[{"data":1,"prerenderedAt":338},["ShallowReactive",2],{"learn-\u002Flearn\u002Fcrosswind-components":3,"learn-nav-\u002Flearn\u002Fcrosswind-components":303},{"id":4,"title":5,"body":6,"date":241,"description":242,"draft":243,"extension":244,"faqs":245,"howTo":255,"keyTakeaways":263,"meta":264,"navigation":265,"path":266,"quiz":267,"seo":294,"series":295,"seriesOrder":296,"sources":297,"stem":300,"topic":301,"__hash__":302},"learn\u002Flearn\u002Fcrosswind-components.md","Crosswind components",{"type":7,"value":8,"toc":231},"minimark",[9,13,19,24,55,58,72,75,79,91,98,113,122,126,133,165,168,172,188,192,224,228],[10,11,12],"p",{},"A wind that is not straight down the runway pushes you sideways, and knowing exactly how much sideways turns a vague unease into a number you can act on.",[14,15,16],"blockquote",{},[10,17,18],{},"This is general educational information, not operational, legal, or regulatory advice. Rules differ by authority and change over time. Always verify against current official sources and follow your operator's approved procedures.",[20,21,23],"h2",{"id":22},"splitting-the-wind-into-two","Splitting the wind into two",[10,25,26,27,31,32,41,42,48,49,54],{},"A reported wind has a direction and a speed, but for a runway what matters is how that wind splits into the part blowing along the runway (the ",[28,29,30],"strong",{},"headwind component",", which helps you) and the part blowing across it (the ",[28,33,34],{},[35,36,40],"a",{"href":37,"className":38},"\u002Flearn\u002Fglossary#gt-crosswind-component",[39],"glossary-link","crosswind component",", which you have to control). The split is pure trigonometry, set out in the ",[35,43,47],{"href":44,"rel":45},"https:\u002F\u002Fwww.faa.gov\u002Fregulations_policies\u002Fhandbooks_manuals\u002Faviation\u002Fphak",[46],"nofollow","FAA Pilot's Handbook of Aeronautical Knowledge (FAA-H-8083-25)"," and the ",[35,50,53],{"href":51,"rel":52},"https:\u002F\u002Fwww.faa.gov\u002Fregulations_policies\u002Fhandbooks_manuals\u002Faviation\u002Fairplane_handbook",[46],"FAA Airplane Flying Handbook (FAA-H-8083-3)",", which give a chart that does the same job graphically.",[10,56,57],{},"With the angle between the wind and the runway called the wind angle:",[59,60,61,67],"ul",{},[62,63,64],"li",{},[28,65,66],{},"Crosswind component = wind speed x sine (wind angle).",[62,68,69],{},[28,70,71],{},"Headwind component = wind speed x cosine (wind angle).",[10,73,74],{},"The geometry is universal: it does not change by authority or aircraft. What changes is how much crosswind your aircraft and you can handle.",[20,76,78],{"id":77},"a-worked-example","A worked example",[10,80,81,82,86,87,90],{},"Runway 36 points to a magnetic heading of ",[83,84,85],"code",{},"360"," degrees (the number is the heading to the nearest ten, with the last zero dropped). The tower reports the wind as ",[83,88,89],{},"060 degrees at 20 knots",".",[10,92,93,94,97],{},"First the angle: the wind is from 060, the runway points to 360, so the wind is ",[83,95,96],{},"60 degrees"," off the nose. Then the components:",[59,99,100,107],{},[62,101,102,103,106],{},"Crosswind = ",[83,104,105],{},"20 x sine(60) = 20 x 0.87 = 17 knots"," (rounded).",[62,108,109,110,90],{},"Headwind = ",[83,111,112],{},"20 x cosine(60) = 20 x 0.5 = 10 knots",[10,114,115,116,121],{},"So that 20-",[35,117,120],{"href":118,"className":119},"\u002Flearn\u002Fglossary#gt-knot",[39],"knot"," wind gives you a 17-knot crosswind and a 10-knot headwind. If your aircraft's maximum demonstrated crosswind is 15 knots, this runway in this wind is already beyond the demonstrated figure, and you would look for a more favourable runway or reconsider the flight.",[20,123,125],{"id":124},"the-sine-rule-of-thumb","The sine rule of thumb",[10,127,128,129,132],{},"You will not always have a calculator on short final, so pilots carry the relationship in their head. Because the crosswind is the wind speed times the sine of the angle, and the sine of a few key angles is easy to remember, the ",[28,130,131],{},"clock-code estimate"," follows:",[59,134,135,142,148,154,159],{},[62,136,137,138,141],{},"about ",[83,139,140],{},"15 degrees"," off: roughly a quarter of the wind as crosswind;",[62,143,137,144,147],{},[83,145,146],{},"30 degrees"," off: roughly half;",[62,149,137,150,153],{},[83,151,152],{},"45 degrees"," off: roughly seventy per cent;",[62,155,137,156,158],{},[83,157,96],{}," off: nearly all of it (the true figure is about eighty-seven per cent, so treating it as ninety per cent is a slight, safe over-estimate);",[62,160,161,164],{},[83,162,163],{},"90 degrees"," off: all of the wind is crosswind.",[10,166,167],{},"It is an approximation of the trigonometry, handy for a quick mental check, not a replacement for working the numbers or reading the