Hazards of Tire Hydroplaning to Aircraft Operation 1963 NASA Langley

https://i.ytimg.com/vi/TFOoFkYGqL8/hqdefault.jpg


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“A 1963 documentary on aircraft hydroplaning and the research conducted at the NASA Langley Research Center’s Landing Loads Facility. Landing gear and tires were tested for tire behavior in various pavement conditions.”

NEW VERSION with improved video & sound: https://www.youtube.com/watch?v=Si-CXLJfzWg

see also: “Automobile Tire Hydroplaning” 1994 NASA

Originally a public domain film from NASA, slightly cropped to remove uneven edges, with the aspect ratio corrected, and mild video noise reduction applied.
The soundtrack was also processed with volume normalization, noise reduction, clipping reduction, and/or equalization (the resulting sound, though not perfect, is far less noisy than the original).

http://en.wikipedia.org/wiki/Aquaplaning
Wikipedia license: http://creativecommons.org/licenses/by-sa/3.0/

Aquaplaning or hydroplaning by the tires of a road vehicle, aircraft or roller coaster occurs when a layer of water builds between the wheels of the vehicle and the road surface, leading to a loss of traction that prevents the vehicle from responding to control inputs. If it occurs to all wheels simultaneously, the vehicle becomes, in effect, an uncontrolled sled. Aquaplaning is a different phenomenon from water on the roadway merely acting as a lubricant. Traction is diminished on wet pavement even when aquaplaning is not occurring…

Causes

Every vehicle function that changes direction or speed relies on friction between the tires and the road surface. The grooves of a rubber tire are designed to disperse water from beneath the tire, providing high friction even in wet conditions. Aquaplaning occurs when a tire encounters more water than it can dissipate. Water pressure in front of the wheel forces a wedge of water under the leading edge of the tire, causing it to lift from the road. The tire then skates on a sheet of water with little, if any, direct road contact, and loss of control results. If multiple tires aquaplane, the vehicle may lose directional control and slide until it either collides with an obstacle, or slows enough that one or more tires contact the road again and friction is regained.

The risk of aquaplaning increases with the depth of standing water and the sensitivity of a vehicle to that water depth…

Response

What the driver experiences when a vehicle aquaplanes depends on which wheels have lost traction and the direction of travel.

If the vehicle is traveling straight, it may begin to feel slightly loose. If there was a high level of road feel in normal conditions, it may suddenly diminish. Small correctional control inputs have no effect…

Recovery

Control inputs tend to be counterproductive while aquaplaning. If the car is not in a turn, easing off the accelerator may slow it enough to regain traction. Steering inputs may put the car into a skid from which recovery would be difficult or impossible. If braking is unavoidable, the driver should do so smoothly and be prepared for instability.

If the rear wheels aquaplane and cause oversteer, the driver should steer in the direction of the skid until the rear tires regain traction, and then rapidly steer in the other direction to straighten the car…

In aircraft

Aquaplaning may reduce the effectiveness of wheel braking in aircraft on landing or aborting a takeoff, when it can cause the aircraft to run off the end of the runway. Aquaplaning was a factor in an accident to Qantas Flight 1 when it ran off the end of the runway in Bangkok in 1999 during heavy rain. Aircraft which can employ reverse thrust braking have the advantage over road vehicles in such situations, as this type of braking is not affected by aquaplaning, but it requires a considerable distance to operate as it is not as effective as wheel braking on a dry runway.

Aquaplaning is a condition that can exist when an aircraft is landed on a runway surface contaminated with standing water, slush, and/or wet snow. Aquaplaning can have serious adverse effects on ground controllability and braking efficiency. The three basic types of aquaplaning are dynamic aquaplaning, reverted rubber aquaplaning, and viscous aquaplaning. Any one of the three can render an aircraft partially or totally uncontrollable anytime during the landing roll.

However this can be prevented by grooves on runways. This was initially developed by NASA for space shuttles landing in heavy rain. It has since been adopted by most major airports around the world. Thin grooves are cut in the concrete which allows for water to be dissipated and further reduces the potential to aquaplane.

Aircraft