AIR FORCERESEARCH INSTITUTEPAPERS

RobertC.Owen

BasingStrategies

forAirRefuelingForces

inAntiaccess/Area-Denial

Environments

2015-1
Air University

AIR FORCE R

Basing Strategies for Air Refueling Forces i

Antiaccess/Area-Denial Environment

Robert C. Owen

AFRI Paper 2015-1

Air University Press

Air Force Research Institute

Maxwell Air Force Base, Alabama
ii

Project Editor

Cheryl King

Library of Congress Cataloging-in-Publication Data

Owen, Robert C., 1951– author.

 Basing strategies for air refueling forces in antiaccess/area-denial 

environments / Robert C. Owen.

 pages cm. — (AFRI paper 2015-1)

 Includes bibliographical references.

 ISBN 978-1-58566-258-6

 1. Airtankers (Military science)—United States. 2. Airplanes—

Air refueling—United States—History. 3. Military bases, American. 

4. Access denial (Military science) I. Title.

 UG1242.T36O94 2015

 358.4’183–dc23

 2015033755 

 

 

Published by Air University Press in September 2015

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and unlimited distribution.

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iii

Contents

List of Illustrations 

About the Author vii

Abstract ix

 Introduction

The Threat 1

Assessing Basing Options 4

Aircraft 10

 Recommendations 

v

Illustration

Figure

1 Relationship of island chains and threat rings 3

2 Airfields in the Bohol Sea area of the southern Philippines 13

3 Fixed and dynamic dispersal vulnerabilities 14

Table

 Fuel offload capacity at varying operational radii 11

vii

About the Author

Robert C. Owen is a professor in the Department of Aeronautical Science 

at Embry-Riddle Aeronautical University, Daytona Beach campus. In this 

position, he teaches courses in manned and unmanned aviation operations, 

law, and history and conducts research in national defense policy issues. Professor Owen joined the Embry-Riddle faculty in 2002, following a 28-year 

career with the United States Air Force. His military career included a mix of 

operational, staff, and advanced education assignments. He is both an Air 

Force command pilot and a commercial pilot, with instrument and multiengine ratings. He flew over 3,400 hours in the Air Force and over 1,000 hours 

in various civilian aircraft. Professor Owen also served on the Headquarters 

Air Force staff and the Headquarters Air Mobility Command staff. His academic 

assignments included tours as an assistant professor of history at the US Air 

Force Academy and as dean of the USAF’s School of Advanced Airpower 

Studies (now the School of Advanced Air and Space Studies), the service’s 

graduate school for strategic planners. In addition to numerous articles and 

monographs, his book publications include the chronology volume of the 

Gulf War Air Power Survey (1995), Deliberate Force: A Case Study in Effective 

Air Campaigning (2000), and Air Mobility: A Brief History of the American 

Experience (2013).

ix

Abstract

This study addresses the challenge of basing air refueling forces in regions 

marked by scarcities of appropriate airfields and powerful antiaccess/area-denial 

(A2/AD) threats from regional enemies. In such conflicts, the scale of required 

tanker deployments likely will overwhelm the number of first-class airfields 

available to accommodate the airliner-based air refueling aircraft in the 

United States Air Force fleet. Moreover, tankers based in forward areas will be 

subject to a wide range of enemy attacks on the ground and in the air. Consequently, this study begins by discussing the nature of the threats posed to 

forward-based air refueling units by modern A2/AD systems and then examines 

various basing concepts to mitigate those threats. The basing concepts 

explored are hardening of aircraft shelters and support facilities, disaggregation of refueling units among prepared bases, and agile disaggregation among 

more austere base infrastructures. The study also includes discussion of the 

potential value of introducing a midsized “tactical” tanker to the fleet able to 

operate from airfields substantially shorter and more weakly surfaced than 

these required by the current fleet of modified airliners. The study concludes 

by recommending greater focus on agile disaggregation, acquisition of a fleet 

segment of tactical tankers, and directions for further analysis.

1

Introduction

The increasing threat to American air refueling forces from sophisticated 

antiaccess/area-denial (A2/AD) capabilities in the hands of potential enemies 

has become a matter of concern for defense planners and leaders.1

 An important product of this concern has been an active discussion of the challenge of 

operating air refueling forces from forward bases under potential or actual 

attack. Generally, this discussion has explored three forward basing concepts; 

hardened, disaggregated, and agile. Hardened bases employ reinforced 

sheltering of aircraft and support facilities to increase their resilience under 

attack. Disaggregation complicates enemy targeting efforts by operating 

forces from many smaller bases rather than just a few large ones. Agile basing 

protects forces by frequently shifting them among a number of bases, thereby 

“improving survivability and complicating the enemy’s targeting.”2

Given these considerations, this study encapsulates the present state of the 

discussion over tanker basing and asks whether an updated US strategy should 

emphasize hardened, disaggregated, or agile concepts. The study begins with a 

qualitative discussion of the threat posed to air refueling forces by a representative 

A2/AD system—that of China. It next discusses the operational and logistical characteristics of each basing option, paying particular attention to its 

ability to underpin the resilience and maximal effectiveness of tanker forces 

under A2/AD threat. This comparative discussion closes with a brief examination 

of aircraft options to exploit the strengths and/or mitigate the weaknesses of 

each basing concept. The study concludes with recommendations for further 

action by the Air Force and the Department of Defense (DOD).

The Threat

If good sense and luck prevail, the United States and China will never find 

themselves at war. However, there is no escaping the fact that the increasing 

power of Chinese A2/AD capabilities and the geography of the western Pacific 

make China a worst-case challenge for tanker basing strategies. Its forces can 

hit US air bases hard, and alternative airfields are relatively scarce and widely 

separated. Consequently, basing strategies that could work in the western 

Pacific in the face of Chinese capabilities likely could work in many other regions. 

