Tactical Fighter Experimental

The Air Force and the Department of Defense were created amid a time of massive military drawdowns and shrinking budgets. However, nuclear weapons, nuclear strategy, and their associated systems were impervious to this drawdown. In the 1950s and 1960s, nuclear strategy permeated every area of the military, as the services must train, organize, and equip to fulfill national strategy. At the time, the entire government revolved around nukes.

The fledgling Air Force wielded considerable political power over its sister services during the formative years of nuclear strategy. The Air Force was considered the golden child of Congress, a panacea for all of the world’s problems. Therefore, it is easy to see why the control of nuclear defense was given to the Air Force over all others. Everything in the world revolved around nukes, and the Air Force revolved around the bomber. Only the bomber could deliver the nuclear weapon.

The policy was Massive Retaliation. However there simply were not enough bombers to execute it effectively, and missiles were not ready yet. The solution: numerous ‘tactical’ fighter-bombers. Fighters belonged to the ‘other’ part of the Air Force, Tactical Air Command (TAC). TAC’s missions were (1) close air support, (2) air superiority, and (3) air interdiction. None of these were nuclear. To get TAC into the nuclear game, their fighters would have to start dropping nukes. Massive Retaliation shifted TAC’s focus from air superiority to nuclear interdiction. What followed was the Century Series Fighters. TAC fielded a new aircraft every three years from 1945-1960. Four of these were fighter-bombers with each new aircraft incrementally better than the previous design.

Then Sputnik happened, and as mentioned in Part 1, all the priorities changed. The military focus on fighter-bombers declined similarly to the decline of the new strategic bomber. In the year after Sputnik, the number of TAC wings declined from 34 to 26. The next year, the number of wings dropped to 18, as theater ballistic missiles entered the European Theatre. The Supreme Allied Commander in Europe publicly stated TAC fighter-bombers in Europe should be replaced with medium-range ballistic missiles.[1] TAC had tied itself to the idea of the fighter-bomber and if that idea changed then TAC would be replaced. Their solution: double down on the nuclear weapon delivering tactical fighter-bomber.

The man behind this plan was Air Force General Frank Everest.[2]  He was uniquely experienced in jet fighters, nuclear weapons, and ballistic missiles and one of the Air Force’s primary advocates of the Massive Retaliation strategy. Everest knew fighter-bombers delivering nuclear weapons was necessary to win in Europe because of the tactical limitation of theater ballistic missiles. He also knew the F-105 was not the aircraft for the job.

F-105 Thunderchief

The F-105 needed a 10,000-foot runway to take off which the majority of European airfields could not support. Of the 94 bases in Europe, only 11 runways were in good working order. Therefore, Everest needed an aircraft that could either use Europe’s short, unimproved runways or take off from the US and strike Europe. Frank Everest was not a compromising sort, so he demanded both. Such an aircraft did not exist, nor did the technology to build one.[3]

As described in Part 1, after Gary Power’s U-2 shoot down, and the illusion of the high-fast flyer’s invulnerability was destroyed, the Air Force made a conscious choice to go low. TAC pioneered the ‘Low-Low-High’ mission profile, low-level, high-speed dash ingress, low-altitude nuclear delivery, and high-altitude high-speed recovery. The new tactical fighter-bomber would dash in low or “on the deck” at 0.9 Mach and dash out high altitude at 2.5 Mach. Air defenses would not spot you coming in, and would not be able to catch you going out. At his core, Frank Everest was a fighter pilot, and as such, nothing trumped speed. Flying in Korea taught him speed equals survivability.[4]

Everest’s requirements of speed combined with the ability to fly trans-Atlantic without refueling, use short runways while carrying nuclear weapons was according to the aircraft industry, “impossible.” Everest’s requirements were at odds with physics. Trans-Atlantic flight required long wingspans perpendicular to the airflow while supersonic flight required swept wings with little surface area. TAC needed an aircraft that could magically change wing shape.

