Fly-by-Wire Technology or a Human Pilot? for Thomas Swartz Technical Communication Instructor Western Michigan University Kalamazoo, MI by Scott Mason IME 1020 Student March 18, 2008 Table of Contents ABSTRACT3 INTRODUCTION4 Definitions and Background4 Purpose and Audience4 Sources4 Limitations4 Scope5 COLLECTED DATA5 How Fly-By-Wire Technology Works5 Present Day and Future of Fly-By-Wire Technology6 Autoland7 Boeing Industries and Fly-By-Wire8 Humans vs. Computers9 Advantages and Disadvantages of Computer Pilot9 Advantages and Disadvantages of Human Pilot10 CONCLUSION10 Summary10 Interpretation of Findings11
Recommendations11 REFERENCES12 ABSTRACT Computer technology has become so advanced within the past few years that computers have more jobs now days then humans. What would you do if someday you came into work and found out you were being laid off due to new advanced technology? These days, pilots are being replaced by a new technology called Fly-by-Wire. Some military aircraft are completely controlled by computer. This means fewer jobs for the pilots who once controlled them. Most commercial aircraft have some kind of autopilot system to help the pilot perform everyday flight maneuvers.
The way to help advance fly-by-wire technology is to advance the knowledge of those who create it. Even though autopilot technology has decreased the amount of aviation accidents within the past few years, we must remember that it is created by humans and is therefore susceptible to human error. INTRODUCTION Definitions and Background With every year that passes the age of technology in which we live advances. Many people would be happy to have a computer do their work rather than physically doing the work themselves. Fly-by-wire technology has made the pilots’ jobs easier and has reduced their workload significantly.
This technology is becoming so advanced that it is believed that within the next few years a human pilot may not even be necessary in the cockpit. Purpose and Audience The purpose of this research paper is to determine how valuable fly-by-wire technology is to the aviation industry. Will it someday take over the entire cockpit? The intended audience is present and future pilots and anyone else with little aviation background. Sources My primary information came from technical journal articles and trade magazines pertaining to fly-by-wire technology.
These articles were retrieved from either Waldo Library itself or from its website. By comparing these articles along with a possible survey I should be able to make conclusions about the pilot’s future in the aviation industry. Some secondary information came from reliable websites about computer technology in general. Limitations The information contained in this paper will be limited to information pertaining strictly to fly-by-wire technology itself and how it works as well as how humans work side by side with this new innovation.
Along with this information, I will discuss what the future has in store for human pilots with the advancement fly-by-wire technology. Scope There are many sources pertaining to fly-by-wire technology. Due to the rapid advancements in computer technology in the past few years, certain jobs have been taken away from humans and given to computers. For this reason I would like to consider what technology is doing to the aviation industry. I would also like to consider the pros and cons of strictly a human pilot vs. Autopilot. COLLECTED DATA How Fly-By-Wire Technology Works
Peninsula Avionics, Inc. The first aircraft autopilot was developed by Sperry Corporation. It connected a gyroscopic attitude indicator and magnetic compass to a hydraulically operated rudder, elevator, and ailerons. It permitted the aircraft to fly straight and level on a compass course without a pilot’s attention, thus covering more than 80% of the pilot’s total workload on a typical flight. This straight-and-level autopilot is still the most common, least expensive and most trusted type of autopilot. It also has the lowest pilot error, because it has the simplest controls.
The autopilot reads its position and the aircraft’s attitude from a global positioning system. These errors are corrected by using satellite navigation systems and altimeters. According to mathematician Nelly Litvak, they also may incorporate error reduction systems such as the carousel system that rotates once a minute so that any errors are dissipated in different directions and have an overall knolling effect. Error in gyroscopes is known as drift. This is due to physical properties within the system, be it mechanical or laser-guided that corrupt positional data.
The disagreements between the two are resolved with digital signal processing, most often a six-dimensional Kalman filter. The six dimensions are usually roll, pitch, yaw, altitude, latitude and longitude. Aircraft may fly routes that have a required performance factor; therefore the amount of error or actual performance factor must be gyroscope. [Art]. Retrieved March 18, 20 [ 1 ] monitored in order to fly those particular routes (Xiong, 2006). The longer the flight the more error accumulates within the system (Litvak, 2006). Gyroscopes use gravity and earth rotation to determine their initial position (earth rate).
