What is one acceptable method for determining aircraft performance and obstacle clearance data?

The use of APG (Aircraft Performance Group) data is considered an acceptable method for determining aircraft performance and obstacle clearance data because it provides precise, manufacturer-specific performance information tailored to particular aircraft types. APG data encompasses various performance measures, including takeoff, climb, cruise, and landing distances, as well as obstacle clearance angles, which are crucial for safe flight operations. This data is generated using standardized procedures and is updated based on the latest aerodynamic research and operational experience, ensuring its accuracy and reliability.

In contrast, while visual flight rules (VFR) define the conditions under which a pilot may operate an aircraft in weather conditions generally clear enough to fly visually, they do not provide specific performance data or obstacle clearance information. Flight manuals can offer essential performance details, but they may not always be as precise or geared towards current operational scenarios as APG data. Online databases can serve as a resource, but the information may not always reflect the most up-to-date or model-specific performance characteristics needed for safe flight operations. Thus, APG data stands out as the most reliable and specific source for performance and obstacle clearance data.