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If one were to scan the progress of air travel over the past 100 years, they would view a picture of great progress. Though at times this progress was made at a slow but steady pace, it often grew by leaps and bounds due to advances in both technology and training. During this blog, we’ll look at several current aviation trends and their impact upon its future.
While the civil aviation industry continues to maintain both profits and growth, it is still sensitive to a number of market drivers. For example, the world economy is expected to grow at a mid-range pace over the next twenty years. Oil prices are now approaching the $70 per barrel price range, but they could reach as high as $100 per barrel by 2030. Many airlines are now adopting a culture based upon financial management, in which the emphasis is on per-passenger profits. While discount fare and other incentive programs support revenue growth, they create a situation of a high number of passengers at a low profit per passenger. To remedy this, airlines in the future will invest in a growing number of right-sized aircraft to increase per passenger profit yields. Over the past three years, per passenger profit yields have decreased by $3 per passenger, while net profit across the airline industry has decreased by 1% over the past two years. The use of right-sized aircraft will partially reduce the need for sweeping fare discounts in order to fill an aircraft.
In 2016 approximately 80% of all global air routes were composed of regional air traffic. The regional air route segment is currently experiencing the greatest growth, with increases of five per cent, per year anticipated over the next twenty years. While these routes generate the greatest per passenger yield, they are mostly served by older aircraft having a 20 to 60 passenger capacity. As these aircraft are retired, they will need to upgrade both their technology and capacity. The latest trend in regional air routes is the paired city concept. Many aircraft servicing these routes have a capacity of 100-150 seats with relatively high per passenger profit yields. Globally, regional air traffic has increased by twenty per cent over the past two decades and is projected to increase at least that amount over the next twenty years, according a number of air traffic studies. In China, the government encourages the city-pair concept to stimulate growth in low volume markets, while Russia and Africa have increased city-pair traffic in recent years. Hubs will become less important as global point-to-point traffic increases.
Along with changes in aircraft, look for changes in the design of airports. The staffing of airports could shrink due to improvements in technology and safety. The future trend for airports is one of a travel experience, as opposed to a mere transit point. They now offer dining, shopping, and a number of activities. With the current technology of airport processes, passengers now have more leisure time, and this pattern is expected to increase in the future. With increased passenger traffic, airports will increase in both size and profitability. In the United States, the FAA mandated Next Gen system, replacing ground-based airspace navigation to a satellite-based system which uses GPS should offer more precise navigation and traffic control at major airports, streamlining air traffic.
A negative factor of air travel in its environmental impact. Global aviation is responsible for about two per cent of the world’s carbon dioxide emissions-a situation projected to get worse over the coming decades. While airlines and governments are acting to reduce some of the impact, limited success has been achieved so far. However, one must realize that fuel represents 30% to 40% of an airlines operating costs, putting airlines in the position of developing more fuel efficient aircraft. For example, the Boeing 737 MAX series of jetliners have winglets designed to reduce drag and improve fuel efficiency by as much as 2%. Such a small amount could add up to millions of dollars over the service life of an aircraft. Attacking the problem from the other end, an increasing number of airlines have begun to use biofuel mixtures in their operations. Biofuels, which are both more efficient and emit less carbon than fossil fuels, have been phased into service by several major airlines. United Airlines partnered with the AltAir refinery to provide biofuel to the airline’s hub at Los Angeles, purchasing fifteen million gallons at a 30% blend over a three-year period. Though not a substantial proportion based upon current airline usage, the United effort holds promise for the future.
Finally, despite the marketing tools of economy airlines and discounted fares, airlines still generate a healthy profit from business and first class passengers. By offering the soft amenities such as meal service and amenity kits, airlines are able to market their in-flight experience. To enhance that experience a number of airlines partner with celebrity chefs, such as Daniel Boulud (Air France) to create specialized menus or contract with outside brands, such as TUMI, to provide upscale amenity kits. This practice will continue to grow, for those who can afford the tickets, the sky is the limit.
From the early days of aviation, the design of airports was a paramount issue. From the narrow grass runways of the 1920s to the wide concrete lanes of today, airport design has come a long way. However, a new concept of the airport may hold promise for the future-the circular airport. During this blog, we’ll present both the advantages and disadvantages of circular runways and their future impact on aviation.
The concept of circular runways has been around for a number of years. In 1919 a circular runway was proposed for downtown Manhattan with the idea of getting direct air access to NYC. This would be accomplished by connecting the runway to a series of skyscrapers. While a practical idea at the time, having an airport on top of major buildings conflicted with the architecture of the area and was only useful for light aircraft. In 1957 the circular airport concept was first designed for jet aircraft. Such an approach was considered because jetliners of the era required more runway than their piston-engined counterparts. The British designer, Sir H. Temptest thought a circular or endless runway, while expensive to build, would save the cost of lengthening existing airports on a long-term basis. By 1964, the US military expressed interest in the idea and conducted a series of tests at the General Motors Proving Grounds near Mesa, Arizona. These tests have conducted a circular based track with a circumference of five miles and a radius of eight-tenths of a mile. The track was forty-five feet wide and was banked from nearly zero degrees on the inside to twenty-two degrees on the outside, which corresponds to the equilibrium take off and landing speeds varying from zero knots to about one-hundred-forty knots. Though pilots found it difficult to land with the correct roll angle on the speed circle corresponding to the landing speed. However, pilots reported that the runway tended to correct their errors regarding landing speed, the point of touchdown and degree of bank. Aids such as a marking on the runway helped them for positioning. After several trials, pilots adjusted to the track and reported exceptional lateral stability with the aircraft finding it’s natural line on the runway corresponding to its speed.
