What is a key precaution of the ELT A/B?

The key precaution of the ELT (Emergency Locator Transmitter) A/B being that it should not be submerged under water for extended periods is important for several reasons. The primary function of an ELT is to transmit a distress signal in the event of an aircraft emergency, allowing search and rescue services to locate the downed aircraft.

Submersion in water can damage the internal components of the ELT, potentially rendering it inoperable when it is needed the most. Water can cause corrosion, short-circuiting, or other types of damage that could impair the device's ability to function correctly. Therefore, ensuring that the ELT remains dry and operational is crucial for the safety of the aircraft and its occupants in emergency situations.

Other options present misunderstandings about the operational capabilities or storage requirements of the ELT, which do not align with the essential operational precautions outlined for these devices.