CHAPTER 6. ORGANIZING ELECTRONIC DISPLAY INFORMATION ELEMENTS
6.1 Organizing Information Elements.
This chapter provides guidance for integrating information into the flight deck related to managing the location of information, arranging the display, windowing, configuring and reconfiguring the display, and selecting the sensors across the flight deck displays.
The following paragraphs include guidance for various flight deck configurations from dedicated electronic displays for the attitude director indicator and the horizontal situation indicator to larger display sizes that use windowing techniques to display various functionalities on one display area. In some flight decks the primary flight information and the navigation display are examples of information that is displayed using windowing techniques. Chapter 5 of this AC provides guidance for information elements including text, labels, symbols, graphics, and other depictions (such as video) in isolation and combination.
6.2 Types and Arrangement of Display Information.
This paragraph provides guidance for the arrangement and location of categories of information. The categories of information include the following:
• Primary flight information including attitude, airspeed, altitude, and heading.
• Powerplant information that covers functions relating to propulsion.
• Other information.
6.2.1 Placement—General Information.
The position of a message or symbol within a display conveys meaning to the pilot.
Without the consistent or repeatable location of a symbol in a specific area of the electronic display, interpretation error and response times may increase. The following information should be placed in a consistent location under normal conditions:
6.2.1.1 Primary flight information. (See paragraph 6.2.3 in this chapter and appendix A of this AC.)
6.2.1.2 Powerplant information. (See paragraph 6.2.4 in this chapter and appendix B of this AC.)
6.2.1.3 Flightcrew alerts. Each flightcrew alert should be displayed in a specific location or in a central flightcrew alert area.
6.2.1.4 Autopilot and flight director modes of operation.
6.2.1.5 Lateral and vertical path deviation indicators.
6.2.1.6 Radio altitude indications.
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6.2.1.7 Failure flags should be presented in the location of the information they reference or replace.
6.2.1.8 Data labels for navigation, traffic, airplane system, and other information should be placed in a consistent position relative to the information they are labeling.
6.2.1.9 Supporting data for other information, such as bugs and limit markings, should be consistently positioned relative to the information they support.
6.2.1.10 Features on electronic moving map displays (for example, very high frequency omnirange stations (VORs), waypoints, etc.) relative to the current airplane position. In addition, the features should be placed on a constant scale for each range selected.
6.2.1.11 Segment of flight information relative to similar information or other segments.
6.2.2 Placement—Controls and Indications.
When a control or indication occurs in multiple places (for example a “Return” control on multiple pages of a flight management function), the control or indication should be located consistently for all occurrences.
6.2.3 Arrangement—Basic T Information.
6.2.3.1 Section 25.1321(b) includes requirements for the “Basic T” arrangement of certain information required by § 25.1303(b).
6.2.3.2 The following paragraphs provide guidance for the Basic T arrangement.
This guidance applies to single and multiple display surfaces.
6.2.3.2.1 The Basic T information should be displayed continuously, directly in front of each flightcrew member under normal (that is, no display system failure) conditions. Section 25.1321(b) requires that flight instruments required by § 25.1303 must be grouped on the instrument panel and centered as nearly as practicable about the vertical plane of the pilot’s forward vision.
6.2.3.2.2 The Basic T arrangement applies to the primary display of attitude, airspeed, altitude, and direction of flight. Depending on the flight deck design, there may be more than one indication of the Basic T information elements in front of a pilot. For example, heading information may appear on backup displays, HUDs, and moving map displays. The primary airspeed, altitude, and direction indications are the respective display indications closest to the primary attitude indication.
6.2.3.2.3 The primary attitude indication should be centered about the plane of the flightcrew’s forward vision. This should be measured from the DEP at the 6-2
flightcrew station (see related regulation). If located on the main instrument panel, the primary attitude indication must be in the top center position (§ 25.1321(b)). The attitude indication should be placed so that the display is unobstructed under all flight conditions. See SAE ARP4102/7 for additional information.
6.2.3.2.4 The primary airspeed, altitude, and direction of flight indications should be located adjacent to the primary attitude indication. Information elements placed within, overlaid, or between these indications, such as lateral and vertical deviation, are acceptable when they are relevant to respective airspeed, altitude, or directional indications used for accomplishing the basic flying task, and are shown to not disrupt the normal crosscheck or decrease manual flying performance.
