Air University Review, January-February 1985

Improving Force Flexibility
Through V/STOL

Lieutenant Colonel Price T. Bingham

WORLD War II revealed the importance of air bases in air operations. German invasions of European countries were marked by early, determined efforts to capture or destroy airfields and annihilate enemy air forces while they were still on the ground. The Germans also assigned great importance to establishing base facilities quickly if captured fields were unavailable. In the beginning phases of the Pacific war, Japanese armed forces followed a similar course of action with regard to destroying enemy air forces and capturing their supporting bases.1

Later, when the Allies took the offensive, air bases continued to be an item of major military concern. The availability of air bases was a major planning factor in Operation Overlord, in General Douglas MacArthur's operations in the Pacific, and in Germany's continuing efforts to ward off approaching Allied forces.2

As the war progressed, it became apparent that air bases possessed a substantial degree of survivability. For one thing, it became increasingly difficult to achieve surprise, since armed forces in war tend to be more alert than when their nations are at peace. Furthermore, high aircraft production rates, the relatively limited damage that could be caused by air base attack munitions, and the ability of most aircraft to operate from relatively austere bases––all contributed to decreasing the effectiveness of air base attacks. Despite these factors, however, by the end of the war in Europe the tremendous power of the Allied air threat forced the Luftwaffe to take several actions to provide a base structure that could sustain its dwindling forces. These actions included new construction (the Luftwaffe had 350 bases in Germany alone during the final days of the war), the use of highways for runways, camouflaging airfields, hardening airfield support facilities, and dispersing support facilities away from the runways.3

Today, these World War II experiences continue to provide an important lesson for those of us who are concerned with air power employment. Flexibility, one of air power's most important characteristics, remains just as dependent on the availability and survivability of supporting base structures as it is on the aircraft's airborne capabilities. Recognizing the close relationship that exists between aircraft and base structure characteristics, Air Force planners might be wise to explore the employment of vertical/short takeoff and landing (V/STOL) aircraft.

Post-World War II Trends

After World War II, the U.S. Air Force concentrated increasingly on long-range combat aircraft and nuclear weapons. The Korean conflict caused a temporary refocusing on shorter-range combat aircraft. However, in Korea, our ability to suppress quickly the weak enemy air threat to our bases, plus our use of safe sanctuaries, caused little attention to be paid to the World War II experiences regarding air base survivability. Furthermore, as the Korean ground battles became less characterized by advances and retreats over large distances, interest in measures to ensure the rapid availability of air bases for aircraft supporting the ground battle also waned. Instead, the peculiar air-to-air combat orientation of the air superiority battle, which resulted from the use of sanctuaries by both sides, allowed emphasis during and after the war to be put mainly on aircraft airborne performance parameters, such as airspeed, combat ceiling, maneuverability, and endurance.

These parameters for aircraft often were improved at the expense of performance characteristics that could contribute to greater base survivability and more rapid base availability. For instance, to achieve greater in-flight performance, aircraft weight and wing loading were increased. These additions, in turn, increased takeoff and landing speeds. As a result, runways had to be longer, harder, and smoother. Performance improvements also made aircraft more complex and support more elaborate and costly. To achieve economies in elaborate and costly support facilities, these facilities were concentrated. The survivability of bases became unspoken, untested, and ignored assumptions.

For a brief period in the 1950s, the U.S. Air Force did seek to reduce the requirement for long, vulnerable runways. Vertical takeoff and landing (VTOL) research aircraft, such as the X-13 Ryan Vertijet, were developed. Also, attempts were made to develop zero-launch aircraft by attaching rocket bottles to the F-100. Unfortunately, the technology of the time was not sufficiently advanced for these concepts to be operationally feasible, and interest in further efforts soon faded.

In 1967, interest in airfield survivability increased suddenly after surprise Israeli Air Force attacks inflicted tremendous losses on Arab air forces, mostly while these forces were still at their air bases. Soon thereafter, the U.S. Air Force and other air forces placed increased emphasis on various defensive measures, focusing generally on passive hardening measures, such as building aircraft shelters.

Air Power and Flexibility
in Modern Warfare

Unfortunately, emphasis on passive hardening measures also introduces a real possibility of developing a rigid mindset in our approach to the problem of attaining greater air base survivability. An uncomfortably similar situation can be found in pre-World War II France. The French built the Maginot Line, a costly, inflexible system of concrete fortifications that protected the French border with Germany from Switzerland to the Forest of Ardennes. French military thinkers considered the hilly Ardennes to be an unpenetrable barrier and thus a suitable feature on which to anchor the Maginot Line. The tremendous expense of the Maginot Line absorbed scarce resources. Worse, it constrained the thinking of the French military. The surprise German assault through the Ardennes in May 1940 proved the superiority of a combination of doctrinal and technological innovations over an approach that depends on narrow technological solutions to solve military challenges. Like the pre-World War II French, we have failed to recognize the advantages of flexibility gained from mobility. Instead, we too may have gained a false sense of security from our reliance on the protection of concrete and steel.

In addition to the dangers of the mindset that result from such an approach to basing, there is a serious question as to whether reliance on a combination of hardening measures, air defenses, camouflage, and rapid repair is really adequate to ensure air base survivability in the environment of modern warfare. The number and variety of Soviet air base attack assets (missiles, aircraft, and special operations forces) and their capability (speed, accuracy, and munitions effectiveness) present a rapidly growing threat. Increasingly, it is becoming quite likely, despite our active defenses, that enough weapons will be able to hit our bases so as to cause significant damage and hamper air operations severely. Moreover, the size and lack of mobility of our fixed bases, the concentration of assets at these air bases (often seventy-two aircraft per base), and the relatively small number of bases available combine to make these facilities extremely lucrative targets. It is very probable that the Soviets would consider the neutralization of these bases to be well worth the dedication of significant resources, possibly including the employment of nuclear weapons.

