in three software categories. Type A Static applications, such as document viewer (PDF, HTML, and XML formats); Flight Crew Operating Manuals, and other printed documents like airport NOTAM; Type B Static or dynamic electronic "charts" to include (though not requiring) panning, zooming, and scrolling;(AC120-76(), Appendix B) Type C use as a Multi-function display (MFD); in at least one case as part of an Automatic Dependent Surveillance-Broadcast system. Type C applications must run only on Class 3 EFB. Initially Type C applications were considered as subject to airworthiness requirements and as such must be developed in conformance with DO-178/ED-12 objectives and run on Class 3 EFB. Later, with release of AC 120-76D in 2017, reference to Type C applications were removed, and their functionality no longer an EFB functions. Regulations United States Federal Aviation Authority While FAR Part 91 Operators (those not flying for hire, including private and corporate operators) can use their pilot-in-command authority to approve the use of EFBs which are PEDs, operator with OpSpecs (Part 135, Part 121) must seek operational approval through the OpSpecs process based on the following requirements: PEDs used as EFB configuration must meet the rapid decompression testing requirements of standard RTCA DO-160E. Any mounting or attachment or data connectivity of PEDs used as EFB to aircraft systems shall be performed in accordance with an approved data (such as Supplemental Type Certificate, Type Certificate or Amended Type Certificate). European Aviation Safety Agency For guidance on airworthiness and operational considerations for Electronic Flight Bags (EFB) for operators within Europe, EASA AMC 20-25 applies. United Kingdom Military Aviation Authority The UK Ministry of Defence takes the approach of clearing the airworthiness of EFB on specific aircraft types as 'Equipment Not Basic to Air System (ENBAS)' as described in Regulatory Article 1340. The Type Airworthiness Authority (TAA) and supporting Delivery Teams are responsible for this clearance to ensure that the EFB device in and of itself does not negatively impact the airworthiness of the aircraft in question. Regarding the approval of use of specific applications, this is the responsibility of the Aviation Duty Holder (ADH) chain. See also Quick Reference Handbook (QRH) Flight Management System (FMS) References Further reading FAA AC 91-78 (July 2007 – Use of Class 1 and 2 EFBs) FAA Order 8900.1 AMC 20-25 (February 2014) Avionics Aviation publications