1. Put your heading on the ADF Card. It helps you to remember what you should see on the compass. It also helps orientate you so that you know if xxx heading is a left or right turn.
2. Using timed turns is easier than reference to the compass but a combinaion of both is best.
3. Look at the ADF. Heading Digits are placed every 30deg.
Rate 1 is 3 deg/ second.
Thus when asked to turn onto xxx heading complete the following;
1. Confirm that the compass heading is still what it should be. If not, reset the ADF card.
2. Count the number of 30deg segments and multiply by 10 seconds.
3. Count the remaining 10 deg segments and multiply by 3 seconds.
Add both together to get timing.
eg heading 290 and asked to turn onto 180
look at card you have 3 30degree segments plus 2 10degree segments. = (3*10) + (2*3) = 33 seconds.
It is a timed turn so Start time then start turn. When time is up, stop turn.
Remember that the turn "co-ordinator" is calibrated for a specific speed and only shows rate 1 if you have 1g, ball in the middle and this speed. However, for the IMC rating simply peg rate 1 and fly in balance.
Having leveled the wings and re-established straight and level flight, check compass. For adjustments of up to 20 degree simply count 1 banana, 2 banana etc For 20 deg plus do another timed turn.
For the compass turn remember to undershoot the nearest pole. Thus in the northern hemisphere undershoot north, overshoot south, no error east or west.
Keep bank angles to 15deg or less to avoid locking the compass card.
The error is about 30degrees at north or south and 0 at East or West. That means if turning onto a heading of north, you stop the turn 30 degrees before you get there. If turning onto south you stop the turn 30 degrees after you pass south.
If turning onto east or west then you stop the turn on the heading.
For points in between simply judge how much to use i.e. a turn onto 045 degrees is under shoot by roughly 15 degrees. i.e. stop tuen 15 degrees before you get there.
As I said previously, the best thing to do is a combination of the two. i.e. Doing a timed turn but if passing through east or west during the turn check that this happens at about the right time.
The most important thing is to be able to fly a constant heading when not turning. It is wandering all over the sky during straight and level that fails most instrument pilots. The turns are expected to firstly be in the correct direction, secondly get you into the ball park heading and thirdly to be finally corrected to the chosen heading which is then maintained.
Hope that helps.
Regards,
DFC