jetcareers - View Single Post - A Little Help With an E6-B Wind Problem?

flyguy · March 13th, 2005, 17:53

[ QUOTE ]
If true heading is given, then it's essentially a backwards wind triangle. Normally you have true course and need to find true heading with the proper wind correction angle.

And this DOES belong in Technical Talk, and you should give yourself twenty lashings with a wet noodle for trying to beat the system for your own gain!

[/ QUOTE ]
That's how I would think to do it, however if you try it on the E6-B it dosn't work. I set the wind mark, 123 at 21, then rotated 253 under the true index and the wind mark on 140 and it is 7 degrees left and I get a groundspeed of about 152. Since we already have true heading I would add the 7 degrees instead of subtract to get true course and come up with 260. Sounds about right but if I test the answer by setting the true course of 260 under the true index and keep the wind dot on 140 I goes to 6 degrees left and groundspeed moves up two notches making my true heading 254 (260 minus 6 degrees left) and groundspeed 154. Its really close but I don't think it works becaue no matter what combination of true course and groundspeed you come up with you will always have to move it to cross check the answer and that changes true heading and groundspeed. In other words, it always works one way but not the other and if it did work this way it should always come out the same both ways. It also seems that there would be more than one combination of true course and groundspeed that would yeild the same true heading and TAS for a given wind. It almost seems like a trick question becasue you need either groundspeed or true course. If I was given groundspeed I could come up with true airspeed and true course, or if I was given true course I could come up with true heading and groundspeed, but it seems there's not enough information to get true course and groundspeed. Unless I'm missing something.

March 13th, 2005, 17:53	#7
flyguy Old Skool Join Date: Apr 2002 Location: Denver, CO Posts: 2,095	Re: A Little Help With an E6-B Wind Problem? [ QUOTE ] If true heading is given, then it's essentially a backwards wind triangle. Normally you have true course and need to find true heading with the proper wind correction angle. And this DOES belong in Technical Talk, and you should give yourself twenty lashings with a wet noodle for trying to beat the system for your own gain! [/ QUOTE ] That's how I would think to do it, however if you try it on the E6-B it dosn't work. I set the wind mark, 123 at 21, then rotated 253 under the true index and the wind mark on 140 and it is 7 degrees left and I get a groundspeed of about 152. Since we already have true heading I would add the 7 degrees instead of subtract to get true course and come up with 260. Sounds about right but if I test the answer by setting the true course of 260 under the true index and keep the wind dot on 140 I goes to 6 degrees left and groundspeed moves up two notches making my true heading 254 (260 minus 6 degrees left) and groundspeed 154. Its really close but I don't think it works becaue no matter what combination of true course and groundspeed you come up with you will always have to move it to cross check the answer and that changes true heading and groundspeed. In other words, it always works one way but not the other and if it did work this way it should always come out the same both ways. It also seems that there would be more than one combination of true course and groundspeed that would yeild the same true heading and TAS for a given wind. It almost seems like a trick question becasue you need either groundspeed or true course. If I was given groundspeed I could come up with true airspeed and true course, or if I was given true course I could come up with true heading and groundspeed, but it seems there's not enough information to get true course and groundspeed. Unless I'm missing something.