6.2.3.2.5 The instrument that most effectively indicates airspeed must be adjacent to and directly to the left of the primary attitude indication (§ 25.1321(b)).
The center of the airspeed indication should be aligned with the center of the attitude indication. For airspeed indications, vertical deviations have been found acceptable up to 15° below and to 10° above when measured from the direct horizontal position of the airplane waterline reference symbol. For tape type airspeed indications, the center of the indication is defined as the center of the current airspeed status reference.
6.2.3.2.6 Parameters related to the primary airspeed indication, such as reference speeds or Mach indication, should be displayed to the left of the primary attitude indication.
6.2.3.2.7 The instrument that most effectively indicates altitude must be located adjacent and directly to the right of the primary attitude indication (§ 25.1321(b)). The center of the altitude indication should be aligned with the center of the attitude indication. For altitude indications, vertical deviations have been found acceptable up to 15° below to 10° above when measured from the direct horizontal position of the airplane waterline reference symbol. For tape type altitude indications, the center of the indication is defined as the center of the current altitude status reference.
6.2.3.2.8 Parameters related to the primary altitude indication, such as the barometric setting or the primary vertical speed indication, should be displayed to the right of the primary altitude indication.
6.2.3.2.9 The instrument that most effectively indicates direction of flight must be located adjacent to and directly below the primary attitude indication (§ 25.1321(b)). The center of the direction of flight indication should be aligned with the center of the attitude indication. The center of the direction of flight indication is defined as the center of the current direction of flight status reference.
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6.2.3.2.10 Parameters related to the primary direction of flight indication, such as the reference (that is, magnetic or true) or the localizer deviation should be displayed below the primary attitude indication.
6.2.3.2.11 If an applicant seeks approval of alternative instrument arrangements by equivalent safety under § 21.21(b)(1), the FAA will normally require well-founded research, or relevant service experience from military, foreign, or other sources to substantiate the applicant’s proposed compensating factors.
6.2.4 Arrangement—Powerplant Information.
6.2.4.1 Required engine indications necessary to set and monitor engine thrust or power should be continuously displayed in the flightcrew’s primary field of view, unless the applicant can demonstrate that this is not necessary (see the guidance in paragraph 6.3.3 of this chapter and appendix B of this AC). The automatically selected display of powerplant information should not suppress other information that requires flightcrew awareness.
6.2.4.2 Powerplant information must be closely grouped (in accordance with § 25.1321) in an easily identifiable and logical arrangement that allows the flightcrew to clearly and quickly identify the displayed information and associate it with the corresponding engine. Typically, it is considered to be acceptable to arrange parameters related to one powerplant in a vertical manner and, according to powerplant position, next to the parameters related to another powerplant in such a way that identical powerplant parameters are horizontally aligned. Generally, place parameter indications in order of importance with the most important one at the top.
Typically, the top indication is the primary thrust setting parameter.
6.2.5 Arrangement—Other Information (For Example, Glideslope and Multi-Function Displays).
6.2.5.1 Glideslope or glidepath deviation scales should be located to the right side of the primary attitude indication. If glideslope deviation data is presented on both an electronic horizontal situation indicator and an electronic attitude direction indicator, the information should appear in the same relative location on each indicator.
6.2.5.2 When the glideslope pointer is being driven by an area navigation (RNAV) system with vertical navigation (VNAV) or instrument landing system (ILS) look-alike functionality, the pointer should not be marked “GS” or “glideslope.”
6.2.5.3 Navigation, weather, and vertical situation display information is often displayed on multi-function displays. This information may be displayed on one or more physical electronic displays, or on several areas of one 6-4
larger display. When this information is not required to be displayed continuously, it can be displayed part-time, but the displayed information should be easily recoverable to the flightcrew when needed. For guidance on part-time displays, see paragraph 6.3.3 of this chapter.
6.2.5.4 Other information should not be located where the primary flight information or required powerplant information is normally presented. See paragraphs 6.2.1 and 6.2.3 of this chapter for primary flight information guidance. See paragraphs 4.7 and 6.2.4 of this AC for powerplant information guidance.
6.3 Managing Display Information.
The following paragraphs address managing and integrating the display of information throughout the flight deck. This includes the use of windows to present information and the use of menus to manage the display of information.
