Analysis of Lesson Plan 4
- Analysis of Lesson Plan 4
Lesson Plan #4 consists of two flights, the first is the final of three lessons on basic maneuvers—having the rather awkward expression of “advanced basic maneuvers”. Here, the student learns speed and flap changes in straight and level flight, as well as climbs and descents incorporating flaps and flap changes. This marks the end of the classic developmental exercises (straight and level flight, climbs, descents and turns). The second flight making up Lesson Plan #4—flight for maximum range and endurance—marks the beginning of the monolithic exercises—that is, generally, single-exercise flights, including slow flight, stalls, spirals, and spins (upper air exercises), as well as slipping. When these monolithic exercises are complete, generally speaking, the student begins circuit training.
Advanced Basic Maneuvers
The first flight of Lesson Plan #4 (referred to as LP#2A) returns to straight and level flight and introduces students to the deployment of flaps during fight. There are lots of good reasons for working the student through this exercise. The use of flaps entails considerable changes in force required on the control column to maintain stable pitch attitude and therefore stable airspeed—flap extension and retraction is typically done near the ground—in the critical overshoot maneuver, for example—where speed and pitch control (so as to maintain altitude control) are clear priorities. Moreover, the misuse of flaps, especially in Cessna 100-series (172s, 152s, and 150s, for example) has a history of high accident risk. As instructors, then, we are highly motivated to train are students well here. The main goal in all this is for students to learn to properly control the nose of the aircraft during flap changes.
Speed and Flap Changes in Straight and Level Flight
With the aircraft trimmed for straight and level flight at a speed within the white arch, first demonstrate the uncorrected response of the aircraft to incremental flap extension—you don’t have to go to full flap deployment, but ensure the student observes both the resultant pitch, roll, and yaw disruption—the pitch changes are generally obvious, while the roll upset relates to slipstream moving asymmetrically over the flap surfaces. Then show the student the same flap changes with the proper corrective inputs to maintain straight and level flight. Then repeat the uncorrected/corrected demonstration sequence with flap retraction. Now the student is ready to try maintaining straight and level flight while deploying and retracting the flaps—assign the appropriate drill and provide for sufficient repetitions until the student has mastered the control column pressure changes, and the countervailing trim changes, necessary for straight and level flight.
You owe it to your student to experience full-flap extensions and retraction with little if any incremental pause. Keep in mind that their ability to maintain straight and level flight during such adverse flaps changes could save the day. Provide a proper demonstration and assign the drill to the student with sufficient repetitions so as to instill comfort and confidence.
As a final drill for the student, assign a series of speed and flap targets for the student using white-arch speeds above the maximum distance glide speed (so as to avoid slow flight) and the full range of flap angles. Again, assign sufficient repetitions so as to instill comfort and confidence in your student.
Flap and Speed Targets during Climbs and Descents
With respect to instruction on the use of flaps during climbs and descent, create a drill sequences based on the prescribed flap and speed settings for the full-flap approach sequence, as well as and the takeoff and departure sequence prescribed by the POH that requires the use of climb flap. Begin with the climb sequences fist (as this is generally the easiest), using the best-rate, best-angle, and best-angle with flaps speed configurations. For the descents, use thee approach speed and flap configuration, including the base-leg and final approach settings prescribed in the aircraft POH for executing a full-flap landing. When these are master, tie the two together, with an overshoot sequence drill requiring a properly executed retraction from the full-flap setting to a best-rate climb with clean flap.
Here are some additional points that may or may not be obvious. This lesson is delivered in the standard “I do—you do” format. Beginning with straight and level flight, specify your speed targets for best rate, best angle, and best angle with flaps configurations. Now specify your altitude targets based on the assumption that you will maintain each configuration for 500’—you start the climb at the best rate of climb speed, then transition to the best angle climb speed, then the best angle climbs speed with prescribed flaps, then revert to the best angle climb speed, and finally the best rate of climb speed. The same consideration apply to the full-flap approach sequence. When flaps are extended or retracted, be sure to demonstrate precise pitch control, holding the nose steady during the extension and retraction phases.
Flight for Maximum Range and Endurance
Begin this by demonstrating the RPM method for reckoning the best power and best economy settings using the mixture. Be sure to take guidance on this using the From the Ground Up if you are not sure of this. With respect to the EGT method for establishing the same settings, I suggest deferring this to the navigation exercises later on if the aircraft is so equipped.
Next have the student set the aircraft up in accordance with the 55% power setting requirements prescribed by the POH (and of course ascertained by the student in the preparatory ground instruction preceding the flight). Once the throttle is set, the student can compare the airspeed values—requiring, don’t forget, the conversion of IAS into the POH’s TAS value (hopefully the airspeed indicator is equipped with an adjustable scale).
The student should then recover the aircraft back to normal cruise flight, to begin the practical method for determining maximum range—here the power should be set to 2500 RPM to begin. The aircraft should be tracking an adequately long track reference so as to avoid disruptive turn maneuvers. Beginning at 2500 RPM, and working down using 100 RPM increments to approximately 1800 or 1900 RPM, record the speed at each increment once the speed has stabilized. The student maintains straight and level flight, keeping the standard traffic scanning practices in play, while the instructor is the secretary and supervisory, recording the incremental speed values. You have reached the bottom RPM increment when the airspeed cannot be stabilized as the student attempts to maintain straight and level flight. When this is reached, take control of the aircraft, return to a normal power setting, and have the student analyse the speed table you have recorded, identifying the proper incremental value that established the most efficient speed setting.
The process is completed for maximum endurance, with only some minor changes. The student need not start at 2500 RPM (clearly the aircraft can maintain level flight); instead start at 2200 RPM. When the student gets to 2000 RPM, have the student reduce in only 50 RPM or “needle width” increments with the added rule that power cannot be advanced (after it has been reduced), as could work the aircraft up the back-side of the power curve. When below-endurance power is reached, airspeed will continue to fall off as the student attempts to maintain altitude. When this occurs return to the previous power setting where level flight was still possible—this of course was noted by the instructor. Note that when returning to this previous power setting, avoid simply adding power from the slow speed condition as this may again position you in the slow flight range—accelerate the aircraft slightly and ask the student to again approach the target endurance power setting with incremental reductions. It’s important to get this right as you next move as instructor is to demonstrate the transition from endurance to slow flight by raising the nose, and then adding slight power to maintain a constant altitude—this won’t work if you are not properly re-established at maximum endurance speed and power when you initiate this demonstration.