The U.S. Air Force (USAF) provides military dominance in the domains of air and space, enabling the Joint Force to project power quickly anywhere in the world at any time. Successful Operation Plan (OPLAN) execution relies on this service being able to rapidly respond to contingencies across the world, to guarantee the global freedom of movement and access that Americans have come to expect, and to project our nation’s power, influence, and reach.1

To support and defend America’s global interests along with the Joint Force, the Air Force focuses on five main missions:

  • Air and space superiority;
  • Intelligence, surveillance, and reconnaissance (ISR);
  • Mobility and lift;
  • Global strike; and
  • Command and control (C2).

The Air Force has used the 2012 Defense Strategic Guidance (DSG) as its framework for determining investment priorities and posture. As a result of the DSG and fiscal constraints, the Air Force has “traded size for quality” by aiming to be a “smaller, but superb, force that maintains the agility, flexibility, and readiness to engage a full range of contingencies and threats.”2 In light of recent budget cuts, the Air Force has characterized this as a key year for the future of the service’s readiness and capabilities:

The FY 2017 budget request represents a “pivot point” for the Air Force to continue the recovery to “balance the force” for today’s readiness and the readiness needed 10 to 20 years from now. However FY 2017 could simply represent a pause to the devastating effects of sequestration level funding that will return in FY 2018.3

But while the Air Force’s fleet has been cut intentionally to maintain capability, continued cuts in capacity will result in a loss of that capability:

Americans have invested in airpower for well over 60 years to ensure the fight is never fair. But today—after many years of continual operations and a few fiscal upheavals—the Nation is at a crossroads, with a fundamental disconnect between its airpower expectations and its airpower capability.

There was a time when the Air Force could trade some capacity in order to retain capability. But we have reached the point where the two are inextricable; lose any more capacity, and the capability will cease to exist.4

Capacity

Due to the constrained fiscal environment of the past few years, the Air Force continues to prioritize capability over capacity. Air Force leadership has also made it clear that near-term reductions will be made in lift, command and control, and fourth-generation fighter aircraft to ensure that its top three modernization programs—the F-35A, Long-Range Strike Bomber (LRS-B), and KC-46A—are preserved.5 The USAF is now the oldest and smallest in its history, and as the demand for air power continues to increase, the problem of capacity limiting capability will continue to grow.6 Unlike some of the other services, the Air Force did not grow during the post-9/11 buildup.7 Rather, it got smaller as older aircraft were retired and replacement programs, such as the F-35, experienced successive delays in bringing new aircraft into the fleet.

The Air Force’s capacity in terms of number of aircraft has been on a constant downward slope since 1952.8 As Air Force officials testified in 2016:

[P]rior to 1992, the Air Force procured an average of 200 fighter aircraft per year. In the two and a half decades since, curtailed modernization has resulted in the procurement of less than an average of 25 fighters yearly. In short, the technology and capability gaps between America and our adversaries are closing dangerously fast.9

This reduction in capacity is expected to continue because of ongoing budgetary pressure. Under BCA-mandated spending caps, the Air Force would shrink to 39 total active duty fighter squadrons,10 of which only 26 would be combat-coded.11 This is a far cry from the 70 active duty fighter squadrons within the Air Force during Operation Desert Storm (1991).12

This Index assesses the Air Force’s fleet of tactical aircraft based on a 2011 Air Force assessment that a force of 1,200 fighter aircraft was required to execute a two-MRC strategy.13 More recently, the service acknowledged that it could reduce the requirement by 100 fighters by assuming more risk.14 Of the 5,456 manned and unmanned aircraft in the USAF’s inventory, 1,303 are fighters, 1,159 of which15 are combat-coded aircraft (not associated with operational testing, evaluation, or training of replacement pilots). The continuation of constrained funding levels will deepen the shortage of fighters and readiness levels, degrading vital air operations as well as operational testing and training expertise.16

Capability

Reductions in funding brought about by the Budget Control Act of 2011 and other budget constraints have forced the Air Force to prioritize future capability over capacity. This strategy centers on the idea of developing and maintaining a capable force that can win against advanced fighters and surface-to-air missile systems that are being developed by top-tier potential adversaries like China and Russia. The only way the Air Force can sustain that technological edge in the current budget environment is by reducing its fleet of aircraft that are moving toward obsolescence.

