FMA Survey Description

March 9, 2018 | Author: aneesh | Category: Aerospace, Systems Engineering, Aviation, Aircraft, Aerospace Engineering
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Flight Mode Annunciation Survey Questionnaire 1. SURVEY OBJECTIVES Flight mode annunicators are used on modern aircraft to tell the pilot or flight crew what the autopilot and/or automation devices are doing. Experience since the introduction of complex automation on modern transport aircraft has shown that the flight crew has not always possessed good situational awareness of the present and future behaviour of the automation, and this has resulted in serious incidents and fatal accidents. An FMA has been developed which portrays information in a graphical rather than alphanumeric format. The objective of this questionnaire to determine if the graphical FMA concept offers any cognitive advantage over the present alphanumeric display. This survey forms part of a master’s thesis being undertaken in collaboration with the International Test Pilots School in Coventry, UK, and the Faculty of Engineering at Bristol University, Bristol, UK. 2. SURVEY METHOD This survey will outline the present alphanumeric FMA as used on the Airbus A320, using several examples. The proposed graphical FMA will then be explained. You will be shown a series of FMA ‘scenes’ (for both alphanumeric and graphical FMA) that make up an aviation ‘scenario’ such as a takeoff or autoland sequence. You are then asked to rate both displays on a cognition scale, answer questions comparing the displays, and finally your opinion is sought on the general concept of the graphical FMA. (When viewing this survey on a CDU, use the page layout view with the page width occupying full screen width for best resolution.) 3. CONFIDENTIALITY As this survey does not require you to identify yourself, all information supplied is completely confidential. If you wish to identify yourself so that I can contact you for further information if required, you are invited to do so at the end of the survey. 4. A320 ALPHANUMERIC FMA DESCRIPTION The flight mode annunciators are located on primary flight display (PFD) for the captain and first officer, and occupy the top ~20% of the display. The diagram to the right shows the general arrangement of an A320 FMA pictured during an instrument approach. The FMA itself is broken down into 5 columns which are generally for the autothrust system (column 1), vertical automation modes (2), lateral automation modes (3), instrument approach information (4), and finally engagement status for the autopilot, flight director, and autothrust system (column 5). The diagram below expands the top portion of the PFD to provide more detail on the FMA itself.

Columns 1, 4 and 5 can be considered as status columns in that the information contained within is mostly of a static nature. Columns 2 and 3, the vertical and lateral mode columns, undergo many mode changes and the active mode is displayed on the top line in green text. The armed mode (the mode that will replace the active mode when certain conditions are met) is displayed on the second line usually in cyan text but in certain conditions, in magenta text. In certain landing conditions, the vertical and lateral modes are combined into one mode that is displayed across both columns 2 and 3. Also shown are the fields for the flight control unit (FCU) selected speed and altitude. The colour convention in general terms are green for active modes, cyan for armed modes or pilot selected values, and white for automation status indications. 5. A320 FMA EXAMPLES The following examples show different descent modes, and the manner in which the A320 alphanumeric FMA changes during a takeoff procedure and a CAT 3 autoland sequence. The pictures are ordered vertically in columns within a page and are also numbered. A brief description of each scene is contained under the picture. 5.1 Similar Descent Example The following pictures show 4 different descent modes. These are managed descent, vertical speed descent, flight path angle descent, and descent on the ILS GP. The four images do not form a sequence, rather are shown as separate images to illustrate different descent modes. When viewing the displays consider the chance of confusing different descent modes.

1. Descent mode, idle thrust selected by autothrust system, vertical mode active in speed hold with altitude capture at 5000’ armed, lateral mode in navigation mode (ie FMS), autopilot engaged.

2. Manual flight under flight director guidance, vertical speed and heading hold guidance provided. Throttles controlled manualy.

3. Manual flight following flight director with autothrust system engaged in speed mode. Flight director providing guidance to specific flight path angle and track.

4. Autopilot flight (1&2) with autothrust system engaged. Autopilot tracking ILS glide slope and localiser signals, cat 3 dual landing criteria established.

