Final answer:
In an emergency on the runway, the two commands used by the Captain are 'Brace' for impact preparation, and either 'Evacuate' or 'Remain Seated' based on the emergency's severity to ensure passenger and crew safety.
Step-by-step explanation:
In the event of an emergency situation where an aircraft must be stopped on the runway, the Captain typically uses two standardized commands to ensure clear communication with passengers and flight attendants. The first command is 'Brace', which is used to instruct passengers and crew to adopt the brace position in preparation for an emergency impact. The second command is either 'Evacuate' or 'Remain Seated', depending on the situation. 'Evacuate' is used in urgent scenarios where immediate disembarkation is necessary, such as a fire or a security threat. On the other hand, 'Remain Seated' indicates that passengers should stay in their seats because evacuation is not immediately required. These commands are crucial for maintaining order and ensuring safety during abnormal or emergency situations.
Flight attendants are trained to act upon these commands promptly, assisting passengers in either bracing or evacuating the aircraft safely. Flight crews participate in recurrent training to stay sharp on procedures, including how to communicate and manage such high-stress situations efficiently.