NASA showed the world how to do the impossible with variable wing sweep.[5] This new technology was the very definition of cutting-edge, and the USAF loved it. In 1960, TAC submitted a requirement for the next Century Series Aircraft using Everest’s requirements.

Herein lies a critical juncture in the development of the Air Force and the development of aircraft. Up to this point, the USAF built aircraft for a defined purpose. Fighters were fighters, pursuit was pursuit, interceptors were interceptors, and bombers were bombers. The existing Century Series aircraft were ‘adapted’ to the nuclear role, not designed for it. This new aircraft was the first to be designed ‘multi-role.’ Everest was making a huge gamble with a multi-role designation. Experts decreed such a heavy, swing-wing design would have poor maneuverability, poor thrust, and a weak air-to-air capability. The Air Force experts at TAC agreed and declared such capabilities obsolete. Dogfighting was dead; missiles would rule the air. Maneuverability was not required, and most engagements would occur beyond-visual-rage. The next war would be fought with nuclear weapons; conventional capabilities were a waste of time. TAC was trying to maintain relevancy by dropping nuclear weapons with a tactical bomber and had no intention of fielding a ‘fighter’ for air superiority.

The Navy also needed a next-gen fighter. However, its version was for fleet defense. The Air Force owned the nuclear mission, and fleet defense was not nuclear. The Navy was directed to get a new fighter, while the Air Force was not, and so the Navy fighter would get funded.[6] Everest knew if the USAF had to share resources with the Navy, the Air Force would prioritize missiles first, followed by bombers, with fighters last. His new fighter would be dead. Everest feared direction to develop a fighter to meet both the Air Force and the Navy’s needs. To prevent this, he changed the requirement to make the new fighter different from any Navy fighter. He increased the requirement for the low-level dash from 0.9 Mach to 1.2 Mach for 400 miles. NASA quickly informed Everest this change was impossible with current technology. He forced the requirement to stand resulting in the one of the largest, and most identifiable issues with the eventual failure of TAC’s new fighter.

JFK won the election in 1960 and immediately made sweeping changes to both the national security strategy and civilian control of the military. JFK was uncomfortable with the military’s nuclear focus and did not agree with the Air Force’s assumption the next war would be entirely nuclear. He needed to balance the threat of nuclear war with an equal threat of conventional warfare. He demanded Flexible Response. Massive Retaliation was dead. This blow to the Air Force was staggering. It had spent the previous 15 years building a force to execute Massive Retaliation, and now it needed a conventional force that did not exist. Conventional warfare, with non-nuclear weapons, did not interest the USAF in 1960.

JFK’s Secretary of Defense, Robert McNamara was a singular personality in the procurement of military hardware during his tenure. McNamara detested each service’s control over its acquisitions because he saw blatant duplication. When he showed up at the Pentagon in 1961, all four services had requirements for new tactical combat aircraft. McNamara required them to form a Joint Acquisitions Program to procure one fighter to meet everyone’s needs. Because the Air Force owned the air, the design would be controlled by the Air Force, but the other services needs were required to be met. The result was the Tactical Fighter Experimental (TFX). Everest’s gamble had failed.

TFX was designed as a tactical bomber but advertised as a multi-mission platform. In theory, variable wing sweep allowed extended subsonic operations, suitable for close air support and fleet defense missions. Supersonic capability made it an effective tactical bomber and a good interceptor for the Navy. McNamara and JFK liked the multi-mission aspect as it supported flexible response. The Air Force was in a Catch-22. Admit TFX was not truly multi-mission and lose control, or stand by multi-mission and get a degraded nuclear mission aircraft.

