Regarding Driftdown, Driftdown Method 2 calculations start from planned cruise altitude and clear terrain by how many feet?

Regarding Driftdown, Driftdown Method 2 calculations start from planned cruise altitude and clear terrain by how many feet?

• A. Method 1
• B. Method 2
• C. Both Method 1 and 2
• D. None of the above

Answer: (B)

Driftdown planning is about choosing an altitude to descend to so you remain clear of terrain while losing cabin pressurization. There are two methods that differ in the starting point and the terrain clearance used in the calculation. In the second method, you begin the drift-down calculations from your planned cruise altitude and apply a fixed terrain clearance of 1,000 feet to it. This approach directly matches the scenario described in the question, which is why it’s the best choice. The other method uses a different starting point or clearance, so it doesn’t fit the stated method.

Driftdown planning is about choosing an altitude to descend to so you remain clear of terrain while losing cabin pressurization. There are two methods that differ in the starting point and the terrain clearance used in the calculation. In the second method, you begin the drift-down calculations from your planned cruise altitude and apply a fixed terrain clearance of 1,000 feet to it. This approach directly matches the scenario described in the question, which is why it’s the best choice. The other method uses a different starting point or clearance, so it doesn’t fit the stated method.