Which alteration does not require a record of entry for a single-harness dual parachute pack?

The alteration concerning the main parachute is the correct choice because it is acknowledged that changes to the main parachute do not necessitate a record of entry for a single-harness dual parachute pack. Generally, the main parachute can be replaced or altered without requiring a detailed documentation update in this specific context, as it is standard practice to periodically inspect and possibly change main parachutes without the formalities that apply to other components.

In contrast, changes to the auxiliary parachute, harness, or parachute container all mandate a record of entry. This requirement is in place to ensure proper documentation of safety-related alterations, helping to maintain integrity and traceability for all components critical to the parachute system. By keeping accurate records of changes to the auxiliary parachute, harness, and container, rigger safety and compliance with regulatory standards are substantially enhanced, thus underscoring the importance of documentation in those areas.