Final answer:
In the flight deck, standby instruments such as a standby attitude indicator, standby airspeed indicator, and standby altimeter ensure pilots can safely operate the aircraft if primary systems fail.
Step-by-step explanation:
The standby instruments available in the flight deck are critical for ensuring safe operation of an aircraft in the event of failure of the primary flight display systems. Typically, these instruments include a standby attitude indicator, which shows the aircraft's orientation relative to the horizon; a standby airspeed indicator, providing information on the aircraft's speed through the air; and a standby altimeter, indicating the aircraft's altitude above mean sea level. These instruments allow a pilot to maintain control of the aircraft manually if the primary systems fail. Modern aircraft may also include a standby magnetic compass and a backup power source to ensure the operation of these critical instruments.