Hi Bob, Richard and All!

Just one I intially got wrong was I over thought the question 2 on page 3.12 and actually used the Conversions - Wind Component chart instead of just opting to take the question on face value without making a conversion.

What I initially did was I decided that since we had a 15kt wind from 350 deg M but a RWY that was 18/36 that based on common sense dictating that we would use RWY 36 which was 10 degrees different in direction to the wind direction.

So I got smart and converted the Wind on the conversion chart, which throws the answer right out. It puts your 15 knots down to only 3 knots if converted, so just stick with the original 15 knots.

So for anyone doing this question they need to know to take the 15 kts as straight down the runway and dont convert.

Please correct me if I am wrong!

Brook

Hi Brook,

Looks like you have actually calculated the crosswind component there mate and not the headwind. You need to read the angle off the runway heading from the scale along the bottom of the chart for headwind and not the top. The top row is for crosswind component. Using the chart for a 15 kt wind 10 degrees off the runway heading you get a 3 kt crosswind and 14kt headwind.

Using the table is more accurate than ignoring headwind/crosswind components altogether but for smaller differences in angle, you can assume pretty much all the wind is headwind. There are a couple of rules of thumb floating about but the wind component table in ERSA GEN-CON certainly is a useful tool.

Cheers,

Rich

Oops! I am a Dufus! Thanks Richard!

So tell me was the chart a factor to be considered in that question or one I would get in an exam?

Brook

Hi Brook,

In this example there was only 1 kit difference so It wouldn't significantly affect your answer. The wind component table is there to be used so why not use it in the exam? It can only make things more accurate and I'd be surprised if the examiner didn't use exact values when working the answer.

Cheers,

Rich