Flight testing is a critical aspect of the development and certification of aircraft or spacecraft. It involves conducting controlled tests and experiments on an aircraft or spacecraft in order to evaluate its performance, safety, and reliability. This process typically involves flying the vehicle in various conditions and scenarios to collect data on its aerodynamics, avionics, propulsion systems, and other critical components. Flight testing is essential for identifying any potential issues or problems with the vehicle and ensuring that it meets regulatory requirements and safety standards before it can be certified for operational use.