The state of aircraft capability includes not only the incorporation of advanced technologies, but also the overall health of the inventory. Most aircraft have programmed life spans of 20 to 30 years, based on a programmed level of annual flying hours. The bending and flexing of airframes over time in the air generates predictable levels of stress and metal fatigue. The average age of Air Force aircraft is 27 years, and some fleets, such as the B-52 bomber, are much older.17 Although service life extension programs can lengthen the useful life of airframes, their dated systems become increasingly expensive to maintain. That added expense consumes available funding and reduces the amount available to invest in modernization, which is critical to ensuring future capability.18

The average age of the F-15C fleet is over 32 years, leaving less than 10 percent of its useful service life remaining.19 That same fleet comprises 42 percent of USAF air superiority platforms.20 The fleet of F-16Cs are, on average, 25 years old,21 and the service has used up nearly 80 percent of its expected life span. KC-135s comprise 87 percent of the Air Force’s tankers and are over 54 years old on average.22

The Air Force’s ISR and lift capabilities face similar problems in specific areas that affect both capability and capacity. The bulk of the Air Force’s ISR aircraft (339 of 482) are now unmanned aerial vehicles (UAVs),23 which are relatively young and less expensive to procure, operate, and maintain.24 The RQ-4 Global Hawk is certainly one of the more reliable of those platforms, but gross weight restrictions limit the number of sensors that it can carry, and the warfighter still needs the capability of the U-2, which is now (on average) 33 years old.25 The E-8 Joint Surveillance Target Attack Radar System (Joint-STARS) and the RC-135 Rivet Joint are critical ISR platforms, and each was built on the Boeing 707 platform, the last one of which was constructed in 1979. The reliability of the Air Force fleet is at risk because of the challenges linked to aircraft age and flight hours, and the fleet needs to be modernized.

A service’s investment in modernization ensures that future capability remains healthy. Investment programs aim not only to procure enough to fill current capacity requirements, but also to advance future capabilities with advanced technology. In fiscal year (FY) 2016, the Air Force structured its budget to preserve funding for its three top acquisition priorities: the F-35A Joint Strike Fighter, the KC-46A Pegasus refueling aircraft, and the Long Range Strike-Bomber.26

The Air Force’s number one priority remains the F-35A. It is the next-generation fighter scheduled to replace all legacy A-10, F-15, and F-16 aircraft. The Air Force’s program of record is for 1,763 aircraft, replacing all F-16, all A-10, and possibly all F-15 aircraft currently in the inventory. The Air Force has not explicitly stated the rationale for purchasing 1,763 F-35s to replace 1,303 fighters currently in its inventory,27 and this has led to speculation that they may partially offset the Defense Department’s reduction of the Air Force’s original plan to purchase 750 F-22As28to a final program of record of just 187.29

The Active Air Force currently has 268 F-15Cs, and there are concerns about what platform will fill this gap when the F-15C is eventually retired. Even with their superior technology, 159 combat-coded F-22As would be hard-pressed to fulfill the wartime requirement for air superiority fighters for a single major regional contingency (MRC).30 The F-22A is world’s most dominant air-to-air fighter and was designed to shoulder the air superiority mission for the Air Force, but with only 187 of a planned 750, this becomes a challenging burden for the F-22 community to carry on its own. The F-35A’s multirole design favors the air-to-ground mission, but its fifth-generation faculties extend well into the air-to-air role,31 which will allow it to augment the F-22A in many scenarios.32

Fulfilling the operational need for fighters will be further strained in the near term because the F-22 retrofit—a mix of structural alterations to 162 aircraft needed for the airframe to reach its promised service life—has been forecasted to run through 2021, a year later than previously predicted.33 As a result of the retrofit, only 62 percent (99 of 169) of the mission fleet of F-22As are currently available.34

Like the F-35B and F-35C (the Marine Corps and Navy variants, respectively), the F-35A has experienced a host of problems including technological and production delays, cost overruns, and purchase reductions caused by budget cuts. As a result, the initial operating capability (IOC) date was pushed from 2013 to 2016. This system of systems relies heavily on software, and the currently fielded version 3I (IOC software) offers approximately 89 percent of the code required to deliver full warfighting capability. It is expected that 3F, the software that will enable full operating capability (FOC), will be fielded in mid-2017, half a year later than planned.35 Given the age of the aircraft that the F-35A will be replacing, every slip in the Lightning II’s program will necessarily affect the warfighting capability of the United States.

