NDB Question

[Yohan20]

Hey guys...I can get an answer by elimination but if someone can throw some insight

Questions:

1. MH of 070 and the RB to an NDB station is 340. In order to intercept a track of 300 (M) outbound from the NDB at 45 degrees, an initial heading of ...........is required.
a) 075 M
b) 165 M
c) 255 M
d) 345 M

The correct answer is d) 345, but I got this through elimination by drawing a diagram and picking the best answer which happened to be right.

Can someone add some insight how the answer is derived?

The second part of the question is:
2. Upon intercepting the required track, the needle of the fixed card ADF will indicate a relative bearing of

a) 045 Degrees
b) 315 Degrees
c) 135 Degrees
d) 225 Degrees

I cannot get this answer....which is c)

Can someone please help....

Thank you all....

[ifitaintboeing]

For the first question, if you draw it out, then the only answer where you would intercept the radial is D.

The answer to your second question: the aircraft is on a heading of 345, established on the 300 radial, therefore the RBI reads 135 degrees.



The relative bearing is where the NDB is in relation to the nose of the aircraft, i.e. the angle between our current heading and the inbound radial = 345 to North to 120 = 15 + 120 = 135 degrees.

Have a go at both questions with the simulator here:

http://www.luizmonteiro.com/Learning_ADF_Sim.aspx

ifitaint...

[Yohan20]

Thank you ifitaintboeing

This helped. Drawing a diagram sure helps on these questions.

[AerocatS2A]

Drawing pictures is an excellent tool. It helps if you can even just picture it in your mind. To get the answer mathematically though:

Question 1.

We want to intercept the outbound track of 300º FROM the NDB at an angle of 45º. The required heading must be either 345º or 255º depending on whether we are north or south of the desired track. Strike out A and B.

Magnetic heading is 070º
Relative bearing to the NDB is 340º
The NDB is 20º left of the nose (360º - 340º)

Therefore, the magnetic bearing TO the NDB is 050º (heading 070º - 20º)
The magnetic bearing FROM the NDB is 230º (050º + 180º)

So we are southwest of the NDB and generally south of the desired track. The heading to intercept the required track must be 345º.

[Yohan20]

Thanks AerocatS2A.
Makes more sense now......appreciate your help

[SFI145]

i) Bearing to NDB = 070-20 = 050M
Cut required = 45
Heading = 300+45 = 345M

ii) Our Heading is 345M which is 45 degrees more than the track required
So we need -45 on the RBI
Tail of the needle on 315
Head of the needle on 135