KAAN Fighter: Turkey’s Indigenous Fifth-Generation Combat Aircraft

Turkey’s KAAN fighter jet discussions have gotten complicated with all the “what does it actually mean for a country without a prior indigenous fighter program to develop a fifth-generation stealth aircraft and how does the KAAN compare to the F-35 it was partly meant to replace in the Turkish Air Force inventory” debates, the KAAN program versus Turkey’s F-35 exclusion and F-16 modernization comparisons, and “what is the realistic timeline and capability level for KAAN to reach operational status given the engine dependency on foreign powerplants that Turkish Aerospace Industries hasn’t yet solved” conversations flying around. As someone who has spent years following non-Western combat aircraft development programs and the specific industrial and technical challenges that determine whether ambitious indigenous fighter programs deliver operational aircraft or remain perpetually developmental, I learned everything there is to know about Turkey’s KAAN fighter program. Today, I will share it all with you.

But what is the KAAN, really? In essence, it’s TAI’s (Turkish Aerospace Industries) fifth-generation fighter development program — a twin-engine, stealth-designed supersonic combat aircraft intended to replace aging F-4 Phantoms in the Turkish Air Force inventory and eventually reduce Turkish dependency on foreign combat aircraft — that made its maiden flight in February 2023, demonstrating that Turkey has achieved the significant milestone of flying an indigenously developed fighter prototype while acknowledging that engine development, avionics maturation, and production scaling remain years away from full operational capability. But it’s much more than a technology demonstration. For Turkish defense policy and NATO’s understanding of member state indigenous capability development, KAAN represents a strategic commitment to aerospace independence that reflects Turkey’s broader defense industrial ambitions following its exclusion from the F-35 program in 2019.

Program Origins and Strategic Context

The KAAN program — formerly known as the TF-X (Turkish Fighter-Experimental) before receiving its official name — began in earnest following Turkey’s 2019 removal from the F-35 Joint Strike Fighter program after its purchase of the Russian S-400 air defense system created incompatibility with F-35 security requirements. The timing deepened Turkish defense establishment motivation to reduce dependence on foreign aircraft suppliers, accelerating investment in TAI’s fighter development capability. Don’t make my mistake of treating KAAN as purely a response to F-35 exclusion — at least if you’re analyzing the program’s full context, because Turkish indigenous fighter development ambitions predated the F-35 exclusion by years, with the TF-X program officially launched in 2011 and reflecting a long-standing industrial policy goal of developing domestic aerospace design and manufacturing capability.

Design and Stealth Features

The KAAN’s design incorporates radar-reducing features consistent with fifth-generation fighter stealth requirements: internal weapon bays to reduce radar cross-section compared to external hardpoint carriage, carefully shaped airframe surfaces designed to deflect rather than return radar energy, and inlet design that conceals engine compressor faces — one of the most radar-reflective elements of conventional aircraft designs. The aircraft is a twin-engine design in the class of the F-22 and Su-57, larger than the F-35, with a twin-tail configuration and a wing design optimized for both supersonic performance and low-observable geometry. That’s what makes KAAN’s design endearing to aviation analysts tracking non-Western fighter development — it represents a genuine attempt to apply fifth-generation design principles rather than simply improving on existing fourth-generation platforms, which is a more ambitious and technically demanding goal.

The Engine Problem: The Critical Unresolved Challenge

The KAAN’s most significant developmental challenge is engine dependency. The current prototype flies on two General Electric F110 engines — the same powerplant used in F-16s, not a purpose-designed engine for a fifth-generation fighter. Turkey’s indigenous engine program, TEI (Turkish Engine Industries), is developing a domestic turbofan under the TÜSA program, but this engine is years behind the airframe development and will not be ready for the initial KAAN production aircraft. First, you should understand the operational and political significance of this dependency — at least if you’re evaluating KAAN as an indigenous capability, because an aircraft that depends on a foreign supplier for its engines is not fully sovereign in the way the program’s strategic rationale requires, and Turkey’s ability to operate KAAN through periods of diplomatic friction with the United States is constrained until domestic engine capability is achieved.

Maiden Flight and Development Status

KAAN completed its maiden flight at Ankara’s Akinci Air Base on February 21, 2023 — a significant achievement that placed Turkey among the limited group of nations that have designed and flown indigenous combat aircraft. Subsequent test flights have expanded the flight envelope and evaluated basic aircraft systems. The development program aims for initial operational capability with the Turkish Air Force in the late 2020s, though this timeline is contingent on avionics development, weapons integration, and the eventual transition to Turkish-built engines that represents the program’s most technically challenging remaining milestone.

Avionics and Combat Systems

The KAAN’s avionics suite is being developed with Turkish industry participation, including ASELSAN’s work on radar and electronic warfare systems. The aircraft is planned to carry an active electronically scanned array (AESA) radar — the sensor type that characterizes fifth-generation fighters’ beyond-visual-range air combat capability. Weapons integration will include Turkish-developed air-to-air and air-to-surface munitions, reflecting the same indigenous capability motivation that drives the airframe and engine development. The electronic warfare and sensor fusion capabilities that differentiate truly fifth-generation aircraft from fourth-generation designs with stealth applied are the aspects of KAAN development that remain most opaque from publicly available information.

Implications for NATO and Regional Air Power

A operational KAAN would represent a meaningful addition to NATO’s European air power capability — Turkey operates one of the alliance’s largest air forces — while also representing a Turkish Air Force capability that operates outside the F-35’s shared logistics and maintenance infrastructure. The geopolitical implications of a NATO member operating a fully indigenous combat aircraft designed without U.S. technology transfer are complex and reflect the broader evolution of Turkey’s strategic positioning within the alliance. Whether KAAN delivers on its full fifth-generation promise will depend on the engine development timeline, avionics maturation, and production investment that turn a capable prototype into an operational fleet.