There is little possibility that reliance on active defenses and hardening measures will be sufficient to ensure base survival in a nuclear environment. Therefore, planners have long recognized that in the strategic nuclear arena the probability of force survival can best be ensured by using mobility, concealment, deception, and dispersal. Such measures also would improve base survivability in the theater war realm, where the attacker's problem is relatively simple because of vastly reduced ranges. Furthermore, by making our theater air base structure less vulnerable to nuclear attack, we provide less incentive for an enemy to employ nuclear weapons against our bases and, thereby, may raise the nuclear threshold.

The impact of chemical weapons on air base survivability is another subject of great concern. Even where air operations could continue following an attack by an enemy using chemical and conventional munitions, the wearing of protective ensembles would severely handicap defensive measures, explosive ordnance disposal, repair efforts, and sortie generation activities. As a result, the number and quality of sorties produced by a damaged and chemically contaminated air base could be reduced substantially.

Even if the threat from nuclear and chemical munitions could be disregarded, the growing effectiveness of conventional munitions for area denial and the destruction of runways, taxiways, aircraft shelters, and other hardened structures make it likely that a capable, determined enemy could seriously impair an air base's ability to operate. If an air base were somehow able to recover from an attack with conventional munitions, the question is at what cost and, even more important, how quickly. The hours or days that it may take for an air base to regain its ability to generate large numbers of effective sorties could spell the difference between victory and defeat.

Some planners assert that after a conventional attack enough portions of an air base's runways and taxiways will remain to permit operations by short takeoff and landing (STOL) aircraft. While this assumption may be accurate, one also must assess the impact on sustained sortie generation capability that would result from having to move aircraft between their shelters and the usable portions of runways and taxiways. Particularly important to consider is the circumstance in which the intervening distance is heavily cratered and infested with area denial munitions.

Still another air base survivability concern must be the cascading impact that the closing of air bases may have within a theater. When air bases are closed, airborne aircraft must divert to air bases that remain open, thereby increasing the importance and impact of enemy attacks on these bases.

As World War II demonstrated, the ability of bases to survive air attacks is not the only concern. Even if concrete and steel could make bases survivable, such air bases are neither mobile nor quickly built. If war occurred in Europe and NATO armies were forced to withdraw, our air forces could not easily relocate, given their dependence on hardened, fixed air bases.

The problem of reliance on fixed air bases is especially acute for the United States, which has worldwide commitments. In many of the areas of the world where we may be required to introduce military forces, no suitable, hardened air bases exist. If our Air Force cannot survive without such facilities, we may not dare to introduce land forces. Likewise, the lack of suitable runways in many regions gives our plans an element of rigidity. If the enemy knows that we must take a particular airfield for sustained military actions to be feasible, he can plan accordingly. Our acquisition of such a base could result in heavy casualties and, perhaps even more important, lost time. Also, it is worth noting that the Battle of Okinawa in World War II suggests the danger of employing aircraft carriers as substitutes for land air bases when conducting sustained operations against a capable enemy.

While aerial refueling provides one way to reduce the disadvantages of a lack of available air bases, it is not a substitute for available air bases. In fact, aerial refueling often imposes significant handicaps. Dependence on aerial refueling requires adequate tanker resources and introduces increased complexity to operations. Most important, however, is the viability of aerial refueling in combat operations against a capable and determined enemy. Air bases capable of supporting tanker operations must be available and survivable. Further, refueling anchors must be protected and the impact of the enemy's ability to disrupt refueling considered. If refueling is disrupted, can targets be attacked? Or worse, can all aircraft safely recover? Other considerations are the increased time that aircraft would take to reach targets and the negative impact on sortie rates.

Aircraft Characteristics
Necessary for Improving Flexibility

The challenge facing the West, particularly the United States, is how to regain the flexibility that our Air Force requires to win the air battle, as we have been able to do in the past. Part of the answer, obviously, is to reduce the dependence of our aircraft on centralized, complex, perhaps vulnerable support facilities. Yet this approach will be far from adequate if the aircraft themselves are tied to long runways, taxiways, and hardened shelters that are expensive and time-consuming to build, defend, and, if damaged, repair.

One solution is to develop aircraft that do not require continuous, elaborate maintenance support or long, wide, hard, smooth surfaces from which to operate. To some degree, technology is providing a means to do this. As a result of recent technological developments, aircraft can be made more reliable and easily maintained. In addition, the length of runway needed for takeoffs and landings is being reduced.

Nevertheless, most aircraft in the current USAF inventory and most of those scheduled for procurement will continue to require runways of considerable length. Conventional takeoff and landing (CTOL) aircraft require long surfaces for landing––often two to three times their takeoff distances. This requirement results from the effect of wing loading on approach speed and normal touchdown dispersal due to judgment in the landing flare. Even STOL aircraft require at least 2000 feet of surface to get airborne.4 Arresting gear, combined with nonflare aircraft, can reduce landing distances; but arresting gear is expensive and even mobile arresting equipment takes precious time to install and operate. The system presently being developed for the Air Force is designed to handle one engagement every two minutes.5

Another problem with reliance on cable or barrier arrestments is the risk resulting from missed engagements. Arresting gear can become fouled by accident or enemy action, and there remains a need for sufficient landing surface both before and after the arresting gear. In addition, conducting simultaneous takeoff and landing operations from the same surface when arresting gear is used introduces significant delays.

