What phase is most critical for terrain clearance?

What phase is most critical for terrain clearance?

• A. Initial climb
• B. Cruise
• C. Descent
• D. Approach

Answer: (A)

Initial climb after takeoff is the stage where terrain and obstacle clearance is most critical. Right after liftoff you’re just above the runway and near surrounding obstacles, and you have to convert takeoff thrust into a positive climb rate quickly to establish a safe flight path. If the required climb gradient isn’t achieved, there’s little time to recover before you may intersect terrain or obstacles. As you continue into cruise, you’re well above the terrain and clearance is maintained by planned altitudes and en route routes. In descent and approach, procedures and minimum altitudes are designed to keep you clear of terrain, but the immediate risk window for terrain clearance is the initial climb when you’re closest to the ground and still establishing the flight path.

Initial climb after takeoff is the stage where terrain and obstacle clearance is most critical. Right after liftoff you’re just above the runway and near surrounding obstacles, and you have to convert takeoff thrust into a positive climb rate quickly to establish a safe flight path. If the required climb gradient isn’t achieved, there’s little time to recover before you may intersect terrain or obstacles.

As you continue into cruise, you’re well above the terrain and clearance is maintained by planned altitudes and en route routes. In descent and approach, procedures and minimum altitudes are designed to keep you clear of terrain, but the immediate risk window for terrain clearance is the initial climb when you’re closest to the ground and still establishing the flight path.