How to - Brake To Vacate (BTV) - Setup & Operation

[richboy2307]

SYSTEM OVERVIEW

The Brake To Vacate (BTV) function optimizes the autobrake deceleration on landing in order to reach the selected runway exit point/ manually entered landing distance. The system takes into account the selected runway condition/braking action in its calculations.

Once armed, the system works autonomously to delay braking in order to reduce brake wear, optimize the runway occupancy time (ROT) and improve passenger comfort.

 

SETTING UP BTV

In order for BTV to function, it needs information such as your stopping target stopping distance and runway condition. This information can be provided by 2 ways:

1. via Exit Selection on the ANF (airport moving map on ND), OR
2. via Manual Distance Entry

Instructions on how to set up BTV using each method is shown below.

1. Exit Selection on the ANF [*Navigraph Only]

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Note: This feature requires an active Navigraph Unlimited subscription. A valid airport map must be loaded on the ANF, which can only be done after successfully connecting your Navigraph account on the OIS Third Party Settings page.

For more information, see the below CONNECT TO NAVIGRAPH section of the ANF FAQ post:

Step 1: Choose Landing Runway on FMS

• Press the F-PLN shortcut key to go to the FMS F-PLN page
• At the bottom left corner, select your DEST airport and select the Landing RWY
  - you can also select your APPR and STAR on this page, however the BTV system only requires the runway at minimum to function
• Choose TMPY F-PLN and then INSERT TMPY to confirm the selection.

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Step 2: Set ANF to your DEST airport

 

Whilst on the ANF display, the currently displayed airport map can be changed via the ARPT SEL function page as follows:

• Change to PLAN mode via the ND Mode Selector Knob
• Change the range to ZOOM via the ND Range Selector knob
• Move the KCCU cursor to the ND screen by
  - Clicking anywhere on the ND screen, OR
  - Clicking the ND key on the KCCU
• Click the double-arrow Additional Function Button at the bottom-right corner of the ND
• Select the (A) ARPT SEL tab
• Choose from the (B) FMS AIRPORTS list to display your Destination
• Click the (D) DISPLAY AIRPORT button to make it the active displayed airport.

  

(Click to enlarge image)

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Note: You can only view other airports in the ND PLAN mode. The airport navigation display is locked to the aircraft position in NAV or ARC modes, so you must switch to PLAN mode in order to center the map on the selected airport.

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Note: Your selected airport ICAO/IATA/Info will appear in

• Yellow when it is the not active airport displayed on the ND
• Green when it is the active airport displayed on the ND

 

Step 3: Choose target Exit via ANF

• Click-and-drag to center the map on your desired exit
• Click the interactable taxiway icon on the runway (interactable elements have a blue border around them)
• Select SET BTV EXIT from the options list
  (You can also UNSET BTV EXIT from the same options list to remove your selection)

Once a target Exit is chosen,

• A blue line will appear along the landing runway to the selected exit showing the chosen BTV target exit, AND
• On the top left corner of the ND, you will see the chosen RWY (and its LDA), BRAKING CONDITION and EXIT as well as the corresponding Runway Occupancy Time (ROT)(in seconds) and TURNAROUND time (in minutes) for MAX REV or REV IDLE usage respectively.

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Step 4: Choose the Braking Action / Runway Condition

• Pull the RWY COND/BRAKING ACTION KNOB-SELECTOR to bring up the RWY CONDITION / BRAKING ACTION matrix on the SD
  (this knob is located just above the landing gear lever)
• Rotate the selector clockwise (or anti-clockwise) to choose between the various RWY CONDITION / BRAKING ACTION options
• After a few seconds, the selected option is validated automatically
• Push the knob selector to hide the RWY CONDITION / BRAKING ACTION matrix on the SD

 
(Click to enlarge image)

 

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Note: You must choose an exit beyond the DRY or WET ROW Stop Bar depending on your runway condition/braking action. These stop bars move as you change the runway condition/braking action.

If you chose an exit that is before the DRY or WET ROW line, the BTV will not be able to stop to reach the exit in time.

 

2. Manual Distance Entry

Step 1: Choose Landing Runway on FMS

• Press the F-PLN shortcut key to go to the FMS F-PLN page
• At the bottom left corner, select your DEST airport and select the Landing RWY
  - you can also select your APPR and STAR on this page, however the BTV system only requires the runway at minimum to function
• Choose TMPY F-PLN and then INSERT TMPY to confirm the selection.

(Click to enlarge image)

Step 2: Open the LANDING function page

• Change to PLAN mode via the ND Mode Selector Knob
• Change the range to ZOOM via the ND Range Selector knob
• Move the KCCU cursor to the ND screen by
  - Clicking anywhere on the ND screen, OR
  - Clicking the ND key on the KCCU
• Click the double-arrow Additional Function Button at the bottom-right corner of the ND
• Select the (A) LANDING tab
• Enter the BTV Exit (B) DISTANCE from threshold for your target
  (This information can normally be obtained from the Airport Ground / Information Charts)

Step 3: Choose the Braking Action / Runway Condition

• Choose the (C) LDG PERF CODE that is most suitable to the reported landing runway condition / braking action.

You can bring up the RWY CONDITION / BRAKING ACTION matrix for reference by,

• Pull the RWY COND/BRAKING ACTION KNOB-SELECTOR to show the matrix on the SD
  (this knob is located just above the landing gear lever)
• Rotate the selector clockwise (or anti-clockwise) to choose between the various RWY CONDITION / BRAKING ACTION options
• Push the knob selector to hide the matrix on the SD

 

  

 
(Click to enlarge image)

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Note: This method of arming BTV is useful users without Navigraph subcription, or if your landing airport/runway is NOT in the ANF database. The effectiveness of the BTV function in this instance is solely dependent on the accuracy of the distance data you feed into it.

 

BTV ARMING &  ENGAGEMENT

The BTV autobrake mode arms when the following conditions are met:

• A BTV exit is selected OR BTV distance is entered manually, AND
• A/BRK pushbutton is pressed

Once successfully armed,

• The A/BRK pushbutton will be lit up green
• The PFD FMA will show BTV in blue

 
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The BTV autobrake mode engages on landing if any one of the conditions is met:

• immediately after ground spoilers extension if the NLG is on ground; OR
• 5s after ground spoilers extension if NLG is not on ground

(Click to enlarge image)

BTV DISARMING & DISENGAGEMENT

The autobrake disarms if any one of the conditions is met:

• The A/BRK pushbutton is pressed again, OR
• The selected landing runway on the ANF is modified, OR
• The BTV exit is deselected, OR
• The FMS runway is changed to a runway that is different from the selected landing runway, OR
• A go-around is performed below 600 ft.
  The reversion occurs during the go-around, when the aircraft climbs above 600 ft. The computation is based on the minimum between the radio altitude, and the aircraft height above the runway threshold.
   

The autobrake disengages if any one of the conditions is met:

• The aircraft ground speed reaches the BTV disconnection speed (approx. 10 kt), OR
• The flight crew uses the brake pedals, OR
• The flight crew presses the A/THR instinctive disconnect pushbutton, OR
• The ground spoilers retract or disarm.
   

When autobrake disengages the the following happens:

• A single chime audio indicator sounds
• The MASTER CAUT lights comes on
• The AUTO BRK OFF memo appears on the PFD and WD.
   

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Note: Reversion to BRK MED if the BTV function becomes inoperative. When this happens you will hear a triple click audio alert and BRK MED appear on FMA with a white box for 10s.