6.21
Immelmann (Figure 6.8).
6.21. Immelmann (Figure 6.8).
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6.21.1. Objective. Complete a vertical, climbing, 180-degree turn with constant nose track.
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6.21.2. Description. The Immelmann is a half loop followed by a half roll, all flown in the same vertical plane. The maneuver is complete after a momentary pause in level flight with wings level on an opposite heading from entry.
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6.21.2.1. Airspeed - 230-250 KIAS.
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6.21.2.2. Power - MAX.
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6.21.2.3. Attitude - Wings level to horizon before and after half roll at top.
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6.21.2.4. Altitude - Approximately 3,000 feet above entry altitude.
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6.21.2.5. FCP visual reference - Wingtips equidistant from horizon in pull-up.
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6.21.3. Procedure. Begin with briefed entry airspeed and power setting. Smoothly pull the nose up using 3-4 Gs. When the forward view of the horizon disappears in the pull-up, maintain wings level (straight pull) by keeping the wingtips equidistant from the horizon. As airspeed decreases, back stick pressure and G loading will decrease and moderate right rudder pressure will be required to keep the aircraft coordinated. To maintain constant nose track, continue to maintain aft stick deflection. Insufficient rudder, as airspeed decreases, may allow the nose to deviate up to 30 degrees off desired track. As the aircraft reaches a point approximately 20 degrees above the horizon inverted (FCP canopy bow on the horizon), relax back stick pressure and apply aileron with coordinated rudder in either direction to initiate a roll to level flight. Airspeed should be approximately 100-120 KIAS. The maneuver is complete after a momentary pause in level flight following the rollout.
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6.21.4. Technique. Align the aircraft with a road or section line to provide a visual reference for a straight pull. Keep aligned with selected reference throughout the Immelmann. If a ground reference is not available, the heading bug may be used to ensure a straight pull. Accelerate to entry airspeed with canopy bow on the horizon. Anticipate entry by nose down attitude (an attitude of 20 degrees nose low requires a 20 KIAS lead point to hit the desired target airspeed by the time the nose is back to level flight). Imagine pulling the control stick to the flightsuit “zipper” to ensure a straight aft. As the horizon disappears, use the cross-check of “wingtip, wingtip, ball” to keep the wings level and flight coordinated. Make sure the wingtips are equidistant from the horizon. Roll away from the wingtip that has the most ground above it to level the wings. As the airspeed slows, increase back stick pressure to keep constant nose track. Near the top of the Immelmann, due to propeller effects, the nose will tend to yaw to the left, which can be detected by cross-checking the ball on the turn and slip indicator. Use the memory aid of “step on the ball” to push on the rudder coinciding with the side the ball is deflected to. Near vertical, tilt the head back and try to locate the horizon as early as possible. If the wings are not level, improper rudder application is most likely the problem.
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