China’s A2/AD order of battle is formidable. It begins with overlapping 

ground-, air-, and space-based information, surveillance, and reconnaissance 

(ISR) systems, including around 100 satellites of various capabilities.3

 The 

bulk of China’s long-range, non-nuclear strike capabilities reside in the 1,900 

or so combat aircraft of the People’s Liberation Army Air Force (PLAAF), 
2

supplemented by missile forces. China’s air fleet includes about 150 H-6 

bombers, some of which can strike out to approximately 2,000 nautical miles (nm) 

when equipped with cruise missiles. China’s missile forces include over a 

thousand short-range ballistic missiles (SRBM), hundreds of cruise missiles, 

and a “limited but growing” fleet of DF-21C and D medium-range ballistic 

missiles (MRBM).4

 In combination, these systems can conduct precisionguided strikes against all major US bases in Korea, Japan, the so-called first 

island chain, and—mainly with cruise missiles—the second island chain.5

Additionally, the Chinese navy fields a growing number of surface and subsurface combatants capable of launching land-attack and antishipping cruise 

missiles. Last, US bases anywhere in the western Pacific could face attacks from 

Chinese special operations forces (SOF) and fifth-column actions from elements of the millions of ethnic and recent-migrant Chinese nationals present in 

every Asia-Pacific country.6

Formidable as the Chinese battle array has become, it is important for 

tanker basing planners to recognize that its power degrades rapidly as the 

distances between China’s bases and targets increase (fig. 1). China’s ability to 

launch the concentrated, all-capabilities “gorilla strikes” called for in its military doctrines is limited to about 400 miles from its launch bases.7

 This distance equates roughly to the range of weapons-laden fighter aircraft, which 

would constitute the bulk of China’s strike capabilities in this “gorilla ring,” 

augmented by SRBMs.8

 Beyond the gorilla ring is the “missile ring,” a zone 

extending 400–1,000 nm from Chinese bases in which long-range missiles 

augmented by limited numbers of strike aircraft would provide the weight of 

their offensive capabilities. While a few hundred missiles represent a real 

threat to US assets in the missile ring, they would not carry the weight and 

persistence of the hundreds of aircraft and short-range missiles in the gorilla 

ring. Beyond the missile ring would be what could be called the “maritime 

ring.” The threat array in this region would be a relatively thin arsenal of 

bombers utilizing China’s limited aerial refueling capabilities and cruise missiles launched by submarines and surface combatants. 

Despite the different threat levels presented within the gorilla and missile 

rings, most unclassified defense analyses have not differentiated among the 

survivability of large aircraft based within them. Regardless of the differing 

weights of potential attacks and of US base defenses, many conclude that persistent, multilayered air and missile attacks will penetrate these rings.9

 Large 

tanker aircraft and their extensive maintenance and logistics support infrastructures would be particularly vulnerable to such penetrations. Consequently, most interested analysts and commanders agree that US tankers and 
3

MONGOLIA

CHINA

LAOS

THAILAND

CAMBODIA

MALAYSIA MALAYSIA

VIETNAM

BRUNEI

Guam

Pelieliu

400 nm

Philippines

Philippine

Sea

East

China

Sea

South

China

Sea

Taiwan

N. KOREA

S. KOREA

First

Island

Chain

Second

Island

Chain

Gorilla

Ring

Missile

Ring

Figure 1. Relationship of island chains and threat rings. (Adapted from

Department of Defense, Military Power of the People’s Republic of China, 

2006 [Washington, DC: DOD, 2006], 15, with addition of threat rings by author.)

other large aircraft “should be operated from bases out of the range of China’s 

conventional ballistic missiles.”10 In other words, they imply that American 

air commanders must abandon the first 1,000 miles or so of available tanker 

bases to preserve their air refueling forces, regardless of the negative impact 

such a retreat would have on their effectiveness.

Several aspects of Chinese military circumstances suggest, however, that completely surrendering operations from within the missile ring may not be necessary. Most importantly, the Chinese military is not organized, experienced, or 

culturally constituted to conduct joint warfare in a fast-paced conflict in the 

face of enemies who are. 11 Moreover, the efforts of senior commanders to 

speed up their decision processes and to articulate their forces with greater 

agility have been, and likely will continue to be, undermined by economic, 

social, and political circumstances beyond their control.12

Of nearly equal importance, the political and military considerations of 

long-range missile operations likely will accentuate the innate caution and 

slowness of Chinese military command and control. Expending MRBMs and 
4

cruise missiles from limited magazines will be national decisions since doing 

so will deplete an important strategic military and political deterrent and reduce the number of weapons available for other missions. If nothing else, Chinese 

leaders will demand a high degree of certainty as to the importance and exact 

locations of the targets against which they release their precious “silver bullets.” 

Unfortunately for them, China’s ISR capabilities do not have the persistence of 

coverage and fidelity to keep elusive and shifting tactical targets located with 

consistency, particularly if the decisions to release them come hours after 

those targets were last detected. Worse, for potential attackers, all of the 

terminal guidance systems utilized by long-range precision weapon systems—

navigation satellites, radar, infrared, electro-optical, laser cueing, and so on—

are subject to shutdown, jamming, blinding, spoofing, and other forms of 

defeat or degradation by defender actions. 

In net, these operational considerations regarding uncertainty and the 

technological limitations of precision weapons suggest the possibility of operating air refueling bases with resilience in the missile rings of future enemies. 

In those rings, US operations can impose great uncertainty on enemy command systems by degrading the fidelity and velocity of their ISR and command, control, and communications systems and by protecting forces through 

sheltering, deceptive basing, and/or maneuvering them faster than they can 

be tracked. These actions would increase and exploit the inescapable reluctance of enemy commanders to take shots at uncertain targets with weapons 

that are in short supply and that must be husbanded in consideration of 

broader strategic concerns. 