The width of takeoff and landing surfaces is as critical as length. The British Aircraft and Armament Experimental Establishment at Boscombe Down conducted a study on such criteria in 1978. This study revealed that an aircraft landing at speeds of 100-120 knots needs a landing surface at least 50 feet wide, especially if obstacles, such as trees, are near the landing surface. Such a requirement rules out the use of roads for landing, unless three or more unobstructed traffic lanes are available.6 As a result, the number of highway locations suitable for CTOL or STOL aircraft operations, even in an area with the road density of western Europe, is quite small.

Still another problem restricting aircraft operations is the quality (load-bearing capability and smoothness) of the operating surface. The California Bearing Ratio (CBR) is a relative measure of the load a given surface can support without significant deformation. The CBR for a wet putting green is four; a baseball outfield, nine; a dirt road's shoulder, ten; and a bituminous pavement (highway), sixty. For comparison, the following is a sample of CBRs required for current tactical aircraft: the A-10 needs approximately ten; the F-16, almost fourteen; the F-4, more than fifteen; the AV-8B, approximately six.7 Often more important than the aggregate strength of the surface, however, is the presence of surface irregularities or deformities.

Compared to other high-performance CTOL and STOL aircraft, a V/STOL aircraft, such as the AV-8B, can operate from a much wider variety of surfaces. Thus, for such aircraft, many more locations are available which can serve as bases. This large number of potential bases can increase significantly the availability of the base structure needed to support sustained air operations in time of war.

V/STOL Aircraft: Current Status

Currently, V/STOL technology is being pursued both in the West and by the Soviet Union. Compared to CTOL aircraft, the time needed to develop a new V/STOL aircraft is increased by the greater importance and complexity of design problems involving weight control and center of gravity. This reality prevents Western air forces from fielding V/STOL aircraft rapidly unless such aircraft are already well along in development. It will also act to postpone the deployment of V/STOL aircraft in the future, unless their development is begun now.

In the West, only one V/STOL aircraft is available now and in production––the McDonnell Douglas, British Aerospace AV-8B/GR.Mk 5 Harrier II. Too often, the AV-8B's performance is confused with that of the earlier AV-8A. This error can cause serious misunderstandings, as the AV-8B offers major improvements over the AV-8A. Due to design changes such as the use of composite materials, a larger air inlet, and a large, wet, supercritical wing, the AV-8B has twice the payload or radius capability of the AV-8A. Taking off vertically, the AV-8B can carry a total payload of 6000 pounds of fuel and munitions. However, with a short takeoff roll, the AV-8B can increase its payload to 17,000 pounds. In this mode, using a takeoff roll well under 1500 feet, the AV-8B is advertised to be able to fly a hi-lo/hi-mission profile over a range of 615 nautical miles while carrying seven Mk-82 (500-pound) bombs. Its Angle Rate Bombing System is credited by the manufacturer and the U.S. Marine Corps with giving it an extremely accurate air-to-ground ordnance delivery capability. Using state-of-the-art avionics, pilot workload is reduced, even during navigation at low altitudes.8

Besides its air-to-ground capabilities, the AV-8B's air-to-air potential is greater than many observers have realized. According to B. R. A. Burns, Chief Aerodynamicist at British Aerospace Aircraft Group, in other than beyond-visual-range (BVR) air-to-air engagements, maximum speed is often less important than maneuverability and the ability to change energy by accelerating or climbing rapidly. He points out that, particularly with modern missiles, there is no escape from close air combat by speed alone; once engaged, only superior maneuverability or tactics will win the day. Except for "slashing attacks on an unwary foe, speed is an embarrassment because rate of turn is restricted by G limits (structural or physiological)." Burns identifies three key parameters for achieving success in air-to-air close combat: maximum sustained (thrust-limited) turn rate, maximum attained (lift-limited) turn rate, and specific excess power.9 The AV-8B performs extremely well in all three of these areas.

The AV-8B's vectoring in forward flight (VIFF) and high thrust-to-weight engine permits agile maneuvering. Also contributing to make the AV-8B a formidable air-to-air opponent are the aircraft's small size, smokeless engine, raised cockpit, electronic countermeasures, AIM-9, and cannon capability. Finally, as the manufacturer points out, composite materials and emphasis on reliability and maintainability have significantly reduced the amount of maintenance support that an AV-8B requires.10

Commonly Perceived Problems
with V/STOL Aircraft

Despite the demonstrated need for more flexibility, high-performance V/STOL aircraft have not been widely recognized as a realistic approach to air combat power. Presently, V/STOL aircraft are operated in small numbers by the Americans, British, Spanish, Indians, and Soviets. In the United States, only the Marine Corps uses such aircraft. The reluctance of most air forces to employ V/STOL aircraft arises from many air power leaders' belief that the advantages of using a V/STOL aircraft are outweighed by the disadvantages. To evaluate the validity of this widely held perception, it is necessary to examine both the accuracy of the most frequently expressed concerns regarding the operational utility of V/STOL aircraft and the possible impact of technological improvements.

The V/STOL aircraft is generally criticized for having a poor safety record and for having shorter range, a smaller payload, and lower airspeed than CTOL aircraft. Other perceived problems with V/STOL aircraft are the cost and lead time required to build such aircraft. Finally, V/STOL aircraft are often associated with dispersed operations, which some critics believe involve such immense logistical and command and control problems that the operations ultimately are not worth the benefits gained.