A second top priority for the USAF is the KC-46A air refueling tanker aircraft. The Air Force has stated that replacing the KC-135 (now over 50 years old) “remains one of the Air Force’s top three acquisition priorities.”36 Though the KC-46 has experienced a series of delays, it reached a milestone in August 2016 that enabled low-rate initial production.37 The Air Force awarded the contract for 19 initial aircraft in August 201638 toward Pegasus’s program of record for 179 aircraft. As it stands now, this system will replace less than half of the current tanker inventory of 391 aircraft. The current program calls for the delivery of 70 aircraft by FY 2020.39

The third major priority for the USAF from an acquisition perspective is the B-21 bomber, formerly called the Long-Range Strike Bomber. The USAF awarded Northrop Grumman the B-21 contract to build the Engineering and Manufacturing Development (EMD) phase, which includes associated training and support systems and initial production lots. The B-21 is the service’s next-generation deep-strike platform, intended to begin replacing a total of 119 B-52 Stratofortresses and B-1B Lancers by the mid-2020s.40 The Air Force has 20 B-2s that apparently will remain in the fleet with an average age of 21 years. The B-21, still in the development phase, will constitute the Air Force’s capability to penetrate highly contested environments defended by the most advanced air defense systems.41

The current plan for procurement includes the acquisition of 100 new bombers at an average cost of $564 million per plane.42 One potential future concern for this program is that with a 100-airframe B-21 purchase, the Air Force’s bomber fleet will fall from 159 aircraft to 120 aircraft.43

The Air Force’s strategy of capability over capacity is encumbered by the requirement to sustain ongoing combat operations in Afghanistan, Iraq, and Syria. In a budget-constrained environment, the need to sustain those ongoing efforts while modernizing an outdated fleet of aircraft for operations in contested environments means that funding has to be pulled from other areas, adversely affecting readiness.

Readiness

Air Force Director of Current Operations Major General Scott West testified to the House Armed Services Committee in July 2016 on his force’s aviation readiness,

The Air Force must be ready to conduct full spectrum operations. That includes the continued conduct of nuclear deterrence operations, continued support of counter terror operations (CT), and readiness for potential conflict with a near-peer competitor…. While we are able to conduct nuclear deterrence operations and support CT operations, operations against a near-peer competitor would require a significant amount of training…. In sum, our readiness is imbalanced at a time when the Air Force is small, old, and heavily tasked.44

Air Force readiness relies on weapon systems availability (sustainment); training; wartime readiness materials (WRM); facilities; and installations.45 While each of the four is important, weapon systems sustainment and WRM are the most critical. Reduced levels of funding, coupled with more than 13 years of continual air campaigns in the Middle East, have taken a significant toll on aircraft, pilot, and maintenance personnel availability.

Munitions are being used faster than they can be replaced. Air-to-surface weapons that offer stand-off, direct attack, and penetrators are short of current inventory objectives,46 and the concurrent shortage of air-to-air weapons could lead to an increase in the time needed to gain and maintain air superiority in future environments,47 particularly highly contested ones.

According to the Air Force, readiness has been declining since 2003. In FY 2013, flying hours were reduced by 18 percent, and 18 of 36 active duty, combat-coded squadrons (50 percent) were temporarily stood down.48 In FY 2014, the Air Force prioritized funding for readiness, but not at a rate to make up completely for cuts in FY 2013, and the shortfalls in readiness have persisted into FY 2016.

Parts inventory shortfalls and a shortage of aircraft maintenance personnel (maintainers)49 have reduced flying hours to the point where fighter pilots who once averaged over 200 hours a year struggled to get 120 hours in 2014.50 In 2015, the average rose to 150 hours through combat deployments, in which the vast majority of a fighter pilot’s time is spent patrolling or loitering (holding), over Iraq, Afghanistan, and Syria, where few sorties actually call for employment and no training is allowed. When they return home, those same pilots often average less than one sortie a week.51

To put this into context, in the1980s and 1990s, the demands on a “full spectrum capable” Air Force fighter pilot required, on average, 200 hours per year, or roughly four hours (or sorties) a week. All of that time was spent in the cockpit conducting combat-relevant missions (something other than flying in circles waiting for a call to action). This amount of flying enabled pilots not only to gain proficiency in a broad range of critical air-to-surface and air-to-air engagements, including low-altitude maneuvering, but also to improve those skills over time. At three hours per week (150 hours per year), a pilot might be able to sustain minimal levels of proficiency, but the Air Force typically would consider an inexperienced pilot (one having less than 500 hours of flying time) with that level of proficiency non-deployable for combat operations. At two hours (or two sorties) or less per week (100 hours per year), a pilot’s skills drop precipitously. With most pilots now receiving 150 hours or less a year, it is hard to fathom which 50 percent of the fighter force is ready for full-spectrum combat.

In 2015, enlisted airmen were deployed for an average of 132 days, and officers were deployed for an average of 128 days,52 but that average is skewed by the fact that only a small number of Air Force personnel actually deploy. The fact that 13.3 percent (64,655 of 485,000) of total Air Force personnel were deployed to contingency operations and exercises in 2015 means that a small percentage of the force is shouldering most of the burden of deploying for combat operations.53 Thirteen continual years of deployment have taken a toll. The Air Force now has a shortfall of 4,000 maintenance personnel and 700 pilots.54 While the service may be able to devise a plan to fill maintenance and pilot billets, it will take years to regain the experience lost through this flight of talent.