Assessing Basing Options

Hardened, disaggregated, and agile basing are options in the context of 

resilient operations within the missile rings of China or other possible opponents possessing robust A2/AD capabilities. In discussing the operational and 

logistical features of these concepts, this analysis focuses on the contributions 

each would make to force resilience and productivity. More specifically, it assesses 

each basing mode’s ability to sow confusion within enemy command structures, protect forces when discovered, sustain maximal effectiveness, continue 

operations despite attacks, and be supportable logistically.

Hardened Bases

In of itself, hardening bases will improve the resilience of air refueling 

forces only marginally. Indeed, shelters may reduce enemy uncertainty by 

marking the most important targets on a base. All of those shelters will be 
5

vulnerable to penetration by large unitary warheads and specialized submunitions. Even shelters built to withstand direct hits by 2,000-pound-class 

warheads would be vulnerable. Faced by the armored doors and 20-foot-thick 

earth and reinforced concrete carapaces of such shelters, potential enemies 

could still defeat them by employing larger weapons, punching through them 

with sequential warheads, or destroying the logistical or ground-maneuvering 

infrastructures (taxiways and runways) needed to utilize the assets they protect.13 Fixed, hardened facilities, in short, will be vulnerable to attack by aircraft penetrating their base defenses and to long-range missile sniping.

Shelters can only be useful, therefore, as elements of layered defensive systems. 

If protected by overlapping shields of cyber and electronic warfare capabilities, effective counterair and missile defenses, and the degradation of enemy 

capabilities by ongoing US and allied offensive operations, hardening can increase the costs of attacking tankers beyond what enemy commanders may be 

willing to pay. Even a defensive shield that deflected or destroyed only 50 

percent of inbound missiles, for example, would oblige enemy commanders 

to shoot several missiles for every shelter they wanted to hit. They would have 

to account for both the reduced probability of penetration and the reality that 

many warheads would strike outside of their nominal average impact accuracies 

or circular error probable. Enemy commanders might be reluctant to expend 

so many scarce weapons against those targets, given the existence of higherpriority concerns such as carrier battle groups and the need to preserve their 

missile magazines as hedges against military or political surprises.

Hardening presents a mix of desirable and troubling logistical and operational impacts. Logistically, base hardening can preserve support systems and 

organizations working at maximal efficiency. But if enemy forces break 

through base defenses, hardening will provide them with their best aimpoints. 

Also, based on the limited unclassified information available, it is reasonable 

to estimate that a large aircraft shelter will cost from $20 to $40 million to 

construct at overseas locations, depending on the level of protection desired.14

So to equip a single base with enough shelters to house, say, 16 tankers that 

spend 50 percent of their time in the air will require construction of at least 

eight primary and probably a few hedge shelters at a potential cost of several 

hundred million dollars. Building a network of hardened bases along the 

Pacific Rim, for instance, would cost billions and provide protection only for 

operations in their areas and only so long as even more costly defensive networks successfully fend off the bulk of enemy attacks. 

Moreover, hardened bases offer minimal ability to support offensive and 

defensive operational surges. Separated by hundreds and even thousands of 

miles from other bases in the hardened network, no single base could shelter 
6

the tanker force concentrations needed to support surge operations or render 

efficient mutual support to distant locations. Perhaps the best way to understand the value of hardened basing, therefore, would be as a premium method 

of sheltering those portions of future tanker fleets that absolutely must be 

based in a particular region all of the time and as far forward as possible, with 

other basing modes providing surge support when required.

Disaggregated

Disaggregation’s effect on resiliency will depend on how and where it is 

done. In theory, the DOD expects that disaggregating aircraft and support 

resources will result in “decreasing vulnerability through redundancy and 

complicating the enemy’s targeting efforts.”15 But if units are merely scattered 

among the unprotected parking areas of several military or civil airfields, the 

promise of decreased vulnerability will be empty. If such “fixed-base” disaggregation is attempted within the gorilla ring, enemies equipped with capable 

ISR and strike forces will locate and attack those units quickly and almost 

certainly with devastating results. Even in the missile ring, disaggregation 

would do little to protect air refueling units operating at fixed locations longer 

than the detect-target-strike cycles of their enemies. Further, today’s aerial 

refueling fleet aircraft dimensions and weight-bearing effects on base surfaces 

already limit and could overwhelm the available basing outside the gorilla 

ring. Ultimately, the current US fleet will have no place to disaggregate if the 

bases available to receive aircraft in the current fleet are already saturated.

The logistics of providing for redundant bases comprise the greatest challenges to the ability of disaggregation to sustain air refueling forces at maximal 

productivity. Dispersing logistics and support echelons among several bases 

will oblige the Air Force to acquire redundant supplies and equipment and, 

quite likely, increase manpower allocations to provide specialist technician 

coverage at all locations. Connecting subunits by air or surface lift could reduce those redundancies. But doing so will increase the pressure on overtaxed 

transportation assets and commanders waiting for the arrival of key supply 

items and pooled specialists to get broken aircraft back into service. Similarly, 

unit moves, particularly by airlift or road marches, likely will interrupt the 

operations and efficiency levels of disaggregated units for hours or even days. 

Little wonder that, even as it considers the advantages of disaggregation, the 

DOD worries that it “could be logistically unsupportable . . . [since it] imposes 

a logistical burden, but . . . offers no direct remedies other than improved 

efficiency.”16
7

Disaggregated units also will face significant and sometimes unique operational risks. Among them will be the security risks incumbent in the warehousing, local support contracts, and host nation access arrangements needed 

to prepare airfields for disaggregated operations. All of these actions will be 

impossible to hide and, in all likelihood, will enable potential enemies to develop air and ground attack folders on every disaggregation base long before 

any shots are fired. Disaggregated units also will be dependent on long-range 

Web, telephone, and radio communications to stay in touch with their chains 

of command and even to perform mundane logistics functions. All of these 

systems are vulnerable to enemy detection, intrusion, jamming, and spoofing 

operations. Separated from their chains of command, junior commanders at 

disaggregated bases also may be overwhelmed by local challenges ranging 

from base security breaches and supply shortages to the presence of enemy 

nationals on their airfields and disputes with local civil and military leaders. 

