RMIT Instructor Rating Mass Briefs Issue 1 /2004 Page 1 SPINNING Aim: To understand the principles of spinning, a condition of stalled flight, and how to recover from a fully - developed spin. Application: Used whilst conducting aerobatics. Revision: Stalled Aerofoil Symptoms ---- Definitions: Spin - A spin is a condition of flight where the aircraft performs a spiral descent. Occurs because on wing stalls before the other. Brief 10 RMIT Flight Training Spinning RMIT Instructor Rating Mass Briefs Issue 1 /2004 Page 2 Principles: A spin occurs as a result of uncoordinated, uncorrected stall. Therefore spinning is associated with low airspeeds. If the stalled aircraft yaws, one wing travels faster, creating more lift. This results in a roll. The falling wing would have an increased AoA, thus becoming more deeply stalled. A result of this would be an increase in drag, which causes a yaw in the direction of the roll. More yaw causes more roll and the aircraft is in motion about all three axes. The aircraft is: - stalled - rolling - yawing - pitching - slipping - rapidly losing altitude at a low airspeed Brief 10 RMIT Flight Training Spinning RMIT Instructor Rating Mass Briefs Issue 1 /2004 Page 3 Considerations: Two Types of Spin Flat Spin: Steep Spin: - Higher nose attitude - Increased drag - Decreased rotation - Reduced rate of descent - Low nose attitude - Higher rotation - Increased rate of descent Centre of Gravity - Rearward CoG encourages nose up pitch, giving a flatter spin, and difficulty in recovering. Forward CoG normally results in a steeper spin. Autorotation - Occurs during the incipient (initial) stage of the spin. Two main features: 1. Autoroll - the more deeply the dropping wing stalls, the more the aircraft wants to roll into the direction of the spin. 2. Autoyaw - dropping wing will generate more drag, yawing the aircraft into the spin. Brief 10 RMIT Flight Training Spinning RMIT Instructor Rating Mass Briefs Issue 1 /2004 Page 4 Spin v. Spiral Dive (not to be confused!) Spin associated with - low IAS (stalled) - high rotation rate - low noise level - possible buffet Spiral Dive associated with - high and increasing IAS - high noise level Air Exercise: Entry - Pick reference point - Manoeuvre checks: Height sufficient to recover by 3000ft. Hatches/Harnesses secure. Engine Temperature & Pressure. Location - not above populated area. Loose articles secure. Lookout (360 turn). - Reduce power to idle (maintain altitude). - When stall occurs, apply full rudder in desired direction and aft control column. During - Count three rotations Recovery - Apply full opposite rudder to stop rotation - Ease control column forward to unstall wings - Level wings and ease out of dive - As nose passes horizon, climb away. Airmanship: - Lookout - Pre-manoeuvre checks - Do not use aileron to pick up wing drop - Speed and manoeuvre limitations not to be exceeded - Smooth coordinated use of controls - Correct handover/ takeover procedure - UNINTENTIONAL STALL OR SPIN SHOULD NEVER OCCUR! Brief 10 RMIT Flight TTrraaiinniinngg SteSeppinTnuirnngs