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Monthly Archives: August 2015

WILLIAM GUY REDMOND JR.

 

We often define the pioneers of aviation in terms of pilots, such as Charles Lindbergh, Amelia Earhart and Chuck Yeager. While being the first to set a record or fly a new type of aircraft carries a certain glamour, such efforts would not be possible without a large number of unsung heroes in the form of designers, engineers and technicians to take a plane from a mere drawing to it’s first flight.  During this blog, we’ll follow the life of one of these heroes.

William Guy Redmond Jr. grew up in Dallas, earning a BS degree in Mechanical Engineering from Southern Methodist University in 1944.  Mr. Redmond then served as a Radar Electronics Officer in the United States Navy, receiving advanced radar training at both Bowdoin College and the Massachusetts Institute Of Technology (MIT) in 1945.  After his discharge from the navy in 1946, Guy worked as an engineer designing and maintaining pipe organ systems.  The following year, he went back to SMU, serving as a faculty member until 1949, earning a BS in Electrical Engineering from the university the same year.  Guy then left SMU in order to pursue a graduate degree in Electrical Engineering, which he received from MIT in 1951.

The 1950s was a time of intense development for both aviation and rocketry.  Jet aircraft were now capable of flying faster than the speed of sound while rockets were able to reach the fringes of space.  Mr. Redmond began his aerospace career with Vought Corporation in 1951 as a servo engineer.  He both designed and invented a number of flight servo relays, inventing a servo trim system used in the F4J Fury and RA5C Vigilante naval aircraft and later the popular Lockheed L-1011 jetliner.  He later served as Electronics Project Engineer on the F-8 Crusader, the predominant naval fighter aircraft of the era.  In 1958 Guy’s career branched out into missile development, serving as head of advanced missile controls.  During that time he created a flexible rocket engine flight control system, which provided both thrust vector control off the launcher, as well as aerodynamic control with airspeed.  Subsequent tests led to Vought producing the Lance missile for the US Army.

 

LLRV#1

 

In 1960 Guy became Chief Of Automatic Flight Control Systems for Vought, which proved to be an assignment of historic proportions.  The following year President Kennedy addressed a joint session of Congress with the stated goal of sending astronauts to the moon and safely returning them by the end of the decade.  Many technical issues loomed from this announcement, most notably a propulsion system which could function in an airless environment, in which the aerodynamic features of an aircraft were of no use.  Also, a sophisticated guidance system was necessary to achieve a precise landing on the lunar surface, in addition to docking with the lunar orbiter.  Mr. Redmond began work on such a guidance system, utilizing automatic throttles and electrical system monitors actuated by computerized signals – a fly- by- wire system.  A fly-by-wire control is a purely electrically signaled control system, necessary in the environment of space. The FBW system is interposed between the astronaut/pilot and the control surfaces of the spacecraft/aircraft.  The computer is able to modify the manual inputs of the pilot in accordance with programmed control parameters. Gyroscopes fitted with sensors are mounted in the spacecraft to sense movement changes in the pitch, yaw and roll axes.  A fly-by-wire system also utilizes several backup computers, in case of failure of the main guidance system.  Guy’s efforts bore fruit with first successful flight of the Lunar Module in 1964.  He later contributed to the design of digital fly-by-wire systems.

Mr. Redmond served as Avionics Engineer on the Space Shuttle program, both designing and developing a number of innovative solutions. He retired from the Lockheed Martin Missile And Fire Control Division at the age of 89.  During his 65 years in the field of engineering, he received 12 patents, as well as  a Technical Innovation Award from NASA, in addition to recognition from both Congress and the Governor Of Texas – making him a true hero of aviation.

NOTE:

I wish to express my appreciation to Nicole Van Schaick, granddaughter of Mr. Redmond, who provided valuable documentation in preparation of this blog.

This blog is the first of a series about the heroes of aviation.

FLY BY WIRE

FBW#1

 

 

Ever since powered flight was first achieved by Wilbur and Orville Wright in 1903, the aviation community has sought both safer and more efficient methods of aircraft flight control.  During the course of this blog, we will trace the development of fly by wire control systems from the basic electrical controls of the 1930s to the enhanced computerized systems of today.

For about thirty years after the Wright Brothers first flight, pilots controlled an aircraft by direct force, by moving control wheels, sticks and rudder pedals linked to cables and pushrods , which pivoted control surfaces on the wings and tails. However, as engine power, speeds and aircraft weight increased, more force was required to effectively direct aircraft control surfaces.   Mechanical and hydraulic control systems were introduced to compensate for the increased power needs upon control surfaces.  Such systems were relatively heavy and necessitated a careful routing of flight control cables through the plane by systems of cranks, pulleys, hydraulic pipes and tension cables.  Although the mechanical and hydraulic systems provided a substantial boost to aircraft controls, they required multiple backup systems in the event of failures, further increasing weight in the design of the aircraft.  Another problem of the hydro/mechanical systems was their insensitivity to outside aerodynamic forces such as spinning, stalling and vibrations during flight.

Electrical transmission to a plane’s control surfaces was first accomplished in 1934 on the Soviet ANT-20, the Maxim Gorky.  The series of mechanical and hydraulic connections were replaced with electrical ones.  This was an extremely large aircraft for its day and the electrical connections worked flawlessly until the collision of the aircraft the following year, proving the potential of electrical flight control.  However, a dedicated electronic signal avionics control system was not tested until 1958 on the Avro Canada CF-105 Arrow.  Ironically, the first vehicle to utilize an electronic flight control system without mechanical or hydraulic backup was the Lunar Landing Research Vehicle or LLRV, which flew successfully in 1964 as part of the Apollo moon program.

A fly by wire control system is a computer system, which monitors pilot control commands and related factors such as altitude, airspeed and angle-of- attack.  The FBW system then relays these pilot inputs to the flight control surfaces in order to keep the aircraft within its designated flight envelope, or safe flight parameters of the aircraft at various speeds, altitudes and other flight conditions.  The fly by wire computer employs electrical signal inputs to create electrical signal outputs which affect the flight control surfaces to produce the desired aircraft attitude.  FBW computers utilize both analog and digital processing with digital units first appearing in quantity in the late 1970s.  The essential difference between digital and analog units lies in how they process information.  Analog computers work in a continuous cycle in which data can accept an infinite set of values, resulting in no loss of data.  The primary limitation of analog units is the time required to initially configure the hardware to the aircraft, in addition to the difficulty of upgrading existing hardware.  Digital systems operate in a designated time environment, in which values are finite.  Any loss of data is supplemented by relatively high resolution and sampling rates, which minimize data loss.  Upgrading a digital unit is merely a matter of downloading current software, achieving a smooth transition coupled with reduced software and maintenance costs.  The flight control systems offer both redundant computer processing and circuitry in case of failure of the primary unit.

Fly by wire technology offers a number of advantages.  Aircraft weight is greatly reduced since mechanical and hydraulic linkages are no longer necessary.  Safety is enhanced due to both redundancy of electrical circuits as well as a quick response and processing time from the FBW unit, supplanting the skill of the pilot.  Fly by wire systems benefit military aviation by allowing engineers the latitude to design an aircraft which may be inherently unstable, but yet be able to attain superior maneuverability under the parameters of the fly by wire computer.  FBW systems require fewer parts and less fuel usage while providing more comfort for passengers because of more precise handling characteristics.  Fly by wire control systems provide for greater safety by establishing control parameters within the capability of the plane with digital units compatible with the entire range of aircraft sensors.