During his confirmation hearing for the position of Chief of Staff of the Air Force, General David Goldfein stated that at current readiness levels, the Air Force cannot muster a surge capacity for major OPLAN contingencies and meet all of the global demand with ready combat forces. In order to meet those contingencies, the Air Force must have 80 percent or more of its combat forces at full-spectrum readiness. Less than 50 percent of combat units are at that level, and while the Air Force could surge forces to meet combatant commander requirements, their lack of readiness would affect its ability to conduct all assigned mission-essential tasks.55 It would also put those pilots at risk.

The Air Force has stated that it lacks the capacity to absorb additional cuts in manpower without also reducing capability. If requirements continue to increase, the Air Force “will have to make difficult decisions on mission priorities and dilute coverage across the board.”56 Even with sufficient funding, recovering from its current status would take no small amount of time. For example, standing down a unit for 60 days results in a degraded (unfit for combat) unit. To return the unit to desired levels of proficiency takes six months to a year.57 As General Goldfein explained, “Bottom line—when an Air Force does not fly, readiness atrophies across the enterprise with impacts that cannot be reversed in the time it took to lose it.”58 The Air Force’s FY 2017 budget submission seeks to strike a balance among capability, capacity, and readiness with the goal of achieving full-spectrum readiness by 2023.59

Scoring the U.S. Air Force

Capacity Score: Strong

One of the key elements of combat power in the U.S. Air Force is its fleet of fighter aircraft. In responding to major combat engagements since World War II, the Air Force has deployed an average of 28 fighter squadrons, based on an average of 18 aircraft per fighter squadron. That equates to a requirement of 500 active component fighter aircraft to execute one MRC. Based on government force-sizing documents that count fighter aircraft, squadrons, or wings, an average of 55 squadrons (990 aircraft) is required to field a two-MRC–capable force (rounded up to 1,000 fighter aircraft to simplify the numbers). This Index looks for 1,200 active fighter aircraft to account for the 20 percent reserve necessary when considering availability for deployment and the risk of employing 100 percent of fighters at any one time.

Two-MRC Level: 1,200 fighter aircraft.

Actual 2016 Level: 1,159 fighter aircraft.60

Based on a pure count of combat-coded fighter/attack platforms that have at least IOC, the USAF currently is only slightly below the two-MRC benchmark. However, this figure should be taken with a few caveats. The F-35 will become a highly advanced and capable multirole platform, but the 75 aircraft that have entered the USAF inventory to date are only nearing IOC and do not yet field many of the capabilities that would constitute full-spectrum readiness.

While the 1,159 figure would normally yield a capacity level of “very strong,” aircraft require pilots to fly them and maintainers to launch, recover, and fix them. With a fighter pilot shortage of 700 and a maintenance shortfall of 4,000 personnel, the ability of the Air Force to meet the wartime manning requirements for fighter cockpits or sufficient maintenance personnel to continually repair, refuel, and rearm aircraft rapidly to meet wartime sortie requirements has been significantly reduced. Those factors, coupled with the lack of funding for a sufficient supply of spare parts, has reduced the capacity for employment from “very strong” in the 2016 Index to a 2017 Index assessment of “strong.”

Capability Score: Marginal

The Air Force’s capability score is “marginal,” a result of being scored “strong” in “Size of Modernization Program,” “marginal” for “Age of Equipment” and “Health of Modernization Programs,” but “weak” for “Capability of Equipment.” These scores have not changed from the 2016 Index’s assessment. However, continued concern with the F-35 program’s progress toward effective replacement of legacy aircraft could cause the USAF’s capability score to decline in future years.

Readiness Score: Marginal

The Air Force scores “marginal” in readiness in the 2017 Index, the same as it scored in the 2016 Index. This is based primarily on the Air Force’s reporting that 50 percent of its combat air forces met full-spectrum readiness requirements in 2016.61 The Air Force should be prepared to respond quickly to an emergent crisis and retain full readiness of its combat airpower, but it has been suffering from degraded readiness since 2003, and implementation of BCA-imposed budget cuts in FY 2013 has only exacerbated the problem. Similar to the other services, the Air Force was able to make up some of its readiness shortfalls under the FY 2015 budget, but given its poor readiness assessment, much more improvement is required.

The Air Force’s current deficits in both pilot and maintainer manpower are also very troubling indicators for readiness. They will strain the service in the immediate term and, if not reversed, could lead to broader readiness challenges in the future.

