Electronic flight bag (EFB) is an electronic information system, comprised of equipment and applications for flight crew, which allows for the storing, updating, displaying and processing of EFB functions to support flight operations or duties.

♦Type A EFB application means an EFB application whose malfunction or misuse has no safety effect. A typical example are company manuals (except QRH and checklists). If the app fails, the crew isn't able to access manuals, however these are manuals for reference only and are not necessary to control the aircraft.

♦Type B EFB application means an EFB application:

(a) whose malfunction or misuse is classified as minor failure condition or below; and
(b) which neither replaces nor duplicates any system or functionality required by airworthiness regulations, airspace requirements, or operational rules.

In the case of type B EFB, these programs or apps may influence safety if they fail or don't perform as expected. These apps are typically performance software that calculates speeds, charts, etc.