Calculating WV,GS, drift without the CRP-5

[coodem]

Does anyone know if there are any formulas that you can work the above out without using the CRP-5

I know the formula for xwind and headwind, but wondering if there were any others to replace the CRP-5

[EpsilonVaz]

Wind Correction Angle: http://upload.wikimedia.org/math/8/e/4/8e453d6b7f834fdf91f19f807fb77f51.png.

True ground speed: http://upload.wikimedia.org/math/7/6/f/76f35d3591271e5150b5c0b6485a58e0.png.

True ground speed is calculated as: http://upload.wikimedia.org/math/1/1/2/11229726db6f16be1fc23814b3783c1a.png.


Hope this helps.

EpsilonVaz

[hollingworthp]

Probably best to stick with the pooleys then ;)

[kwachon]

Just look at the FMS or :}

Wind Components/Correction
Wind Correction Angle 1. To determine the wind correction angle you must know the crosswind component at that altitude. 2. Divide the crosswind component by your True Airspeed in miles per minute, which will yield the wind correction angle. Ex. If the crosswind component is 14kts and the True Airspeed is 2 miles per minute (120kts),the wind correction angle is 7 degrees (14/2=7 degrees)

Wind Components 1. The 45 degree multiplier is 0.7 for headwind, tailwind & crosswind components. 2. And, for every 15 degree variation in wind direction from the 45 degree position, the 0.7 multiplier is adjusted by 0.2 Ex. Your heading is 090 and the wind is 165 degrees at 14kts. The wind is 75 degrees off the nose. (165-90=75) The headwind multiplier is 0.3, So your Headwind Component is 4kts (14*0.3=4kts) The crosswind multiplier is 1.0, So your Crosswind Component is 14 kts (14*1.0=14kts)

[coodem]

Thanks for all the help. Looks like its going to be easier to learn the CRP-5, I was just hoping there might be a way to get exact figures, but with a formula like that, I think I am going to run out of time or very likely to make a mistake.

I'm working towards the FMS, but before I get to use it they want me to be able to use the CRP

[wbryce]

Keep it simple, you can use clockcode to determine what wind correction to apply providing you work out max drift, which is quite simple using the 1/60 rule:- (60%Tas)*Windspeed.

Its the exact same method for crosswind calculations: If the wind is 30 degrees off your track then clock code says apply half of your max drift into wind and you now have your heading to fly. If its 50 degrees off track, then mathmatically its 5/6ths of max drift but realisticly when flying in the aircraft or even on the ground just take a little bit of max drift and apply the correction. Anything greater than 60 degrees you just apply full max drift, very simple to use in the air or on the ground - very useful for inflight diversions too! Works for headwind/tailwinds for groundspeed calculations too but you inverse the clockcode...

[dfspilot]

http://www.scenery.org/faq_aviation.htm
try this hope it helps.

[r44flyer]

I use max drift/clockcode for calculating wind correction.

For GS, I use the cosine rule. degrees the wind is off the nose/tail*cos = percentage of windspeed to add on or subtract. eg. 30knot wind, 20degree off the nose, 20cos = 94% = 28knots headwind.

I've had 3 pints so someone correct me if I'm wrong. lol.