Deviation

[slick1537]

I just started flight planning in my last ground school and I feel pretty confident I could plan a flight with my E6B and compass thingy, however what Im not sure about is deviation. It seems to me that wind would play the biggest part on getting a correct heading during a deviation. Any tips or tricks on how to make your wind adjustment on the fly with your new heading?

[Jeff]

I just started flight planning in my last ground school and I feel pretty confident I could plan a flight with my E6B and compass thingy, however what Im not sure about is deviation. It seems to me that wind would play the biggest part on getting a correct heading during a deviation. Any tips or tricks on how to make your wind adjustment on the fly with your new heading?

 

I'm not sure if you're talking about magnetic deviation or deviating to an alternate LZ. Magnetic Deviation is the error in the ship's compass due to interference from electronic/electrical equipment on board. You will find your answer on the compass correction card that is displayed on or very near the magnetic compass.

 

If you're talking about deviating to an alternate LZ, then keep your wind plot on the wind side of the E6B. Do not erase it after flight planning. Take the E6B with you on the flight. Once you get your new course, work out the problem on the wind side to estimate ground speed and wind correction angle.

 

Hope this helped

 

~Jeff

[Gomer Pylot]

The thing to do (and it can be difficult) is to keep a picture in your head of your course, and its relationship to the deviation you made. It's not uncommon to deviate around weather, or to take a look at something you see in the distance if you're on a joyride. A good GPS with a moving map makes this easier, and makes learning how the deviations affect your required heading easier also. It's mostly a matter of practice and experience. I learned it back in the days before GPS was thought of, flying across the Gulf with a watch, a compass, and the waves for navigation tools. With experience, you can gauge the wind to within a couple of knots, and the direction very accurately. You learn to work it all out in your head, and pick up a heading that will take you to the destination. When you have to do it, you learn, and quickly.

Edited October 13, 2007 by Gomer Pylot

[slick1537]

From what I gathered from my instructor, it wouldn't be practical to bring the E6B with you on your flight. However I don't think it would take very long to just pull, spin the dial and slide it to the proper speed to get your wind correction angle, then again im not a rated pilot. I guess what im asking is are then any good rules of thumb when it comes to calculating a good wind correction angle in your head?

[palmfish]

Swag it.

 

The greatest correction angle is needed when the winds are coming at you from 90 degrees off to the side, and the least (none) when they are directly in front of or behind you.

 

Before you launch, you'll have already planned the correction for your planned headings, but in the corner of your route card, also write down the correction for the winds at 90 degrees (for example, if the winds are from 150, write down the correction needed if you're heading 060 / 240). If you know the correction at 90 degrees, then you can estimate the correction for the winds at 45 degrees (half of 90 degrees) on the fly. If you can do this, then you could also estimate the correction for the winds at 30 and 60 degrees. Knowing all this in advance will let you interpolate the correction for any heading.

 

Since the actual winds are always different than the forecast winds, you're going to be continually tweaking your corrections in flight anyways. That's why the most important thing you need to do while flying (especially instruments) is stay ahead of the aircraft by visualizing in your mind your current position and where you'll be in 2 minutes, 10 minutes, etc.

 

Also, as a memory aid while you're flying your route, take one of the instruments in the cockpit you're not currently using (maybe the heading bug, radar alt bug, #2 RMI, etc.) and dial in the heading that the winds are currently coming from. Now you'll always have a graphic image where the winds are hitting you from. I use this same memory aid to remember assigned altitudes, headings, etc.

 

I hope that's what you were asking...

Edited October 14, 2007 by palmfish

[Gomer Pylot]

Headwinds will affect you more than tailwinds, because they slow you, and therefore affect you longer. The best way to go about it is to pay attention at the start of the flight, and see how the wind is affecting your flight path in relation to landmarks, and make the adjustments early, before you get blown off course. It's usually not a huge problem for helicopters, because they don't fly that far, and thus can't get that far off course, in most cases. If you pay attention to your position on the flight, and have picked out some landmarks along the route, you won't get lost.

[Jeff]

From what I gathered from my instructor, it wouldn't be practical to bring the E6B with you on your flight. However I don't think it would take very long to just pull, spin the dial and slide it to the proper speed to get your wind correction angle, then again im not a rated pilot. I guess what im asking is are then any good rules of thumb when it comes to calculating a good wind correction angle in your head?

 

I don't think it would be impractical, except for local flights or flights in the traffic pattern. I don't take mine with me because I do most of my flying with a combination of VOR and GPS. Any flights that might be a little close on fuel, I find a potential fuel stop or two along the way so I can stop if I find wind conditions to be more adverse than forecast. (By more adverse, I mean either less of a tailwind or more of a headwind.) HOWEVER, any flight I go on that requires pilotage and dead reckoning, I will take my E6B so that in the case of a diversion or unforecasted winds adverse to my plan, I can re-calculate winds, headings, groundspeeds, and most importantly fuel required. Gomer is right in his statement regarding figuring it out in your head based on experience. But his method is based on experience. There are two ways you can get that experience: the hard way or the easy way. I'm not sure which one is which, but if I were you, I'd take my E6B along on the first few cross-country flights. But I would caution you not to crash the helicopter playing around with your E6B. Flying is your first priority! If you get into that desparate of a situation, and ATC can't help you out, then land somewhere and figure it out.

 

~Jeff

[rick1128]

Since you are using sectionals for normal flight training, a trick for figuring a course to an alternate is by placing a plotter between your present position and your new destination. Then by keeping the same angle, move the plotter to the nearest VOR circle. And that will give you your new course. Doing this in a helicopter is more difficult than doing this in a F/W. I have done it by replacing the plotter with my thumb and forefinger and drawing an imaginary line between them. You will be with in a few degrees. And by using pilotage you should be able to find the destination with little difficulty. As for compass deviation, it is generally just a degree or two, so unless you are doing total DR it will not make a major differance.

[slick1537]

All good information and what I was looking for. For some reason it never occured to me that I could just do a few calculations before hand and write them on my sheet.

[Gomer Pylot]

Maybe it's just me, but I've never thought it was that hard. I've carried a plotter and an E6B for many thousands of miles, but I don't ever remember pulling either out while flying. Well, I have used the E6B to figure TAS at altitude, just out of curiosity, but never for using the wind side. The only use I've found for the plotter was to draw 5-pointed stars on some platforms so the customer could paint them, wanting the Texas flag on the helideck. For the distances we generally fly in helicopters, you just don't have to be that precise with wind corrections. Getting it to within 10 degrees is usually close enough, and that isn't so hard. When you're starting out, it can be rather scary, because you don't realize what you're seeing, or what distances you're covering, but with a little experience it get a lot easier.

[slick1537]

Update: I have just finally done my first diversion flight, well wasn't really a diversion, but it was us jumping in the helicopter with no planning and my instructor saying, take me to this airport. I guess it isn't really that hard out here with the mountains of new england. Small cities marked on the sectional are pretty easy to pick out nestled in between the mountains and vegetation. What other tips do you guys have when it comes to picking out landmarks on the sectional. Any good ones to look for/avoid when in a urban setting vs a mountainous setting. I find railroads and power lines are great out in the mountains because they carve a nice line out of the trees, but are horrible around cities because you can't see them ad mist the sprawl.

[Goldy]

I find railroads and power lines are great out in the mountains because they carve a nice line out of the trees, but are horrible around cities because you can't see them ad mist the sprawl.

 

All I fly is in urban settings. Don't bother looking for the wires, look for the towers that support them, and fly over the top of each tower. You can see a tower from 2 miles out.