Landing an airliner is not simply a matter of touching down and applying the brakes. On a busy airport, the aircraft must also decelerate to a suitable taxi speed, reach an available runway exit and clear the runway in a predictable way. Airbus developed Brake to Vacate, usually abbreviated to BTV, to automate part of that process. Airbus states that BTV is available on the A350 and A380 and that the function optimises autobrake deceleration after touchdown so that the aircraft can vacate at an exit selected by the flight crew. [1]
The important point is that BTV is not simply another fixed autobrake setting. Conventional autobrake modes are normally selected according to a target deceleration level. BTV adds the selected runway exit to the calculation. The system works backwards from the position where the crew wants to leave the runway and controls deceleration so the aircraft reaches that area at an appropriate speed. Airbus describes the aim as optimising runway occupancy while also managing braking energy and passenger comfort. [1] [2]
The difference between autobrake and Brake to Vacate
An autobrake system controls wheel braking automatically after landing according to the mode selected by the crew and the logic built into the aircraft. BTV still uses automatic braking, but Airbus describes it specifically as a function that optimises the deceleration needed to leave the runway at the crew-selected exit. That makes the intended exit a planning input rather than leaving the crew to judge, after touchdown, whether a particular taxiway can be reached comfortably. [1]
This distinction matters because runway occupancy is a system-level issue. An aircraft that decelerates more aggressively than necessary may use more brake energy, while an aircraft that decelerates too gently may pass the preferred exit and remain on the runway longer. BTV is designed to reconcile those competing objectives by calculating a deceleration profile around a defined exit. Airbus also identifies reduced brake wear and improved passenger comfort among the benefits of optimised automatic braking. [1] [3]
The crew still chooses the exit
BTV does not independently decide where an aircraft should leave the runway. Airbus describes the function as operating against an exit selected by the flight crew. The crew therefore remains responsible for the operational choice, taking account of the runway, airport layout, landing conditions, taxi plan and other relevant information available to them. The automation then uses the selected exit as the target around which it manages post-touchdown deceleration. [1]
On the A350, Airbus couples this capability with the aircraft’s on-board airport navigation functions. Airbus describes the On-board Airport Navigation System, or OANS, as displaying the airport apron, runways and taxiways together with the aircraft’s position. In the wider Airbus landing-assistance architecture, this airport information gives the crew a clearer picture of where the aircraft is relative to the planned exit and the subsequent taxi route. [2]
Why the calculation begins before touchdown
A runway exit can only be targeted sensibly if the aircraft has enough distance to decelerate from landing speed to the speed required to turn off. Airbus’ description of BTV makes clear that the function is integrated into landing preparation rather than being an isolated brake command applied after touchdown. The crew selects the desired exit, and the aircraft can present information that helps confirm whether the planned landing and exit are compatible with the assumptions being used. [1] [2]
Airbus also places BTV alongside its Runway Overrun Warning and Runway Overrun Protection functions on the A350. Airbus says these systems were first introduced on the A380 and were further developed on the A350, where the landing interface can allow crews to check aircraft capability for the runway available using selected assumptions, including runway-condition information. That does not make BTV a replacement for landing-performance assessment; rather, Airbus presents the functions as complementary parts of a broader landing-assistance suite. [2]
What the aircraft is trying to optimise
There are several physical quantities behind any landing deceleration. The aircraft arrives with kinetic energy that must be reduced, and wheel brakes are one of the systems that absorb part of that energy. Airbus notes that brake temperature, brake wear and braking intensity are operational considerations, and its maintenance guidance recommends avoiding unnecessarily strong braking merely to reach a particular exit when the next exit would be operationally acceptable. [3]
That provides the engineering context for BTV. Instead of treating the shortest possible runway occupancy as the only objective, the function seeks an automatic deceleration profile that reaches the selected exit without unnecessary braking. Airbus specifically states that use of autobrake or BTV can provide a single brake application with optimised braking intensity, and it identifies reduced braking energy and brake wear as benefits of appropriate automatic braking. [3]
Why brake energy matters
Aircraft brakes are energy-absorbing components. Airbus explains that carbon brakes are subject to wear and that high temperatures can increase oxidation of the carbon material. The amount of heat absorbed during a landing depends on how much of the aircraft’s deceleration is achieved through the wheel brakes rather than aerodynamic drag and reverse thrust, together with the speed, mass and operational technique involved. Airbus therefore treats brake-energy management as both an operational and maintenance consideration. [3]
Airbus’ guidance also explains why a crew may sometimes accept a later runway exit. Taking over from autobrake and applying strong manual braking simply to make an earlier exit can increase brake wear and temperature. If operational circumstances permit, using the next exit can reduce that demand. BTV’s underlying value is therefore not just that it can help an aircraft leave the runway at a planned point, but that it can do so with a calculated automatic deceleration rather than forcing the pilots to chase the exit through late braking inputs. [3] [1]
Passenger comfort is part of the design objective