Overall U.S. Air Force Score: Marginal

The Air Force is scored as “marginal” overall. This is an unweighted average of its capacity score of “strong,” capability score of “marginal,” and readiness score of “marginal.” While the overall score remains the same as the previous year’s, the accumulating shortage of pilots and maintainers has begun to affect the ability of the Air Force to generate the amount of combat air power that would be needed to meet wartime requirements.

2017_Index_of_Military_Strength_MilitaryPowerUSAF


  1. The Honorable Deborah Lee James, Secretary of the Air Force, and General Mark A. Welsh III, USAF Chief of Staff, “Fiscal Year 2016 Air Force Posture,” statement before the Subcommittee on Defense, Committee on Appropriations, U.S. Senate, 
February 25, 2015, p. 9, http://www.appropriations.senate.gov/imo/media/doc/hearings/FY16%20Air%20Force%20Posture
    %20Statement%20(Final)%20022515.pdf (accessed August 26, 2016). 

  2. The Honorable Michael B. Donley, Secretary of the Air Force, and General Mark A. Welsh III, Chief of Staff, United States Air Force, “Fiscal Year 2014 Air Force Posture Statement,” statement before the Committee on Armed Services, U.S. House of Representatives, April 12, 2013, p. 2, http://www.dtic.mil/dtic/tr/fulltext/u2/a584783.pdf (accessed August 26, 2016). 

  3. U.S. Department of Defense, Office of the Under Secretary of Defense (Comptroller), Chief Financial Officer, United States Department of Defense Fiscal Year 2017 Budget Request: Defense Budget Overview, February 2016, p. 8-25, 
http://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2017/FY2017_Budget
    _Request_Overview_Book.pdf (accessed August 26, 2016). 

  4. The Honorable Deborah Lee James, Secretary of the Air Force, and General Mark A. Welsh III, USAF Chief of Staff, “Fiscal Year 2016 Air Force Posture,” statement before the Subcommittee on Defense, Committee on Appropriations, U.S. House of Representatives, February 27, 2015, p. 11, http://docs.house.gov/meetings/AP/AP02/20150227/102998/HHRG-114-AP02-Wstate-WelshM-20150227.pdf (accessed August 26, 2016). 

  5. Ibid., p. 18. 

  6. Honorable Deborah Lee James, Secretary of the Air Force, and General Mark A. Welsh III, Chief of Staff of the Air Force, “Air Force Posture,” statement before the Committee on Armed Services, U.S. House of Representatives, March 16, 2016, pp. 7–8, 
http://docs.house.gov/meetings/AS/AS00/20160316/104662/HHRG-114-AS00-Bio-JamesD-20160316.pdf (accessed August 26, 2016). 

  7. James and Welsh, “Fiscal Year 2016 Air Force Posture,” p. 6. 

  8. Technological advances in aircraft materials and structure greatly extended the service life of USAF equipment. As a result, the USAF was able to sustain its force structure while procuring fewer aircraft. See Colonel James C. Ruehrmund Jr. and Christopher J. Bowie, Arsenal of Airpower: USAF Aircraft Inventory 1950–2009, Mitchell Institute for Airpower Studies, November 2010), p. 8, http://higherlogicdownload.s3.amazonaws.com/AFA/6379b747-7730-4f82-9b45-a1c80d6c8fdb/UploadedImages/Mitchell%20Publications/Arsenal%20of%20Airpower.pdf (accessed August 27, 2014). 

  9. James and Welsh, “Air Force Posture,” March 16, 2016, p. 7. 

  10. Dr. William A. LaPlante, Assistant Secretary of the Air Force (Acquisition); Lieutenant General James M. “Mike” Holmes, Deputy Chief of Staff (Strategic Plans and Requirements); and Lieutenant General Tod D. Wolters, Deputy Chief of Staff (Operations), “Fiscal Year 2016 Air Force, Force Structure and Modernization Programs,” statement before the Subcommittee on Airland Forces, Committee on Armed Services, U.S. Senate, March 19, 2015, p. 9, 
http://www.armed-services.senate.gov/imo/media/doc/LaPlante_Holmes_Wolters_03-19-15.pdf (accessed August 26, 2016). 

  11. Figure 3-4, “Air Force Structure,” in U.S. Department of Defense, United States Department of Defense Fiscal Year 2015 Budget Request: Estimated Impacts of Sequester-Level Funding, April 2014, p. 3-4, 
http://archive.defense.gov/pubs/2014_Estimated_Impacts_of_Sequestration-Level_Funding_April.pdf (accessed August 26, 2016); Ronald O’Rourke, “Tactical Aircraft Modernization: Issues for Congress,” Congressional Research Service Report for Congress, 
July 9, 2009, http://fas.org/sgp/crs/weapons/RL33543.pdf (accessed July 10, 2015). 

