← All explained questions · Abnormal and Emergency Considerations

How does a modern 406 MHz ELT improve on the older 121.5 MHz type?

Choices

✓ It transmits a digital signal to satellites with better location accuracy and identificationcorrect
406 MHz ELTs are received by satellites and carry identifying data.
It requires no battery
ELTs still require a battery.
It only works on the ground before takeoff
An ELT activates after a crash, not only before takeoff.
It replaces the need for a transponder
An ELT and a transponder serve different purposes.

Why

A 406 MHz ELT transmits a digital distress signal to satellites, providing far better location accuracy and aircraft identification than the older 121.5 MHz units.

FAA source: AIM 6-2-4 (Emergency Locator Transmitter)browse the reference library →

This is taught in Getting Found and Getting Out: ELTs, Equipment and Egress — study the lessons free, then practice with grading and mastery tracking.

Original study question written for this course — representative of FAA knowledge-test topics, not an actual current FAA exam question.