Introduction

In the shifting balance of modern airpower, one class of aircraft quietly shapes the outcome of conflicts: the light fighter jet. From the lean interceptors of the late 1950s to the agile multirole designs of the 2020s, engineers have chased the same objective: maximum combat effectiveness with minimum cost, weight, and complexity.

This challenge summons you as a lead designer in that ongoing race. Your task is to create a realistic light fighter—fictional, adapted, modernized, or inspired by real-world aircraft. Your design should feel plausible in form and function, belonging to the lineage of lightweight fighters from the late Cold War to the present day.

Mission requirements are clear: your aircraft must excel in air‑to‑air combat, from BVR engagements to close‑range dogfights, while remaining affordable, efficient, and suitable for mass production. Agility, energy management, sensor capability, and weapons integration must coexist with reliability, maintainability, and reasonable operating costs.

In this arena, there are no experimental sci‑fi prototypes—only believable machines that could have flown in service. Here, realism, engineering ingenuity, and your best building techniques converge to define the ultimate light fighter concept.

Will your jet become the backbone of an air force and a feared presence in the skies—or just another promising project cancelled before it ever leaves the drawing board?

Philosophy Aircraft Types

• Light and agile fighter jets from the late 1950s to the 2020s, designed with a realistic and plausible approach. Aircraft should reflect the philosophy of lightweight dogfight and interceptor platforms—optimized for maneuverability, efficiency, and versatility rather than sheer power.
• Designs may be fictional, modernized, or inspired by real aircraft, but must remain believable in terms of aerodynamics, proportions, and technology level for their era. The focus is on performance balance, cost-effectiveness, and practicality, true to the light fighter concept.
• Inspiration: Northrop F‑5 Freedom Fighter, Dassault Mirage F1, IAI Kfir, Chengdu J‑7, HAL Tejas, Saab JAS 39 Gripen, AIDC F‑CK‑1 Ching‑kuo, KAI FA‑50, PAC  JF‑17 Thunder, Aero L-159 ALCA, Mitsubishi F‑1, Dassault Mirage III, Yakovlev Yak‑130, Hongdu L‑15, Mig-21 Fishbed, F-16 Fighting Falcon, KAI KF-21 Boramae, Dassault Mirage 2000, Mitsubishi F-1, Mikoyan-Gurevich MiG-35 Fulcrum, Mikoyan-Gurevich MiG-23 Flogger, Boeing T-7 Red Hawk, Hongdu JL-8, BAE Systems Hawk...

Construction Rules

• Direct successor to the previous official challenge post.
• Parts: Each aircraft must contain between 200 and 650 parts.
• Entries: A maximum of two aircraft per player is allowed.
• Mods: NO MODS — vanilla SimplePlanes only.
• Cockpit: A fully functional VR cockpit with a correct pilot view is mandatory.
• Details: Detail control (weight and drag) may be set to 0.
• Aircraft description: a) Year of introduction; b) Manufacturer; c) Variants or options; d) Technical specifications; e) Key features or notes.
• Not allowed: a) Infinite fuel; b) Negative weight blocks; c) Exploit parts (invisible wings, hidden structures, etc.)
• Fair play: If cheating or out-of-limit modifications are detected, the aircraft will be disqualified immediately.

Performance

• Maximum loaded weight: 12,000 kg (≈ 33,069 lb) — Fuel and weapons include.
• Power/weight ratio (loaded): between 0.50 and 1.30
• Maximum speed (sea level): Mach 1.2 (≈ 915 mph / 1,470 km/h).
• Maximum speed (36,000 ft): Mach 2.0 (≈ 1,320 mph / 2,125 km/h).
• Landing gear: Retractable tricycle configuration required.

Armament

• Missiles: Maximum total of 10 missiles, in any combination from the approved list. All weapons are provided in this post.
• Guns: One cannon or gun maximum, selected from the approved list of this post. All cannons or guns are provided in this post.
• Countermeasures: Up to 2 flare and 2 chaff dispensers, only from this post. All countermeasures dispensers are provided in this post.
• Fair play: Other Custom weapons or missiles are prohibited. It will cause disqualification.
• Mix weapons: Any combination of the weapons provided in this publication is permitted, within the allowed limits.

Evaluation: Phase 1 - Aircraft

• Realistic Model, Details & Build Quality - 1000 pts - Authentic flight behavior, and proper maneuverability. The aircraft must meet limits, include a functional VR cockpit, and show high visual and structural quality without technical flaws.
• Realistic Weapons - 250 pts - Used armament (cannons and missiles) must be exclusively those provided and properly integrated, functioning according to challenge rules.
• Fair Play - 250 pts - Strict compliance with all rules. Any detected cheating, unauthorized modifications, or significant rule breaches will disqualify the aircraft.
• Technical Description - 100 pts - Detailed post with year of introduction, manufacturer, options, specifications, and characteristics, enhancing understanding and immersion.
• Performance Cost - 500 pts - Points inversely proportional to the Performance Cost of the aircraft, measured against the Performance Cost of the other players' aircraft.

Evaluation: Phase 2 - Warfare

• Fights are conducted with the game AI.
• Each matchup consists of 7 rounds.
  - Rounds 1 and 2: BVR (Long-range) engagement.
  - Rounds 3 and 4: Medium-range engagement.
  - Rounds 5, 6, and 7: Close-range Dogfight.
• For each round won, 50 points are awarded to the aircraft.
• Total points are added to the overall score.
• All fights will be recorded on video and published on YouTube channel

Awards

• 1st position - 2 spotlight + 10 upvotes
• 2nd position - 1 spotlight + 10 upvotes
• 3rd position - 10 upvotes
• 4th position - 7 upvotes
• 5th position - 5 upvotes
• Contestant - 1 upvote

Deadline - March 27, 2026

No further submissions will be accepted. After that date, the entire evaluation process will take 2 or 3 weeks.