5.2 A320 Takeoff Example The following sequence of pictures shows a normal takeoff, with acceleration segment, intermediate level of at 3000’, and climb to and level off at F250.

1. Takeoff ground roll. Speed reference system active, climb mode armed; runway track active, nav armed; autothrust selected – TOGA, flight director 1 information displayed.

2. Airborne through 35’. Lateral navigation mode engaged.

3. Autopilot 1 engaged.

4. Climb power selected.

5. Climb becomes the active vertical mode, altitude capture (FMS constraint) armed.

6. Altitude hold active vertical mode, continued climb becomes the armed mode.

7. Climb the active vertical mode, altitude capture (cruise altitude) becomes the armed mode.

8. Altitude hold in cruise active vertical mode.

5.3 Cat 3 Autoland Example The following sequence of pictures shows a category 3 autoland approach from prior to ILS interception to the end of the landing ground roll.

1. Level at 2000, Autopilot autothrust engaged, flight director 1 displayed, speed mode selected.

3. Intercepting glide slope and localiser. Approach capability improved to CAT 3 DUAL.

2. Approach mode armed (G/S and LOC armed), DH selected, present approach capability indicated.

4. Tracking glide slope and localiser.

7. Autothrust reduction to idle.

5. Land mode active. 8. Idle manually selected.

6. Commencement of flare. 9.Ground roll out.

6. GRAPHICAL FMA DESCRIPTION The concept of display for the graphic FMA is to provide all of the relevant mode information in one location on the PFD, rather than the current three locations (PFD, flight control unit, and multipurpose control display unit - Airbus). The current and the next significant automation modes are displayed in a graphical format. The total display will represent a truth data summary on the current operation of the aircraft and the intended course of action of the automation. The information to be provided is that contained in the current Airbus FMA display, as well as the currently commanded parameters such as altitude airspeed vertical speed or flight path angle, or track heading or MCDU navigation. The engagement or otherwise of the autothrust, autopilot and flight director is also presented. The following figure shows the general positional layout of items within the proposed graphical FMA display.

When the lateral or vertical mode does not contain a significant next mode, as would be the case in the cruise (altitude hold, and FMS navigation), these modes are presented graphically across both the present and future mode fields. 6.1 Graphical FMA Schema The following points briefly outline the concept of operation of the graphical FMA. A diagram showing the icons to be used follows. 1. The displays are static images of the automation mode, not the relevant tracking performance of the aircraft. The various mode icons will not change relative position with changed tracking performance.

2. Intermediate modes such as localiser, glide slope, or altitude capture are not shown. The display shows the next major mode (ie localiser or glide slope track, or altitude hold) at the commencement of the capture process. 3. Three levels of automation are considered, normal, higher and lower. 4. Normal automation is based on flying with autopilot and autothrust systems engaged, and with matching FCU and FMS altitude constraints. Normal automation is presented in green. Icons associated with normal automation are displayed in green. 5. Lower automation involves basic autopilot functions such as V/S-Heading and FPATrack, and manual control of the aircraft and throttles. Lower automation is presented in cyan. 6. Higher automation levels involved advanced features of the FMS (or MCDU) such as altitude constraints or geometric path descents not selected on the FCU. Higher automation is presented in magenta. Icons associated with higher automation modes are displayed in magenta. 7. The FCU selected speed and altitude values are displayed above the speed and altitude tapes in blue. 8. Airspeed is controlled via longitudinal pitch changes when idle is selected manually or by the autothrust system. 9. Airspeed is controlled via the autothrust system when an autothrust “SPEED” icon is shown. This indicates that the autothrust system is in speed mode and using variable thrust settings between idle and climb thrust to achieve a speed objective. 10. Managed speed is an automation pilot aid on Airbus aircraft in which the flight computer determines the appropriate speed for the given flight phase and configuration, and this speed is shown as a green dot on the PFD airspeed tape. When using managed speed, a green dot is shown at the top of the airspeed tape, and the airspeed in green above the aircraft icon. 11. Speed reference system (SRS) is a managed speed mode used after takeoff and during go-arounds in which the computer determines the appropriate speed for the configuration and weight. SRS is indicated above the aircraft when active.

