Cockpit Text Communications: Evaluating the Efficiency and Accuracy of Different Keyboards

Non-voice data exchanges will become a primary method of communication between pilots and Air Traffic Controllers as the Federal Aviation Administration’s plan for the Next Generation Air Traffic Control System (NextGen) evolves. In support of this communication evolution, pilots will need the most efficient interface tools in order to accurately and quickly exchange text messages with Air Traffic Control. Keyboards, or similar input devices, will be become a necessity in the cockpit. This study aims to investigate and compare the typing speed and accuracy possible using three sizes of two-hand, QWERTY keyboards: a full size (100%), a medium size (92%), and a small size (thumb typing home theater PC keyboard) that could be used for aviation data exchanges. Each study participant was administered 15 typing tests having aviation specific content, on each keyboard, including 5 tests of short length, 5 tests of medium length, and 5 tests of long length. The results of this study suggest that in terms of words per minute typing speed, participants using the medium size keyboard had a slightly faster typing speed than with the large keyboard, while the small keyboard produced a considerably slower typing speed than either the medium or large keyboards. In terms of accuracy, participants using the small keyboard had the highest level of accuracy, followed by the medium keyboard, while the least accurate keyboard tended to be the large keyboard. Overall, findings suggest that the optimal size of two-handed, QWERTY keyboard for use in an aircraft cockpit was the medium keyboard. 1 For a picture of the QWERTY keyboard, see appendix A. KEYBOARD IN THE COCKPIT 3! Literature Review Aircraft cockpit design has evolved over the years as improvements in automation and navigation capabilities have changed the way pilots interact with automated aircraft and air traffic control services. A probable reason for this is Moore’s Law, which states that every twelve to eighteen months, the processing power of computers double while its corresponding cost holds constant (Downes, 2009). Because of this reality, new technologies, powered by computers are being quickly developed to better control and navigate aircraft, as well as providing for improved communication between them. This can be observed in cockpit changes that include the use of LCD monitors and complex digital displays for aircraft and flight information instead of traditional, analog-style gauges. Flight Management Systems (FMS) are increasingly utilized to program the flight from takeoff to landing. Additionally, a related trend is the effort to move from traditional voice to a text-messaging type of communication know as Data Communications (Data Comm). These changes are part of the first phase of the Next Generation Air Transportation System (NextGen). A compelling reason to transition from voice communications to Data Comm is that a text reference does not have to be remembered while a voice communication does. Risser’s study (2004) using Datalink a text system used to exchange messages between Air Traffic Control (ATC) and pilots demonstrated an advantage in receiving text commands over voice commands, particularly those with longer lengths and more complex content. DeMik (2008) conducted a similar experiment using Datalink in a simulated single-pilot general aviation environment, and replicated earlier results validating those findings. DeMik states: The results of this study [Text communications in single-pilot general aviation operations: Evaluating pilot errors and response times] revealed a statistically significant KEYBOARD IN THE COCKPIT 4! decrease in both human performance measures of errors in pilot recall/execution and response times in moving from the conventional voice ATC commands to the CPDLC [Controller-Pilot Data Link Communication] text commands for pilots operating an FTD [Flight Training Device] that simulated the single-pilot general aviation work environment. It was also shown that results were significant across all levels of air traffic control command loads (high, moderate, and low). (2009, p. 39) However, Data Comm should not completely replace voice communications, but rather add to a dual modality of communication (Demik, 2009). As a consequence of these initial findings, the FAA has made Data Comm a part of NextGen. According to the Federal Aviation Administration (FAA): Data Communications (Data Comm) will assume an ever-increasing role in controller to flight crew communication, contributing significantly to increased efficiency, capacity, and safety of the National Airspace (NAS). The evolution of Data Comm in the operational environment will be based upon the incremental implementation of advanced communication capabilities. Data Comm represents the first phase of the transition from the current analog voice system to an International Civil Aviation Organization (ICAO) compliant system in which digital communication becomes an alternate and eventually predominant mode of communication. (Data Communications, 2009, par. 1) Currently, human factors research is being conducted on the Data Comm human interface, and a Network Service Provider is being solicited. In 2011, a revised departure clearance capability for Data Comm will occur. Between 2012 and 2016, en route clearance capability for Data Comm will become available (U.S. Department of Transportation, Federal Aviation Administration, 2010). KEYBOARD IN THE COCKPIT 5! At the present time, Data Comm works by the Air Traffic Controller sending a text clearance to the aircraft. The FMS acknowledges receipt of the transmission by displaying a bold ‘message’ text at the top of its screen in the cockpit, which alerts the pilot that a communication has been received by the aircraft. The pilot depresses a button to view the detailed message, reviews the message, and then pushes a ‘will comply’ button to signify acceptance of the clearance (U.S. Department of Transportation, Federal Aviation Administration, 2010). This works effectively for ground clearances and ATC messages, but offers scant opportunity for pilots to send custom messages back to ATC, such as pilot reports or other helpful information they might want like to convey. Currently, the only way to submit a non-voice message to ATC from most aircraft is to use the single-hand, alphabetic keyboard on the FMS. The FMS has been a familiar part of advanced cockpit instrumentation. Traditionally, an alphabetic, one-hand keyboard was used to facilitate FMS input. It can be inferred that this style keyboard was intended for one hand use due to its size and cockpit placement. Recently, however, some FMS keyboards have been designed with a QWERTY layout instead of the popular alphabetical layout. QWERTY keyboards have been installed in the cockpit of the Airbus A380, and Airbus plans on using the same FMS and keyboard on their next generation of the A350 (Kingsley-Jones, 2006). There have been issues with older FMS interfaces, and this change could be an effort to make programming the FMS easier through use of a keyboard style that is ubiquitously used in many other common computer interfaces. For example, in an evaluation of the American Airlines Flight 957 accident, Endsley & Strauch (1997) noted that due to the difficulty of the FMS interface, “The requirement to reprogram the FMS and cross KEYBOARD IN THE COCKPIT 6! check the entries at the last minute certainly played a role in this accident” (p. 4). A QWERTY layout might conceivably be a fix to these types of concerns. The A380 features a full (100%), two-handed QWERTY keyboard that is primarily used with the Onboard Information Terminals (OIS) where some data can also be sent from the OIS to the FMS (Dornheim, 2006). It can be inferred that this keyboard was intended for two-handed use due to its and size and cockpit placement. Even though Airbus is shifting from an alphabetically arranged keyboard to QWERTY keyboards, Boeing is still using an alphabetic keyboard for the FMS input on their latest model aircraft, the 787 (Kingsley-Jones, 2006). FMS keyboards were initially designed for insertion of flight plan data prior to takeoff, and to accommodate changes to the plan while in-flight. However, as part of the Next Generation Air Transportation System (NextGen), Data Communications (Data Comm) are also being transferred to the cockpit, where FMS keyboards are utilized to execute the communication. Testing the effectiveness of Data Comm as a replacement for traditional voice communication has been accomplished, but there has been little testing to determine which keyboards are best suited for use in the cockpit. The current study will attempt to answer that question. Most studies of keyboard design and layout have focused on ergonomics the field of study dedicated to designing devices and equipment that best fits the human body. However, some design work has emphasized creation of customized keyboards that are dependent upon the type of text to be entered. For example, Francis and Oxtoby (2006) utilized a computer program, Keyboard Tool, to create a custom keyboard best suited for specific text to be typed using only a single hand. Test results showed a decrease in text entry time, but the researchers acknowledged KEYBOARD IN THE COCKPIT 7! that it would be better to have standard 10-finger, two-handed typing if the physical environment would allow it. Another study compared the learning curves of full-size, two-handed split-angle, chord, contour split, and Dvorak (named after its founder, Dr. August Dvorak) keyboards against a conventional QWERTY keyboard (Anderson, Mirka, and Kaber, 2009). The split fixed-angle, chord, and contour split keyboards were designed to be ergonomic, and presented a layout similar to a QWERTY keyboard. The Dvorak keyboard is a layout alternative to the QWERTY keyboard and was designed to allow faster