Crosswind application(s)
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From: Malaysia
Crosswind application(s)
I bear a question that may seem silly and simple to many. However, I still am a cadet and my instructor requires me to figure the application out myself (and obviously, I'm unsure of the actual application). I hope that this question isn't too frivolous for you gentlemen. Let's have an example question: You're coming in for a finals approach, landing at 70 knots, RW27 with a crosswind component of 180/25. How would you go about in applying the rule of thumb, if any. Thank you gentlemen for your time.
Jet Blast Rat
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From: Sarfend-on-Sea
Re: Crosswind application(s)
This would not be a case for a rule of thumb, as for landing you will only require the crosswind component not the drift angle, and clearly here the crosswind is 25 knots. You do not fly a calculated heading on final, but a heading constantly adjusted to keep the centreline. Are you asking about landing wind components or about drift on a naviation leg? They are different although they can use one of the same techniques (the clock-face rule).
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From: Orlando, Florida
Re: Crosswind application(s)
For a student pilot - the first Rule of Thumb that comes to mind in those conditions is "Go Around" - and, in all seriousness, that COULD be the first answer you give your instructor when he aks you for one.
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From: Malaysia
Re: Crosswind application(s)
Originally Posted by Send Clowns
This would not be a case for a rule of thumb, as for landing you will only require the crosswind component not the drift angle, and clearly here the crosswind is 25 knots. You do not fly a calculated heading on final, but a heading constantly adjusted to keep the centreline. Are you asking about landing wind components or about drift on a naviation leg? They are different although they can use one of the same techniques (the clock-face rule).
Keygrip: Yes sir, that has already been done and he now requires me to initiate corrections during landings whenever there is a particular crosswind in effect. Yes, as a student pilot, our Xwind limitations would be no more than 20kts max, but I do require this application for further flights and to satisfy my current instructor's question/assignment to me.
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From: GA, USA
Re: Crosswind application(s)
Crosswind limitations of 20 kts as a student pilot ?
Are you sure you don't mean 5 kts or so?
Rule of thumb:
10 degrees cross 1/6th of windspeed is crosswind component
20 2/6 ,,
30 3/6 ,,
40 4/6 ,,
50 5/6 ,,
60 or more 6/6 or full crosswind.
Are you sure you don't mean 5 kts or so?
Rule of thumb:
10 degrees cross 1/6th of windspeed is crosswind component
20 2/6 ,,
30 3/6 ,,
40 4/6 ,,
50 5/6 ,,
60 or more 6/6 or full crosswind.
Thread Starter
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From: Malaysia
Re: Crosswind application(s)
B2N2: Yeap, 20kts. It is stated in our trainining SOP's. In anycase, that's basically just a method of determining exactly how much crosswind we'll be getting. My question has yet to be answered as a whole, and that is in referrence to what Send Clowns has mentioned earlier and that is we apply drift to fly centreline during landing. Is that all we need to bear in mind during a crosswind landing? I figured that this matter bears more weight now because it would seem that not long ago, an accident/crash happened to some airline (can't recall the details) due to the fact that the F/O did not carry out proper crosswind applications during landing and the captain failed to determine the fault and thus the mishap. In short, I'd just like to know, all we have do is apply a wind corrected heading to fly centreline during approach or is there something more to it than just that? And, anyone mind enlightening me on the clock-face rule? Thanks gentlemen.
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From: Europe
Re: Crosswind application(s)
ToPocHi
This links might be of interest
http://www.fly-safely.org/story.asp?id=79
http://www.eraa.org/intranet/documen...DINGLIMITS.pdf
http://www.flightsafety.org/news/nr99-05.pdf
This links might be of interest
http://www.fly-safely.org/story.asp?id=79
http://www.eraa.org/intranet/documen...DINGLIMITS.pdf
http://www.flightsafety.org/news/nr99-05.pdf
Last edited by tribo; 2nd January 2006 at 08:44.