Automatic braking is noticeable in the cabin because passengers experience the longitudinal deceleration directly. A system that calculates the braking required for a known runway exit can avoid some unnecessary changes between gentle and aggressive braking. Airbus explicitly includes passenger comfort among the intended benefits associated with BTV, alongside runway-occupancy and brake-energy optimisation. [1]
This is an example of a wider design philosophy in modern transport aircraft: automation is most useful when it manages several constraints at once. In BTV’s case, the manufacturer describes a system that links the selected exit with automatic deceleration and the aircraft’s airport-navigation and landing-support environment. The result is not simply stronger or weaker braking, but braking planned around a specific operational outcome. [1] [2]
The role of runway condition
The braking capability available on a runway is not constant in every condition. Airbus says the A350 implementation of BTV and its associated runway-warning and protection functions introduced runway-contamination levels into the system logic. The crew can use the interface to check landing capability against the available runway using selected assumptions. This is particularly important because the exit that is practical under one set of runway conditions may not be appropriate under another. [2]
It is important not to overstate what this means. Airbus does not describe BTV as eliminating the need for operational judgement, runway-condition assessment or standard landing-performance procedures. Its own material presents BTV as a pilot aid embedded within a wider set of functions. The selected exit, the assumptions used and the crew’s compliance with procedures remain fundamental to how the system is used. [1] [2]
Why predictable runway occupancy helps an airport
Airbus developed BTV partly around the idea of optimising runway occupancy. At airports handling a succession of arrivals and departures, the time between touchdown and runway vacation is one of the elements that affects how efficiently the runway can be used. A function designed to deliver the aircraft to a selected exit using a calculated deceleration profile can make that part of the landing more predictable than relying solely on an ad-hoc manual decision after touchdown. [1]
That does not mean BTV itself determines airport capacity. Runway capacity also depends on runway geometry, air traffic procedures, traffic mix, weather, separation requirements and many other factors. The narrower, source-backed claim is that Airbus designed BTV to optimise runway occupancy for the individual landing aircraft by helping it reach the crew-selected exit with an appropriate automatic deceleration. [1]
BTV on the A380 and A350
Airbus states that Brake to Vacate is available across the A380 and A350 fleets. The manufacturer also says BTV and the associated runway-warning and protection concepts were introduced first on the A380 and were further improved for the A350. The A350 implementation forms part of a cockpit environment that also includes airport-navigation functionality and other landing-assistance features. [1] [2]
For an operator, the practical value of such a function depends on approved aircraft configuration, operating procedures, airport data and crew training. Airbus’ public material describes the capability and its intended operational use, but it does not remove the operator’s responsibility to use the aircraft in accordance with approved manuals and procedures. That distinction is important when discussing any automated flight-deck function: the technology supports the crew; it does not replace the operational framework in which the aircraft is flown. [1] [2]
What happens if the planned exit is no longer suitable?
The premise of BTV is a crew-selected exit, so the planning remains dependent on the operational situation. Airbus’ BTV briefing is specifically aimed at explaining how crews use the function and how A350 and A380 characteristics apply. The system should therefore be understood as procedure-driven automation: its outputs are meaningful only when the inputs and assumptions used by the crew remain appropriate to the landing being conducted. [1]
Airbus’ separate brake-care guidance reinforces the same principle from the maintenance side. It advises crews not to use unnecessarily strong braking merely to make a particular exit when another exit is suitable. That guidance demonstrates why the operational target must remain subordinate to the aircraft’s actual condition and the circumstances of the landing. [3]
The engineering idea behind BTV
At its simplest, Brake to Vacate turns a runway exit into a controlled deceleration objective. The flight crew defines where it intends to leave the runway, and the aircraft manages braking so that the target can be reached in a controlled way. Airbus’ public explanations consistently link the function with optimised runway occupancy, braking energy and passenger comfort rather than presenting it as a device for maximising braking effort. [1] [3]
That is why BTV is technically interesting. It shows how modern aircraft automation can link navigation information, crew intent and a physical system such as wheel braking. Instead of operating those elements as unrelated functions, Airbus combines them around a clear operational task: land, decelerate and reach the intended runway exit with a calculated braking profile. [1] [2]
Verified Sources / References
- Airbus Flight Safety — BTV Operations Briefing
- Airbus — 5 Reasons Pilots Love Flying the A350
- Airbus Flight Safety — Take Care of Your Brakes
Editorial Notice: This article was prepared using information considered reliable and publicly available at the time of publication. Every reasonable effort has been made to ensure accuracy; however, aviation information can develop or be revised, and subsequent information may alter the facts or context reported. If you believe any material is inaccurate, misleading, improperly attributed or should be reviewed for amendment or removal, please contact us with the article title, the specific passage concerned and supporting evidence. We will assess legitimate requests promptly and, where appropriate, correct, clarify, update or remove the material.