Definition
A formal written approval issued by the FAA that permits a specific operator, pilot, or aircraft to conduct an operation, use a piece of equipment, or follow a procedure that is not otherwise authorized by standard regulations. In the EFB context, an LOA is the document that grants an operator permission to use an Electronic Flight Bag in place of paper charts and publications.
Plain English
An official FAA permission slip. It says, in writing, that a particular operator or pilot is allowed to do something specific that the normal rules do not automatically allow.
Context Anchor
Seen in FAA guidance, operator manuals, EFB approval discussions, and records showing that a particular use or procedure has FAA authorization.
Derivation
Plain English. 'Authorization' comes from the Latin auctor, meaning one who grants or originates. A Letter of Authorization is literally a letter that grants authority -- written permission from the FAA.
Why Pilots Care
Determines whether a pilot may legally rely on an EFB for approach plates, charts, or performance data during flight.
Intuition Check
Do not read this as just a normal business letter. In FAA use, a letter of authorization is an official permission document with specific limits and conditions.
Example Sentence 1
The operator received an LOA from the FAA permitting use of tablet-based charts in place of paper during all phases of flight.
Example Sentence 2
The pilot carried the LOA in the aircraft to demonstrate FAA approval for electronic chart use during an IFR flight.