chart.",[20,169,171],{"id":170},"what-maximum-demonstrated-crosswind-means","What \"maximum demonstrated crosswind\" means",[10,173,174,175,178,179,183,184,187],{},"Many pilots treat the figure in the flight manual as an absolute limit, and for some aircraft it is, but the term is precise. The ",[28,176,177],{},"maximum demonstrated crosswind component"," is the value a test pilot of average skill demonstrated the aircraft could be safely landed and taken off in during certification, then published in the manual or on a placard. As the ",[35,180,182],{"href":51,"rel":181},[46],"FAA Airplane Flying Handbook"," explains, for many light aircraft it is a ",[28,185,186],{},"demonstrated value rather than a regulatory limit",", so exceeding it is not necessarily prohibited, but it is well beyond what was tested and your skill, the conditions, and your operator's rules all bear on the decision. Check your own aircraft's flight manual, because for some types it genuinely is a limit.",[20,189,191],{"id":190},"common-pitfalls","Common pitfalls",[59,193,194,206,212,218],{},[62,195,196,205],{},[28,197,198,199,204],{},"Tower wind is magnetic; the ",[35,200,203],{"href":201,"className":202},"\u002Flearn\u002Fglossary#gt-metar",[39],"METAR"," is true."," The wind read to you for take-off and landing is in degrees magnetic, matching the runway numbers, while the written METAR is degrees true, so do not mix the two when working the angle.",[62,207,208,211],{},[28,209,210],{},"Use the gust, not the mean."," A gusting wind can put the crosswind over your limit at the worst moment, so base the component on the gust value.",[62,213,214,217],{},[28,215,216],{},"A negative headwind is a tailwind."," If the wind is more than 90 degrees off the nose, the cosine goes negative, and you are looking at a tailwind component that lengthens your landing.",[62,219,220,223],{},[28,221,222],{},"Demonstrated is not always a limit, but treat it with respect."," Knowing the difference is not licence to ignore the figure.",[20,225,227],{"id":226},"in-pilot-efb","In Pilot EFB",[10,229,230],{},"Pilot EFB includes a crosswind and headwind calculator among its quick tools, and it shows you the decoded wind in the METAR, alongside your weather, NOTAMs, flight time, and logbook in one offline-first place. It is a study and planning aid, not a certified Electronic Flight Bag, and it does not know your aircraft's published crosswind figures or your operator's policy. Treat its output as a cross-check, work the limit from the reported wind and your own aircraft data, and follow your operator's crosswind policy. Saved weather stays readable offline; pulling a fresh observation needs a connection.",{"title":232,"searchDepth":233,"depth":233,"links":234},"",2,[235,236,237,238,239,240],{"id":22,"depth":233,"text":23},{"id":77,"depth":233,"text":78},{"id":124,"depth":233,"text":125},{"id":170,"depth":233,"text":171},{"id":190,"depth":233,"text":191},{"id":226,"depth":233,"text":227},"2026-06-01","How to resolve a reported wind into its crosswind and headwind components with simple trigonometry, a worked example, the sine rule of thumb, and what a maximum demonstrated crosswind really is.",false,"md",[246,249,252],{"q":247,"a":248},"How do you calculate the crosswind component?","Take the angle between the wind direction and the runway heading, then multiply the wind speed by the sine of that angle. The headwind component is the wind speed multiplied by the cosine of the same angle. So a 20-knot wind 60 degrees off the runway gives a crosswind of about 17 knots and a headwind of about 10 knots.",{"q":250,"a":251},"What is the maximum demonstrated crosswind component?","It is the crosswind value a test pilot demonstrated the aircraft could be landed and taken off in safely during certification, published in the flight manual. For many light aircraft it is a demonstrated figure rather than a hard operating limit, as the FAA handbooks explain, though your operator or your own judgement may set a lower limit.",{"q":253,"a":254},"Is there a quick rule of thumb for crosswind?","Yes. Because the crosswind is the wind speed times the sine of the angle, a wind about 30 degrees off the runway gives roughly half its speed as crosswind, about 45 degrees gives roughly seventy per cent, and about 60 degrees or more gives nearly all of it. It is an approximation of the trigonometry, useful for a mental estimate but not a substitute for the calculation.",{"name":256,"steps":257},"How to work out the crosswind component",[258,259,260,261,262],"Find the angle between the wind direction and the runway heading.","Take the reported wind speed; for a gusting wind, use the gust value to stay on the safe side.","Multiply the wind speed by the sine of the angle to get the crosswind component.","Multiply the wind