Interpreting HSI Instrument Rating Test Questions

Since I have discussed a new method for tracking and intercepting a victor airway I thought it might be interesting to go through the instrument rating knowledge test and answer some of the questions using this technique.  Perhaps, this method will make the test questions easier than using the recommended procedure in the Instrument Flying Handbook.

Below I have presented both the aircraft position and the HSI.  You can enlarge the pictures by clicking on them.

IR HSI Pictures on VORIR Aircraft Position

The steps to answer these questions:

  1. The course deviation indicator (CDI) will shade the headings needed to fly in order to intercept the selected course.  If we need to fly east to intercept the course, we must currently be west of the course.
  2. The TO/FROM flag  will tell you that if you fly those shaded headings in the quadrature, you will either fly towards the station or farther away.
  3. The heading on top of the HSI is the current aircraft heading.

Let’s delve in and go through each of the HSI displays and then we will discuss the aircraft that don’t have an associated HSI display.  For learning purposes, try to answer which aircraft belongs to each HSI before continuing. 

  1. The first HSI show that a southerly heading will cause us to intercept the 090° or 270° radial.  The TO/FROM flag indicates that a southeasterly heading will intercept the course and proceed closer to the station.  Last we are currently heading on a 200°  If a southeasterly heading will intercept and track closer to the station then the airplane must be opposite or in the northwest quadrant.  The only airplane that is flying a southwesterly heading in the NW quadrant is aircraft 1.
  2. The second HSI shows a northerly heading will intercept the 090° or 270° radial.  The TO/FROM flag has a easterly heading to track towards the station.  Thus a northeasterly heading will intercept and track towards the station.  On a heading of 135° in the SW quadrant indicates airplane 19.
  3. The third HSI shows a NW heading will intercept the 360° or 180° and track to the station.  The aircraft is in the SE quadrant and it’s current heading of 315° indicates airplane 12.
  4. The fourth HSI shows us that a northeasterly heading will intercept the 360° or 180° radial and track towards the station.  The current heading of south shows the proper aircraft to be number 17.
  5. The fifth HSI shows a southwesterly heading will track the 360° or 180° radial and track towards the station.  On the airplane’s current heading of 360° the only aircraft position is number 6
  6. The last HSI shows us centered on the 360° or 180° radial with a northerly heading to track towards the station.  It current northeasterly heading indicates that aircraft 16 is the correct answer

How did you do?  I think following the three step method really works.  What about the other airplanes that weren’t the answer to the HSI quesitons?

  1. Aircraft 1 to 4 in the northwest quadrant.  What would the HSI look like if the OBS was set to 180° radial?  The 270° radial?  For each aircraft imagine rotating the HSI so the current heading is always on top.HSI NW Quadrant
  2. Aircraft 6 to 10 in the NE quadrant.  Same question and imagine rotating the HSI’s so the aircraft’s current heading is on top.HSI NE Quadrant
  3. Aircraft 11 thru 14 are in the SE quadrant.  Same question as before.HSI SE Quadrant
  4. Aircraft 17 thru 20 are in the SQ quadrant.  Same question as before.HSI SW Quadrant
  1. #1 by Ken on November 11, 2018 - 5:44 pm

    I finally can get this question right. Studying for my ATP written, and if anyone takes the time to draw this out and use your logic, they can’t possibly get one of these wrong. Genius!

  1. Instrument Rating Training – IT Pilot

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