6.3.1 Window.
A window is a defined area that can be present on one or more physical displays. A window that contains a set of related information is commonly referred to as a format.
Multiple windows may be presented on one physical display surface and may have different sizes. Guidelines for sharing information on a display, using separate windows, are as follows:
6.3.1.1 The window(s) should have fixed size(s) and location(s).
6.3.1.2 Separation between information elements within and across windows should be sufficient to allow the flightcrew to readily distinguish separate functions or functional groups (for example, powerplant indication) and avoid any distractions or unintended interaction.
6.3.1.3 Display of selectable information, such as a window on a display area, should not interfere with or affect the use of primary flight information.
6.3.1.4 For additional information regarding the display of data on a given location, data blending, and data over-writing, see Aeronautical Radio, Inc. (ARINC) Standard 661-5, Cockpit Display System Interfaces to User Systems.
6.3.2 Menu.
6.3.2.1 A menu is a displayed list of items from which the flightcrew can choose.
Menus include drop-down and scrolling menus, line select keys on a multi-function display, and flight management system menu trees. An option is one of the selectable items in a menu. Selection is the action a user makes in choosing a menu option, and it may be done by pointing 6-5
(with a cursor control device or other mechanism), entering an associated option code, or activating a function key.
6.3.2.2 The hierarchical structure and organization of the menus should be designed to allow the flightcrew to sequentially step through the available menus or options in a logical way that supports their tasks. The options provided on any particular menu should be logically related to each other.
Menus should be displayed in consistent locations, either a fixed location or a consistent relative location, so that the flightcrew knows where to find them. At all times the system should indicate the current position within the menu and menu hierarchy.
6.3.2.3 The number of sub-menus should be designed to assure timely access to the desired option without over-reliance on memorization of the menu structure. The presentation of items on the menu should allow clear distinction between items that select other menus and items that are the final selection.
6.3.2.4 The number of steps required to choose the desired option should be consistent with the frequency, importance, and urgency of the flightcrew’s task.
6.3.2.5 When a menu is displayed, it should not obscure required information.
6.3.3 Full-Time versus Part-Time Display of Information.
Some airplane parameters or status indications are required to be displayed by the regulations (for example, powerplant information required by § 25.1305), yet they may only be necessary or required in certain phases of flight. If it is desired to inhibit some parameters from full-time display, a usability level and functionality equivalent to a full-time display should be demonstrated.
6.3.3.1 When determining if information on a display can be part-time, consider the following criteria:
6.3.3.1.1 Continuous display of the parameter is not required for safety of flight in all normal flight phases.
6.3.3.1.2 The parameter is automatically displayed in flight phases where it is required, when its value indicates an abnormal condition, or when it would be relevant information during a failure condition.
6.3.3.1.3 Display of the inhibited parameter can be manually selected by the flightcrew without interfering with the display of other required information.
6.3.3.1.4 If the parameter fails to be displayed when required, the failure effect and compounding effects must meet the requirements of all applicable regulations (for example, § 25.1309).
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6.3.3.1.5 The automatic or requested display of the inhibited parameter should not create unacceptable clutter on the display. Also, simultaneous multiple “pop-ups” should not create unacceptable clutter on the display.
6.3.3.1.6 If the presence of a new parameter is not sufficiently self-evident, suitable alerting or other annunciations should accompany the automatic presentation of the parameter.
6.3.3.2 Pop-up display of information. Certain types of information, such as terrain and TCAS, are required by the operation regulations to be displayed, yet they are only necessary or required in certain phases of flight (similar to the part-time display of required airplane parameters (see paragraph 6.2.3 of this chapter)), or under specific conditions. One method commonly employed to display this information is called “automatic pop-up.” Automatic pop-ups may be in the form of an overlay, such as a TCAS overlay on the moving map, or in a separate window as a part of a display format. Pop-up window locations should not obscure required information. Consider the following criteria for displaying automatic pop-up information:
6.3.3.2.1 Information is automatically displayed when its value indicates a predetermined condition, or when the associated parameter reaches a predetermined value.
6.3.3.2.2 Pop-up information should appropriately attract the flightcrew’s attention while minimizing task disruption.
6.3.3.2.3 If the flightcrew deselects the display of the automatic pop-up information, then another automatic pop-up should not occur until a new condition/event causes it.
