Subject: ACCEPTANCE AND USE OF
SYSTEMS, AND ELECTRONIC MANUALS
Initiated by: AFS-300
AC No: 120-78
1. What is the purpose of this advisory circular (AC)?
a. This AC is not mandatory and does not constitute a regulation. This AC provides
guidance on the acceptance and use of electronic signatures to satisfy certain operational and
maintenance requirements. This AC also provides guidance on the acceptability of electronic
recordkeeping systems and electronic maintenance manuals, including inspection procedures
manuals, quality assurance, operations manuals, and training manuals required by Title 14 of the
Code of Federal Regulations (14 CFR). After the Federal Aviation Administration (FAA)
accepts an electronic system, that system may be used to generate aircraft records (such as load
manifest, dispatch release, aircraft maintenance records, maintenance task cards, pilot training
records, flight release, airworthiness release, flight test reports, etc.) when these records can be
NOTE: In this AC, the term “electronic signature” refers to either electronic
signatures or digital signatures. The specific electronic signature used
depends on the end user’s preference and the system application.
b. This AC describes an acceptable means, but not the only means, of complying with the
FAA’s operational and maintenance requirements. Specifically, handwritten signatures, records
and mechanic’s stamps continue to be acceptable. However, if you use the electronic means
described in the AC, you must conform to it in all important respects.
2. Who does this AC apply to?
Air carriers under 14 CFR parts 121, 129, or 135
Operators under 14 CFR parts 91, 125, 133, or 137
Persons performing airmen certification under 14 CFR parts 61, 63, 65, 141, and 142
Individuals performing maintenance or preventive maintenance under 14 CFR part 43
Repair stations under