Thread Starter
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From: Malaysia
Re: Crosswind application(s)
tribo: Thank you sir for the links. They are very helpful indeed. Thus, I can conclude that crosswind limitations are something that we must strictly adhere to. I can see why now. I'd always thought factors like microbursts/downdrafts, windshear, rain ice/severe ice accretion, poor visibilility are the main aviation hazards when related to meteoroligical conditions especially during landing but I suppose that ruling crosswinds aside (even if it's as low as 10kts) wouldn't be that wise of an idea. Probably it's because I haven't heard from any senior pilots making a fuss about crosswinds before or it never had seemed for once that an instructor here struggled to land an aircraft under adverse crosswind conditions. Has anyone here had difficulties relating to crosswinds alone, and I mean as a standalone factor (be it wide-bodied jet aircrafts to single-engine propeller aircrafts).
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From: UK
Re: Crosswind application(s)
ToPocHi
The crosswind component varies as a function of the sine of the wind angle (the difference between your track and the wind direction). As the sine of 90 is 1 you have full crosswind in your scenario; if the wind was 30 degrees off track you would have a crosswind component of sine 30=0.5. As your approach speed is 70kts it would seem that you are flying a light training aircraft which will probably have a Demonstrated max crosswind limit of about 17kts.
The point your instructor is making, I would imagine, is that although it would be possible to track the centreline all the way down final in this case, it would be unlikely that there would be enough rudder authority to correct the drift before touchdown. It would also be illegal to attempt to land with the crosswind compenent outside the demonstrated safe limits for that aircraft. This is an airmanship test and the answer to your instructor should be "The crosswind is outside the limits for the aircraft and I need to ask for another runway or divert to an airport that has a more suitable runway." Of course, this scenario should be dealt with at the pre-flight planning stage as 25 kt winds are usually predicted in the Tafs.
The crosswind component varies as a function of the sine of the wind angle (the difference between your track and the wind direction). As the sine of 90 is 1 you have full crosswind in your scenario; if the wind was 30 degrees off track you would have a crosswind component of sine 30=0.5. As your approach speed is 70kts it would seem that you are flying a light training aircraft which will probably have a Demonstrated max crosswind limit of about 17kts.
The point your instructor is making, I would imagine, is that although it would be possible to track the centreline all the way down final in this case, it would be unlikely that there would be enough rudder authority to correct the drift before touchdown. It would also be illegal to attempt to land with the crosswind compenent outside the demonstrated safe limits for that aircraft. This is an airmanship test and the answer to your instructor should be "The crosswind is outside the limits for the aircraft and I need to ask for another runway or divert to an airport that has a more suitable runway." Of course, this scenario should be dealt with at the pre-flight planning stage as 25 kt winds are usually predicted in the Tafs.
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From: Europe
Re: Crosswind application(s)
Originally Posted by ToPocHi
but I suppose that ruling crosswinds aside (even if it's as low as 10kts) wouldn't be that wise of an idea.
airplane had crosswinds of approximately 8 kt. The
pilots reported that it was difficult to stay on course.
They had to reduce thrust-reversal repeatedly in order
to stay on the runway. Here the weathervane effect
effected the airplane and contributed to the extension
of the braking distance.
http://www.bfu-web.de/nn_53140/EN/Pu..._Hahn_DC10.pdf
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From: Wiltshire
Re: Crosswind application(s)
The simple answer to your question of clock/crosswind.
Up to 15 degrees off runway heading - 1/4 windspeed = crosswind component
Up to 30 degrees off runway heading - 1/2 windspeed = crosswind component
Up to 45 degrees off runway heading - 3/4 windspeed = crosswind component
60 degrees + off runway heading = full windspeed as crosswind component.
Up to 15 degrees off runway heading - 1/4 windspeed = crosswind component
Up to 30 degrees off runway heading - 1/2 windspeed = crosswind component
Up to 45 degrees off runway heading - 3/4 windspeed = crosswind component
60 degrees + off runway heading = full windspeed as crosswind component.
