Optimising Landing Braking Distance (War Thunder)

While commenting on some random rookie Q/A I realised this information isn't exactly anywhere on the internet so I've created this page. This guide excludes the belly slide or the indestructible engine sliding technique used on some planes like the Kikka, Me262, R2Y2, F3D and so on. Also if you do that there's a bug with a chance to send you flipping through the air.

Considering how safe WT is to landing fast and how long the majority of airfields are for pre-jet aircraft. When you're especially lazy (which is why I always do these erratic landings) or being a plain idiot in a jet aircraft landing or when you need to land faster than the stall speed (due to low tail and the lack of tail skid physics in War Thunder - especially an issue in the russian MiG jets line) it is very easy to land too fast for the airstrip. However once you're on the ground and your normal straight-line distance could be a little too far, it's not all over. You optimise time to save a second or two so you can reload quicker which is especially important in late jet ranks (tiers) where you're fighting a zombie rush of B-29 bombers and can't afford to waste too much time on the ground, and you optimise braking distance to save your butt from falling off the edge of the airfield plateau "cliff" or crashing into whatever.

And thus:

Here are some techniques you can use to optimise your brake distance and/or time:

Gun Recoil

An instantaneous means but can cost you quite a bit in SL over time. A Mitsubishi T-2 pilot may sometimes choose not to use their cannons with custom belts at all in a sortie so they may save 2100SL on each sortie by not using them on landing too. Custom belts if Since about early 2019 Gaijin has fixed a bug so that if you for example have 6 guns with 1800 ammo (Sabre) and you fire off 900 rounds with 900 to spare, you save yourself 3 clips worth of ammo in your spendings. Use you guns only if you really need to or you are just plainly optimising your stopping distance or time or if you're using some spare ammo or your ammo is just so cheap that you don't care about it or it is free. It always rounds down so if you only have one clip just use it until the next division of your clip (so if you for example have 1152 rounds in the sabre, you may use it up until you reach at most 905 rounds). The only difference between optimising distance versus time is when you fire these guns. Fire the guns as soon as possible (even in the air if it doesn't upset your stability) to optimise distance and on the ground with the last bullets leaving your gun when you stop to optimise time.

Aerodynamic Drag

Usually this is isn't much once you're on the ground unless you're a tail wheeled aircraft. Note that some aircraft whose nose attitude lies nose-down relative to the horizon such as the F-86 Sabre may have a few different optimum drag flap settings. The Sabre in question for example, shouldn't be on the ground with combat flaps, and consequently It should also take-off with combat flaps because that minimises drag. Either have it on landing or no flap setting to optimise induced drag.

Types of aerodynamic drag:

• • Form/Parasite Drag (Absolute minimum drag the body can experience). Usually this is pretty low however some aircraft have air brakes or propellers. Use them if they are available. No aircraft in WT have reverse thrust so we don't cover that here. Propeller driven aircraft sometimes has the option to expand radiators and to fine the propeller pitch angle (set propeller pitch angle to 100% in these aircraft) however they can risk over-speeding the engine and destroying it, although some overspeeding damage is actually reversible by reducing the engine RPM (The game doesn't care about manifold pressure except for overheating). Note that propeller pitch control and propeller RPM control are very different. Not many aircraft in WT have direct pitch control and AFAIK, the bf109 E series and the I-16/I-15 are perhaps some of the very few often used aircraft that actually have such systems. Apparently IRL though, I-16 has an automatic pitch system and the Hs.129 doesn't but we won't get into aircraft specific borked FMs. Air drag chutes don't pull your plane back and help stabilise any drift like they would seem, they just slow the plane down in general like a regular fixed air brake only with more drag and a limited functioning range. Learn the maximum and minimum deployment speed limits of your chute! Not that they vary much...

