Help! with Gen Nav for ATPL

[VanderVlietm]

Please can someone help me...

I am finding it really hard to try and work out the following question.

You have departed point A (N50 30" E120 11") on a heading of 225degrees, you fly for 80 NM. What is your current position?

Do I use trig for this or am I being really stupid and need to use the convergancy formulae to work this one out.

Thanks very much, its been driving crazy the whole day.

[MrHorgy]

Take a look at the answers. if I remember the answer spread for the question, just some lateral thought is required (not meaning you have none), and no actual calculation.

I imagine the answer would be something along the lines of N49.00 E121.00.

Normally, there is only one answer that fits. The position will have to be to the south west of the initial position A (as the hdg is 225), so your looking at a Latitude that is decreasing, and a Longtitude that is increasing.

Horgy

[instructorpenguin]

Hi prev answer applied east west wrong way.

Use trig to establish lat. first as convergence not applicable to lat.

80*sin 45= 56.56 =50:30n-oo:57= 49:33n Check because only one answer will have this figure.

If time permits at end of exam or if 2 answers have this lat.

sin 45 = cos 45 so 57 nm traveled west. 57/cos mean lat 50:00 (0.64)= 0009. 120:11-0009=118:42

Given the above CAA questions tend to use 80nm and 45 deg which gives 1 deg lat so prev guy gave good advice. If in doubt draw it out!! in rough as a picture is worth a thousand words.

Good luck

[MrHorgy]

Ahh yes silly me, looking at that again I went the wrong way! Good luck with it anyway.

Horgy

[VanderVlietm]

Thanks for your help!

I was trying to work it all out using trig and pythagoras but that didn't work as I got the answer wrong.

Seems like drawing out a rough sketch is the best option and then ruling out one by one the correct answer.

Thanks again