When does sterile flight deck begin again during descent?

• A. At landing gear extension
• B. When passing through 10,000 feet
• C. At 20,000 feet
• D. Upon reaching cruising altitude

Answer: (B)

Sterile flight deck is about minimizing nonessential conversation and tasks during critical phases of flight to keep pilots focused on flight safety. As you descend toward the airport, the descent into the approach is a high-workload, high-attention period. The established trigger to re-enter sterile conditions is when you pass through 10,000 feet. That means once you cross that altitude on the way down, nonessential talk and activities should be minimized again to maintain focus during the approach and landing.

The other options don’t fit because gear extension, reaching 20,000 feet, or cruising altitude aren’t the defined points that signal a return to sterile conditions during descent. The key idea is alignment with the approach phase: crossing 10,000 feet marks the switch back to sterile behavior to support safe, precise handling as you prepare to land.