They then measure acceleration to calculate where they are in relation to where they were to start with. Present Day and Future of Fly-By-Wire Technology The technological age in which we live is so advanced and computer-friendly that present day aircraft can basically fly itself. The United States military is already using this technology to their advantage. The F-8C test airplane is the first airplane to fly with a digital fly-by-wire system as its primary means of control and with no mechanical reversion capability. This amazing new technology has saved he lives on thousands of United States Military Pilots.
Passengers on any aircraft with fly-by-wire technology will notice a great difference throughout their travels. Computerized flight control systems are significantly more advanced when compared to autopilot in air carriers from the past decade alone. They are able to detect even the smallest bit of turbulence, correct deviations, and make control corrections before the crew has time to notice. The ability to make minor adjustments while controlling constant speed and altitude over long flights results in ultimate flight performance. This system works much like cruise control on an automobile.
Less fuel is needed if the throttle remains untouched over distant flights. With the help of fly-by-wire technology, in the end, corporations save money while passengers are able to enjoy a smoother flight. This Technology is so advanced that it is being used in cars know days too. As demonstrated by our military/commercial aircrafts, fly-by-wire technology has been used to increase the handling of aircraft and has effectively allowed us to place craft into flight that would not have left the ground without fly-by-wire technologies.
These same concepts are now being applied to drive-by-wire systems. The steering controls of current automobiles have been “tried and proven true” over the years, however; a by-wire system could dramatically increase the steering abilities of people in a critical situation even before they believe they needed it. This would allow the person driving the vehicle to concentrate more on the strategies involved in driving, rather than the nuances of it. When it comes to commercial aviation not to many people would board an aircraft without a pilot in command. (Beghi 2006) Autoland
Autoland systems were designed to make landing possible in visibility too poor to permit any form of visual landing, although they can be used at any level of visibility. Autoland requires the use of a radio altimeter to determine the aircraft’s height above the ground very precisely so as to initiate the landing flare at the correct height. For safety reasons, once autoland is engaged, it will proceed to landing without further intervention, and can be disengaged only by completely disconnecting the autopilot. This prevents accidental disengagement of the autoland system at a critical moment.
Because autoland systems are fully automated and can be extremely precise, instrument approaches and landings made with them can be smoother than an instrument or visual approach which is hand-flown to a landing by a pilot. This can be due to fatigue after a long flight which will not allow a human to concentrate as well. Also, in situations of heavy fog, rain, or snow even instrument rated pilots may struggle greatly with a landing. Traditionally autoland systems have been very expensive, and have been rare on small aircraft.
However as display technology has developed the addition of a head up display (any transparent display that presents data without obstructing the user’s view) allows for a trained pilot to manually fly the aircraft using guidance cues from the flight guidance system (Wagner 2007). This significantly reduces the cost of operating in very low visibility, and allows aircraft which could not otherwise perform fully coupled autolandings to make a manual landing safely at lower levels of look ahead visibility or runway visual range.
Boeing Industries and Fly-By-Wire In the past, Boeing has been hesitant to adding fly-by-wire technology to their aircraft because it thought that the computers might not allow the pilot to have the final say in an emergency. On Airbus (the second-largest maker of airplanes) aircraft, the computers have the final say, and will never push an aircraft past its predetermined limits. Boeing did not want the computers to have the final say over the pilots, though, so it had to develop a form of fly-by-wire that was substantially different from Airbus’s system.
Boeing tried to keep the feel and control of the aircraft as similar as possible to older models while still integrating the fly-by-wire computers to assist the pilot, make the cockpit neater and save weight. They came up with a system that allows the computer to assist the pilot in only using flight controls. According to Jorgensen’s article, a pilot puts input onto a control lever and the computer makes corrections based on outside factors. For example; let’s say the pilot pushes down slightly on the yoke, wanting to go down at a 3° angle to the horizon.
