2 Questions, Radio Navigation
 

Hi

Im going through the VOR chapter in Radio Navigation. I would be pleased if someone of you could explain and help with these 2 questions.

Question 1

An aircraft is on the airway bondary range 100nm from a VOR marking the airway centre line. Assuming that each dot equates to 2 degrees, how many dots deviation will be shown on the deviation indicator?

A) 3.0 dots
B) 2.5 dots
C) 2.0 dots
D) 1.5 dots

Correct answer is: D

Question 2

An aircraft is required to intercept and home to a VOR along the 064 Radial. The OBS should be set to:

A) 064 to get correct needle sense and a TO indication.
B) 244 to get correct needle sense and a TO indication.
C) 064 to get correct needle sense and a FROM indication.
D) 244 to get correct needle sense and a FROM indication.

Correct answer is: B

Thanks

/M

ok I get the question 2, but no idea of question 1...

If you do the trig:

arctan(5/100) = 2.86 degrees (5NM airway width, 1 in 60 rule)

If one dot is 2 degrees then deflection is 2.86/2 = 1.43 dots (Answer D)

Bobby

RA=60D


You need the angle which is A, therefore: A=(60xD) / R
Range = 100nm
Airway boundary Distance = 5nm
(60x5)/100 = 3 degrees which is 1 and half dots..
If that makes sense..

mx4, if you battle with the second question, here's an easy way of remembering how to set up the OBS to intercept a radial.

I always teach FROM -> top TO -> bottom. Meaning:

If you intercept a radial to fly FROM a station, then the radial you wish to intercept must be on the TOP of the OBS, and a FROM indication must be showing.

If you wish to intercept a radial TO a station, then the radial ou wish to intercept must be set on the BOTTOM of the obs... i.e set the reciprocal on the top of the obs, and a TO indication must be showing.

FROM TOP, TO BOTTOM.

Helped me!

..and always draw the picture..it helps no end..

Although it's fair to assume for the sake of an exam that the OBS is set to the airway track, the problem with question 1 is that it does not specify what the OBS is set to. Therefore, it is impossible to say what the needle will indicate.