The Shenyang Aircraft Design Institute (SYADI), also known as the 601 Institute, is a Chinese military aircraft design firm and a subsidiary of the state-owned Aviation Industry Corporation of China (AVIC). It works closely with the Shenyang Aircraft Corporation (SAC), one of China's oldest and most important aircraft manufacturers, to design military aircraft. 

Noted aircraft and programs

The institute has been central to the development of several of China's most important military aviation projects, including: 

Shenyang J-8: The 601 Institute developed this family of interceptor aircraft, which was introduced into service in the 1980s. A notable variant was the J-8II, which replaced the aircraft's nose intake with a radome for improved radar.

Shenyang J-15: SYADI played a key role in developing this carrier-based, multirole fighter, nicknamed the "Flying Shark".

Shenyang J-35: The institute is leading the development of this new twin-engine stealth fighter, which has both land-based and carrier-based variants.

Sixth-generation fighters: The institute is pursuing advanced research and development for China's next-generation fighters, focusing on integrating AI, unmanned aircraft control, and other advanced systems.

AVIC 601-S: SYADI and Shenyang Aerospace University have jointly developed this series of low-observable, flying-wing unmanned aerial vehicles (UAVs).

The Shenyang Aircraft Design Institute (SYADI), a subsidiary of the Aviation Industry Corporation of China (AVIC), has been implicated by U.S. government actions, though not directly sanctioned under its own name. U.S. restrictions have primarily targeted its parent company, AVIC, and other related entities due to their involvement with China's military apparatus.