Who may maintain or alter the main parachute for intentional jumping?

The maintenance or alteration of the main parachute for intentional jumping must be performed by an appropriately certificated parachute rigger. This is because parachute rigging involves specialized knowledge and skills that are critical for ensuring the safety and reliability of the equipment. A certificated rigger has demonstrated their capability through comprehensive training and testing, which includes understanding the specific materials, construction, and aerodynamics involved in parachute systems.

By requiring maintenance or alterations to be conducted by a qualified rigger, regulatory bodies ensure that all work performed on parachutes meets industry safety standards and practices. This is crucial, as any unapproved changes or improper maintenance can lead to failures during operation, posing significant risks to the jumper's safety.

The other options may imply varying degrees of knowledge or ownership, but only a certificated rigger is trained and authorized to make alterations or perform maintenance on parachutes for intentional jumping. This ensures that any modifications are safe, reliable, and comply with aviation regulations.