Agile

Agile basing offers opportunities to mitigate the shortfalls inherent in disaggregated and hardened basing. This particularly would be true if the Air 

Force could employ this concept in a manner that truly got “inside” enemy 

detect-target-strike cycles. Doing so likely would require a concept characterized by agile disaggregation and dynamic dispersal. Agile disaggregation would 

involve dispersing tanker forces in small units among sets of civil and/or military airfields and moving at least some of those penny-packet units to other 

bases every day or so. Dynamic dispersal would involve frequent, probably 

hourly, movement of the aircraft and some or all of the key assets located on 

each operating airfield. In net, a truly agile basing concept would be a shell 

game in which the shells (bases) and the peas (aircraft and assets) would shift 

locations constantly and unpredictably.

This combination of agility and dispersal would infuse great uncertainty in 

the weapons release decisions of enemy commanders. They would never be 

sure that their precious and finite resources of long-range missiles and aircraft 

strike assets would find their intended targets where they were last observed. 

Decisions regarding MRBM releases would be particularly affected since data 

just an hour or so old would create a possibility that their warheads would hit 

empty dirt rather than targets of value. Additionally, if the tanker aircraft on 

those airfields could utilize their unpaved margins and other areas for parking, they could be dispersed far enough apart to preclude any single unitary 

warhead or even cluster or other area warheads from hitting more than one 

aircraft at a time, if they hit anything.
8

Anyone familiar with the logistic, operational, and command and control 

elements of air refueling operations will immediately see the challenges to 

achieving their agile disaggregation and dynamic dispersal. The most daunting 

logistical challenge will be satisfying the huge fuel requirements of air refueling units. A disaggregated expeditionary unit of six KC-46s flying three maximum offload sorties per day, for instance, would consume about 620,000 gallons of fuel daily. Thus, disaggregated units must be on or near airfields 

equipped with permanent high-volume storage and distribution systems or 

expeditionary fuels systems of equivalent capacities. Moving self-supporting 

units between airfields also can degrade their operational efficiency, increase 

personnel fatigue, disrupt communications linkages, challenge the situational 

awareness of senior commanders and staffs, and have a host of other impacts 

on unit productivity. Whatever the operational promise of agile basing, its 

logistics and human characteristics can seem daunting. Fortunately, there are 

good reasons to think that the concept could work.

The historical record provides many examples of agile basing of large, landbased aircraft, usually in conjunction with sea-based support in maritime environments. From the earliest days of naval aviation, the Navy used seaplane 

tenders to support bombing and patrol operations. During World War II, the 

Army Air Forces’ Project Ivory Soap employed a fleet of ships to provide 

logistics, maintenance, and other base services for B-29 and P-51 groups in 

the Pacific campaigns.17 On a smaller scale, the Navy successfully operated 

converted landing ship tanks from 1957 to 1970—the USS Alameda County

(AVB-1) and USS Tallahatchie County (AVB-2)—to support patrol bombers 

and other aircraft at ashore bases in the Mediterranean. Presently, the Maritime 

Administration’s Ready Reserve Fleet includes two much larger advanced basesupport ships for the US Marine Corps—the USS Wright (T-AVB-3) and USS 

Curtis (T-AVB-4).18 The Marines exercise these ships frequently and successfully in support of all types of aviation units, including KC-130s.19

The common element of sea basing in all of these historical examples made 

sense at the time and offers grist for thought about the future. They suggest 

that sea-supported basing of tanker units can maximize the agility, productivity, and resilience of ashore tanker units. By housing most of the command, 

logistics, medical, and other support elements of disaggregated tanker units 

in an organized and climate-controlled environment, a ship base could decrease the disruption, fatigue, and productivity impacts of shifting ashore 

units frequently. This strategy would minimize the operational impacts and 

transportation costs of relocating supported units since only minimum 

essential personnel and materiel would operate ashore. For example, the USS

Tallahatchie County could disembark the entire shore establishment required 
9

by a PV-2 Neptune squadron (9–10 aircraft, about 200 personnel, a dozen 

vehicles, and 19 large trailers) and have it in operation in just four hours. 

Packing up and reembarking the unit took about the same amount of time.20

Connected to their base ship by amphibious craft and helicopters, sea-supported 

tanker units also would reduce supply and specialist personnel redundancies 

by drawing their support from common pools on the ship. General resilience 

would be improved by the absence of any need to pre-position supplies and 

establish location-specific access and support contracts at any airfields utilized eventually for agile sea basing. It would also be enhanced by the ability 

of the ship’s landing craft and helicopter “connectors” to support disaggregated airfields operating within a radius of around 200 nm.21

Further, modern expeditionary and amphibious warfare systems reinforce 

the practicality of sea basing air refueling assets. A new or reconditioned 

amphibious warfare ship, for example, could house the necessary support elements. It also could carry the amphibious craft and helicopters needed to disembark, reembark, and sustain onshore units. Importantly, an amphibious 

warfare ship could carry the expeditionary fuel-handling and storage-equipment 

sets and their set-up personnel critical to sustaining the maximal effectiveness and agility of the air units. For example, a single combination of an amphibious assault bulk fuel system (AABFS) to link an offshore tanker ship to 

an airfield and the tactical airfield fuel dispensing system (TAFDS) to put the 

fuel on the planes could satisfy the 620,000-gallons-per-day fuel requirement of the KC-46 force already discussed.22 Both of these systems can be set 

up by two small teams of specialists and begin filling in about six hours.23

Moving these fueling systems among bases can take longer, particularly if the fuel 

storage bladders of the TAFDS must be drained and repacked. But delays could be 

reduced by establishing relatively inexpensive bladder sets at several bases and 

leapfrogging the pumping hardware and support teams between them.

