Amended EFB guidelines streamline approval steps

 - February 4, 2008, 9:26 AM

The FAA has issued a long-awaited amendment to an advisory circular that outlines operational guidelines for anyone seeking to fly with so-called electronic flight bag (EFB) portable computers. Eliminating confusion that accompanied the original draft AC, the revised document, AC 120-76A, clarifies many of the requirements for certification, airworthiness and operational approval of EFB devices.

Aircraft operators and EFB suppliers late last year had asked the FAA to make changes to the earlier draft to help resolve technical issues and eliminate what some believed were a number of cumbersome requirements.

Changes to the AC permit pilots to use panning, scrolling and zooming functions when viewing navigation charts, something that originally had been prohibited. The circular also adds the statement that permanent mounts for class-2 and -3 devices “may be necessary,” a change that seems to leave the mounting question open to local FAA officials, whose job it will be to approve EFB installations in aircraft.

The original AC required a permanent mount, but operators complained that a mount could get in the way during emergencies (such as while donning oxygen masks), especially in smaller cockpits. Interestingly, the AC defines knee straps and clipboards as suitable mounts, as contrasted with requirements for other types of cockpit mounts that must be tested and shown to withstand 9g forces.

Another hotly debated point was whether to allow a moving aircraft symbol to be placed on the EFB display showing aircraft location. Some pilots reasoned that such symbology would enhance situational awareness by allowing them to keep track of exactly where they were on an approach or other instrument procedure. FAA officials, however, were concerned that a moving-map symbol could create confusion. In the end, the FAA decided to allow use of a moving aircraft symbol on the ground during taxi, but said the symbol must disappear once airborne.

The amended AC also adds three new categories of application software (type A, B and C) that may be loaded onto the three classes (class 1, 2 and 3) of EFB. Jeppesen Jepp-View charting software, as an example, would be considered type-B software and could be used with class-2 or -3 devices, generally handheld tablet computers with LCD touch screens. Type-A software would be non-flight critical applications, such as performance calculations, generally stored on a class-1 PDA. Conversely, type-C software is considered the most critical of the classifications, and would include certified software that communicates through the Arinc 429 databus with other aircraft systems.

Class Breakdown
While Part 135 operators and fractional-ownership providers must adhere to the AC, the circular does not apply to other turbine aircraft operators, meaning most Part 91 operators who are flying with off-the-shelf tablet computers can continue to do so without fear that a ramp check will bring unwanted consequences.

The three classes of EFB range from small PDAs and handheld pen-tablet computers to fully certified devices capable of interfacing with EICAS, FMS and navigation sensors. Flight crews who want to view navigation charts on an EFB display will be interested mainly with class-2 and -3 devices. These may be used for viewing navigation charts during all phases of flight, including takeoff and landing, provided some means of backup– either a second EFB or paper charts–are present in the cockpit.

Class-1 EFBs may be used on the ground and during flight as a source of “supplemental information,” but not for viewing navigation charts. They would generally consist of a simple PDA loaded with checklists, weight-and-balance calculators and other types of flight-relevant software. (The AC specifically states that PDAs may not be datalinked, but again this applies only to commercial operations–that’s good news for companies that market airborne datalink services, such as weather reporting, for display on a PDA.)

While class-2 and -3 devices may be used for viewing approach charts, there are some notable differences between the two, not the least of which is price. The typical class-2 device currently sells for an uninstalled price of between $3,000 and $10,000. Universal Avionics, meanwhile, has gained TSO certification for its $36,000 Universal Cockpit Display (UCD), a unit with a remote-mounted computer that is capable of interfacing with FMS and other aircraft systems. The UCD is also a little larger and has better resolution than lower-priced devices, making it easier to use than some units with smaller screens.