While some of these concerns are valid, at least presently, there are clear indications that continued technological advances should overcome most of these objections to the future employment of V/STOL aircraft. For one thing, an increase in the use of composite materials should further reduce aircraft empty weight and thus improve both range and payload. Simultaneously, using such materials will increase aircraft reliability by reducing susceptibility to corrosion. The properties of composite materials also make sweptforward wings a viable possibility. Employing sweptforward wings, according to Glenn L. Spach of the Grumman Aerospace Company, offers the prospect for a lighter aircraft with improved maneuverability and better low-speed handling characteristics.11

Meanwhile, advances in engine technology are making V/STOL aircraft more viable due to improved thrust-to-weight ratios, as well as overall gains in engine efficiency, safety, reliability, and, potentially, maximum airspeed. Plenum chamber burning technology, in particular, offers significant promise for improving the maximum airspeed of V/STOL aircraft. Developments in avionics and fly-by-wire controls should contribute to aircraft weight reductions also, while increasing capability, reliability, and safety. Increased system reliability, combined with greater use of the current remove-and-replace maintenance procedures, should reduce the maintenance and supply burdens of dispersed operations.

Considering these technological trends, we can expect follow-on V/STOL aircraft to continue the dramatic improvements in overall capabilities begun with the AV-8B. As with the AV-8B, V/STOL aircraft operating in a short takeoff mode soon should be able to approach most small- to moderate-sized theater-based CTOL and STOL fighter/attack aircraft in range and payload capabilities.

Technology can increase the safety of V/STOL aircraft operations as well. Improvements in the AV-8B have resulted in a 65 percent reduction in pilot workload during VTOL operations compared to that required in the AV-8A. Even without considering such improvements, one can fairly state that V/STOL aircraft safety has been a seriously misunderstood issue. Seldom noticed is the fact that the early accident rate of the AV-8A has not been that exceptional when compared to the initial accident rates of high-performance CTOL aircraft. Few critics have noted either that the accident rate of the Royal Air Force's Harrier has always been significantly less than that of the U.S. Marine Corps' aircraft.12 In addition, since late 1977 the Marines' AV-8 accident rate has declined dramatically, in part due to modifications in the selection and training of AV-8 pilots.13

Similarly, even if one ignores potential engine and munitions improvements that recent technology may provide, one might conclude that limitations in current airborne V/STOL aircraft performance are not so great as some tacticians have thought. Although the advantages resulting from high airspeed are well recognized in air-to-air combat, maximum airspeed is only one of many important considerations in aircraft design. The desirability of a specific capability must be weighed against the requirements of the aircraft's primary role, as well as other tradeoffs that must be made.

For example, it is necessary to determine whether supersonic capability is necessary, or merely desirable, for aircraft with a primary air-to-surface role. For such aircraft, armed with modern all-aspect air-to-air missiles, it may be that the difference between a maximum airspeed of mach .9 and 1.5 is not so important as aircraft maneuverability and turn rate, acceleration, aircraft size and signature, cruise speed, endurance, and target-acquisition capability. When all of these factors are considered, V/STOL aircraft with capabilities similar to the AV-8B may have sufficient air-to-air potential to be acceptably mission-flexible for an aircraft with a primary role of air-to-surface attack.

Harrier Performance
in the Falklands/Malvinas

The potential of air power depends on more than just the airborne characteristics of aircraft. To reach an accurate judgment regarding the operational flexibility of V/STOL, we must examine British operations in the Falklands/Malvinas conflict of 1982. These operations revealed the great potential of V/STOL aircraft by showing how the unique characteristics of Harrier aircraft improved flexibility. V/STOL capability allowed Harriers to land vertically on the crowded flight decks of the carriers HMS Hermes and HMS Invincible without the carriers turning into the wind. The Harriers operated even when the flight decks were moving vertically through as much as thirty feet due to heavy seas and when visibility was severely reduced. One Harrier recovered on the HMS Hermes in a horizontal visibility of fifty meters.

To aid in recovery during reduced visibility, the carriers often dropped flares in their wakes, which the Harriers, due to the use of vectored thrust, were able to follow up slowly to the ships. The Sea Harriers also used their Blue Fox radar to assist in bad-weather recovery. With no previous experience in operating from carriers, RAF Harrier pilots flew from the container ships Atlantic Conveyor and Contender Bezant to the decks of the carriers. Other RAF Harriers used air refueling to deploy directly from Ascension Island to the carriers, a distance of approximately 3370 nautical miles.

Soon after the British landing at San Carlos, Royal Engineers built an 850-foot matting strip. This simple strip provided the Harriers with a base that allowed them to increase their endurance over the battle area significantly. They would fly air patrol from the carriers, which were located well east of the Falklands/Malvinas (to reduce exposure to the Argentine air threat), and land at the San Carlos strip for refueling. Other Harriers at this strip would await tasking calls to provide support for ground forces, reducing response time without maintaining inefficient airborne alert. Once, when a helicopter damaged the matting strip, Harriers recovered vertically and refueled on the aft platforms of assault ships HMS Fearless and Intrepid.14

After recapturing the Falklands/Malvinas, the British deployed McDonnell Douglas F-4Ks to the runway at Port Stanley for air defense, but only after the runway had been lengthened to accommodate these aircraft. The runway was originally 4100 feet long and had to be extended to at least 6000 feet, even with the use of arresting cables. Until this runway extension was accomplished, Sea Harriers sat air defense alert.15

USMC Harrier Employment Concept

Recognizing how the unique capabilities of V/STOL aircraft could aid them in their expeditionary mission, the U.S. Marine Corps procured AV-8A Harriers and developed an extensive employment concept. The USMC concept depends on the speed with which Harrier bases can be built so that Marine ground forces can receive air support. The concept includes three different types of bases: the forward site, facility, and main base.