Marrying the agile basing concept with the right aircraft also can improve 

resiliency and productivity. In theory, any aircraft can be agile-based. However, airliner-derived refueling aircraft, such as the Boeing KC-46A and the 

Airbus A330 multirole transport tanker (MRTT), require sea-level runways 

of 8,000 to 10,000 feet in length to operate safely at their full gross weights. 

Given the limited numbers of such runways in many regions of the world, this 

requirement could restrict the ability of these aircraft to disaggregate with 

enough unpredictability to confuse enemy commanders as to where they 

might be or go next. In contrast, military tactical transport-derived air refuelers, 

presently the Lockheed KC-130J and Airbus A400M, can operate at full gross 

weight from sea-level runways of 4,000 to 5,000 feet in length. Moreover, they 

can be towed across and taxi or park on unpaved surfaces equivalent to 
10

saturated clay soils. As a consequence, they can practice dynamic dispersal 

with a vengeance, moving frequently between maximally dispersed locations. 

If the maximal agile disaggregation and dynamic dispersal of these aircraft 

equates to greater resilience in forward locations (and it does), then it also 

equates to greater productivity. These transport tankers are less capacious 

than airliner designs, but being able to base forward and survive would greatly 

improve their net offloads to receiver aircraft. 

Last, an agile-based ship should have an acceptable chance of surviving—

at least in the missile ring. As would other Navy ships operating in that threat 

environment, it would preserve itself through a combination of maneuver, 

deception, terrain and shallow-water masking, electronic warfare, close-in 

weapons, and other defenses. The base ship would move constantly, using 

busy shipping areas and geographic features to mask it from detection and 

strike by space systems, over-the-horizon radars, aircraft, missiles, and submarines. It would stop only periodically and for an hour or so to disembark 

and reembark airfield teams and equipment. Equipped with the sensors and 

close-in defensive weaponry typical of any amphibious warfare ship, a base 

ship would have a good chance of defeating or diverting the guidance sensors 

of bombs, missiles, and torpedoes and of fending off small boat attacks. These 

systems also could defeat manned or unmanned aircraft and surface craft 

maneuvering into position to provide guidance cueing for enemy weapon 

systems. Of course, the base ship would be defending itself as an element of 

integrated air and naval operations aimed at degrading an enemy’s general 

offensive capabilities. In sum, an agile-base support ship would face risks 

common to other ships in the area, but it would not be a sitting duck or 

doomed to sinking at the onset of operations.

Aircraft

To differing degrees, the effectiveness of each of the basing concepts under 

consideration will reflect the operational characteristics of the aircraft matched 

to it. The salient operational characteristics of air refueling aircraft are their 

range/offload curves—how much fuel they can deliver to receivers at what distances from their bases. Given the scope of the basing concepts under consideration, however, it will be important to consider other aircraft features, such as the 

length and strength of the runways and other infrastructure they need and their 

secondary airlift capacities. The weight-bearing requirements of a given aircraft 

will constrain the number of airfields it can utilize in a given region, its ability 

to operate from damaged airfields, and its capacity to utilize unpaved areas for 

taxi and dispersed parking. The airlift capacities of air refueling aircraft affect 
11

their ability to contribute to the mobility of their own units and to augment 

general airlift efforts when their air refueling capabilities are not needed.

Realistically, only three tanker aircraft are currently suitable for consideration in 

a basing analysis. The first two—the Boeing KC-46A and the Lockheed KC-130J—

already comprise the core air refueling modernization programs of the Air Force 

and the Marines, respectively. The third in-service aircraft available is the Airbus 

Industries A400M. This aircraft falls between the KC-46A and KC-130J in size and 

range/offload characteristics. Like the KC-130J, the A400 has probe-and-drogue 

refueling capability only. But, given the high percentage of sorties that US Navy and 

Marine aircraft would fly in maritime or littoral campaigns, probe-and-drogue refuelers would (and do) make valuable contributions to overall refueling efforts. As a 

valuable byproduct, their use also frees the boom-equipped fleet to focus on servicing Air Force aircraft. All other air refueling aircraft designs available are either too 

old or limited in numbers to be reasonable candidates for forward basing (the 

Boeing KC-135R and McDonnell-Douglas KC-10A) or are designs that offer or 

would offer only marginal advantages over aircraft presently in the fleet (the Airbus 

A330 MRTT and the developmental Embraer KC-390). Any proposals to develop 

other aircraft for air refueling operations almost certainly would fail in the context 

of the penurious budgetary circumstances of the current US defense program. Consequently, it is useful here to encapsulate the comparative assets of the three candidate aircraft (table).

Table. Fuel offload capacity at varying operational radii (pounds x 1,000)

Radius of 

action (nm) 0 500 750 1,000 1,250 1,750

Operation on 

unsurfaced 

areas?