  • Induced Drag (Angle of the wings, flaps etc.). This may push the plane down or pull it up into the air. It may seem logical that a Sabre should land with flaps up rather than landing because you get more normal force into the ground and thus tire traction yeah? Well not in war thunder! As long as you're touching the ground you get a flat rate depending on the flight model so don't worry about that real physics stuff. Now if you're a helicopter you have special grants: You have a rotor system spinning above your head. Helicopter rotor drag is can be a bit weird depending on your collector setting, but basically you want to find the magic point between maximum collector, not leaving the ground due to lift and as much back pressure (pulling the stick towards you to pitch the helicopter up) without the tail hitting the ground.

Ground based Drag:

Basically whatever happens with the ground. Now unlike real life with the type of tires you fit onto aircraft, WT's landing gear physics aren't spectacular and maximum ground drag isn't necessarily mean running down the runway in a straight line. This actually comes to our benifit because it also cuts into our straight line distance when you turn.

• There is a flat braking force unless you have variable-press foot pedals but most people don't care about that since they aren't a necessary function in WT and the brakes should always be either fully on or fully off. Don't worry about damaging brakes, skidding and puncturing tires in WT, such maintenance problems don't exist in this game, just slam them down on landing.

• There is a maximum sideways force applicable. This means the maximum braking force you can receive depends on the angle between the sideways brake force and the straight line force and the best way to stop is actually to basically drift sideways like how takumi fujiwara's tofu car does in hairpin turns. The longest "distance" you can land on an airfield while optimising the straight-line landing distance path should appear like a fish hook or spiral so ideally you should actually land from the corner of the airfield seciond and drift in a bit arc that gets tighter as you slow down, rather than simply wiggling your tail like a lot of people do in realistic battles. However this comes at catch at a risk of destroying (IRL you would "fold" a strut or puncturing or "depart" the tire IRL) your landing gear. Now onto the limitations:

  1. (Global Constant) Maximum Sideways Force on the landing gear: 50 kph / 27 knots / 31 mph (Estimate). Simple 2D Trigonometry is applicable for the maximum angle of sideslip on the ground based on the above speed limit. For example if you're travelling at 70 kph, you can sideslip up to around 30 degrees. The optimum sideslip angle is around in the graph below in kph. It's best to side slip less than the maximum because a mistake (especially with tail wheeled aircraft where the centre of gravity may not be behind the main undercarriage/wheels and the drag force will make your plane ground loop/spin). Note that the 50kph limit value ALSO APPLIES TO HELICOPTERS (not that there are any aside from the rocket interceptors which will tilt over anyway) WITH FIXED SKIDS. This is why you always see me doing my helicopter skid-landings reasonably straight until I slow down enough even if the environment doesn't require me to.

  2. Tilt-over risk

     1. The maximum sideways speed is 50kph before they break off, although many planes have their CGs a little too high for the width of the base of that the landing gear covers (e.g. Spitfire, Bf109) and it may tilt the plane if you do this. However as long as the wingtip doesn't hit the ground faster than something like 2m/s and you aren't going too fast (unknown maximum speed limit number, sorry) the wing won't break off and you should be fine. You can calculate the maximum sideways force for the plane using a bit of trigonomerty if you know where the exact centre of gravity of the plane is but most people do, so you can just learn by trial and error but honestly at that point you're better off just not tilting the plane based on feel. This is a more than just mental maths draining than the landing gear break-off limit (next paragraph) because you need 3-dimensional vector consideration with aerodynamic and centre of gravity inertia forces rather than just plain 2D as the area that the landing gear covers is usually a triangle shape. In addition to this, you can aid or prevent the roll-over by using your wing ailerons or in a helicopter, the rotor but the maths for that get even more complicated because you'll need to calculate the lift for each wing so just forget it, so in short just learn not to tilt your aircraft by feel for each aircraft through trial and error.

 Optimising Braking Distance Angle: X axis: Speed (Km/Hr). Y axis: Angle from your movement vector versus your nose angle in Degrees