speed by the cosine of the angle to get the headwind component; a negative result means a tailwind.","Compare the crosswind component against your aircraft's maximum demonstrated crosswind and against your own limits.",null,{},true,"\u002Flearn\u002Fcrosswind-components",[268,277,285],{"q":269,"options":270,"answer":275,"explanation":276},"How do you calculate the crosswind component from a reported wind?",[271,272,273,274],"Wind speed multiplied by the cosine of the wind angle","Wind speed multiplied by the sine of the wind angle","Wind speed divided by the wind angle","Wind speed multiplied by the wind angle in degrees",1,"The crosswind component is the wind speed times the sine of the wind angle. The headwind component is the wind speed times the cosine of the same angle.",{"q":278,"options":279,"answer":233,"explanation":284},"A 20-knot wind 60 degrees off the runway gives roughly what crosswind and headwind components?",[280,281,282,283],"A 10-knot crosswind and a 17-knot headwind","A 20-knot crosswind and no headwind","A 17-knot crosswind and a 10-knot headwind","A 15-knot crosswind and a 15-knot headwind","20 x sine(60) is about 17 knots of crosswind, and 20 x cosine(60) is 10 knots of headwind. So that 20-knot wind gives a 17-knot crosswind and a 10-knot headwind.",{"q":286,"options":287,"answer":292,"explanation":293},"What does the maximum demonstrated crosswind component mean for many light aircraft?",[288,289,290,291],"A demonstrated value rather than a regulatory limit","An absolute regulatory limit that must never be exceeded","The strongest wind the engine can tolerate","The crosswind at which the wings will stall",0,"It is the value a test pilot of average skill demonstrated the aircraft could be safely landed and taken off in during certification. For many light aircraft it is a demonstrated value rather than a regulatory limit, though your own limits, the conditions, and your operator's rules still apply.",{"title":5,"description":242},"plan-a-vfr-cross-country",5,[298,299],{"label":47,"url":44},{"label":53,"url":51},"learn\u002Fcrosswind-components","Operations","5Ysa2LlyKMoUeDK7MaQ5qhMUh09NHTACy9Rs0KSFfpM",{"related":304,"newer":319,"older":324,"series":329},[305,311,315],{"path":306,"title":307,"description":308,"date":309,"topic":301,"draft":243,"minutes":310,"series":263,"seriesOrder":263},"\u002Flearn\u002Fcold-temperature-altimeter-corrections","Cold-temperature altimeter corrections","Why a pressure altimeter over-reads in cold air, leaving you lower than indicated, and how to correct minimum altitudes for temperature on an approach in mountainous or freezing conditions.","2026-06-21",4,{"path":312,"title":313,"description":314,"date":309,"topic":301,"draft":243,"minutes":310,"series":263,"seriesOrder":263},"\u002Flearn\u002Fmode-s-and-ads-b-explained","Mode S and ADS-B explained","How Mode S adds a 24-bit address, selective interrogation and a data link to the transponder, the difference between elementary and enhanced surveillance, and how ADS-B broadcasts your GPS position.",{"path":316,"title":317,"description":318,"date":309,"topic":301,"draft":243,"minutes":296,"series":263,"seriesOrder":263},"\u002Flearn\u002Fthe-global-reporting-format-for-runway-conditions","The Global Reporting Format for runway conditions","How the Global Reporting Format (GRF) describes a contaminated runway, including the runway condition code (RWYCC) from 6 to 0, the assessment matrix (RCAM), and how the report is split into thirds.",{"path":320,"title":321,"description":322,"date":323,"topic":301,"draft":243,"minutes":310,"series":263,"seriesOrder":263},"\u002Flearn\u002Fdeclared-distances-tora-toda-asda-lda","Declared distances: TORA, TODA, ASDA and LDA","What the four declared distances mean, how clearway and stopway extend them, and why the length of runway you can actually use is rarely just the runway.","2026-06-02",{"path":325,"title":326,"description":327,"date":328,"topic":301,"draft":243,"minutes":310,"series":263,"seriesOrder":263},"\u002Flearn\u002Fholding-patterns-explained","Holding patterns explained","The standard holding pattern, how the legs are timed, the three entry procedures, and the maximum holding speeds, with the ICAO and FAA figures attributed because they differ.","2026-05-31",{"slug":295,"title":330,"part":296,"total":296,"prev":331,"next":263},"Plan a VFR cross-country",{"path":332,"title":333,"description":334,"date":335,"topic":336,"draft":243,"minutes":337,"series":295,"seriesOrder":310},"\u002Flearn\u002Fchoosing-an-alternate-aerodrome","Choosing an alternate aerodrome","When an alternate is required, the FAA 1-2-3 rule and alternate minimums, the EASA planning-minima approach, and the practical checks of weather, approaches, runway and services.","2026-04-22","Briefing",7,1781989191329]