. The airframe is warranted for ten years or 10,000 hours and the landing gear components for twice that time.
The reduced, warranted maintenance requirements, in turn, will result in reduced maintenance manning, just as the C-17’s three-member aircrew size will reduce aircrew-manning requirements compared to present MAC aircraft. The C-17’s cockpit design holds the flight deck crew to two pilots, similar to modern commercial airliners. The cargo compartment has been designed for operation by a single loadmaster. As a result, the C-17 — in spite of higher wartime utilization and higher crew ratios per aircraft — will have the lowest aircrew requirement of any large military airlift aircraft.
The unit flyaway cost of the C-17 expressed in FY ’84 dollars, the Air Force reported to Congress, is pegged at $85 million, compared to $141 million for the C-5. The procurement cost (which includes support equipment, simulators, and tech data) is estimated at $94 million for the C-17, compared to $150 million for the C-5.
The importance of the C-17 as a pivotal element of the Airlift Master Plan was summed up recently by the heads of the Army, Air Force, and Marine Corps to the Secretary of Defense and Congress in this statement: “The design characteristics and performance capabilities incorporated in the C-17 make it the best solution to satisfy overall airlift requirements and meet long-range objectives.”
Daily Report: Read the day's top news on the US Air Force, airpower, and national security issues.
AFA is closed on Monday for the President's Day holiday. The next Daily Report will be Tuesday, Feb. 20.
Tweets by @AirForceMag