# What am I doing wrong in this RBI exercise?

• The GYRO indicates the flight direction of the aircraft.

• The RBI indicates where the non-directional beacon(a location on ground that’s sending the plane signals) is located.

• Top of the RBI is always North. The yellow arrow point towards the beacon, however this is relative to the flight direction of the aircraft.

I always seem to mix it up. Can someone explain what exactly am I doing wrong here?

I seem to be selecting the correct symbol but when it comes to the grid then I mix it up.

You've got the heading right. Now rotate the whole view of both instruments to the aircraft orientation, and you see the direction in which the Relative Bearing Indicator (RBI) points. Now it's easy to place it onto the correct position on the card.

The RBI points towards the beacon, but does so relative to the aircraft The dial with the compass in the background is not rotating automatically with the gyro compass, so unless it is manually alligned to the gyro, the top is always north.

• It might be a lot easier to put towards nose, port, starboard, and tail on the radio beacon. (although any circle can be thought of as 360 degrees). Oct 1, 2020 at 19:49

If the RBI is of the fixed card variety, the N is not indicative of North. It only indicates the direction the nose of the aircraft is pointing. You can actually dispense with the cardinal direction letters and just focus on the bearing numbers.

The gyro on the left gives you the orientation of the aicraft and the RBI arrow gives you the direction of the beacon relative to your aircraft. First one, you have the aircraft facing south and in the aircraft the beacon is at your right (3 o'clock). Second one you are flying east and the beacon is at your 10 o'clock.

In order to fly directly to the beacon you need to put the needle vertical. The needle is actually showing you what turn you need to make to fly directly to the beacon. In the first example you need to rotated 90° to the right if you want to reach the beacon.

It's actually simple. Despite seemingly different mechanical operation, both instruments have the same type of indication: namely, they show the world moving around you. This is so called 'direct' indication. Note that both faces have a picture of the aircraft (i.e. you as the pilot), and it is fixed.

The difficulty probably comes from the fact that to answer the required way, you need to convert this mental picture to the 'reverse' indication. The answer would be trivial if both instruments were of the reverse type, i.e. would rotate the aircraft picture within a fixed frame. (They exist but less common). Luckily, when flying, you don't usually need to do this mental conversion, especially if you tend to rotate your map 'heading up'. Flying may be easier than answering the exam.

To interpret these indications coherently, it's probably better to think about the North for the gyro: the card could be replaced by the traditional compass hand pointing north. Also, direct indication is 'selfish': it's all about 'me'.

So, we have:

1. North is behind me, beacon is to the right of me. Now just find the right cell: North is up, so my 'behind' must be up, and beacon towards the starboard.

2. North is to the left, beacon left-ahead (10-11 o'clock).

Etc.