Cargo hold 

size L/W/H 

in feet

C- 130Ja 82 51 44 36 28 12 Y 40/10/9

A-400Mb 138 89 77 66 55 32 Y 58/13/13

KC-46Ac 207 155 144 134 122 110 N 111/16/9d

(Presumes round-trip transit, two hours on station, and one hour reserve fuel.) 

a

Based on C-130J air refueling performance data provided by Headquarters Marine Corps Aviation Division/APP-5 

(Plans, Concepts and Integration), to the author, e-mail, 13 June 2014. Basic presumptions are 83K pounds of transferable 

fuel (tanker configuration), a 5K/hour burn rate, and 320-knot true airspeed cruise.

bBased on extrapolations of data provided in EADS North America briefings: “All A400Ms Are Tanker and Receiver 

Capable,” 2014; and “A400M: Combat Delivery to Point of Need,” 2013. Basic presumptions are 9.0K/pounds/hour fuel 

burn rate and a 400-knot cruise.

c

Given the public unavailability of nonproprietary information on the KC-46’s expected range/offload characteristics, this 

data is a product of integration and interpretation of data from several sources including Boeing, “767 Airplane Characteristics for Airport Planning,” September 2005, http://www.boeing.com/assets/pdf/commercial/airports/acaps/767.pdf; 

Air Force Pamphlet 10-1403, Air Mobility Planning Factors, 12 December 2011, http://static.e-publishing.af.mil/production/1/af_a3_5/publication/afpam10-1403/afpam10-1403.pdf; and “Boeing 767-300ER,” in Jane’s All the World’s Aircraft 

2012–13, ed. Paul Jackson (London: HIS Global, 2012), 998. These data, therefore, are reasonably accurate but not definitive. Basic presumptions: 207K pounds of transferable fuel, 10K/pounds/hour burn rate, and 460-knot cruise.

dIn contrast to the rectangular cross sections of the C-130 and A400M, that of the KC-46 is the upper arch of a tubular 

fuselage. Consequently, its peak height is nine feet, but it decreases to less than six feet at the sides.
12

Aircraft for Hardened Bases

Given that their costs will limit the number of large-aircraft shelters constructed, base hardening should be matched to the most capable aircraft available in terms of range/offload capabilities. In the Air Force’s program-ofrecord fleet—what it has and intends to acquire—the most capable air 

refueling aircraft will be the KC-10 and the KC-46. Their higher offload 

capacities and greater speeds will allow these aircraft to refuel larger or more 

aircraft and penetrate deeper into contested airspaces that have a low to medium 

threat risk and still survive. In comparison to KC-46s, KC-10s would require 

marginally larger shelters.24 Whether the operational return on investment of 

moving KC-10s forward would be worth their additional shelter costs is a 

matter for more detailed analysis than possible here. 

Aircraft for Disaggregated Basing

All tanker aircraft types are suitable for disaggregated basing so long as 

bases are available and they have adequate runways and parking areas. Their 

ability to operate from shorter and softer airfields, combined with greater 

maneuverability on the ground and ability to taxi or be towed on unsurfaced 

areas, would give C-130s and A400s some flexibility and resiliency advantages 

over airliner-derived tanker designs, such as KC-10s and KC-46s. However, 

the advantage is likely to be marginal, particularly in the gorilla ring where 

enemy capabilities to detect, target, and strike air refueling assets will be at 

their peaks. Those capabilities and the near certainty that enemies will know 

which airfields were prepared to host fixed-base disaggregated operations will 

render air refueling aircraft, facilities, and personnel highly vulnerable to a 

wide range of attacks.

Aircraft for Agile Basing

Again, any of the three aircraft could participate in agile basing, but the 

ground maneuverability of the C-130J and A400M would offer significant advantages in resilience. Compared to airliner-derived designs, C-130Js and 

A400Ms will be able to utilize many more of the kinds of airfields typical of 

lesser-developed areas of the world (including austere landing zones) and to 

shift about those airfields more flexibly and with greater dispersal. The airfields clustered around the Bohol Sea in the southern Philippines offer an almost ideal environment for sea-based support of agile and disaggregated 

tanker basing (fig. 2). All of them are within support distance of a single ship 

maneuvering in the area, and all are near coastlines or harbors that would 
13

allow refueling from tanker ships. While few of the available fields have runways adequate for fully loaded KC-46s, all of them could handle C-130Js and 

A400Ms. 

South

China

Sea

Bohol Sea

Pacific

Ocean

Mindanao

Samar

Panay

Iloilo

Bacolod-Silay

Bacolod

Dumaguete

San Jose

Tacloban

Surigao

Mambajao

Butuan

Lumbia

Ozamiz Laguindingan

Pagadia

Zamboanga

Santos

Bangoy

KC-46-capable 

aireld

KC-130J-/A400M-capable 

aireld

Ormoc

Mactan

Bohol

Tagbilaran

Negros Cebu

Figure 2. Airfields in the Bohol Sea area of the southern Philippines

Additionally, the ability of these military transport-derived tankers to 

taxi, be towed, and to park on unsurfaced areas will greatly increase the 

uncertainty of enemy forces attempting to target them. The paved parking 

spots at most of these airfields are located on single ramps capable of accommodating only a few aircraft. Aircraft constrained to use such parking areas 

would be vulnerable to destruction in mass by unitary and area weapons 

(fig. 3). The predictability of these parking areas also would allow enemy 

commanders to release weapons against them with a high probability of success, even when shooting “in the blind.” However, most of these airfields also 

have runway margins and other areas composed of various grades of laterite 

and are therefore usually able to sustain the movements of C-130Js and 

A400Ms. By dispersing dynamically among such off-concrete parking spots, 

disaggregated tanker units would deny enemy commanders any certainty of 
14

hitting useful targets with weapons released on the basis of anything but realtime or near-real-time information.

Lethal radius of 2K-lb

unitary or area warhead

Tow in/out

parking spot

1,000’

Fixed

Dispersal

Dynamic

Dispersal

Figure 3. Fixed and dynamic dispersal vulnerabilities

It is important to understand that the A400M and KC-130J are not equivalent aircraft. While both aircraft can operate from the same airfields, the 

A400M offers substantial operational advantages over the smaller aircraft. 