Based on extensive testing, USMC plans allow for as little as one to two days for nineteen to twenty-five men to build an austere VTOL Harrier forward site in a light forest. Negligible time for construction would be required if an existing surface, such as a road, could be used. A forward site for one to four Harriers would consist, at a minimum, of a 72 x 72-foot pad in an area cleared 150 feet beyond the pad. According to the USMC concept of operations, it would be located in a secure area twenty nautical miles from the forward edge of the battle area (FEBA) and would be used for ground loiter. If fuel and ordnance were available there, the forward site could be used for sustained daytime visual flight rules (VFR) operations. For planning purposes, twelve sorties per day could be flown from a forward site on the supplies provided by three CH-53E sorties. (This calculation assumes that the twelve sorties consume thirty-six tons of fuel and ordnance, including six 500-pound bombs per sortie. A CH-53 has about a thirteen-ton lift capability when flying in excess of seventy nautical miles without refueling.) Normally, no maintenance would be performed at a forward site.

The second type of base envisioned in the USMC plan, the Harrier facility, is an intermediate-sized land base located nominally fifty nautical miles from the FEBA. Organizational maintenance would be provided at a facility, which could support day and night VFR operations. Marine planners think that a facility with a 600 x 72-foot runway suitable for six to ten V/STOL aircraft would be constructed and ready for operations in twenty-four to seventy-two hours, depending on terrain or manpower used. All necessary construction equipment (an estimated 325 tons) could be delivered from a main base in thirty CH-53 sorties.

According to plans, a main base would be located about 50 nautical miles behind the facilities or 100 nautical miles from the FEBA. Operations from a main base will be day or night and all-weather. A main base would be equipped to provide organizational-and intermediate-level maintenance for a squadron of twenty V/STOL aircraft.16

Basing Availability Advantages
of V/STOL Aircraft

As the British revealed at San Carlos and the Marines have recognized in their Harrier employment concept, one of the most obvious advantages of employing V/STOL aircraft is its capability of operating from bases that can be built quickly. Besides those bases that might be constructed rapidly, more potential bases are presently available for V/STOL than for CTOL aircraft. In Denmark alone, there are 102 runways more than 3500 feet in length, but only 23 of these have surfaces suitable for CTOL aircraft. According to McDonnell Douglas, the V/STOL AV-8B can operate from all 102.17

Operationally, V/STOL capability increases flexibility by allowing simultaneous takeoff and landing operations. The vertical landing capability allows pilots of V/STOL aircraft to set emergency bingos (minimum recovery fuel) only high enough for return to any friendly base or, in extremus, friendly territory. In contrast, pilots of CTOL aircraft not only must reach a suitable airfield but also must accept increasing risk if their bingos do not provide for fuel to reach alternate or divert bases.

Often when all-weather capability is mentioned, only navigation and weapons delivery, not aircraft recovery, is addressed. However, as was demonstrated in the Falkland Islands/Malvinas, one advantage of V/STOL aircraft results from their greatly reduced approach speeds, which allows the recovery of V/STOL aircraft in weather far below CTOL minimums. This capability would be particularly valuable in an environment where external landing aids may not be available.

Due to reduced basing requirements, bases suitable for V/STOL aircraft usually can be found or built closer to the enemy than bases for CTOL aircraft. This more forward basing is a significant advantage in a ground combat environment characterized by extensive movement or vast distances, even when possible increased exposure to enemy actions is considered: simply put, aircraft based closer to an enemy air or surface targets can respond more quickly than those based farther away. This capability is significant because of the importance of time in warfare. Enemy air or surface forces that are threatening friendly forces must be attacked quickly. For certain interdiction targets, particularly those involving moving forces, the usefulness of target location information is directly dependent on the delay between when the target was located and when it can be attacked.

For an aircraft to reach the same target in the same time as another based nearer the target, it must have both greater airspeed and range. For air-to-surface missions, where munitions usually are carried externally, significant increases in airspeed are not feasible, due to drag. The alternative to greater airspeed––airborne alert––requires range/endurance achieved by trading weapons payload for fuel or by relying on aerial refueling. Moreover, close proximity to the enemy allows a given force to fly far greater numbers of sorties than a force with a similar in-commission rate that is based farther away and must spend more time en route.

Fuel savings is another advantage. A study that compared employment of V/STOL aircraft to CTOL aircraft that were based 200 nautical miles farther from the target found that using V/STOL aircraft reduces total fuel consumption substantially. This advantage remained even after analysts considered the fuel that trucks consumed in transporting the necessary aircraft fuel forward to the V/STOL operating location.18

The increased operational flexibility gained from V/STOL capability has still another potential advantage. As the Falklands/Malvinas campaign demonstrated, RAF Harrier pilots without previous special training were able to operate from ships. Thus, a V/STOL force could make feasible far greater interservice cooperation in both aircraft procurement and operations. For example, if, during a future conflict, sufficient aerial refueling assets or en route CTOL air bases were not available for ferrying Air Force tactical aircraft to a distant theater, V/STOL aircraft could use ships equipped with the Arapaho system, not necessarily large-deck aircraft carriers, to reach the theater. In the Arapaho program, the Naval Air Systems Command has developed a portable, modularized aviation facility intended for installation aboard container ships. It can be installed in less than twenty-four hours and includes all components necessary for V/STOL aircraft operations: flight deck, hangar, fuel, and crew accommodations. It is estimated to cost less than $20 million per set.19

Basing Survivability Advantages
of V/STOL Aircraft

Continuing improvements in both munitions and delivery systems make the future threat to air bases one of immense concern. It is in light of this rapidly developing threat that the impact of V/STOL characteristics must be considered. The same increase in basing availability gained by using aircraft with V/STOL characteristics also provides a significant opportunity for enhancing basing survivability. This opportunity is the direct result of the fact that a V/STOL-equipped force can be more easily dispersed than a CTOL or STOL force. The ability to disperse also acts to improve the effectiveness of mobility, concealment, and deception measures. When carefully integrated, these different measures produce an extremely survivable basing mode.

