by Jonathan M. Stern
The rectangular course is a useful exercise for preparing to deal with traffic patterns. Flying the maneuver requires an appropriate division of attention between the flight path and the ground references. The object is to maintain altitude and airspeed while flying a rectangular track that keeps the airplane equidistant from all sides of a rectangular shape on the ground.
A square or rectangular field should be selected so that the wind is aligned with one of the boundary lines. The airplane should be between 1/2 and 1/4 mile away from the ground reference as each leg is flown. Each turn should be initiated when the airplane is abeam the corner, and bank angles should not exceed 45 degrees. Figure 5.2 diagrams the rectangular course maneuver with a downwind entry being made.
Figure 5.2. The rectangular course provides useful experience and training for negotiating traffic patterns.
The downwind leg is flown without any wind correction, but the leg is quickly completed because the tailwind increases groundspeed. As the first corner is passed, make a 45° banked left turn more than 90° to complete the turn with a wind correction angle to the left. As the turn proceeds and the tailwind changes to a left crosswind, continually decrease the bank angle. Throughout the maneuver, when banking, the requisite bank angle is a function of groundspeed. With a direct tail-wind, the bank will be at its steepest.
Reference to the ground helps to determine the appropriate crab angle to maintain the ground track with what is now a crosswind on the base leg. As you reach the next corner, use a medium bank turn initially, shallowing the bank to a shallow bank turn as the airplane turns back into the wind.
On the upwind leg, no crab is necessary to maintain alignment with the desired ground track. As you reach the third corner, begin a shallow bank in order to turn onto the crosswind leg. As the turn continues, the bank must steepen as the headwind is translated into a crosswind. This turn onto the crosswind leg is less than a 90° turn, because you need to roll out with a right crab to compensate for the wind. Finally, at the fourth corner, make a left turn with a moderate bank increasing during the turn onto the downwind leg to a 45° bank.
When you have flown all four legs of the rectangular course, the maneuver is complete.
Flight Simulator's Flight Analysis features comes in handy with ground reference maneuvers. To use the Course Tracking feature, take the following steps:
- Before beginning the maneuver, select Options/Flight Analysis.
- Select Course Tracking.
- Select Record Course and Display Course.
- Select Track Length: Long.
- Press OK.
- Fly the maneuver.
- At completing the maneuver, pause the simulation and observe the Course Track with the map view.
Select the Windwork situation. This situation places you at 4,500 feet above Midway Airport with an appropriate wind for flying a rectangular course maneuver. The outer perimeter of Midway Airport has boundary lines that run generally East/West and North/South. This area may be used for flying the rectangular course (see Figure 5.3). Practice flying a rectangular course.
Figure 5.3. The perimeter of Chicago's Midway Airport may be used for flying the rectangular course.