logo
#

Latest news with #Fixed-TimeDisturbanceObserver

Landing stealth J-36 jets on moving carriers? China's new tech may solve it
Landing stealth J-36 jets on moving carriers? China's new tech may solve it

Business Standard

time22-04-2025

  • Science
  • Business Standard

Landing stealth J-36 jets on moving carriers? China's new tech may solve it

China is developing an advanced control system aimed at enabling the safe and accurate landing of its sixth-generation stealth fighter, the J-36, on moving aircraft carriers. According to a research paper published in the peer-reviewed Acta Aeronautica et Astronautica Sinica - China's leading aviation journal, the system is being designed by the AVIC Chengdu Aircraft Design and Research Institute in collaboration with the Nanjing University of Aeronautics and Astronautics, the South China Morning Post (SCMP) reported. The J-36, an unconfirmed designation in line with China's military aircraft naming convention, is a tri-engine, tailless flying-wing jet. It was spotted in flight over Chengdu in December, generating significant interest in global defence circles due to its stealth features, large payload capacity, and potential for long-range strikes. Challenges in landing J-36 stealth jet The J-36 has been designed to have a tailless stealth flying design, but in doing so, it creates flight control problems — notably on aircraft carrier landings. Conventional aircraft use their tail sections and horizontal stabilisers to stabilise pitch and in terms of overall aerodynamic stability. However, flying-wing aircraft lack such horizontal stabilisers, so control is provided by other surfaces that include elevons, spoiler-slot deflectors, and pitch flaps. These can get in their own way, causing destabilizing aerodynamic forces. Another major challenge is the 'ship-airwake effect', which refers to the turbulent airflow generated by an aircraft carrier in motion. This can seriously throw off a jet's flight path during the final approach, especially when the sea is rough and the carrier deck is moving. To tackle this, researchers have created a 'direct force control' system. It separates flight path adjustments from the jet's orientation, allowing real-time control of lift without changing the aircraft's pitch. The technology uses Jacobian matrices to calculate how small changes in control surfaces influence aerodynamic forces, bypassing the need for older, less accurate aerodynamic databases. The system also integrates a Fixed-Time Disturbance Observer (FTDO) — a module adapted from robotics—that detects and neutralises cross-coupling effects between control surfaces. The FTDO operates within seconds, even under rough simulated sea conditions with wave heights of up to six metres. How will the system help carrier-based operations? The new control system was tested through multiple simulated landings under extreme conditions, including crosswinds, turbulent airwakes, and dynamic deck movements, SCMP said. In each scenario, the aircraft was able to land with minimal altitude error—just two centimetres in some tests. Across all sea conditions, most touchdown points fell between the second and third arresting wires, showing a high level of consistency and precision. The system also includes 3D thrust vectoring and drag rudders built into the wings—features that help maintain control even when conventional methods fall short. Spoiler-slot deflectors manage airflow over the rear of the aircraft, helping preserve stability in unpredictable situations. How does China's tech differ from the US? Unlike the US Navy's Magic Carpet system, which relies on pre-set gain schedules for standard aircraft, the Chinese approach treats each control surface as a dynamic element. That means the system can adapt on the fly, using fast, efficient algorithms to constantly recalculate inputs—giving pilots much more stability during the final, critical moments of landing. What's next for the Chinese J-36 stealth fighter? The research is still in the developmental phase, but it represents a major step towards enabling China's sixth-generation aircraft to operate from aircraft carriers in deep-sea theatres. The team behind the system has indicated that the next phase will involve improving the robustness of the control architecture, especially under scenarios involving failure or damage to key components, SCMP said. This development aligns with China's broader naval ambitions, which include expanding the People's Liberation Army Navy's ability to project power far from the mainland. By enabling stealth-capable, high-payload aircraft like the J-36 to operate from carriers, China aims to boost its maritime strike capabilities and strategic deterrence.

DOWNLOAD THE APP

Get Started Now: Download the App

Ready to dive into the world of global news and events? Download our app today from your preferred app store and start exploring.
app-storeplay-store