One of the most obvious advantages of force dispersal is the corresponding reduction in the target value of any particular location. Unfortunately, due to basing availability requirements, it is more difficult to find an adequate number of bases suitable for dispersing a CTOL force than it is for a similar size V/STOL force. Even in Europe, the potential for dispersal is limited by the large numbers of CTOL aircraft compared to the relatively few CTOL bases available. The cost of building the necessary number of additional CTOL bases is prohibitive; however, it would cost considerably less to vastly increase the number of locations suitable for V/STOL aircraft. Perhaps an even greater problem with constructing CTOL bases is time. During an intervention into unprepared areas, it is unlikely that there will be time to construct the necessary numbers of CTOL facilities to allow for dispersal.

A few military analysts have criticized the dispersion of air forces as too costly or complex for logistical and command and control reasons. However, in fairness, it is necessary to weigh the perceived disadvantages of dispersion against the known disadvantages of a nondispersed CTOL force. The cost of building, maintaining, defending, and, if damaged, repairing these expensive CTOL air bases is high, particularly if one considers that many of them may later be abandoned, as they were in Southeast Asia. Also, dispersion may not be as difficult as some critics imagine. Ground forces have long recognized that it is both necessary and possible to support and control dispersed units. Further, modern ground forces often use equipment with maintenance, fuel, and munitions requirements similar to those of aircraft. If carefully planned, dispersed air forces might use the same, or portions of the same, logistical and command and control structure already existing for land forces, thus reducing costs. RAF Harrier operations have shown that dispersion can be successful and affordable. Twelve years of Harrier experience also have allowed the U.S. Marine Corps to develop and verify concepts for dispersal. The lessons learned by both the Royal Air Force and the Marines would be of immense value in the development of a concept for dispersed operations suitable for the special needs of the U.S. Air Force.

AV/STOL-equipped force able to disperse quickly also could have the mobility to change operating locations frequently. Mobility, when used by such a force already dispersed into a large number of locations out of an even larger number of potential locations, greatly increases an enemy's search and attack problems. Not only would an enemy have to search a large number of potential locations, but also the longer the time between when the enemy finds an occupied location and when he attacks, the greater his uncertainty that the location will still be occupied when he attacks. To counter this uncertainty, an enemy would attempt to launch an attack as rapidly as possible after locating an occupied location––which, in turn, would decrease his available time for putting together an attack, planning the most survivable routes for his aircraft, and ensuring accurate navigation and weapons delivery.

Even when an occupied location is attacked, a V/STOL force has the potential, through vertical takeoff, to get airborne much faster and, therefore, with less warning than a similar size CTOL force would need. In addition, surviving V/STOL aircraft, unlike CTOL aircraft, can take off vertically from a damaged runway and deploy to another location.

The capability of an aircraft to take off vertically is extremely important. Many studies on conventional air base attack show that although a portion of a runway suitable for STOL operations would probably remain intact, getting aircraft to and from their shelters to this usable portion of the runway is no easy matter. Moving aircraft over damaged, and perhaps mined, taxiways poses immense problems, as shown by the delays that back-taxiing causes on airfields when only one taxiway to a runway is available. Besides greatly reducing a force's ability to generate sorties, such a situation increases the time that aircraft would be out of their revetments and vulnerable to attack.

In regard to operating from a damaged location, the use of vectored thrust from a V/STOL aircraft like the AV-8 has the added advantage of allowing landing aircraft, if necessary, to use their own jet blast to clear debris from an operating surface. Conversely, a CTOL aircraft does not have this ability and would require a sweeper to clear a runway surface and engineers to repair any damage before the CTOL aircraft could land safely.

In an environment where forces are dispersed and mobile, concealment and deception also become extremely effective. Properly planned concealment and deceptive measures can act to reduce greatly an attacking force's certainty that it has, in fact, found an occupied operating location, no matter how current its intelligence. In contrast, a force based at a few, fixed locations will experience little gain in survivability, no matter how elaborate its concealment and deception measures.

Using these capabilities, V/STOL aircraft could be employed in theater combat from dispersed locations similar to the Marine Corps' forward sites. A scheduled sortie surge period would begin when these aircraft took off vertically from their widely dispersed, concealed locations and flew to strips where fuel and munitions were prepositioned. At these strips, the V/STOL aircraft would top off their fuel, arm, and then, using a short takeoff roll, fly their missions. Afterward, the aircraft would return to the original or a new strip to refuel and rearm. Many strips could be prepared quickly and used only for short periods of time. Such an employment concept, accompanied by deception measures, would make it extremely difficult for an enemy to find and destroy many of these aircraft on the ground or to disrupt their ability to generate a high, sustained sortie rate. After flying its scheduled sorties, each V/STOL aircraft would return to its original concealed location for maintenance and crew change. Because such a location could be very small and would be used infrequently and then only for a short period of time, concealment and deception measures could be simple yet prove effective.

