Which regulation details the airworthiness standards for heavier airplanes like the Boeing 737?

The regulation that details the airworthiness standards for larger aircraft such as the Boeing 737 is FAR Part 25. This part establishes the necessary criteria for the design, construction, and performance of transport category airplanes, which includes those designed for commercial airlines and other similar applications.

FAR Part 25 encompasses various aspects of aircraft operation, including structural integrity, stability, control, and the safety of systems used in such larger aircraft. Transport category airplanes typically need to meet more rigorous standards due to their size, operational complexity, and the number of passengers or cargo they may carry.

In contrast, FAR Part 23 pertains to smaller general aviation airplanes, while FAR Parts 27 and 29 are designated for rotorcraft (helicopters). These other regulations deal with different categories and sizes of aircraft, which do not apply to larger transport aircraft like the Boeing 737. Therefore, FAR Part 25 is the correct reference for the airworthiness standards relevant to heavier airplanes.