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From: Wor Yerm
Re: Crosswind application(s)
ToPocHi, I think that you are making meal of this! I also believe that whilst formulae may be used, they rarely are. The Mark I Human Being (the type that flies planes for a living), when doing "square" (boring?) circuits, merely places the aircraft on the extended centreline, nose a bit into the wind (a guessed heading). Then they wait and see what happens to the track made good and make adjustments as appropriate. No maths, no formulae, just common sense!
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From: yyz
Re: Crosswind application(s)
Originally Posted by apruneuk
ToPocHi
It would also be illegal to attempt to land with the crosswind compenent outside the demonstrated safe limits for that aircraft. .
It would also be illegal to attempt to land with the crosswind compenent outside the demonstrated safe limits for that aircraft. .
WTF Illegal no, ill advised maybe. There are limits, and then there are demonstrated. Don't confuse them
Thread Starter
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From: Malaysia
Re: Crosswind application(s)
rigpiggy, oldfella: So, that's the clock-face rule. Simple, yet essential. Thank you sirs for the clarification. One more thing that has to do with breaching the SOP's, wouldn't that be considered illegal and can be considered an offence to (local) civil aviation law? Although instructors tell me so, I personally see pilots breaking the SOP's as they like as in flying the plane as they will. Nothing much that can be done there now, can it? Or it's become such a norm that authorities now take it as they come as well. No such thing as the last straw here eh?
Piltdown Man: Perhaps so, but it's all for improving one's flying capabilities. However, from past scenarios and incidents/accidents/crashes, doesn't it somewhat show that crosswind applications are important and they cannot be neglected? Isn't that the probable cause for so many accidents to still take place, even though the pilots behind the controls are vastly experienced? Just my two cents though. I personally have been flying the 'Mark I Human Being' way myself, until told off by my instructor. (and by the way, my instructor's from New Zealand) That's when he told me to find the application out.
Thank you all for your time and effort to attending this question here. I've learnt a lot from this thread itself. Thank you again sirs. Cheers.
Piltdown Man: Perhaps so, but it's all for improving one's flying capabilities. However, from past scenarios and incidents/accidents/crashes, doesn't it somewhat show that crosswind applications are important and they cannot be neglected? Isn't that the probable cause for so many accidents to still take place, even though the pilots behind the controls are vastly experienced? Just my two cents though. I personally have been flying the 'Mark I Human Being' way myself, until told off by my instructor. (and by the way, my instructor's from New Zealand) That's when he told me to find the application out.
Thank you all for your time and effort to attending this question here. I've learnt a lot from this thread itself. Thank you again sirs. Cheers.
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From: Wiltshire
Re: Crosswind application(s)
ToPocHi
The simple formulae behind the clock method can be used to determine the crosswind component in reverse if you have a drift indication on your instruments.
Drift angle multiplied by groundspeed in nm/minute = crosswind component.
e.g. Drift = 8 degrees, GS on approach = 150
Crosswind component = 8 x 2.5 = 20kt.
Useful if ATC have passed the wind on the field, use clock method to determine crosswind for landing. Check crosswind component inbound e.g. 1500ft. If there is a significant difference there may be a bit of shear on the approach.
The simple formulae behind the clock method can be used to determine the crosswind component in reverse if you have a drift indication on your instruments.
Drift angle multiplied by groundspeed in nm/minute = crosswind component.
e.g. Drift = 8 degrees, GS on approach = 150
Crosswind component = 8 x 2.5 = 20kt.
Useful if ATC have passed the wind on the field, use clock method to determine crosswind for landing. Check crosswind component inbound e.g. 1500ft. If there is a significant difference there may be a bit of shear on the approach.
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From: Somewhere between Cape Reinga and Invercargill
Re: Crosswind application(s)
Hi.
Speaking as a 35 hour ppl student here so you`ve been warned! The advice I have been given is to take the angle of of the wind from your track and add 20 and that is the %age crosswind. This doesn`t work for a 90 degree xwind as in your example (110% xwind conponent!) but works well with smaller angles.
EG landing rw 27 wind is 240/30: angle is 30 degrees of the rw hdg, therefore 30 + 20 = 50% of the wind as an xwind so 15 knots.