The Air Force and the Navy agreed one aircraft for the both services was a bad idea. TFX was a long-range interdiction aircraft to the Air Force that needed a good amount of fuel to accomplish a Low-Low-High profile.  The supersonic dash at low-level needed a heavy frame and a long, thin design, this translated into an 80,000-pound aircraft and over 85 feet long. The Navy TFX could not exceed 50,000 pounds and 56 feet due to aircraft carrier basing.[7]

In June of 1961, General Curtis LeMay took over as the Air Force Chief of Staff. McNamara believed LeMay’s background and personality worked to his advantage. LeMay was the most powerful man in uniform and believed 100% in the bomber. He believed fighters were for fun while bombers did the real work.  With LeMay on McNamara’s side in the TFX battle, a joint fighter aircraft was a guarantee. LeMay wasn’t supposed to care about TFX and therefore agree with the Secretary. However, LeMay knew the truth about TFX. It was a bomber. McNamara believed it was a multi-role fighter. LeMay saw it as a replacement to the B‑58 Hustler and hoped the Navy would leave the program. Resulting in the Air Force getting the tactical nuclear bomber LeMay and Everest wanted.

F-4 Phantom II

McNamara had to re-establish his control over the Air Force. The F-105 Thunderchief was still in production as 1,500 aircraft had not yet been built. McNamara canceled the contract and cut all production of the F-105.  He followed that up by mandating the Air Force procure the F‑4 Phantom as its new air superiority fighter.[8]  His intent was three-fold.

First, the F‑4 had no nuclear mission. McNamara had to prove that a conventional aircraft was useful to the Air Force. Second, it had been in Navy service for a few years, and McNamara needed to show one aircraft could satisfy multiple service needs. And third, it temporarily put the Air Force subservient to the Navy in matters of air superiority. LeMay had no choice but to buy F‑4s. However, he felt he could prolong the procurement and cancel it when McNamara was no longer the Secretary. At the time, the average lifespan of a Secretary of Defense was two years. LeMay felt he could wait him out. Unfortunately for LeMay, McNamara was the longest serving Defense Secretary in history.

None of the bidders for TFX had ever completed a joint service bid, and it showed. The bidding and selection process was the most drawn-out and politically charged in history. Boeing had been in on TFX from Eisenhower days. They had worked with NASA and the Air Force and had a robust and workable design. Boeing’s design was superior to the others in every way. However, it still took four rounds of bidding. In the end, the Evaluation Board, Source Selection Board, Commanding Generals, and Service Secretaries all agreed on the Boeing proposal. To everyone’s surprise, McNamara chose General Dynamics. Under pressure from the services over this choice, McNamara relented on one point: he allowed two versions to be developed, one for the Air Force, one for the Navy. TFX was now the F‑111.


By 1963, engineers discovered what NASA told Everest in 1960. Low-level, Mach 1.2 for 400 miles was impossible. The General Dynamics design could not achieve supersonic flight at sea-level. The design had too much drag coupled with too much boundary layer disturbance. When this design issue surfaced, it brought with it dozens of others, including underpowered engines, compressor stalls, inlet airflow, and weight problems. Congress got involved. The Senate Permanent Subcommittee on Investigations from the Committee on Government Operations convened hearings.  The contract could be invalidated at any minute.

Flight testing continued through 1964 and 1965. Test pilots complained incessantly about the aircraft’s issues, backed up by mounds of technical data. The plane was underpowered, sluggish, and prone to compressor stalls. However, General Dynamics was not contractually obligated to send any data to the Air Force. Therefore, the Secretary of the Air Force was presented only with rosy projections of success which he passed on to McNamara. Based on those projections, they recommended the F-111A proceed directly into full production, although flight testing was not complete, nor successful. The now authorized Navy version, F-111B, did not even exist.[9]

In 1966, the entire program went sideways. For the past 15 years, prioritizing nuclear interdiction over air superiority led to the Air Force prioritizing speed and technology over performance. By 1966, the real failure of this strategy became apparent. The F‑100 and F‑105 were not performing in Vietnam. The F‑100 was so inept that commanders in Vietnam allowed it only rear echelon missions. The F‑105 was being shot down by enemy SAMs and fighters at an alarming rate. Half of all F‑105s built ended their short lives in the jungles of Vietnam and Laos.[10] These aircraft were not being used in their design roles. This strategy was an overwhelming failure. The F-111 was the culmination of that failed strategy. Rather than address this strategic deficiency with the F‑111, the Air Force did nothing. By mid-1966, McNamara took personal control over the program. The Air Force no longer controlled the development of the F‑111.