The A400M’s 420-knot cruise speed compares well to the 350-knot speed of 

the C-130J. Faster speed equates to refueling combat aircraft at higher altitudes and supporting them deeper into contested airspaces while retaining 

the ability to evade enemy interceptors. For example, an enemy fighter flying 

at 540 knots and trying to run down a fleeing A400M 100 miles away would 

require 49 minutes to close the gap but only 32 minutes to do the same thing 

with a KC-130J. Seventeen additional minutes is a long time for fighter pilots 

watching fuel gauges and for signs of enemy attacks on them! Also, the 

A400M’s substantially larger range/offload capacity over the C-130J would either 

increase the fuel available from a given number of aircraft at an agile base or 

reduce the number of aircraft based forward to satisfy a given demand. The 

A400M’s larger cargo “box” size and payload also enhances its utility as an organic 

mobility platform for disaggregated tanker units and as an augmenter of general 

airlift efforts at times of reduced demand for its refueling capabilities. 

Recommendations

Drawing on unclassified data, this study sought to broaden discussion of 

whether an updated US strategy should emphasize hardened, disaggregated, 
15

or agile concepts. It pursued that question by describing the worst-case 

antiaccess/area-denial threat environment US and allied tanker forces might 

face in the future. It then discussed the characteristics of each of the basing 

options in relation to that threat environment and closed with a consideration 

of which of the available aircraft types would be most compatible with each 

basing option.

The salient finding of the study is that the USAF should incorporate all 

three concepts into its air refueling program in a combination that optimizes 

overall fleet operational and life-cycle costs, resilience, and effectiveness. On 

a relatively limited scale and as elements of multilayered defense networks, 

hardened bases can offer an effective albeit very expensive means of protecting a small portion of the tanker fleet that absolutely must be based well forward. Simple disaggregation involving infrequent movements of supported 

units offers some opportunity to protect tanker forces. But the requirement to 

establish supply warehouses, access agreements, and the like would limit the 

protection offered by this concept to deployed forces unless they also accelerated their rate of movement. Fixed or semifixed disaggregation, therefore, 

would be best employed in the face of A2/AD capabilities degraded previously 

by friendly operations. Agile basing of disaggregated forces in the missile ring 

likely would offer the most generally resilient and cost-effective method of 

basing air refueling forces forward. Sea basing to support land-based aerial 

refuelers in insular or littoral areas also could maximize their basing agility 

and logistically supportable disaggregation. For air planners, the survivability 

of a supporting sea base in forward operations is a troubling question but one 

perhaps best answered in close discussion with the experts in the Navy and 

Marines. Finally, this study suggests that if the Air Force gets serious about 

agile basing, it needs to take a closer look at the advantages offered by the 

middle-option candidate aircraft—the A400M. 

This study ends, therefore, by reaffirming that a mixed solution to the basing 

challenge likely will be the optimal one and by suggesting the obvious—that 

this issue is a realm of continued study. Most importantly, perhaps, the ongoing 

and generally classified discussion of large-aircraft basing options needs 

broadening to embrace a more energetic version of agile basing and to include and inform a broader gallery of analysts and interested parties. An 

intellectually open and informed look at sea basing in support of Air Force 

refueling and other operations deserves to be a part of this inquiry, as does the 

full range of aircraft options available. Without doubt, looking at these issues 

will obligate the Air Force to cross some interservice turf and expertise 

boundaries and, possibly, confront some politically well-entrenched manufacturer interests. If the Air Force intends to fight with its tankers forward, 
16

these would be necessary next steps in developing the capabilities to do that 

in increasingly dangerous A2/AD environments.

Notes

1. The US Department of Defense generally defines antiaccess as “those actions and capabilities, 

usually long-range, designed to prevent an opposing force from entering an operational area” 

and area denial as “those actions and capabilities, usually of shorter range, designed not to keep 

an opposing force out, but to limit its freedom of action within the operational area.” See DOD, 

Joint Operational Access Concept (JOAC), ver. 1.0, 17 January 2012, 6.

2. Ibid., 19–20.

3. Ben Blanchard, “China’s President Xi Urges Greater Military Use of Space,” Reuters, 15 April 

2014, http://uk.reuters.com/article/2014/04/15/uk-china-defence-idUKBREA3E03G20140415; and 

DOD, Annual Report to Congress: Military and Security Developments Involving the People’s Republic of 

China 2014 (Washington, DC: DOD, 2014), 65.

4. Aircraft and missile force numbers from DOD, Annual Report to Congress, 2014, 7, 27, 

and throughout; Mark A. Stokes and Ian Easton, Evolving Aerospace Trends in the Asia Pacific 

Region: Implications for Stability in the Taiwan Strait and Beyond (Washington, DC: Project 49 

Institute, 2014), 12-3; and Jonathan F. Solomon, “Defending the Fleet from China’s Anti-ship 

Ballistic Missiles: Naval Deceptions’ Roles in Sea-Based Missile Defense (master’s thesis, 

Georgetown University, 2011), 25.

5. “Missile Threat: DF-21/-21A/-21B/-21C/-21D (CSS-5),” George C. Marshall and Claremont 

Institutes, 14 November 2012, http://missilethreat.com/missiles/df-21-21a-21b-21c-21d-css-5/; 

and “Missile Threat: HN-1/-2/-3,” George C. Marshall and Claremont Institutes, 9 April 2013, http://

missilethreat.com/missiles/hn-1-2-3/?country=china#china.

6. A useful chart can be found at “Mapping Migration,” Economist, 17 November 2011, 

http://www.economist.com/blogs/dailychart/2011/11/diasporas.

7. Roger Cliff et al., Entering the Dragon’s Lair: Chinese Antiaccess Strategies and Their Implications for the United States (Santa Monica, CA: RAND, 2007), 37–8 and 113–15.

