# Do commercial aeroplanes use ABS to brake?

I have read that the wheel brakes on an aeroplane are by for the most efficient means of stopping it. I was wondering whether in low grip situations, such as in rain or snow, an ABS (Anti-lock Braking System) system is used to ensure the wheels do not lock. If not, why is this not necessary?

• Yes, for much longer than automobiles do. Nov 11 '15 at 12:45
• I heard somewhere that is easier than for cars because you have direct access to ground speed thanks to some wheels that has no brake. Thus, you can adjust the brake strength to avoid having too great speed difference between braked wheels and non-braked wheels. Nov 11 '15 at 23:34
• I can't think of any car with unbraked wheels ... excluding antiques. Nov 12 '15 at 14:46
• Define "commercial". A C172 in commercial operation does not have ABS brakes. Apr 10 '19 at 17:17
• @a.out: A C-172 doesn't have enough payload capacity to carry any useful amount of passengers or freight. Oct 11 '19 at 5:38

Yes, they do. They are called Anti-Skid and they go from Mark I of 1948, with simply an on-off switch triggered by wheel lock, till Mark V (or at least that's the last I've seen), with quite complex control systems and sensors behind.

The full details are a bit long to include them all here (there are entire book sections about them). For a brief overview, see this presentation from slide 12 till 18.

• The basic system developed for airplanes is what led to ABS in automobiles; planes had it first. Nov 11 '15 at 19:21
• Anti-skid Mark I may date from 1948, but the idea and implementations of it date from the late 1920s. Nov 11 '15 at 22:08
• To extend the comparison with automobiles, Anti-Skid is rather more like a modern traction control system than simply anti-lock brakes. The braking system is actively manipulating the braking effort on all wheels to assist in vectoring the vehicle.
– J...
Nov 12 '15 at 12:00

It is not called ABS but Anti-Skid, but the principle is similar. All large aircraft have it.

The purpose is however slightly different. In aircraft the nose wheel has relatively little weight on it and is usually not braked, so directional control, the main reason for ABS in cars, is possible¹ even without anti-skid. However due to the higher speeds and weights involved, aircraft have much higher risk of skidding and hydro-planning and when either happens, it can severely damage the tires, so the anti-skid is to prevent that.

¹ To an extent. Since the nose wheel has little weight on it, it also has limited authority, so if the braking force becomes too asymmetric, the nose wheel can't compensate for it.

• aircraft have much higher risk of hydro-planning and the anti-skid is to prevent that that's secondary, the risk for aircraft is skidding even without any water: it leads to uneven usage of the tires, up to puncturing them.
– Federico
Nov 11 '15 at 18:51
• Skid damage: aerospaceweb.org/question/planes/q0245a.shtml
– Phil
Nov 12 '15 at 20:19
• @Phil Fascinating. 90-degree lock on the front gear, caused by an improperly installed shock absorber. Classic poka-yoke! Nov 12 '15 at 20:59
• Aircraft also usually have a rudder, which tends to help with directional control. Also, runways are generally far flatter and evener than roads. Dec 10 '18 at 4:11
• @Federico: In the realm of possible badness of consequences, blown tires << high-speed overrun. Oct 11 '19 at 5:39

The ABS systems in automobiles were based on the systems that had been in use in aircraft for decades.

ABS was first developed for aircraft use in 1929 by the French automobile and aircraft pioneer Gabriel Voisin, as threshold braking on airplanes.

The first ABS system used in a car was the Dunlop Maxaret system, which was developed for aircraft (and used in a lot of British aircraft in the 1950s and 1960s). It was used in the Jensen FF, introduced in 1966. From 1971, car manufacturers introduced purpose-built automotive ABS.