  12. “The Air Force in Facts and Figures,” in “USAF Almanac 1996,” Air Force Magazine, Vol. 79, No. 5 (May 1996), p. 59, 
http://www.airforcemag.com/MagazineArchive/Magazine%20Documents/1996/May%201996
    /0596facts_figures.pdf (accessed August 26, 2016). The Air Force uses a variety of categorizations to describe or refer to its inventory of aircraft and units. This can make assessing Air Force capacity a challenge. “TACAIR,” or tactical aircraft, units refers to any aviation unit that operates tactical aircraft, normally thought of as fighter or attack aircraft such as the F-15, F-16, A-10, F-22, and F-35. This generic term can include operational and training squadrons in the Active, Reserve, and Air National Guard components. “Combat coded” aircraft and related squadrons specifically refers to aircraft and units assigned a wartime mission. For the purpose of assessing capacity and readiness, this Index refers to combat-coded aircraft and units maintained within the Active component of the U.S. Air Force. See Report No., 112–329, National Defense Authorization Act for Fiscal Year 2012, Conference Report to Accompany H.R. 1540, U.S. House of Representatives, 112th Cong, 1st Sess., December 12, 2011, p. 25, http://www.gpo.gov/fdsys/pkg/CRPT-112hrpt329/pdf/CRPT-112hrpt329-pt1.pdf (accessed August 26, 2016). Note that these numbers differ from those reported in the 2015 and 2016 editions of this Index. The numbers reported earlier accounted for all combat-coded squadrons in the total Air Force, meaning those in the Active, Reserve, and Air National Guard components. The revised numbers reported here are only those in the Active component so as to maintain the Index’s focus on combat power in the Active components of the Joint Force. 

  13. LaPlante, Holmes, and Wolters, “Fiscal Year 2016 Air Force, Force Structure and Modernization Programs,” p. 8. 

  14. Ibid. 

  15. International Institute for Strategic Studies, The Military Balance 2016: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2016). Summed totals of Air Force Fighter Aircraft (1,303) and the subtracted seven AETC fighter squadrons and one ACC fighter squadron (8 x 18 = 144) that are RTU (non-combat-coded) squadrons. 

  16. Ibid., pp. 8–9. 

  17. James and Welsh, “Fiscal Year 2016 Air Force Posture,” p. 12. 

  18. Ibid., p. 7. 

  19. “The Air Force in Facts and Figures,” May 2016, p. 37. Age posted is “as of Sept. 30, 2015.” Ten months were added due to the delay between publication of the Air Force Almanac and this publication. 

  20. International Institute for Strategic Studies, The Military Balance 2016, Pp. 46–48. 

  21. “The Air Force in Facts and Figures,” May 2016, p. 37. Age posted is “as of Sept. 30 2015.” Ten months were added due to the delay between publication of the Air Force Almanac and this publication. 

  22. Ibid. 

  23. International Institute for Strategic Studies, The Military Balance 2016, p. 47. This reference is missing 31 MC-12s (see “The Air Force in Facts and Figures,” May 2016, p. 37) that were added to reach a total of 482. 

  24. Aaron Mehta, “Sources: U-2 in USAF Budget Request,” Defense News, January 30, 2015, 
http://www.defensenews.com/story/defense/policy-budget/budget/2015/01/30/u2-in-usaf-fy16-budget-request/22603521/ (accessed August 26, 2016). 

  25. “The Air Force in Facts and Figures,” May 2016, p. 37. Age posted is “as of Sept. 30, 2015.” Ten months were added due to the delay between publication of the Air Force Almanac and this publication. 

  26. James and Welsh, “Fiscal Year 2016 Air Force Posture,” p. 18. 

  27. Colonel Michael W. Pietrucha, U.S. Air Force, “The Comanche and the Albatross: About Our Neck Was Hung,” Air & Space Power Journal, May–June 2014, pp. 133–156, http://www.au.af.mil/au/afri/aspj/digital/pdf/articles/2014-May-Jun/F-Pietrucha.pdf?source=Govt (accessed August 26, 2016). 

  28. Jeremiah Gertler, “Air Force F-22 Fighter Program,” Congressional Research Service Report for Congress, July 11, 2013, p. 7, 
https://www.fas.org/sgp/crs/weapons/RL31673.pdf (accessed July 25, 2016). 

