xwind limit assy. consideration
 

I have viewed other threads on the subject but am hoping if someone could shed some light on how a wet runway or a loss of engine would affect xwind performance.:O

1# With a dry runway/optimum braking action - max x-wind.
With no braking action - no x-wind permitted. Downgrading somewhere in between.
2# Engine failed - just make sure you land with zero thrust, and you don't need reverse thrust - then you're ok.

IF you have no takeoff penalty due to crosswind then it is likely that the cert testing demonstrated little or no need to use differential braking to maintain heading/centreline. In that case the effect of a wet runway on the takeoff crosswind limits should be negligible.

IF it was determined that differential braking was required then there SHOULD be some kind of lower limit on a wet runway to account for reduced steering capability from the brakes.

We always try to demonstrate Xwinds without diff braking.

Thank you both for your reply.I gather from your posts that the crosswind limitation is solely a consideration in maintaining directional control on the runway during a landing or a rejected takeoff with the aid of differential braking.

Are the airborne handling characteristics considered in the equation (so to speak) if for instance a critical engine is lost with maximum xwind adding to the rudder correction required.
If I remember correctly the xwind limit on the light turbo-prop Embraer 110 was TKOFF 18kts and LDG 25kts.:p

Crosswind control with jet transport aircraft is certainly not acceptable using differential braking, on the types that I have flown.
Come to think of it, not on heavy turboprops/pistons either.

Except for C46/DC3's etc.

Now with light piston aircraft, a completely different story.

Xwind limit isn't just a ground handling issue, the whole T/O or landing is assessed. But in the context of the original question, it's obviously ground handling that's impacted by the wet runway.

In-air one will be concerned with e.g. excessive bank angles (fear of tip strike) and any difficulty due to turbulence (which is usually associated with high winds)

Back to the question



Wet runway and crosswind:

On landing NO effect
On take-off it does effect, wet rwy max. crosswind (guideline) is lower than on a dry rwy.

Main reason is lesser grip of the nosegear in case of engine failure.

Hence:

Engine inop and crosswind:
On landing NO effect
On take off it does effect, wet rwy max. crosswind (guideline) is
lower than on a dry rwy.

Main reason is lesser grip of the nosegear.
On landing no effect but in the landing roll-out there is ofcourse a noticable easy handling yaw difference due assymetrical reverse thrust.



A runway with either standing water / slush, snow or ice is affected on max crosswind (guideline) on BOTH take off and landing.


Cheers.