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View Full Version : Hydroplaning/Aquaplaning - Operation Perspective


lion-g
1st Aug 2008, 14:14
Hi Guys,

Just wanna check with you guys, from the operational perspective, how do you go about tackling aquaplaning when approaching a contaminated R/W or taking off from the R/W ?

In a way, by using the suggested formula, 9*sqrt(Tyre pressure(PSI)), and 7.7*sqrt(Tyre pressure(PSI)), what the significance of having the value and any technique to overcome aquaplaning if it actually happens on a slippery R/W, for T/O and LDG ?

Any guys who have experiences aquaplaning so far can share their experiences and the technique they use to overcome it?

Thanks a lot in advance,
Beginner in Jet Aviation

Milt
2nd Aug 2008, 00:40
Aquaplaning. You can't overcome it - it just happens.
One has to use other means than wheel brakes and nose wheel stearing to reduce speed and stay on the straight and narrow. Reverse thrust is best with as much aerodynamic braking as possible. If that is not enough be prepared for a go round and go someplace else..!! You could always wish for a braking parachute.

Intruder
2nd Aug 2008, 03:05
Land with your velocity vector straight down the runway.

Use reverse thrust and aerodynamic contorls to the max extent possible.

Use autobrakes and anti-skid when available.

Fly the airplane until it's stopped!

lion-g
2nd Aug 2008, 03:08
HI,

The point about velocity factor, if the planing occurs when we have full reversers deployed, do we stowed the reversers immediately as the velocity vector will probably put the a/c off the centreline ?

Just my thought.

Intruder
3rd Aug 2008, 02:05
There is a situation described in our 747 FHB that describes exactly that, on slippery runways such as ice and packed snow. I have never encountered it, and know of only 1 Captain who has. If you are flying the airplane all the way down the runway, you would not discretely recognize the situation until you found that rudder and aileron control do not keep you on the centerline. Idle reverse would be the next action, and out of reverse if you could not control it.

Generally, though, the 747 straightens itself on the runway after touchdown. If you have enough traction for the autobrakes and antiskid to work, then you probably have enough such that the reversers will not push you off the runway.

Boroda
3rd Aug 2008, 03:10
And positive touchdown is positive.