What must be adhered to when flying an experimental aircraft?

When flying an experimental aircraft, adherence to Part 91 rules is essential because these regulations provide the necessary framework for the operation of general aviation aircraft, including experimental types. Part 91 regulates the operation of all aircraft in the United States under various circumstances and is specifically relevant to experimental aircraft, which often do not adhere to commercial standards set forth in other parts, such as 121, 125, and 135.

Part 91 covers various aspects including pilot certification, aircraft airworthiness, flight planning, and responsibilities during flight operations. Experimental aircraft are not typically operated for compensation or hire, falling instead under the category of recreational or private flying, which is captured under Part 91. Adhering to these regulations helps ensure safety and compliance with federal aviation requirements, thereby allowing pilots flying experimental aircraft to operate them legally and safely in the national airspace system.