If the plane is in turbulence that is causing it to already angle down 5°, the computer will probably change the pilot’s signal to 2°s up, causing the plane to go to the pilot’s intended 3° descent. A similar thing will happen if the pilot does not give a signal at all, but the plane angles down because of turbulence. The computers will realize that the plane is going down and automatically adjust so that the plane becomes level again (Jorgensen, 2006). Humans vs. Computers Advantages and Disadvantages of Computer Pilot
There are many obvious advantages to using fly-by-wire technology. It is more reliable than a mechanical system due to having fewer parts to break and malfunction. Fewer parts mean less maintenance because they are easier to maintain and troubleshoot. By replacing movable metal parts with wire to control the airplane, designers have more freedom to work due to more space in the fuselage to work with. Wire is also lighter and smaller than metal parts which reduce the overall weight of the aircraft allowing greater speed, fuel consumption, and payload.
Another great advantage to computer controlled aircraft is seen in the United States Military. By having a computer control the airplane means there is no human onboard. If is shot down then the human pilot who should have been controlling the aircraft is now safe. The ultimate disadvantage to this technology is that humans create computers making them susceptible to human error. If there is no human pilot on board when there’s a system failure, who will recover the aircraft? What we have to worry about is the degree of impact of this failure.
It’s well and good to say that all technologies fail and this one is bound to too, but the point becomes how much will the failure of a this system cost us in lives and injury. Also, when it comes to commercial aviation not to many people would board an aircraft without a pilot in command. Advantages and Disadvantages of Human Pilot Some advantages to having a human pilot that uses this technology is the ability to relieve the pilot’s workload without eliminating the pilot. It may assist him/her but in case of an emergency equipment failure the human pilot can make the desired decision.
The disadvantage to autopilot is that the pilot tends to pay as much attention to what is going on. Instead they rely on the computer’s ability to operate the aircraft. Even with this new technology, many avionic travelers are hesitant to get into an aircraft that has no human pilot onboard. No matter how much work the pilot actually does, general aviation, in my opinion, will never eliminate the human factor within the cockpit. CONCLUSION Summary Each year the amount of general aviation accidents continue to decrease. About 80% of all accidents are due to human error with the other 20% relating to mechanical failures.
If the human is almost completely eliminated from the cockpit, then eventually so will human error. With every new aircraft that has been produced, the workload for the pilot has been reduced due to new advancements in fly-by-wire technology. Without the advancements in autopilot technology, yearly accidents would either rise or stay consistent due to human error. According to “Electrical Flight Control Technologies for Rotorcrafts,” the future may not even require actual human pilots. Pilotless aircraft is already being used in some military aircraft today.
With each day that passes, fly-by-wire technology comes closer to taking complete control within the cockpit. Interpretation of Findings I believe that the invention and use of fly-by-wire technology is necessary to a certain point. On the positive side of it, it lessens the workload for the pilots allowing them to concentrate on other issues or even emergency situations. I also feel that it may be very useful and life-saving when it comes to military aircraft. Instead of using actual human pilots in combat, military aircraft can be controlled by computer from a safe distance.
When it comes to commercial aviation most people would not trust their lives in the hands of strictly a computer. Also, because computers are built by humans then they are susceptible to human error. I believe that the best solution to the fly-by-wire technology and human pilots is that, no matter how much this technology is used, human pilots are a necessity in commercial aviation. Recommendations Even with this new technology, many avionic travelers are hesitant to get into an aircraft that has no human pilot onboard.
No matter how much work the pilot actually does general aviation, in my opinion will never eliminate the human factor within the cockpit.
REFERENCES Beghi, A. ; Nardo, L. ; Stevanato, M. (2006) Observer-based discrete-time sliding mode throttle control for drive-by-wire operation of a racing motorcycle engine. IEEE Transactions on Control Systems Technology, v 14, n 4, p 767-775. Retrieved on February 10, 2008 for the compendex database. Jorgensen, N. The Boeing 777: No chainsaw massacres, please! Journal of Integrated Design and Process Science, v 10, n 2, 2006, p 79-91 Litvak, N. 2006) Optimal picking of large orders in carousel systems. Operations Research Letters, v 34, n 2, p 219-227. Retrieved on February 23, 2008 from the compendex database. Wagner T. (2007) Digital autoland control laws using quantitative feedback theory and direct digital design. Journal of Guidance, Control, and Dynamics, v 30, n 5, p 1399-1413. Retrieved on March 2, 2007 from the compendex database. Xiong, R. (2006) An extended Kalman filter for in situ sensing of yttria-stabilized zirconia in chemical vapor deposition. Computers and Chemical Engineering, v 30, n 10-12, p 1657-1669.