Aircraft Control Surfaces and Components Aerospace Engineering © 2011 Project Lead The Way, Inc. Aircraft Components and Control • Aircraft range from simple home-built machines to complex fighter jets • All aircraft have common structural and control components that allow for controlled flight Aircraft Components Five typical components Empennage Wing Fuselage Power Plant Landing Gear Empennage and Wing Components Elevator Empennage and Wing Components Vertical Stabilizer Rudder Flaps Ailerons ElevatorElevator Horizontal Stabilizer Horizontal Stabilizer Empennage Vertical Stabilizer Trim Tab Horizontal Stabilizer Elevator Trim Tab Rudder Aircraft Components Aircraft Components Vertical Stabilizer Empennage Rudder Horizontal Stabilizer Elevator Flaps Cockpit Aileron Fuselage Power Plant Wing Aircraft Components Rudder and Empennage Vertical Stabilizer Elevator and Horizontal Cockpit Stabilizer Flaps Ailerons Power Plant Fuselage Wing Fuselage Wing Ribs Spar Wing Strut Winglet Center of Gravity Center of Gravity (CG) is point where weight of object is balanced Centroid located on Centroid of object with multiple lines of symmetry the line of symmetry is located at intersection of lines of symmetry Stability • Aircraft with positive stability returns to steady flight after disturbance Stability • Aircraft with positive stability returns to steady flight after disturbance • Maneuverability is an indication of an aircraft’s ability to handle the stress of maneuvers • Controllability is an indication of an aircraft’s ability to react to pilot inputs Aircraft Attitude • Aircraft have three axes of flight which intersect at the center of gravity Lateral Longitudinal Axis Axis Vertical Axis Aircraft Attitude • Aircraft have three axes of flight which intersect at the center of gravity • Aircraft must be stable around these three axes for controlled flight Center of Pressure Center of Gravity Aircraft Attitude • Aircraft have three axes of flight which intersect at the center of gravity • Aircraft must be stable around these three axes for controlled flight • Aircraft must be controlled to rotate around these three axes to change direction Center of Pressure Center of Gravity Aircraft Stability and Movement Around Three Axes of Flight Lateral Roll Longitudinal Axis Axis Pitch Vertical Axis Yaw Aircraft Roll Stability and Control To turn left, the aircraft must roll left. Right wing must raise and left wing must Longitudinal Axis descend. Right aileron is lowered and left aileron is raised. Aircraft Roll Stability and Control To turn left, the aircraft must roll left. Right wing must raise and left wing must Longitudinal Axis descend. Right aileron is lowered and left aileron is raised. Flight Controls that Cause Ailerons and Flaps to Move Yoke rotated Left and right left flaps lower Left aileron raises Right aileron lowers Flaps lever lowered Aircraft Pitch Stability and Control Lateral To descend, the pilot Axis reduces power and lowers the elevator to pitch down Pitch Down Lower the elevator Push the yoke forward Aircraft Yaw Stability and Control Vertical To yaw the aircraft Axis nose left, the rudder must deflect left. Push left pedal away from you. Yaw Left Aircraft Motion and Control Axis Motion Stabilized by Control Pilot Control Longitudinal Roll Wings Aileron Yoke twist left or right Lateral Pitch Horizontal Elevator Yoke forward stabilizer or aft Vertical Yaw Vertical Rudder Rudder pedals stabilizer Lateral Longitudinal Roll Axis Pitch Axis Vertical Yaw Axis Why Do Airplane Designs Differ? The differences more than aesthetic Consider how a design affects lift and drag and other characteristics Wing Vertical Location How will the wing location affect aircraft performance? High Wing Mid Wing Low Wing High Wing • High wing generates the most lift of the three wing locations because airflow is continuous with minimal interruption • Improved pilot downward visibility without wing obstruction • Center of gravity is high • Pusher engine avoids introducing turbulence over wing Mid Wing • Mid wing generates the least lift of the three wing locations Low Wing • Low wing generates lift as a median of three wing locations because airflow is almost continuous with some interruption • Increased ground effect increases lift during takeoff and landing because the wing airflow acts against the ground • Limited pilot downward visibility because of wing obstruction Wing Configuration How will the wing configuration affect aircraft performance? Biplane Canard Wings Multiple Wings – Biplane • Increased wing area generates more lift • Increased wing area generates more drag Canard Wings • Canard wings provides major wing surface area well forward of the center of gravity • Center of gravity being farther rearward improves pitch control Vertical Stabilizer How will the vertical stabilizer affect aircraft performance? Twin vertical stabilizers Triple vertical stabilizers V-Tail Twin Vertical Stabilizers • Two vertical stabilizers improve yaw control Triple Vertical Stabilizers • Three vertical stabilizers improve yaw control • Could be needed to compensate for the limitation of other features V-Tail • Early versions of the design made it difficult for a pilot to control yaw • Note the relative percentage of wing that is flap versus aileron. Power Plant How will the power plant affect aircraft performance? Tractor power plant Pusher power plant Variable direction power plant Tractor Power Plant Engine Propeller Pusher Power Plant Engine Propeller Variable Direction Power Plant Exhaust smoke from vertical thrust Landing Gear How will the landing gear affect aircraft performance? Oleo Strut Tricycle Floats Tail dragger Landing Gear – Oleo Strut Oleo strut Brakes Tire Axle Rim Landing Gear – Floats Conventional Gear vs. Tail-Dragger Main Gear (2 wheels) Tail Wheel Tricycle Gear Main Gear Nose Wheel (2 wheels) Specialized Landing Gear How will the landing gear affect aircraft performance? Rough field Soft field Rough Field Landing Gear • Rough field landing gear has smaller wheels to allow large shock absorbers • Large shock absorbers • Absorb impact of a rough terrain • Propeller is above tall grass Soft Field Landing Gear • Soft field landing gear has large wheels to minimize sinking into terrain Aircraft Size and Shape How will the aircraft size affect aircraft performance? Fuselage size Engine size Specialized configuration Aircraft Size Lockheed C-5 Galaxy Aircraft Size Aircraft Size Boeing 777 Engine Intake Specialty Aircraft Instrument Panel How will the instrument panel affect aircraft performance? Simple instrument panel General aviation instrument panel General aviation instrument panel References Jeppesen (2007). Private pilot: Guided flight discovery. Englewood, CO: Jeppesen. Jeppesen Sanderson, Inc. (2006). Guided flight discovery private pilot images [CD-ROM]. Englewood, CO: Jeppesen Sanderson, Inc. National Aeronautics and Space Administration (2009). Airplane parts definitions. Retrieved from http://www.grc.nasa.gov/WWW/K- 12/airplane/airplane.html National Aeronautics and Space Administration (2009). Wilber and Or. Retrieved from http://grin.hq.nasa.gov/IMAGES/SMALL/GPN-2002- 000126.jpg References Chapple G. (Photographer). (2012). Shuttle 1. [Photo]. Lockheed Martin (2010). C-5M first flight-3a. Retrieved from http://www.flickr.com/photos/lockheedmartin/357061040 6/in/set-72157618866063402 Lockheed Martin (2010). F-35 Lightning II. Retrieved from http://www.lockheedmartin.com/products/f35/ Lockheed Martin (2010). Lockheed Martin C-130 in flight. Retrieved from http://www.flickr.com/photos/lockheedmartin/976461432/ Meyer, A. (2010). X-Plane (Version 9.21rc2) [Computer software]. Columbia, SC: Laminar Research. References Senson, Ben. (2010). Madison Memorial High School, Wisconsin..