The several ground technicians were all seasoned professionals. Although dismantling an engine wasn't an easy task, they managed to take down the entire engine along with the intake duct after some effort.
Even though Chen Xin had already looked at the design drawings of the Yun-9, there's still a difference between blueprints and the actual object. Some things can only be ascertained by seeing the real object, or knowing how to proceed.
After seeing the actual engine, Chen Xin clarified his thoughts.
According to Chen Xin's conception, a method that can be completed within a week while considering cost and modification efficiency is to install an air filter on the intake duct. This is the simplest and most practical approach, also the most economical.
It requires no major modifications to the aircraft, nor significant investment.
