How do you use wind data
Thread Starter
Joined: Dec 2002
Aviation Qualifications: ATP+Mil
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From: Where the Quaboag River flows, USA
How do you use wind data
Anyone,
Given:
Runway 15
Winds: 260/15G20 Variable 240-330
How would apply the winds to make the landing calculation? Apply the basic wind, factor in the gusts or use the variable wind to arrive at an exceedence of the 10 knot tailwind component?
In the military heavies, we always used the "worst case", so added to the gust, the worst variable and, in this case, the wind limit was exceeded.
GF
Given:
Runway 15
Winds: 260/15G20 Variable 240-330
How would apply the winds to make the landing calculation? Apply the basic wind, factor in the gusts or use the variable wind to arrive at an exceedence of the 10 knot tailwind component?
In the military heavies, we always used the "worst case", so added to the gust, the worst variable and, in this case, the wind limit was exceeded.
GF
Joined: Mar 2001
Posts: 4,563
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From: I wouldn't know.
Most conservative or worst case, whatever you want to call it, still the correct way to do it. Our operation manual specifically includes gust values into the landing wind limit calculation, and of course the worst case wind direction has to be taken into account.
Joined: Oct 2001
Posts: 104
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From: North of Watford
Firstly, Why are ATC insisting that you use a runway with an excessive TWC?
Secondly V ref + calculations are predicated on the HWC of the wind. eg a 90deg x wind at 20 kts HWC nil therefore Vref +5 any gusts would cause additions. But the question remains that landing with a gusting TWC is setting yourself up for a rather unnecessary incident. Insist that the runway is changed
Secondly V ref + calculations are predicated on the HWC of the wind. eg a 90deg x wind at 20 kts HWC nil therefore Vref +5 any gusts would cause additions. But the question remains that landing with a gusting TWC is setting yourself up for a rather unnecessary incident. Insist that the runway is changed
Joined: Jan 2006
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From: US
Our manuals state that gusts are not limiting.
Judgement call with gusts. You can't go wrong using worst case but by not making it limiting it allows some leeway.
Nice having significant amounts of water around airports. You can see the gusts on the water. Are the gusts everywhere or less frequent? Again, comes down to judgement.
Judgement call with gusts. You can't go wrong using worst case but by not making it limiting it allows some leeway.
Nice having significant amounts of water around airports. You can see the gusts on the water. Are the gusts everywhere or less frequent? Again, comes down to judgement.
Joined: Mar 2001
Posts: 4,563
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From: I wouldn't know.
We used to have no guidance on gusts at all in regard to limits. It changed a lot after an incident of our biggest competitor in hamburg a few years back. Since then all limits are including gusts.
Joined: Jul 1999
Posts: 272
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From: England
misd-agin - Which manuals, the operations manuals or the POH? There is a big difference, often an operator will put information into their operations manuals that is not supported or substantiated by the manufacturers’ information.
Thread Starter
Joined: Dec 2002
Aviation Qualifications: ATP+Mil
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From: Where the Quaboag River flows, USA
The airport in question is a mountainous, essentially one-way, operation. Mountainous airports can have the worst combination-one way AND treacherous winds affected by heating in the valley or foehn conditions.
Thanks and anymore replies, I'd be pleased to listen to.
GF
Thanks and anymore replies, I'd be pleased to listen to.
GF
Thread Starter
Joined: Dec 2002
Aviation Qualifications: ATP+Mil
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From: Where the Quaboag River flows, USA
FlightPathOBN
KASE, If you must know, BUT the location is irrelevant, the question is the correct, WRT certification, method to apply winds.
GF
KASE, If you must know, BUT the location is irrelevant, the question is the correct, WRT certification, method to apply winds.
GF
Joined: Jan 2010
Posts: 37
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From: Los Angeles
we use half of the head wind plus (gust -wind speed),not less than 5 and not above 20 or the flap manuv speed -5
If you really want to land,teel the ATC,too strong wind for me,then he will tell you the wind is weak now.
If you really want to land,teel the ATC,too strong wind for me,then he will tell you the wind is weak now.
Joined: Oct 2003
Posts: 1,300
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From: Canberra Australia
Wind From or To
Who was/were the idiots who decided that we should use a wind direction of where it is coming from instead of where it is going to? I guess it was some sailor standing on his poop deck and I'll bet his course is not where he has come from!!
Who was/were the idiots who decided that we should use a wind direction of where it is coming from instead of where it is going to? I guess it was some sailor standing on his poop deck and I'll bet his course is not where he has come from!!
Joined: Mar 2012
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From: Dark Side of the Moon
Well in that case I would use the reciprocal runway (RWY33). Worst case on that runway would be ALL crosswind, as opposed to a significant tailwind possibly on RWY15. Assuming RWY33 not a possibility then I would use the gusts to determine if the tailwind was within limits.
Joined: Mar 2011
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From: engineer at large
Everything from the FAA guidance is worst case. I would love to use a component wind...I dont mean for the winds, but for the gusts, just dont see a lot of support for that...
Bears sorting it out with your chief...
Bears sorting it out with your chief...
Last edited by FlightPathOBN; 24th June 2012 at 22:20.
Joined: Mar 2011
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From: engineer at large
Let me run that down...my reference point is from the design of the procedures, and some of the components and coding in the FMS....I will see what, if any, relates to flight ops....
That is quite a variable wind, and I can certainly see many issues setting up the config for final. As everyone is noting, the system allows for a simple input...
Land fast, brake hard.
That is quite a variable wind, and I can certainly see many issues setting up the config for final. As everyone is noting, the system allows for a simple input...
Land fast, brake hard.
Last edited by FlightPathOBN; 24th June 2012 at 18:22.
