What is the maximum altitude for extended flaps on the ERJ 170/175?

The maximum altitude for using extended flaps on the ERJ 170/175 is indeed 20,000 feet. This limitation is critical for ensuring safe aerodynamic performance and maintaining control of the aircraft. Operating the flaps beyond this altitude could lead to undesired flight characteristics, as the aircraft's design is optimized for flap deployment within specific altitude ranges.

Extending the flaps at higher altitudes may also produce increased drag, which could affect the aircraft's climb performance and overall stability. Therefore, adherence to this limitation is essential for pilots to ensure safe and efficient operation of the ERJ 170/175 during various phases of flight.