When is an automatic ELT required for part 135 operations?

An automatic Emergency Locator Transmitter (ELT) is required for part 135 operations when exceeding 50 nautical miles from departure. This requirement is based on the need for enhanced safety measures during flight, particularly as distance from the departure airport increases. The rationale behind this is that the further an aircraft travels, the more difficult it may be for search and rescue teams to locate it in the event of an emergency.

Having an automatic ELT ensures that if an accident occurs, the device will automatically transmit a distress signal, increasing the chances of a swift and effective response by search and rescue personnel. This is particularly important in commercial operations where the safety of passengers and crew is paramount.

The other options do not reflect the specific regulatory requirement that triggers the need for an automatic ELT in part 135 operations, emphasizing the significance of distance from the departure point in establishing safety protocols.