The rectangular course is a fundamental ground reference maneuver required for the private pilot license.
However, it is so fundamental and so critical to landing that it is often ignored as a ground reference maneuver. Instead, it is frequently considered only within the context of the traffic pattern.
The traffic pattern is generally a rectangle, and the rectangular course is meant to promote your skills in the traffic pattern, but that isn’t the whole story. The rectangular course is also great for learning wind management and crabbing since it is the only ground reference maneuver with straight sections.
How to fly a rectangular course
Finding a suitable field to practice this maneuver is not always easy, depending on where you fly. Look for a fairly large rectangle. It should be big enough that you will be able to fly each leg for a bit of distance. The long sides of the triangle should be at least a half of a mile long, but a full mile is even better. crosswind and base legs of that pattern can be shorter but they shouldn’t be too short, certainly not much less than half a mile.
The other thing that makes a rectangle hard to find is that it needs to be generally aligned with the wind. See the diagram below from the FAA showing the orientation of the wind.
Once you have selected a rectangle, slow to maneuvering speed at about 1000 AGL, which will serve as your traffic pattern altitude. Use this opportunity to do some clearing turns.
You enter the maneuver just like you enter the traffic pattern at an airport, on a 45-degree angle to downwind. As you turn to join downwind, you will have the wind pushing from behind, so expect a higher groundspeed. The downwind leg will go by quickly and then it will be time to turn.
As you begin the base turn expect to use a lot of bank angle. You start off with a strong tailwind so your groundspeed is high.
The turn does not end at a heading 90 degrees from where you started. Instead, you will need to turn beyond the course you intend to fly and point your nose towards the wind. Once you level off you will be crabbed into the wind and ready to fly a straight base leg. The amount of crab needed will vary based on the wind and you may need to adjust it as you go.
From the base leg to upwind your turn will be less than 90 degrees, because you were already crabbed towards the upwind leg. Expect to use a shallow bank angle as your groundspeed slows down during the turn.
Once you are established on upwind prepare for the crosswind turn, which will also be less than 90 degrees so that you end up crabbed into the wind again.
Finally, make a fairly steep turn to downwind and then exit the rectangle at pattern altitude on an outbound 45 from the point where you would have begun a turn to base.