  29. Jeremiah Gertler, “F-35 Joint Strike Fighter (JSF) Program,” Congressional Research Service Report for Members and Committees of Congress, April 29, 2014, p. 2, http://fas.org/sgp/crs/weapons/RL30563.pdf (accessed August 26, 2016). 

  30. Gertler, “Air Force F-22 Fighter Program,” p. 7. 

  31. John Venable, “Operational Assessment of the F-35A Argues for Full Program Procurement and Concurrent Development Process,” Heritage Foundation Backgrounder No. 3140, August 4, 2016, p. 2, 
http://www.heritage.org/research/reports/2016/08/operational-assessment-of-the-f-35a-argues-for-full-program-procurement-and-concurrent-development-process. 

  32. Dave Majumdar, “Can the F-35 Win a Dogfight?” War Is Boring, December 17, 2013, p. 1, 
https://warisboring.com/can-the-f-35-win-a-dogfight-95462ccd6745#.5pvpajaos (accessed August 30, 2016). 

  33. James Drew, “F-22 Raptor Retrofit to Take Longer, but Availability Hits 63%,” FlightGlobal, July 6, 2015, 
http://www.flightglobal.com/news/articles/f-22-raptor-retrofit-to-take-longer-but-availability-hits-414341/ (accessed July 13, 2015). 

  34. Ibid. 

  35. Lara Seligman, “F-35 Full Combat Capability Will Be Four Months Late,” Defense News, March 23, 2016, 
http://www.defensenews.com/story/defense/air-space/2016/03/23/f-35-full-combat-capability-four-months-late/82187648/ (accessed August 26, 2016). 

  36. United States Air Force, Fiscal Year 2017 Budget Overview, February 2016, p. CM-9, 
http://www.saffm.hq.af.mil/shared/media/document/AFD-160209-036.pdf (accessed August 26, 2016). 

  37. “KC-46A Pegasus Aerial Tanker Completes Firsts,” Defense Industry Daily, August 22, 2016, 
https://www.defenseindustrydaily.com/the-usafs-kcx-aerial-tanker-rfp-03009/ (accessed August 30, 2016). 

  38. Colin Clark, “Boeing Wins $2.8B for KC-4 Tanker Low Rate Production,” Breaking Defense, August, 18, 2016, 
http://breakingdefense.com/2016/08/boeing-wins-2-5b-for-kc-46-tanker-low-rate-production/ (accessed August 30, 2016). 

  39. U.S. Department of Defense, Office of the Under Secretary of Defense (Comptroller, Chief Financial Officer, United States Department of Defense Fiscal Year 2016 Budget Request: Overview, February 2015, p. 8-17, 
http://comptroller.defense.gov/Portals/45/Documents/defbudget/fy2016/FY2016_Budget_Request_Overview_Book.pdf (accessed August 26, 2016). 

  40. Bill Carey, “U.S. Air Force Sheds Some Light on Coming LRS-B Contract,” AINonline, March 10, 2015, 
https://www.ainonline.com/aviation-news/defense/2015-03-10/us-air-force-sheds-some-light-coming-lrs-b-contract 
(accessed July 13, 2015). 

  41. U.S. Department of Defense, United States Department of Defense Fiscal Year 2016 Budget Request: Overview, p. 8-18. 

  42. Lieutenant General James M. “Mike” Holmes, USAF Deputy Chief of Staff (Strategic Plans and Requirements), and Lieutenant General Arnold W. Bunch, Jr., USAF, Military Deputy, Office of the Assistant Secretary of the Air Force (Acquisition), “Subject: Hearing on Air Force Bomber/Tanker/Airlift Acquisition Programs–HASC Seapower and Projection Forces,” statement before the Subcommittee on Seapower and Projection Forces, Committee on Armed Services, U.S. House of Representatives, 
March 1, 2016, p. 4, http://docs.house.gov/meetings/AS/AS28/20160301/104353/HHRG-114-AS28-Wstate-BunchA-20160301.pdf (accessed August 26, 2016). 

  43. Jeremiah Gertler, “Air Force B-21 Long Range Strike Bomber,” Congressional Research Service Report for Members and Committees of Congress, April 14, 2016, p. 9, https://www.fas.org/sgp/crs/weapons/R44463.pdf (accessed August 26, 2016). 

  44. Major General Scott West, Director of Current Operations, Deputy Chief of Staff for Operations, Headquarters, U.S. Air Force, “Subject: Military Aviation Readiness and Safety Hearing,” statement before the Subcommittee on Readiness, Committee on Armed Services, U.S. House of Representatives, July 6, 2016, pp. 1–2, 
http://docs.house.gov/meetings/AS/AS03/20160706/105159/HHRG-114-AS03-Wstate-WestS-20160706.pdf 
(accessed August 26, 2016). 