It`s far from perfect but works well for moderate angles. For 30 degrees only it is exact, as sine 30 is 0.5
Cheers
James
Speaking as a 35 hour ppl student here so you`ve been warned! The advice I have been given is to take the angle of of the wind from your track and add 20 and that is the %age crosswind. This doesn`t work for a 90 degree xwind as in your example (110% xwind conponent!) but works well with smaller angles.
EG landing rw 27 wind is 240/30: angle is 30 degrees of the rw hdg, therefore 30 + 20 = 50% of the wind as an xwind so 15 knots.
It`s far from perfect but works well for moderate angles. For 30 degrees only it is exact, as sine 30 is 0.5
Cheers
James
Originally Posted by ToPocHi
I bear a question that may seem silly and simple to many. However, I still am a cadet and my instructor requires me to figure the application out myself (and obviously, I'm unsure of the actual application). I hope that this question isn't too frivolous for you gentlemen. Let's have an example question: You're coming in for a finals approach, landing at 70 knots, RW27 with a crosswind component of 180/25. How would you go about in applying the rule of thumb, if any. Thank you gentlemen for your time.
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From: Here and there
Re: Crosswind application(s)
You guys are over thinking this to death, and I wonder if you are all looking at the wrong part of the landing.
First, as someone else has already mentioned, to get the correct drift angle you point the nose in to wind, then adjust as necessary to keep on centreline, simple. Second, I'm thinking his instructor maybe after the actual landing technique, i.e., in the flare you align the aircraft with the runway with rudder and apply into-wind-aileron to stop the aircraft drifting. Touch down one wheel at a time and Bob's your Uncle!
First, as someone else has already mentioned, to get the correct drift angle you point the nose in to wind, then adjust as necessary to keep on centreline, simple. Second, I'm thinking his instructor maybe after the actual landing technique, i.e., in the flare you align the aircraft with the runway with rudder and apply into-wind-aileron to stop the aircraft drifting. Touch down one wheel at a time and Bob's your Uncle!
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From: Wellington,NZ
Re: Crosswind application(s)
Agree this is being overthought. The crosswind component on the ground will often be different - sometimes significantly so - to that on the approach. In the OP scenario I would probably turn onto a final of about 250, and if the standard approach speed was 70, probably use 80+, and no flap. (raises touchdown speed, improves control response, reduces drift angle).
The main difficulty I've had, as a PPL, with x/w, is when its gusty, as it usually is, and constant drift re-corrections have to be applied throughout the flare and touchdown. This is real life. In my job as an ATCO the only problem I have is if someone screws up and closes the runway. Hardly ever happens. OP, I think you're being far too academic about this. And I doubt very much your x/w limit is 20. You can land a cherokee/c172 etc with 25 (or more) x/w, but you have to seriously know what you're doing. This is advanced training, and not a training SOP at PPL stage.More likely your instructor wants to know you are capable of knowing when to say "No"
The main difficulty I've had, as a PPL, with x/w, is when its gusty, as it usually is, and constant drift re-corrections have to be applied throughout the flare and touchdown. This is real life. In my job as an ATCO the only problem I have is if someone screws up and closes the runway. Hardly ever happens. OP, I think you're being far too academic about this. And I doubt very much your x/w limit is 20. You can land a cherokee/c172 etc with 25 (or more) x/w, but you have to seriously know what you're doing. This is advanced training, and not a training SOP at PPL stage.More likely your instructor wants to know you are capable of knowing when to say "No"
Thread Starter
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From: Malaysia
Re: Crosswind application(s)
Right on everyone, thanks for sharing your ideas and opinions on this. I've got more than enough feedback to know what to do, and to understand completely the various applications available there to correct for landing scenarios with crosswind component. My instructor was somewhat impressed with what I had to tell him regarding crosswind landings alone (based on the feedback here), and although it may seem something 'frivolous', I'd bet that in the near future when I graduate, all this will definitely come in handy. Thank you gentlemen and safe skies.