Defining the "world's first 6th-generation fighter" among the Chengdu J-36, Shenyang J-50 (or J-XX), and the hypothetical F-47 involves a mix of technical, operational, and historical criteria, but it’s tricky because the term "6th generation" lacks a universally agreed-upon definition as of March 22, 2025. Each contender—China’s J-36 and J-50, and the U.S.’s speculated F-47—brings unique claims, but pinning down the "first" depends on how you weigh factors like flight date, capability, and deployment. Let’s break it down based on what’s known.

What Makes a 6th-Generation Fighter?

No official standard exists yet, but analysts (e.g., from Simple Flying, The National Interest) generally agree on key traits beyond 5th-gen (F-22, J-20, F-35):

• Advanced Stealth: Near-invisible RCS across all frequencies, often with tailless or blended designs.

• Hypersonic or Near-Hypersonic Speed: Mach 5+ potential, or sustained supercruise.

• AI Integration: Autonomous or optionally manned ops, with AI-driven sensor fusion and decision-making.

• Swarm/Drone Synergy: Commanding loyal wingman drones or swarm tactics.

• Next-Gen Weapons: Directed energy (lasers) or hypersonic munitions.

• First Flight/Operational Status: A practical benchmark for "first"—when it flies and when it’s combat-ready.

The Contenders

Chengdu J-36 (China)

• First Flight: December 26, 2024—confirmed by viral videos over Chengdu, Sichuan (New Atlas, Asia Times). A tailless, trijet, double-delta design, escorted by a J-20S.

• Status: Prototype/test phase as of March 2025. No official PLA designation or induction timeline, but analysts call it a 6th-gen demonstrator (19FortyFive, Quora sentiment).

• Capabilities:

• Stealth: Tailless design suggests low RCS, possibly 0.01-0.05 m² (speculative, no hard data).

• Speed: Likely supercruise (Mach 1.5+), with unconfirmed scramjet potential (China’s Mach 28 wind tunnel, X posts).

• AI: Wang Haifeng (CAC chief) hints at “full-frequency stealth” and “first-sight-first-shoot” situational awareness (Bulgarian Military), implying advanced AI.

• Range: Unknown, but Chengdu’s focus on deep penetration suggests 2,000+ km.

• Claim to "First": Earliest public flight (December 2024), beating U.S. timelines. Posts on X (e.g., @zhao_dashuai) argue it “sets the rules” for 6th-gen warfare.

Shenyang J-50 (or J-XX, China)

• First Flight: Also December 26, 2024, alongside J-36 (19FortyFive, Defense Express). A smaller, twin-engine, tailless delta, escorted by a J-16.

• Status: Prototype, less publicized than J-36. Speculative designation (J-50 or J-XX), no clear timeline.

• Capabilities:

• Stealth: Similar tailless design, likely comparable RCS to J-36.

• Speed: Twin-engine setup suggests Mach 2-3, possibly supercruise, but less ambitious than J-36’s trijet.

• AI/Systems: Limited data—assumed to lag J-36’s “high-performance fighter” focus (The Diplomat).

• Role: Possibly a lighter complement to J-36, akin to F-35 vs. F-22.

• Claim to "First": Tied with J-36 for flight date, but its lower profile and simpler design weaken its case.

F-47 (United States)

• First Flight: Unknown—speculative as of March 2025. CNN (March 21, 2025) reports Trump announcing an F-47 by Boeing, tied to Next Generation Air Dominance (NGAD), but no confirmed flight. Secret testing is rumored for 5+ years (X, @ohgkg).

• Status: NGAD aims for 2030 service, replacing F-22s (Wikipedia, Simple Flying). Boeing’s involvement suggests production readiness, but no prototype is public.

• Capabilities:

• Stealth: Expected RCS below F-22’s 0.0001 m², with advanced coatings.

• Speed: Supercruise confirmed (Mach 1.5+), hypersonic potential unclear.

• AI: NGAD emphasizes AI, drones, and optionally manned ops (USAF Chief via X, @YusufDFI).

• Range: Likely 3,000+ km, per NGAD’s Pacific focus.

• Claim to "First": USAF claims it’s “the world’s first crewed 6th-gen fighter” (X, @YusufDFI), but no flight evidence trails J-36/J-50 by months or years.

Defining “World’s First”

1. First Flight:

• Winner: J-36 and J-50 (December 26, 2024). Both flew publicly before any F-47 sighting. J-36 edges J-50 due to its prominence and trijet complexity.

• F-47: No flight date—secret tests don’t count without proof. NGAD’s 2030 goal suggests a 2026-2028 prototype, lagging China.

2. Operational Deployment:

• Current: None are operational. J-36/J-50 are prototypes; F-47 is pre-production.

• Projection: China’s state-driven pace could see J-36 in service by 2030-2032 (Quora, Asia Times). F-47’s 2028-2030 target (CNN) is competitive but later than China’s flights.

• Winner: Too early—F-47 might deploy first if China delays, but J-36 has the head start.

3. 6th-Gen Features:

• J-36: Tailless stealth, possible AI, deep-strike focus—checks most boxes, but speed (Mach 3?) and drone integration are unconfirmed.

• J-50: Similar stealth, less ambitious tech—borderline 5.5-gen.

• F-47: NGAD promises AI, drones, and unmatched stealth (USAF claims), potentially trumping China in capability, not timing.

• Winner: F-47 might lead in full 6th-gen traits, but J-36’s flight proves it’s viable now.

Conclusion: World’s First?

• By First Flight: Chengdu J-36 is the world’s first 6th-generation fighter to fly (December 26, 2024), beating J-50 (same day, less focus) and F-47 (no flight yet). It’s the earliest tangible step into 6th-gen airspace.

• By Capability: Too speculative—F-47’s NGAD pedigree could outshine J-36 in AI/drone tech by 2030, but J-36’s trijet design and China’s hypersonic R&D (Mach 28 tunnels) suggest parity or edge today.

• By Deployment: TBD—China’s J-36 might beat F-47 to service, but India’s GDP gap (5x smaller) and slow tech pace (Tejas: 33 years) hint at delays mirroring AMCA.

Verdict: J-36 is the "first" today by flight milestone—China’s surprise drop shocked the world (19FortyFive, Reddit). F-47 could claim “first true 6th-gen” later if it delivers NGAD’s full vision, but right now, it’s playing catch-up. J-50’s a footnote unless Shenyang ups its game. What’s your metric for “first”—flight, tech, or fielding?