Confidence in survivability measures is an important aspect not often assessed in theater warfare. In the strategic arena, particularly when we debate the advantages of aircraft versus those of missiles, a point often made in behalf of the air leg of the Triad is the ability to exercise aircraft fully––a feature that missiles do not offer. We recognize that ability as valuable. We achieve a higher degree of confidence in the reliability of that portion of our force which we can exercise. A similar case can be made regarding our confidence in ensuring the survivability of our theater air forces. It is possible to exercise V/STOL aircraft employment, which uses such measures as dispersion, mobility, concealment, and, to a degree, deception. In contrast, it is difficult or, to be more accurate, impossible to exercise simultaneously and successfully, let alone frequently, all the measures (such as point air defense, explosive ordnance disposal, runway repair, and chemical protection) necessary to ensure survivable CTOL air base operations.

Proposal for Air Force V/STOL Aircraft

Careful examination of the potential threat to our theater air bases raises serious questions as to whether it is either economically or militarily sound for theater air forces to consist solely of CTOL and STOL aircraft operating from fixed CTOL bases. This concern is especially applicable in regard to the early critical stages of a conflict against an enemy who can attack at the time and place of his choosing, employing large air, missile, and special operations forces armed with conventional (and possibly chemical and nuclear) weapons. Similar questions about our force composition arise when we consider whether the United States has the capability to intervene effectively in large remote regions where few, if any, hardened CTOL bases exist.

To achieve the most flexible capability, the Air Force should maintain a force that includes a mix of various types of CTOL, STOL, V/STOL, and VTOL aircraft. The best aircraft for some missions will remain, for the reasonable future, CTOL and STOL aircraft––particularly for long-range bombing, aerial refueling, and airborne warning and command and control missions. We have a heavy investment in these conventional aircraft, and it would take too much money and time to convert to an exclusively V/STOL and VTOL force. For airlift missions in the near future, VTOL and V/STOL capability could only complement CTOL and STOL aircraft, due to the present range and payload limitations of VTOL and V/STOL airlift aircraft. However, to improve our flexibility by increasing the numbers of locations into which airlift aircraft can operate, a significant portion of Air Force airlift capability should be at least STOL, rather than CTOL.

For theater air missions, such as counterair, interdiction, close air support, and electronic combat and reconnaissance, the conventional and STOL-capable theater force structure can be made more effective if a portion of the force is V/STOL-capable. If some of these theater missions were performed by V/STOL aircraft, our existing CTOL airfields would not need to support so many aircraft. As a result, it would be easier to disperse and shelter the remaining aircraft, making these airfields less lucrative targets, possibly reducing the airfield attack effort that an enemy would make, and thus decreasing air base defense and repair problems. Further, possession of a force that consisted, in part, of V/STOL aircraft also would significantly increase our ability to intervene into remote, unprepared regions.

Therefore, our goal must be to strike the proper balance between V/STOL and CTOL/ STOL for our theater air forces. For the Air Force to make the most rapid progress in achieving a truly flexible force, development of a V/STOL capability should be pursued energetically. Fortunately, as we have seen, V/STOL aircraft limitations are being rapidly reduced by new technological developments.

In the near term, the Air Force should procure a limited number of AV-8Bs, if necessary substituting them for some of the programmed CTOL aircraft. Building on RAF and USMC experience, the Air Force should begin developing and testing its own V/STOL employment concepts. Research also should be undertaken to modify the AV-8B to carry advanced air-to-air missiles, as well as standoff air-to-surface missiles. Ideally, all future tactical fighter aircraft should be V/STOL-capable, with appropriate support for dispersed, mobile operations.

At the same time, research efforts should be accelerated to increase basing flexibility. One step: converting our current force structure from CTOL to STOL-capable by employing new aeronautical technologies such as variable nozzles. Energetic efforts also should be given toward reducing aircraft support requirements, while simultaneously making necessary support more mobile.

Dispersal will require more rotary-wing aircraft, ground vehicles, and STOL air transports, or a combination thereof. The cost and complexity of these transportation requirements, as well as the greater communications requirements, possibly could be ameliorated by coordination with the Army and the Marine Corps. RAF Harrier operations in Europe, where both land and air units use the same communications network, have shown how the communications problems might be approached jointly.

Given the importance of air base survivability and availability, the Air Force must change its present approach to aircraft and support force design to an approach that is better suited to the conditions inherent in modern warfare. Airborne capability alone should not continue to dominate aircraft design considerations.20 Until aircraft no longer have to land for refueling, rearming, repair, and crew change, basing and support structure requirements will remain as important as airborne characteristics in determining the actual capability of air power.

