These devices are used as loose equipment and are typically stowed during critical phases of flight (below 10,000 feet).[1] A Class 1 EFB is considered a Portable Electronic Device (PED). Class 1 EFBs, such as Cockpit iPads, may be used to display Type B applications in critical phases of flight provided that they are 'secured and viewable'.[2] Class 2 – Portable Electronic Devices, and range from modified COTS equipment to purpose-built devices.[2] Mounting, power (ship's power as primary) or data connectivity of an EFB typically requires the application of an STC, Type Certificate or Amended Type Certificate. (ref: FAA Order 8900.1)[2] Class 3 – Considered "installed equipment" and subject to airworthiness requirements and, unlike PEDs, they must be under design control. The hardware is subject to a limited number of RTCA DO-160E requirements (for non-essential equipment—typical crash safety and Conducted and Radiated Emissions testing).[2] Class 3 EFBs are typically installed under STC or other airworthiness approval.[2]