Originally posted by bounder
b)the bombsight is sensitive to lateral drift, so will compensate for any crosswind. the difficulty in bombing above the windlayer is to set your course deviation so that you pass over the target; but the bombsight will, if correctly calibrated, always tell you precisely where your eggs will land.
If you calibrate your sight correctly, the sight will compensate for any drift you are experiencing. The problem is that unless you have your course adjusted properly so that the drift puts you over your target, the course change you have to make to put the crosshairs on your target will throw off your calibration.
On the other hand, if you know your desired course to your target, you can figure the course adjustment you need to make to compensate for the drift, so your plane's ground track will be the course you want. First, look at the angle between your desired course and the wind, and then look up the angle and wind speed on the chart below to get the crosswind component (the number below the diagonal line) and the component along your line of flight (the number above the diagonal line):
Add or subtract the component along your line of flight to your
true airspeed (as appropriate, depending on where the wind is coming from), and then cross-index that speed with the crosswind component on this table:
That gives you the number of degrees that you have to turn into the wind to kill your drift. To verify that you've made the correct course change to kill the drift, when you go into calibration mode, you should not see any lateral motion of the ground in the sight view; iif you still have drift, you'll see the ground moving sideways as well as down toward the bottom of the sight.
