Hi guys,
I am trying to solve this question but can understand how
Q--you are flying north of an NDB, maintaining a track of 235M while allowing 15 degrees of right drift. ATC asks you to intercept the 270M track from the NDB. What will be the relative bearing indication on ADF when you have intercepted the required track, assuming no change to you present heading.
A--215, b--200, c--230, d--245
If some one can explain that would be really helpful.

Hi Gaurav,

You can use the HAT trick to solve this. This technique is discussed in the IREX textbook on page 27.


We want to intercept the track 270 degree bearing FROM the NDB and you maintain a HDG of 235 degrees. Therefore, the HAT trick becomes:


The relative bearing must be "+35 FROM". The FROM means the needle is pointing into the lower half of the ADF face, and the +35 means it is pointing 35 degrees off of 180 degrees (see below).

180 + 35 = 215 degrees relative. The answer is (A).

To get a better idea, let's look at the instruments. The first image shows where you are in relation to the beacon when you intercept the 270 FROM:


This image shows how you can confirm your answer by transposing the indication of the fixed card ADF (on the right hand side) over to the DI (on the left). This is what you will do in the cockpit as an alternative technique to the HAT trick.


Hope that helps,

Cheers,

Rich

Hi Richard

Sorry I think you are wrong. Your heading is 220 as you are allowing for 15 R drift.
220 + 60 = 270
Therefore 230 relative
Answer C

Hey, well spotted! I just checked the original post and realised I had misread it! The pilot was indeed TRACKING 235 and not HEADING 235.

As you pointed out, to maintain a track of 235 with 15 degrees of right drift, they must have been heading 220.

Using the HAT TRICK
220 + 50 FROM = 270

So, the relative bearing is indeed 230 (180 +50).

Thanks for pointing that out

Cheers,

Rich