Despite all the issues, General Dynamics kept churning out production model aircraft. McNamara, not realizing the aircraft was in full production, thought there was time to fix the design. General Dynamics said nothing, knowing that any changes to the design at this point result would be costly and lead to more profit. No one in senior government positions seemed to realize the aircraft was in production because flight testing was still ongoing. Never before had an aircraft gone into production before the completion of developmental testing.

By the end of 1966, McNamara finally received all of the flight test data. These data revealed the F‑111 was the heaviest tactical fighter ever, with the lowest thrust-to-weight ratio of any supersonic fighter, and the highest ratio of weight-to-wing area. For the uninitiated, these things are all bad. When it was revealed the low-level supersonic dash could only be performed for 30 miles instead of a required 400 miles, Congress once again became involved.

235 aircraft had already been purchased, therefore canceling the program outright was a bad investment. The Senate halted all work on the Navy version and mandated the Air Force version get a new engine and new inlets. The new engine was incompatible with 141 of the aircraft already produced. Therefore those aircraft remained underpowered, sluggish, and incapable of the long duration dash for their entire lifespan. To add insult to injury, McNamara recommended the Air Force procure a separate bomber version of the F‑111, which the Air Force wanted seven years prior. In 18 months, the F‑111 went from 2 versions (Air Force and Navy) to 5 versions (all Air Force).

The following year, McNamara retired. The day after his departure, the Senate canceled the Navy version. Surprising almost no one, reports from Vietnam showed the F‑111 was a marginal tactical bomber and a horrible fighter.[11] By late 1968, the Air Force and Navy had both come to the realization the F‑111 would not be the premier US fighter of the 1970s. The F-111 wasn’t even a top ten fighter in 1968.

After all of this, the Air Force and the Navy still did not have the fighter it needed. Congress and the Department of Defense asked the services again to acquire a fighter jointly. Both Air Force and Navy adamantly refused. The Air Force, finally recognizing its deficient air superiority mission, started a purpose driven program and got the F‑15, while the Navy pursued a purpose-built fleet defense fighter and got the F‑14.

After the entire debacle, the Air Force received 437 F‑111s in 5 different variants. The program ended up costing $9B (FY68), three times the original cost and received one-third the original number of aircraft. The Air Force blamed the Navy for undercutting its requirements, and the Navy blamed the Air Force for forcing it into an aircraft it never wanted. While it briefly played a role as a tactical bomber and nuclear bomber, the F-111 never matured in these roles. It eventually found a home as an electronic jammer and primitive SEAD (suppression of enemy air defenses) platform and excelled in this niche for over twenty years.


F-35 Parallels

While there are correlations between the Strategic Bomber and the F-35, the comparison between TFX and F‑35 are much more direct. In retrospect, the Tactical Fighter Experimental program was little more than a dress rehearsal for the Joint Strike Fighter program. Almost all of the issues with the F-35 were repeats from the F-111, 45 years later.

In both cases, the program prioritized technology over performance. The Century Series aircraft did this as well.  TFX, at its heart, ignored performance and the failure of the F‑111 highlighted the fallacy of this strategy. The F-15 was the return to performance. The F‑35 is showing similar issues when it comes to technology vs. performance. The USAF has done the same thing with bombers, however, ‘performance’ is judged differently. Performance factors to judge bombers are range, endurance, and maximum payload. The B-2 is less capable than the B-52 by these factors but more capable in today’s threat environment. Prioritizing technology over performance is not necessarily bad. However, with a ‘multi-role’ platform, it could be less capable. The B-2 is not multi-role. It’s a bomber. The F‑111 was not multi-role but rather forced into a multi-role designation through politics. The multi-role aspect destroyed the F‑111.  The F‑35 is multi-role and judging it against the performance factors of bombers, in addition to factors attributed to fighters, like maneuverability and speed,  will show its lack of performance against specific mission sets.