7. GRAPHICAL FMA EXAMPLES The following examples show different descent modes, and the manner in which the graphical FMA will change during a takeoff procedure or a CAT 3 autoland sequence. The pictures are ordered vertically in columns within a page and are numbered. 7.1 Similar Descent Example The following pictures show 6 different descent modes. The ‘scenes’ shown are not part of a sequence, rather are shown as separate images to illustrate different descent modes. This sequence has similar scenes to that displayed in section 5.1 above. The pictures are ordered vertically in columns within a page and are numbered. When viewing the displays consider the chance of confusing different descent modes. navigation. Autopilot 1 engaged, no flight director information.

1. Autothrust engaged, idle selected; descent at constant 250 (idle path descent) with altitude capture at 5000; FMS lateral navigation. Autopilot 1 engaged, no flight director information.

2. Autothrust engaged, variable thrust to maintain 250. Descent at constant 350 fpm ROD (repressurisation segment at top of descent) with altitude capture at 5000; FMS lateral navigation. Autopilot 1 engaged, no flight director information.

3. Autothrust engaged, variable thrust to maintain 250. Descent to achieve waypoint/altitude objective (geometric path descent) with altitude capture at 5000; FMS lateral

4. Autothrust engaged, variable thrust to maintain 250 selected by pilot. Manual flight from right sidestick, flight director 1 displaying guidance for descent at constant – 3.3º flight path angle with no altitude capture, and lateral navigation as selected track.

5. Manual thrust, no speed target. Manual flight from left sidestick, flight director 1 displaying guidance for descent at constant 3300 fpm ROD with no altitude capture., and lateral navigation is selected heading.

6. Autothrust engaged and holding 125 on ILS glide slope and localiser. Autopilots 1 and 2 engaged with cat 3 dual approach criteria met. Flight director 1 information displayed.

7.2 A320 Takeoff Example The following sequence of pictures shows a normal takeoff, with acceleration segment, intermediate level of at 5000’, and climb to and level of at F250. This sequence matches the one displayed in section 5.2 above.

1. Takeoff roll. SRS armed vertical mode; runway track active lateral, nav armed; autothrust selected – TOGA, left pilot flying, flight director 1 displayed.

2. Airborne. SRS active, climb armed vertical mode; nav active mode.

7.3

5. Climb mode at airspeed 250 active vertical mode, altitude hold armed (FMS altitude).

6. Altitude hold active (FMS altitude), continued climb armed.

3. Autopilot 1 engaged.

7. Climb mode at airspeed 290 active vertical mode, altitude hold armed (cruise altitude).

4. Thrust auto-reduced to climb thrust.

8. Level at cruise altitude.

Cat 3 Autoland Example The following sequence of pictures shows a category 3 autoland approach from prior to ILS interception to the end of the landing ground roll. This sequence matches that displayed in section 5.3 above.

1. Level prior to ILS intercept. Autothrust engaged speed target 180 manually selected; altitude hold active vertical, nav active lateral; autopilot 1 engaged, flight director 1 information displayed.

2. Approach mode armed. G/S intercept/track armed vertical mode; LOC intercept/track armed lateral mode.

6. Autoland criteria met.

3. Localiser intercept/tracking. Managed speed selected (green dot) computed target 140; LOC intercept and tracking commenced.

7. Commencement of autoland flare.

8. Autothrust thrust reduction to idle. 4. Autopilot 2 engaged, Cat 3 dual approach criteria met.

9. Idle manually selected. 5. Glide slope intercept/tracking commenced. New managed speed target 125 (due configuration change)

10. Ground rollout.

Please complete the questions contained in the attached word file “FMA Survey-Questions.doc)” . Complete survey return details are contained at the conclusion of the questions file. Please do not return this file with your survey questions. (It over fills my yahoo inbox). Thank you for your time.

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