FAA Ground School Practice Test

What altitude should a pilot maintain when approaching to land on a runway served by a VASI?

1. At or below the glide slope

2. At the glide slope

3. Above the glide slope until necessary

4. At a lower altitude than glide slope

The correct answer is: Above the glide slope until necessary

When approaching to land on a runway served by a Visual Approach Slope Indicator (VASI), the pilot should maintain an altitude above the glide slope until it is necessary to descend to the glide slope. This is because the VASI is designed to help pilots maintain the proper approach angle during landing. By flying above the glide slope initially, the pilot ensures that they can visually assess their alignment with the runway and make adjustments as needed without risking an early descent that could lead to issues such as being too high or low on approach. Maintaining this altitude provides the pilot with a safety buffer, allowing them to step down onto the glide path smoothly when ready to land. This approach enhances safety by giving the pilot the flexibility to respond to any potential obstacles or errors in the approach, ensuring a proper descent before reaching the runway threshold.