***Meaning*** :: <u>L</u>etter <u>o</u>f <u>A</u>uthorization ***Definition*** :: A Flight Standards District Office ([[FSDO]]) issues an LOA to an operator when the FSDO authorizes an operator to operate under the provisions of an [[MEL]]. Together, the LOA, the procedures document, and the MMEL constitute a Supplemental Type Certificate ([[STC]]). The operator must carry the STC in the aircraft during its operation ***Source*** :: [[AC 91-67]] #glossary #acronym