Determining WCA on the Garmin G1000

[tech log]

Difference between track and heading = single drift

Fly single drift when you fly up the hold axis towards the beacon

Fly double drift when going outbound if the wind is from the non holding side (For example, hold axis is 360 degrees, this would wind be from the west, from the left)

Fly triple drift when going outbound if the wind is from the holding side

Your track on the G1000 is the magenta diamond on the pfd

Flying inbound to the beacon, adjust your heading so the blue nav aid needle is on the green course bar, i.e. on the hold axis, and the magenta diamond is on top of that. You have now found your single drift value aka the WCA. Mentally double or triple that value to come up with the heading you need to fly outbound on.

For example, let's say hold axis is 360 degrees, right hand hold, wind is 270/20 knots. You are flying directly to the beacon on the 360 QDM, bang on the hold axis, the needle is nicely aligned with the green course bar, the magenta track diamond is nicely aligned too.

20 knots crosswind from the left, at light aircraft speeds, basically gives max drift of 10 degrees.

The wind is 90 degrees off the hold axis so you use all of it. All crosswind, no head or tailwind.

So to maintain that nicely aligned hold axis, your WCA is going to be 10 degrees into wind. Which will be 350 degrees.

You're about to turn outbound over the beacon. Wind is from the non-holding side so double drift. Single is 10 so that's 20 degrees.

Recall that wind correction must be into wind. This is simple enough but is frequently an awkward concept to mentally calculate when your capacity is being squeezed in flight. You'll get there with practice.

With the hold axis being 360 degrees, that means the outbound track you want is 180 degrees.

With double drift, with the correction being applied into wind, that means you want an outbound heading of 200 degrees. So you'll turn past the outbound axis of due south 180 degrees, further to the right, to the south west, with the theory being that the crosswind from the west will not push you towards the east and thus miles out of the hold protection area because you've accounted for it by turning into it with the double drift.

Wind was all crosswind, so no time correction required, after 1 minute outbound you should be perfectly located, neither wide or narrow, ready to turn inbound directly on the hold axis, remembering to now hold single drift (350 degrees heading) inbound to the beacon again.

Is your instructor teaching you the gate method where at the 1 minute outbound point you should be at the imaginary 'gate', 30 degrees off the hold axis?





Holding is a flying technique that unfortunately can't be brute-forced. It has to click in your head. Once it does it will be easy but until it does it is a big capacity drain. Especially in those 40kt winds.

The golden rules with the G1000 are get the needle in the course bar and get the magenta diamond on top of that when tracking inbound, and to trust in the techniques like time correction and the curve of pursuit for parallel entries. Remember, it's not a problem to fly a hold and end up wide or narrow, you just correct for it with a heading change and will hopefully be spot on with the next lap. Once you've got single drift worked out you should be ok.

What will help you is to draw lots of diagrams on paper, make up various hold axis and wind scenarios and have a good think of what the EHSI should look like. Consider what changes you'd make to your outbound heading if you were hypothetically narrow or wide when turning inbound to the beacon, or at the gate if you're using that method.

If you have a USB joystick there are G1000 simulation products available you can practice at home with. Using Garmin's G1000 trainer at home, making myself deliberately wide and narrow to understand how the needles would then look, is how I got holding to click in my head.