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xwind limit assy. consideration

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Old 2nd Oct 2004, 23:44
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Cool 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.
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Old 3rd Oct 2004, 01:56
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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.
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Old 3rd Oct 2004, 11:52
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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.
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Old 3rd Oct 2004, 22:26
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Unhappy

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.
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Old 4th Oct 2004, 03:57
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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.
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Old 4th Oct 2004, 10:29
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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)
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Old 4th Oct 2004, 19:30
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Lightbulb

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.
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