What is the maximum altitude at which flaps and gear may be extended?

What is the maximum altitude at which flaps and gear may be extended?

• A. 20,000'
• B. 18,000'
• C. 15,000'
• D. 25,000'

Answer: (B)

Extending flaps and landing gear is limited to a specific altitude because these devices are only certified to operate within a defined envelope. The aircraft’s systems and structure are tested to work safely up to a certain height, and above that altitude the deployment could introduce unacceptable loads or unreliable performance. Therefore you may extend them only up to 18,000 feet. Deploying at higher altitudes is outside the approved operating envelope, which is why the maximum is 18,000 feet. The other options exceed or are below that limit, so they aren’t the maximum allowable altitude for extension.

Extending flaps and landing gear is limited to a specific altitude because these devices are only certified to operate within a defined envelope. The aircraft’s systems and structure are tested to work safely up to a certain height, and above that altitude the deployment could introduce unacceptable loads or unreliable performance. Therefore you may extend them only up to 18,000 feet. Deploying at higher altitudes is outside the approved operating envelope, which is why the maximum is 18,000 feet. The other options exceed or are below that limit, so they aren’t the maximum allowable altitude for extension.