  45. Donley and Welsh, “Fiscal Year 2014 Air Force Posture Statement,” p. 17. 

  46. LaPlante, Holmes, and Wolters, “Fiscal Year 2016 Air Force, Force Structure and Modernization Programs,” p. 16. 

  47. Ibid., p. 17. 

  48. Brian Everstine, “Reduced Flying Hours Forces USAF to Ground 17 Combat Air Squadrons,” Military Times, April 8, 2014, 
http://www.militarytimes.com/story/military/archives/2013/04/08/reduced-flying-hours-forces-grounding-of-17-usaf-combat-air/78539120/ (accessed August 26, 2016) The numbers in this article were cross-referenced with the combat-coded, active duty squadrons found in International Institute for Strategic Studies, The Military Balance 2014: The Annual Assessment of Global Military Capabilities and Defence Economics (London: Routledge, 2014). 

  49. Jennifer Griffin and Lucas Tomlinson, “‘Wiped Out’: Air Force Losing Pilots and Planes to Cuts, Scrounging for Spare Parts,” Fox News, May 14, 2016, http://www.foxnews.com/politics/2016/05/14/wiped-out-air-force-losing-pilots-and-planes-to-cuts-scrounging-for-spare-parts.html (accessed August 30, 2016). 

  50. Julian E. Barnes, “Warning Sounded on Cuts to Pilot Training,” The Wall Street Journal, December 19, 2013, 
http://www.wsj.com/articles/SB10001424052702304773104579268651994849572 (accessed August 26, 2016). 

  51. Scott Maucione, “Air Force Puts a Number on Maintenance Staffing Deficit,” Federal News Radio, June 16, 2016, 
http://federalnewsradio.com/defense/2016/06/air-force-puts-number-maintainence-staffing-deficit/ (accessed August 26, 2016). 

  52. Ibid. 

  53. Stephen Losey, “Air Force Deployment Tempo Brings New Kinds of Strains,” Air Force Times, March 29, 2016, 
http://www.airforcetimes.com/story/military/2016/03/29/air-force-deployment-tempo-brings-new-kinds-strains/82163738/ (accessed August 26, 2016). 

  54. News Transcript, “Department of Defense Press Briefing by Secretary James and Gen. Goldfein on the State of the Air Force in the Pentagon Briefing Room,” U.S. Department of Defense, August 10, 2016, 
http://www.defense.gov/News/Transcripts/Transcript-View/Article/911083/department-of-defense-press-briefing-by-secretary-james-and-gen-goldfein-on-the (accessed August 30, 2016).
     

  55. Hearing to Consider the Nomination of General David L. Goldfein, USAF, for Reappointment to the Grade of general and to be Chief of Staff, United States Air Force, Committee on Armed Services, U.S. Senate, June 16, 2016, “Advance Policy Questions,” 
pp. 7–8, http://www.armed-services.senate.gov/hearings/16-06-16-nomination_-goldfein (accessed August 30, 2016). 

  56. General Larry O. Spencer, Vice Chief of Staff of the Air Force, “Subject: Current Readiness of the U.S. Air Force,” statement before the Subcommittee on Readiness, Committee on Armed Services, U.S. House of Representatives, March 26, 2015, p. 3, 
http://docs.house.gov/meetings/AS/AS03/20150326/103193/HMTG-114-AS03-Wstate-SpencerL-20150326.pdf 
(accessed August 31, 2016). 

  57. Donley and Welsh, “Fiscal Year 2014 Air Force Posture Statement,” p. 3. 

  58. General David L. Goldfein, Chief of Staff of the Air Force, “Subject: Department of the Air Force 2017 Budget Request and Readiness Posture,” statement before the Subcommittee on Readiness, Committee on Armed Services, U.S. House of Representatives, February 12, 2016, p. 4, http://docs.house.gov/meetings/AS/AS03/20160212/104347/HHRG-114-AS03-Wstate-GoldfeinD-20160212.pdf (accessed August 26, 2016). 

  59. U.S. Department of Defense, United States Department of Defense Fiscal Year 2016 Budget Request: Overview, p. 8-21. 

  60. This number represents total active component fighters. This Index considers requirements, such as aircraft, that are needed to perform Operation Noble Eagle (ONE), an ongoing mission to defend American airspace. Details regarding ONE are limited and largely unavailable to the public. Because the exact number of active component fighter aircraft participating in ONE is unknown, those fighters that may be tasked with the ONE mission are not counted in this total. 

  61. West, “Subject: Military Aviation Readiness and Safety Hearing,” p. 2.