Turkey has just told the world it's building a fighter jet engine in the same thrust class as the one inside the F-35 — and the claim is equal parts genuinely impressive and quietly confusing. The short version: Turkey's indigenous-engine ambitions for its KAAN stealth fighter are real, well-funded and moving faster than most outsiders expected. The "F-35-level" headline number that made the rounds around 21 June 2026? That one needs an asterisk.

Let's separate the metal from the marketing.

The jet: KAAN, Turkey's F-16 replacement

The TAI KAAN (formerly "TF-X") is Turkey's twin-engine, fifth-generation stealth fighter, built to replace the Turkish Air Force's large F-16 fleet after Ankara was ejected from the F-35 programme in 2019 over its purchase of Russian S-400s. It made its maiden flight on 21 February 2024 — a 13-minute hop from Mürted airfield near Ankara. Serial-production jets are now contracted, with first deliveries targeted around 2028-2029.

Here's the catch every pilot already spotted: those early KAANs don't fly on a Turkish engine. They fly on two General Electric F110-GE-129 turbofans — the same proven engine family that powers late-model F-16s. Turkey has taken delivery of an initial batch of F110s and is negotiating with Washington for more. Which is exactly why the indigenous-engine project matters so much: a fighter that depends on US engines also depends on US export approval.

KAAN’s maiden flight, 21 February 2024 — the hop that started the clock on the engine question.

The real engine: TEI-TF35000

The credible, on-the-record programme is the TEI-TF35000, developed by TUSAS Engine Industries (TEI) together with TRMOTOR under Turkey's defence-industry secretariat. It's targeting roughly 35,000 lbf of thrust — which puts it above the F110 (around 29,000 lbf with afterburner) and squarely in the company of the F-22's Pratt & Whitney F119. That's a serious, top-tier military turbofan figure, and TEI has been refreshingly specific about it.

The programme reached Critical Design Review in early 2026, with first engine tests targeted for 2026 and integration into KAAN penciled in for around 2032. TEI also says the TF35000 is being designed for supercruise — sustained supersonic flight without afterburner — a genuine fifth-generation hallmark.

So where does "F-35-level" come from?

This is where the June 2026 reporting gets spicy. At the SAHA 2026 defence fair in Istanbul, Turkey's Ministry of National Defence R&D centre unveiled a second, separate powerplant — the GÜÇHAN turbofan — and quoted a thrust figure of 42,000 lbf. That's the number that lit up the headlines, because it sits right alongside the F-35's single Pratt & Whitney F135 (roughly 43,000 lbf in afterburner).

Impressive on a slide. The problem, as analysts were quick to point out, is that KAAN is a twin-engine jet whose airframe was sized around two ~35,000-lbf engines. Bolting in a pair of 42,000-lbf monsters isn't an upgrade — it's a different aircraft.

Reality check: is the timeline credible?

Building a frontline fighter engine from scratch is arguably the single hardest thing in aerospace. Only a handful of countries — the US, UK, France, Russia and China — can do it end-to-end. China took roughly 15 to 20 years to go from first test to mature frontline service. India has been chasing its Kaveri engine since the 1980s.

Turkey's plan — first run in 2026, KAAN integration by 2032, fully domestic-engined jets by the mid-2030s — is ambitious to the point of audacious for an engine that, at the time of writing, hasn't run yet. That said, Turkey has earned some benefit of the doubt: it has gone from a standing start to a world-leading combat-drone industry, a flying fifth-gen prototype, the Hürjet trainer and a growing family of indigenous powerplants in under two decades.

The honest read for anyone who knows engines: the TF35000 is a credible, top-class target and the most consequential part of the whole story. The "F-35-class" framing is technically true on paper and largely beside the point in practice. Watch for that first 2026 test run. That's when Turkey's engine talk has to start turning into measured thrust on a test stand.

Sources: Aerospace Global News (21 June 2026); Aviation Week; Army Recognition; Türkiye Today; Breaking Defense; TEI.