8. For missile range specifications, see DOD, Annual Report to Congress, 2014, 85. Given 

the unavailability of definitive information on Chinese aircraft capabilities, this study presumes 

that their radii of action with strike-profile weapons loads will be roughly equivalent to those 

of late-model F-16s and F-18s, which fall between 350–450 nm.

9. John Stillion and David T. Orletsky, Airbase Vulnerability to Conventional Cruise-Missile 

and Ballistic-Missile Attacks: Technology Scenarios and U.S. Air Force Responses (Santa Monica, 

CA: RAND, 1999), 99; and Christopher J. Bowie, The Anti-access Threat and Theater Air Bases

(Washington, DC: Center for Strategic and Budgetary Assessments, 2002), 58–65, for examples 

of this widely held position.

10. Cliff et al., Entering the Dragon’s Lair, 99.

11. DOD, Annual Report to Congress, 2014, 32.

12. For insights into China’s uncertain and contradictory approach to modernized command 

and control, see Zhao Shengnan, “New Joint Command System ‘On Way,’ ” China Daily, 3 January 

2014, http://usa.chinadaily.com.cn/china/2014-01/03/content_17212780.htm; and for the military’s quick rebuttal, see Bai Tiantian and Liu Yang, “No Joint Command: MOD,” 6 January 

2014, Global Times, http://www.globaltimes.cn/content/835937.shtml. For analysis of the 

situation, see James Mulvenon, “Rearranging the Deck Chairs on the Liaoning? The PLA Once 
17

Again Considers Reorganization,” China Leadership Monitor, 14 March 2014, http://www.

hoover.org/publications/china-leadership-monitor.

13. Carlo Kopp, “Hardening RAAF Air Base Infrastructure,” Air Power Australia, 5 February 

2008, 20.

14. This figure probably is on the low side of actual costs. Given the unavailability of direct 

data, it is an extrapolation of available costing data for standard hangars and smaller hardened 

shelters. It also reflects the very useful engineering and costing data on a notional large aircraft 

hangar provided by Thomas Watts, presently the general manager of Spantech Pty Ltd, Australia. 

Criticisms by individuals ready to release better data would be welcome.

15. DOD, Joint Operational Access Concept, 20.

16. Ibid., 37.

17. Bruce Felknor, “Top Secret Project Ivory Soap—Aircraft Repair Ships,” American Merchant 

Marine at War, accessed 24 February 2014, http://www.usmm.org/felknorivory.html.

18. David Kummer, “Aviation Logistics Support: The T-AVB’s Role in Aviation Logistics 

Planning,” Marine Corps Gazette, September 2012, 52–53.

19. “Logistical Impact of Seabasing,” Second Line of Defense, accessed 20 July 2014, http://

www.sldinfo.com/the-logistical-impact-of-seabasing/; and Bradley Weisz, “The Bold Alligator 

2012 Approach,” Vimeo, video, 04:54, accessed 21 July 2014, http://vimeo.com/35058483. 

Colonel Weisz, deputy commander of Expeditionary Strike Group Two, was discussing exercise 

Bold Alligator 2012, an experiment in supporting multiple ship-based aviation units from a 

single T-AVB. General information on T-AVB employment from John Reardon, US Maritime 

Administration, Division of Sealift Operations and Emergency Response, datasheet provided 

to author, 25 May 2014.

20. Capt Charles Walker, USN, retired, telephone interview by the author, 27 March 2014; 

and Timothy R. Neuman, telephone interview by the author, 4 March 2014. Captain Walker 

commanded the Tallahatchie County in 1968–69. See also Tallahatchie County veterans website, 

accessed 20 June 2014, http://www.usstallahatchiecounty.com.

21. The cruise speed of the UH-60 helicopter is about 150 knots and its operational radius 

about 300 nm. Given the operating and maintenance characteristics of helicopters, however, 

the practical radius of routine support likely will be shorter.

22. Current expeditionary fuel systems include the Air Force’s system of Fuels Operational 

Readiness Capabilities Equipment (FORCE) and the Marine Corps’ AABFS and TAFDS. The 

Marine Corps systems are particularly relevant to maritime environments since they can be set 

up, connected to offshore tanker ships, and put into initial operations in just a few hours.

23. See Marine Corps Systems Command (MCSC), “Tactical Airfield Fuel Dispensing System 

(TAFDS),” TM 12359A-OD, data sheet, accessed 5 August 2014, http://www.marcorsyscom

.marines.mil/Portals/105/pdmeps/docs/FUEL/B0675.pdf; MCSC, “Amphibious Assault Fuel 

System (AAFS),” TM 12359A-OD, accessed 5 August 2014, http://www.marcorsyscom.marines.

mil/Portals/105/pdmeps/docs/FUEL/B0685.pdf; and Lance Cpl Keenan Zelazoski, “Fueling 

Fighting from Ship to Shore: Bulk Fuel Co. Demonstrates Capabilities of Amphibious Assault 

Fuel System,” 1st Marine Logistics Group, 15 April 2014, http://www.1stmlg .marines.mi/

News/1stMLGNews/tabid/17231/Article/545107/fueling-fight-from-ship-to-shore-bulk-fuelco-demonstrates-capabilities-of-amph.aspx. 

24. The KC-10 is 181 ft. long, with a wingspan of 165 ft. and a height of 58 ft. while the dimensions of the KC-46 are 165 ft., 157 ft., and 52 ft., respectively.

19

Abbreviations

AABFS amphibious assault bulk fuel system

A2/AD antiaccess/area denial

DOD Department of Defense

ISR information, surveillance, and reconnaissance

MRBM medium-range ballistic missile

nm nautical mile

SOF special operations forces

SRBM short-range ballistic missile

TAFDS tactical airfield fuel dispensing system

ISBN:978-1-58566-258-6

ISSN:1537-3371

http://aupress.au.af.mil