Accelerating the USAF Buy of Advanced F-35As

By Lt Gen Josephy Gustella, USAF (Ret), Douglas Birkey and Lt Col Eric Gunziner, USAF (Ret.) with Aidan Poliing

Published in June 2023, this Mitchell Institute Paper argued for accelerating the USAF buy of advanced F-35As.

Key Points

The Air Force’s fighter inventory is also too small to meet real-world demand today. In 1990, the service had 4,556 fighters. Today, it has 2,176. U.S. national security leaders must concurrently address multiple threats, none of which can be ignored without risking severe consequences.

Combatant commander demands routinely exceed the capacity of the Air Force’s fighter fleet.

The Air Force needs to buy new fighters at an aggressive rate. Equally important, it needs to procure the right mix of capabilities to ensure the force will remain relevant over the long term.

A major portion of this modernization must be met by robust F-35 acquisition. After significant development and investment, the F-35 is on the cusp of fielding an extensive array of upgrades via TR-3 and Block 4 that range from improved sensors and enhanced electronic attack systems to the added ability to carry a broader weapons portfolio and connect with more actors across the battlespace.


The Air Force faces a severe fighter aircraft shortfall. The current inventory is both small and old, a significant problem given today’s threat environment.

The rapid military rise of China and an increasingly aggressive Russia, paired with nuclear threats posed by Iran and North Korea, demand robust military capabilities in an adequate capacity. This includes modern fighter aircraft, which are crucial for the viable projection of joint military power.

The Air Force arrived at this precarious position over decades in which multiple decisions left fighter modernization efforts curtailed and canceled.

Aircraft mostly procured in the 1980s Reagan defense buildup saw their lives extended to cover the gap. Now, after four decades of hard use, their service lives are coming to an end. These aircraft are not viable against modern threats, expensive to sustain, and on the verge of structural exhaustion.

The key to reset this is the F-35 and its latest updates: Technology Refresh 3 (TR-3) and Block 4, involving more than 80 individual upgrades added to the aircraft over the next several years. The combination of stealth, sensors, processing power, and connectivity is essential for success in the modern battle space. The F-35’s price point of $80M per unit also means it is affordable in volume.

The Air Force has long wanted this model of the aircraft, and with TR-3 and Block 4 capabilities now in the final phases of testing, the program is on the verge of crossing a major threshold into the operational realm. This means any dollar obligated from this point forward will be procuring TR-3-enabled Block 4 F-35s.

The modern threat environment and current force structure shortfalls demand the Air Force rapidly modernize its fighter aircraft inventory at scale. F-35s, especially those equipped with TR-3 and Block 4 capabilities, will form a major portion of that capacity.