| Home | Privacy | Contact |

Pilot's Handbook of Aeronautical Knowledge
Flight Controls

| First | Previous | Next | Last |

Pilot's Handbook of Aeronautical Knowledge



Table of Contents

Chapter 1, Introduction To Flying
Chapter 2, Aircraft Structure
Chapter 3, Principles of Flight
Chapter 4, Aerodynamics of Flight
Chapter 5, Flight Controls
Chapter 6, Aircraft Systems
Chapter 7, Flight Instruments
Chapter 8, Flight Manuals and Other Documents
Chapter 9, Weight and Balance
Chapter 10, Aircraft Performance
Chapter 11, Weather Theory
Chapter 12, Aviation Weather Services
Chapter 13, Airport Operation
Chapter 14, Airspace
Chapter 15, Navigation
Chapter 16, Aeromedical Factors
Chapter 17, Aeronautical Decision Making




Mechanical flight control system.
Figure 5-1. Mechanical flight control system.

As aviation matured and aircraft designers learned more about
aerodynamics, the industry produced larger and faster aircraft.
Therefore, the aerodynamic forces acting upon the control
surfaces increased exponentially. To make the control force
required by pilots manageable, aircraft engineers designed
more complex systems. At first, hydromechanical designs,
consisting of a mechanical circuit and a hydraulic circuit,
were used to reduce the complexity, weight, and limitations
of mechanical flight controls systems. [Figure 5-2]

Hydromechanical flight control system.
Figure 5-2. Hydromechanical flight control system.

As aircraft became more sophisticated, the control surfaces
were actuated by electric motors, digital computers, or fiber
optic cables. Called "fly-by-wire," this flight control system
replaces the physical connection between pilot controls and
the flight control surfaces with an electrical interface. In
addition, in some large and fast aircraft, controls are boosted
by hydraulically or electrically actuated systems. In both
the fly-by-wire and boosted controls, the feel of the control
reaction is fed back to the pilot by simulated means.

Current research at the National Aeronautics and Space
Administration (NASA) Dryden Flight Research Center
involves Intelligent Flight Control Systems (IFCS). The goal
of this project is to develop an adaptive neural network-based
flight control system. Applied directly to flight control system
feedback errors, IFCS provides adjustments to improve
aircraft performance in normal flight as well as with system
failures. With IFCS, a pilot is able to maintain control and
safely land an aircraft that has suffered a failure to a control
surface or damage to the airframe. It also improves mission
capability, increases the reliability and safety of flight, and
eases the pilot workload.

Today's aircraft employ a variety of flight control systems.
For example, some aircraft in the sport pilot category rely on
weight-shift control to fly while balloons use a standard burn
technique. Helicopters utilize a cyclic to tilt the rotor in the
desired direction along with a collective to manipulate rotor
pitch and anti-torque pedals to control yaw. [Figure 5-3]

Helicopter flight control system.
Figure 5-3. Helicopter flight control system.

For additional information on flight control systems, refer
to the appropriate handbook for information related to the
flight control systems and characteristics of specific types
of aircraft.