340 Crash
Moderators: sky's the limit, sepia, Sulako, North Shore
Hydroplaning occurs when your wheels lock.
Anti-Skid prevents your wheels from locking during a skid.
If the airplane was travelling down the runway in runway soaked conditions, just because full brakes were applied doesn't mean that the wheels stopped turning or locked. This is the purpose of anti-skid, so if the anti-skid was working, then the entire airplane wouldn't have hydroplaned. I agree with the "driving down the street" example, however when full brakes are applied to a vehicle's anti-lock system, it doesn't mean your wheels will stop turning, it means that you're giving your computer an opinion of what you'd like to do and based on the deceleration of the other wheels, it will determine what speed to decelerate the slowest wheel. This is how hydroplaning is prevented. Anti-skid, meaning anti-skid.
Anti-Skid prevents your wheels from locking during a skid.
If the airplane was travelling down the runway in runway soaked conditions, just because full brakes were applied doesn't mean that the wheels stopped turning or locked. This is the purpose of anti-skid, so if the anti-skid was working, then the entire airplane wouldn't have hydroplaned. I agree with the "driving down the street" example, however when full brakes are applied to a vehicle's anti-lock system, it doesn't mean your wheels will stop turning, it means that you're giving your computer an opinion of what you'd like to do and based on the deceleration of the other wheels, it will determine what speed to decelerate the slowest wheel. This is how hydroplaning is prevented. Anti-skid, meaning anti-skid.
Hydroplaning doesn't depend on wheels locking. It is simply the process of your wheels loosing contact with the ground in the presence of water. As a matter of fact, NASA has a formula to determine the critical hydroplaning speed of aircraft tires in water with a depth of greater than 0.1 inches and it isn’t dependant on braking action at all. Regardless the size of the airplane, the formula is:
critical speed = 9 * (SQRT P)
Where speed is in Knots and P is the pressure of the tire in PSI.
The speed at which a vehicle’s tires begin to hydroplane can be improved a little by the tread pattern. But there isn’t a lot of variability in the tread pattern of airplane tires. Yes, braking aggravates the situation since locking up the tires will reduced the braking action to nil, but again, you certainly do NOT have to lock the tire up to hydroplane.
When free wheeling tires come into contact with water of a sufficient depth, they will actually slow down while hydroplaning even with no braking applied. Directional control from the tires is lost at this point.
So what is the purpose of anti-skid? To optimize braking action. If you are above the critical tire speed, anti-skid does nothing to avoid hydroplaning. As a matter of fact, braking action is nil while the vehicle is hydroplaning whether you have brakes or anti-skid or not. The key here is to avoid landing on runways with standing water on them of any significant depth.
Oh...and one other thing. The automobile system you are describing sounds more like traction control and/or stability control rather than ABS (anti-skid). ABS just modulates brake pressure when wheel lock is detected. It doesn't poll each wheel for speed.
critical speed = 9 * (SQRT P)
Where speed is in Knots and P is the pressure of the tire in PSI.
The speed at which a vehicle’s tires begin to hydroplane can be improved a little by the tread pattern. But there isn’t a lot of variability in the tread pattern of airplane tires. Yes, braking aggravates the situation since locking up the tires will reduced the braking action to nil, but again, you certainly do NOT have to lock the tire up to hydroplane.
When free wheeling tires come into contact with water of a sufficient depth, they will actually slow down while hydroplaning even with no braking applied. Directional control from the tires is lost at this point.
So what is the purpose of anti-skid? To optimize braking action. If you are above the critical tire speed, anti-skid does nothing to avoid hydroplaning. As a matter of fact, braking action is nil while the vehicle is hydroplaning whether you have brakes or anti-skid or not. The key here is to avoid landing on runways with standing water on them of any significant depth.
Oh...and one other thing. The automobile system you are describing sounds more like traction control and/or stability control rather than ABS (anti-skid). ABS just modulates brake pressure when wheel lock is detected. It doesn't poll each wheel for speed.
Toronto 340
He landed long with a tail wind.
The rest of this blithering is nonsense.
The rest of this blithering is nonsense.
Last weekend a newspaper article about fire rescue in YVR specified their ability to reach the end of any runway in under three minutes and the ability to use all their foam in 7 minutes.
If you are still pinned inside 10 minutes after the crash... I guess you are out of luck??
If you are still pinned inside 10 minutes after the crash... I guess you are out of luck??
