The purpose of flight testing after an alteration is to ensure safe operation and obtain approval for return to service. Which statement best captures this requirement?

• A. The alteration must be tested by an appropriately-rated pilot and approved before returning to service
• B. No flight test is needed if the aircraft passes a ground check
• C. The test can be skipped if the operator has prior similar alterations
• D. The test may be conducted by the owner without rating

Answer: (A)

After an alteration, you need to prove in flight that the modification behaves safely across the actual operating envelope and that the aircraft can be returned to service with regulatory approval. This requires a flight test conducted by someone who is appropriately rated for the balloon and the specific alteration, so they can assess handling, control response, performance, and any system interactions under real conditions. Ground checks alone can miss issues that only show up in the air, such as changes to balance, lift characteristics, or stability. A prior-similar-alteration or an owner performing the test without the proper rating cannot substitute for a formal flight test with the right qualifications, since safety and regulatory compliance depend on a qualified pilot validating the modification in flight and granting the required release to service.