6.3.3.2.4 If an automatic pop-up condition is activated and the system is in the wrong configuration or mode to display the information, and the system configuration cannot be automatically changed, then an annunciation should be displayed in the color associated with the nature of the alert, prompting the flightcrew to make the necessary changes for the display of the information. This guidance differs from the part-time display of information required by part 25 because the required information should be displayed regardless of the configuration.
6.3.3.2.5 If a pop-up or simultaneous multiple pop-ups occur and obscure information, it should be shown that the obscured information is not relevant or necessary for the current flightcrew task. Additionally, the pop-ups should not cause a misleading presentation.
6.3.3.2.6 If more than one automatic pop-up occurs simultaneously on one display area, for example a terrain and TCAS pop-up, then the system should 6-7
prioritize the pop-up events based on their criticality. Pop-up display orientation should be in track-up or heading-up.
6.3.3.2.7 Any information to a given system that is not continuously displayed, but the safety assessment determines it is necessary to be presented to the flightcrew, should automatically pop-up or otherwise indicate that its display is required.
6.4 Managing Display Configuration.
The following paragraphs address managing the information presented by an electronic display system and its response to failure conditions and flightcrew selections. The following paragraphs also provide guidance on the acceptability of display formats and their required physical location on the flight deck, both during normal flight and in failure modes. Manual and automatic system reconfiguration and source switching are also addressed.
6.4.1 Normal Conditions.
In normal conditions (that is, non-failure conditions) there may be a number of possible display configurations that may be selected manually or automatically. All possible display configurations available to the flightcrew should be designed and evaluated for arrangement, visibility, and interference.
6.4.2 System Failure Conditions (Reconfiguration).
The following paragraphs provide guidance on manual and automatic display system reconfiguration in response to display system failures. Arrangement and visibility requirements also apply in failure conditions. Alternative display locations used in non-normal conditions should be evaluated by the FAA or its designees to determine if the alternative locations meet the criteria for acceptability.
6.4.2.1 Moving display formats to different display locations on the flight deck or using redundant display paths to drive display information is acceptable to meet availability and integrity requirements.
6.4.2.2 In an instrument panel configuration with a display unit for primary flight information positioned above a display unit for navigation information, it is acceptable to move the primary flight information to the lower display unit if the upper display unit fails.
6.4.2.3 In an instrument panel configuration with a display unit for primary flight information positioned next to a display unit for navigation information, it is acceptable to move the primary flight information to the display unit directly adjacent to it if the preferred display unit fails. It is also acceptable to switch the navigation information to a centrally located auxiliary display (multi-function display).
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6.4.2.4 If several possibilities exist for relocating the failed display, a recommended flightcrew procedure should be considered and documented in the AFM.
6.4.2.5 It is acceptable to have manual or automatic switching capability (automatic switching is preferred) in case of system failure; however, the ARAC recommendation for revising § 25.1333(b) requires that the equipment, systems, and installations must be designed so that sufficient information is available to assure control of the airplane’s airspeed, altitude, heading, and attitude by one of the pilots without additional flightcrew action, after any single failure or combination of failures that is not assessed to be extremely improbable.
6.4.2.6 The following means to reconfigure the displayed information are acceptable:
6.4.2.6.1 Display unit reconfiguration. Moving a display format to a different location (for example, moving the primary flight information to the adjacent display unit) or the use of a compacted format may be acceptable.
6.4.2.6.2 Source/graphic generator reconfiguration. The reconfiguration of graphic generator sources either manually or automatically to accommodate a failure may be acceptable. In the case where both the captain and first officer’s displays are driven by a single graphic generator source, there should be clear, cautionary alerting to the flightcrew that the displayed information is from a single graphic generator source.
6.4.2.6.3 In certain flight phases, manual reconfiguration may not satisfy the need for the pilot controlling the airplane to recover primary flight information without delay. Automatic reconfiguration might be necessary to ensure the timely availability of information that requires immediate flightcrew member action.
6.4.2.6.4 When automatic reconfiguration occurs (for example, display transfer), it should not adversely affect the performance of the flightcrew and should not result in any trajectory deviation.