The United States Air Force has a tradition of responding with imagination to the challenges it faces. We must continue this tradition by constantly and carefully examining our performance against the requirements of combat effectiveness. Constant vigilance is necessary to avoid the type of climate prevalent in the British Royal Navy before World War II. As Admiral Sir Herbert Richmond noted then, peacetime routine had corroded the military mind so that it lacked stimulation to think of war, while the twin gods became orthodoxy and conformity. Admiral Richmond was disturbed that "well-intentioned questions and suggestions were met with unthinking hostility on the part of the Admiralty, and by administrators in general, who not only felt that such ideas held personal reflections upon themselves, but also that, if adopted, they would make more work and upset the pleasant and well-ordered routine."21

Center for Aerospace Doctrine, Research, and Education
Maxwell AFB, A1abama


1. Matthew Cooper, The German Air Force 1933-1945, An Anatomy of Failure (London: Jane's, 1981), pp. 97-120, 198-201; Air Marshal Sir Victor Goddard, Skies to Dunkirk (London: William Kimber, 1982), p. 128, Williamson Murray, Strategy for Defeat, The Luftwaffe 1933-1945 (Maxwell AFB, Alabama: Airpower Research Institute, January 1983), pp. 38. 84; Adolf Galland, The First and the Last––The Rise and Fall of the German Fighter Forces, 1938-1945 (New York: Ballantine Books, 1965), pp. 218-19, 232, 274-75; Len Deighton, Fighter: The True Story of the Battle of Britain (New York: Alfred A. Knopf, 1978), p. 240; B. H. Liddell Hart, History of the Second World War (New York: G. P. Putnam's Sons, 1970), pp. 59, 227-29.

2. Kenn C. Rust, The Ninth Air Force in World War II (Fall Brook, California: Aero Publishers, 1967), pp. 87, 116; Condensed Analysis of the Ninth Air Force in the European Theater of Operations (Washington, D.C.: Army Air Force Office of Assistant Chief of Air Staff, March 1946), pp. 3-21. Denis Warner and Peggy Warner, The Sacred Warriors: Japan's Suicide Legions (New York: Van Nostrand Reinhold, 1982), p. 287.

3. Charles E Hunt, Airfield Survivability and Post-Attack Sortie Generation, Concept Issue Paper 80-2, Hq USAF/XOXID, February 1980, pp. 6-21.

4. B. R. A. Burns, "Advanced Fighter Design," Air International, September 1983, p. 123.

5. "USAF Tests Arresting Systems," Aviation Week and Space Technology, 2 January 1984, p. 45.

6. Wing Commander Peter Millar, The Maginot Mentality, Air War College Essay, Academic Year 1982-83, p. 6.

7. "Rapidly Deployable Airstrips for Strategic Aircraft" (Marina del Rey, California: R and D Associates, January 1982), pp. 26-27; McDonnell Douglas, AV-8B Rapid Deployment Overview, MDC A6827 (St. Louis: McDonnell Douglas Corporation, 1980), pp. 24-25.

8. McDonnell Douglas, AV-8B Operations Summary, MDC A6121 (St. Louis: McDonnell Douglas Corporation, 1980), pp. 3-11; U.S. Marine Corps, AV-8B V/STOL Program, Volume III, AV-8A: Concept Validation––-AV-8B: Performance Fulfillment, pp. 6-1 to 6-22.

9. Burns, p. 123.

10. McDonnell Douglas, AV-8B Operations Summary, pp. 3-11.

11. Roy Braybrook, "Aircraft Design Philosophy," Air International, April 1984, pp. 187-90.

12.Data on losses of various aircraft are revealing and merit our attention:

Aircraft Losses

Aircraft Type Flight Hours
Flight 90000 hours 213000 hours
AV-8A 25 50 (includes RAF)
A-4 37 64
A-7 37 73
F-8 44 79
A-6 16 33
F-4 17 44
F-100 39 78
F-102 27 38
F-104 43 88
F-105 31 47
F-106 15 26
A-10 8 17
F-15 4 15
F-16 10 30

Data on the first six aircraft in this listing (AV-8A through F-4)were obtained from U.S. Marine Corps, A V-8B V/STOL Program, Volume III, pp. 4-11 to 4-12; figures for the other eight aircraft (F-100 through F-16) were provided by the U.S. Air Force Inspection and Safety Center, Data Analysis Section. USAF aircraft losses are rounded to the nearest whole number.

13. U.S. Marine Corps. AV-8B V/STOL Program, Volume III, pp. 4-11 to 4-12.

14. British Aerospace, V/STOL in the Roaring Forties, 1982.

15. David A. Brown, "British to Establish Military Presence on Falklands," Aviation Week and Space Technology, 21 June 1982. pp. 20-21.

16. U.S. Marine Corps, AV-8B V/STOL Program, Volume III, pp. 2-1 to 2-23; McDonnell Douglas, AV-8B Operating in NATO: An Evaluation of the USMC AV-8B V/STOL Light Attack Aircraft in NATO Environment, MDC A6139 (St. Louis: McDonnell Douglas Corporation, 1979), pp. 40-45.

17. McDonnell Douglas, AV-8B Operating in NATO, pp. 28-35.

18. Ibid., pp. 42-49.

19. Naval Air Systems Command, ARAPAHO––Final Report, 3 February 1983.

20. M. B. Berman with C. L. Batten, Increasing Future Fighter Weapon System Performance by Integrating Basing, Support, and Air Vehicle Requirements, Rand, N-1985-1-AF, 1983, p. 26.

21. Robin D. Higham, The Military Intellectuals in Britain 1918-1939 (New Brunswick, New Jersey: Rutgers University Press, 1966), p. 55.


Lieutenant Colonel Price T. Bingham (USAFA) is a Military Concepts Analyst in the Doctrine and Concepts Division, Center for Aerospace Doctrine, Research, and Education, Hq Air University. At Hq USAF, he was an air operations officer and a member of the Air Staff in the War and Mobilization Planning Division. He has flown fighters in Tactical Air Command, United States Air Force in Europe, and Southeast Asia. Colonel Bingham is a previous contributor to the Review.


The conclusions and opinions expressed in this document are those of the author cultivated in the freedom of expression, academic environment of Air University. They do not reflect the official position of the U.S. Government, Department of Defense, the United States Air Force or the Air University.

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