Under what condition can the flight spoilers be extended to EMER?

The flight spoilers can only be extended to EMER in an emergency condition because their primary function is to provide a rapid deceleration and increase descent rate when the aircraft is experiencing an unexpected situation that requires immediate action. In emergencies, extending the spoilers can help to quickly reduce altitude and speed, which is crucial for managing the aircraft's performance and ensuring safety.

During normal operations, utilizing spoilers is typically done under controlled circumstances and not to the emergency limit, as this could affect aircraft performance and handling characteristics. Additionally, the use of flight spoilers is not dictated by weather conditions; they are specifically designed to aid in emergency scenarios and are not a standard response to environmental factors. Therefore, extending them to EMER is strictly limited to emergency situations to ensure that pilots can respond effectively when faced with critical challenges.