SAE ARP60494

This Aerospace Recommended Practice (ARP) addresses direct touch interactive electronic display systems installed in the cockpit/flight deck for use by pilots. Direct touch refers to interactivity where the display screen is the input surface. This entire direct interactive electronic display system is referred to as the touch system throughout this document and covers those items related to direct interactive touch on display devices. In cases where only the display and touch device are being considered, this is referred to as the touch screen. The ARP covers system design guidelines as well as the considerations and recommendations for system performance and human factors. This ARP is intended to cover systems installed in 14 CFR Part 23, 25, 27, and 29 aircraft. As an ARP this document collects what are considered good practices by developers, users, and regulators of touch systems. The state of touch technology and the application of that technology is still evolving. As a result, it is premature to develop quantitative guidance for some key touch characteristics. In addition to the recommendations, this document provides considerations to address these cases by listing the issues that need to be assessed in a specific application. This ARP only applies to touch systems that are part of the installed equipment in the cockpit. However, the tendency for non-installed devices, such as Portable Electronic Devices (PED) hosting Electronic Flight Bag (EFB) applications, to move into a primary role in the cockpit should not be ignored whether or not the function is regulated. In this regard the ARP may provide useful information for the designers of PED type devices, especially those hosting EFB applications. Touch screens were introduced in the early 1990s in military cockpits to perform simple functions and more recently in commercial avionics both for installed and non-installed devices such as Portable Electronic Devices hosting Electronic Flight Bag applications. Touch screens are widely used in consumer electronics (e.g., tablets and cell phones) leading to novel human machine interfaces and interactions. However, the guidelines and recommendations for touch screens from the consumer industry are not sufficient to cover their implementation in cockpits/flight decks and hence this ARP is needed to ensure that the continued implementation of touch interactive display capabilities to be used by pilots will be acceptable. Guidance material on the integration and use of touch interactions for cockpit display systems is essential to address the new benefits and issues raised by introducing the touch modality into the cockpit. Certification Review Items have been issued by the European Aviation Safety Agency during the introduction of touch screens in commercial or helicopter cockpits. While the Federal Aviation Administration has included high level guidance for the introduction of touch screens into the electronic displays in AC 20-175 “Controls for Flight Deck Systems”, specific recommendations on how to meet that guidance are missing. More specific guidance and recommendations will be useful to the industry to ensure that touch screens developed for use by pilots will consistently and effectively meet the regulatory rules and high level guidance. Human machine interaction factors such as single pilot versus dual pilot interaction, touch feedback, erroneous action and crew workload are addressed in this document.