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Maintenance4 min read

ELT Battery Replacement: The Compliance Item Most Owners Forget

FAR 91.207 requires ELT batteries to be replaced at specific intervals. They're cheap to replace and expensive to forget. Here's everything you need to know.

SO
Sarah Okonkwo
CTO, A&P/IA
ELT Battery Replacement: The Compliance Item Most Owners Forget

ELT Battery Replacement

The Emergency Locator Transmitter is one of the smallest, cheapest, and most-forgotten compliance items on the aircraft. Missing its replacement interval renders the aircraft unairworthy.

The rule

FAR 91.207(c) requires batteries used in the ELT to be replaced (or recharged, for rechargeable units):

1. When the transmitter has been in use for more than one cumulative hour

2. When 50% of their useful life (or charge) has expired

The manufacturer sets the useful-life date — check the ELT itself for the replacement date marked on the battery.

Documenting compliance

The replacement must be recorded in the maintenance record with the new expiration date. A common mistake is to replace the battery and not write it up.

Catching it before the annual

myaircraft.us tracks your ELT battery expiration and reminds you 30 days before. Upload your records and we'll find the last replacement date automatically.