Prioritizing technology over performance is exacerbated when paired with unreasonable requirements. The requirement for the F‑111 was the supersonic low-level dash. With the F‑35, the requirement is the vertical takeoff capability. These requirements ultimately jacked each program. The low-level 1.2 Mach dash speed was political, to distance Air Force requirements from Navy requirements. TAC remained adamant it needed the faster supersonic low-level dash rather than the achievable and survivable 0.9 Mach low-level dash, but that design supported Navy requirements. We relearned the same lesson years later when the low-level B-52 was shown to be just as survivable as the low-level B-1.[12] The vertical takeoff component of the F‑35 was done to appease the Marines and gain political buy-in.

Mis-prioritized and unreasonable requirements lead to under-performance.  Summed up as, ‘jack of all trades, master of none.’ Purpose-built aircraft have historically excelled in those areas the design optimized. Are these aircraft capable of handling multiple different roles? No, they are not, and viewed as a waste of money. The F-117 was spectacularly successful in the penetrating, surgical strike role for which it was designed. In a dogfight for which the F-117 was not designed, it will lose. Because the F‑111 was not an ‘expert’ at anything, it took years to find a niche for the platform. Is the F‑35 destined for a similar fate?

Of course, the cost overruns and schedule issues cannot be overlooked. In part 1, Buckley laid out his thesis supporting cost overruns with immature technology. TAC fell victim to this thesis. The Century Series lulled TAC into believing acquiring supersonic, jet aircraft was easy. Each Century Series aircraft was incrementally better than its predecessor. There were advances in technology but in baby steps, not jumps. The F-111 was a quantum leap in technology over the F-105, as the B-70 was a quantum leap over the B-52. Leaps forward in technology, mean leaps more in cost. The forthcoming B-21 is NOT a leap in technology to keep cost (relatively) down. The F-35 also follows the F-111’s example of production before testing is complete, and the associated issues with cost overruns. The F-35 program is relearning all of the reasons why this has historically been a bad idea. Cost overruns place the F‑35 on the same pathway as the F‑111, F‑22 and the B‑2. These aircraft buys were less than their original numbers because of higher costs. The US is supposed to buy more than 2,000 F‑35s. If history is any guide, it is only a matter of time before Congress cuts that number in half.

The TFX taught the joint community it was not ready for joint acquisitions. F‑35 will spend more than a trillion dollars reminding the joint community it is still not ready.




[1] William H. Kaufmann, The McNamara Strategy (New York: Harper and Row. 1964), 72.

[2] The story of Frank Everest is worth reading. Check it out.

[3] Brian L. Reese, Major. “Development of the TFX F-111 in the Department of Defense’s Search for Multi-Mission, Joint-Service Aerial Platforms.” Master’s Thesis, US Army Command and General Staff College, Fort Leavenworth, Kansas, 2011, pg 15.

[4] Reese, 16.

[5] Variable wing-sweep, technically, was not a new concept. However NASA Langley was the first to demonstrate it. The problem was as the wings moved, the aircraft’s center of gravity (CG) moved, which had a disastrous effects on the angle of attack. NASA Langley moved the pivot of the wings out along the wings rather than in the center of the fuselage. With this lateral pivot, CG issues disappeared.

[6] Reese, 19.

[7] Richard Austin Smith, “The 7-Billion Dollar Contract That Changed the Rules.” Fortune. March, 1963. pg 99.

[8] Reese, 27-28.

[9] U.S. Senate, TFX Hearings

[10] Reese, 42.

[11] Reese, 45.

[12] USAF, USN, NASA studies show that when operating low-level in a terrain-following or terrain-avoidance mission profile, speed is almost irrelevant. Survivability is the same for speeds ranging from 0.6 Mach up to 1.5 Mach. At low-altitude, speed doesn’t matter nearly as much as we’d like to believe.

Nicole Petrucci

Editor-in-Chief at Angle of Attack
Space cadet, combat knitter, kitty lover.

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