6.4.2.6.5 When the display reconfiguration results in the switching of sources or display paths that is not annunciated and is not obvious to the flightcrew, care should be taken that the flightcrew is aware of the actual status of the systems when necessary, depending on flight deck philosophy.
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6.5 Methods of Reconfiguration.
6.5.1 Compacted Format.
6.5.1.1 The term “compacted format,” as used in this AC, refers to a reversionary display mode where selected display components of a multi-display configuration are combined in a single display format to provide higher priority information following a display failure. The “compacted format” may be automatically selected in case of a primary display failure, or it may be manually (automatic selection preferred) selected by the flightcrew. Except for training purposes, the “compacted format” should not be selectable unless there is a display failure. The concepts and requirements of § 25.1321, as discussed in paragraph 6.2.3 of this chapter, still apply.
6.5.1.2 The compacted display format should maintain the same display attributes (color, symbol location, etc.) and include the same required information, as the primary formats it is replacing. The compacted format should ensure the proper operation of all the display functions it presents, including annunciation of navigation and guidance modes, if present.
However, due to size constraints and to avoid clutter, it may be necessary to reduce the amount of display functions on the compacted format. For example, in some cases, the use of numeric readouts in place of graphical scales has been found to be acceptable. Failure flags and mode annunciations should, wherever possible, be displayed in a location common with the normal format.
6.5.2 Sensor Selection and Annunciation.
6.5.2.1 Automatic switching of sensor data to the display system is recommended, especially with highly integrated display systems to address those cases where multiple failure conditions may occur at the same time and require immediate flightcrew action. Manual switching may be acceptable in less complex systems or if immediate flightcrew action is not required.
6.5.2.2 Independent attitude, direction, and air data sources are required for the captain and first officer’s displays of primary flight information (see § 25.1333). If sources can be switched such that the captain and first officer are provided with single sensor information, each of them should receive a clear annunciation indicating the vulnerability to misleading information.
6.5.2.3 If sensor information sources cannot be switched, then no annunciation is required.
6.5.2.4 There should be a means of determining the source of the displayed navigation information and the active navigation mode. For approach 6-10
operations the source of the displayed navigation information and the active navigation mode should be available on the primary flight display or immediately adjacent to the primary flight display.
6.5.2.5 The selected source should be annunciated if multiple or different types of navigation sources (flight management system, instrument landing system, global navigation satellite system (GNSS) landing system, etc.) can be selected (manually or automatically).
6.5.2.6 An alert should be given when the information presented to the flightcrew is no longer meeting the required integrity level, in particular when there is a single sensor or loss of independence.
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CHAPTER 7. ELECTRONIC DISPLAY SYSTEM CONTROL DEVICES
7.1 General.
Each electronic display system control device has characteristics unique to its operation that need to be considered when designing the functions the display system controls, and the redundancy provided during failure modes. Despite the amount of redundancy that may be available to achieve a given task, the flight deck should still present a consistent user interface scheme for the primary displays and a compatible, if not consistent, user interface scheme for auxiliary displays throughout the flight deck.
7.2 Multi-Function Control Labels.
Multi-function controls should be labeled such that the pilot is able to—
7.2.1 Rapidly, accurately, and consistently identify and select all functions of the control device;
7.2.2 Quickly and reliably identify what item on the display is “active” as a result of cursor positioning, as well as what function will be performed if the item is selected using the selector buttons and/or changed using the multi-function control; and
7.2.3 Determine quickly and accurately the function of the control without extensive training or experience.
7.3 Multi-Function Controls.
The installation guidelines below apply to control input devices that are dedicated to operating a specific function (for example, control knobs and wheels), as well as new control features (for example, a cursor control device (CCD)).
7.3.1 “Hard” Controls.
7.3.1.1 Mechanical controls used to set numeric data on a display should have adequate friction or tactile detents to allow a flightcrew without extensive training or experience to set values (for example, setting an out-of-view heading bug to a displayed number) to a required level of accuracy within a time appropriate to the task.
7.3.1.2 The input for display response gain to control should be optimized for gross motion as well as fine positioning tasks without overshoots. In accordance with § 25.777(b), the direction of movement of the cockpit controls must meet the requirements of § 25.779. Wherever practicable, the sense of motion involved in the operation of other controls must correspond to the sense of the effect of the operation on the airplane or on the part operated. Controls of a variable nature using a rotary motion must 7-1