While the Mesa tests were successful, it was nearly fifty years before further research was conducted on circular runways. This was largely due to construction costs of circular runways, which require about twice the length of linear runways, as well as the precise banking of the runway. However, interest in the concept was revived in 2011 as a result of the “Fentress Global Challenge: Airport Of The Future” study initiated by two university students, one from Standford and the other from Malaysia’s University Of Science, concurrently as the Dutch consortium NLR began to research the feasibility of circular runways. Both studies indicated a number of advantages associated with circular runways. The first advantage is both a safety and fuel consideration. Since the runway is a circle, an aircraft may both take off and land in a direction which avoids the effects of crosswinds, enabling a safe landing or takeoff. The aircraft also saves fuel in the process, as well having fewer emissions to the environment. Circular runways allow air controllers to control takeoffs and landings at any point along the circle, thus reducing noise pollution. Circular runways can handle the same number of departures or arrivals as straight runways. While the runway length is about twice that of a straight runway, the airport as a whole takes about one-third the space of a linear airport. Construction costs have also decreased in recent years, with the cost of a circular airport at about 1.5 times the cost of a straight airport. Also, by having less total space than a linear airport, circular airports are more adaptable to smaller communities. However, circular runways have a few disadvantages. Perhaps the most difficult aspect of operating from a circular runway will be landing on a banked runway since the weight of the wings is not shared equally and could damage the plane’s tires due to unequal stress. Landing from a corner will also be difficult and pilots will need training specific to circular runways.
Circular runways are feasible with current technology and construction techniques. Today’s aircraft characteristics allow takeoffs and landings with both speeds and low altitude bank angles compatible with operation on a circular track. The circular runway accommodates intermodal transport, in addition to improved operations planning and navigation equipment. Perhaps the greatest obstacle to circular runways is that of public acceptance.
Tragic as the events of September 11, 2001, were, they forced a needed examination of global aviation security. In this blog, we’ll look at both current problems and approaches to enhance the security of global air travel.
Since the 1970s, trade, technology, and economic growth have merged to form a state of globalization, in which the welfare of people, firms, and nations have become ever more interconnected. Concurrently, civil aviation has evolved from a heavily regulated system of government-sponsored air services and airports to an increasingly competitive global structure, in which private organizations compete with their publicly held counterparts. Global air traffic has increased exponentially over the last forty-five years, in spite of economic recessions, military conflicts, health epidemics and acts of terror. Due to the nature of its operations, civil aviation has always been a target for violent acts. The first violent incidents involving civil airliners were hijack attempts, which began in the 1960s. By the late 1970s, these were on the decline due to international treaties and plain-clothed security personnel on board the aircraft. During the 1980s bomb attacks designed to draw attention were on the rise, decreasing in later decades. By the 1990s, aviation security had evolved into a complex system combining intelligence agencies and airport security personnel coupled with electronic devices from which to detect, bombs, weapons and prohibited items.
The terror attacks of September 11, 2001 were the most graphic example of the ever-evolving threat of terror attacks against aviation. The attacks demonstrated how civil aircraft could be used as weapons to kill large numbers of civilians and destroy assets on the ground. Since that time governments have created a number of new organizations to direct airport security systems, as well as massive investments in both technology and personnel. Though both airlines and airports have faced challenges resulting from heightened security efforts, the traveling public has been willing to bear them to promote a secure travel environment.
Today, there are several factors affecting the security of global aviation. Technology is rapidly enabling the ability of terror groups and other bad players to inflict large-scale damage. While the capability for such efforts has been confined to a few major nations, such technology is now available to a number of non-state organizations. The merging of cyber and physical capabilities are creating new security issues. One only need to see a virtual reality game to understand how closely simulations can approximate real-world situations. Many systems in civil aviation such as traffic management systems, passport control system, departure control systems, hazardous materials transport and reservation systems are all vulnerable to outside hacking. Computerized aircraft flight systems pose an equally serious threat. GPS navigation systems, fuel control systems, flight control and maintenance only serve to increase the points of cyber vulnerability. As aviation becomes more computerized, human proficiency becomes less effective. Though automated systems are becoming more flexible to handle a variety of situations, minimizing human involvement. However, when humans have less opportunity to practice and develop skills, they become less capable of acting in a timely and appropriate manner when emergencies arise. Perhaps the most vulnerable points in many automated systems are those in which humans interact with automated programs.
However, a number of solutions are available to enhance global flight security. There is currently too much emphasis on molding new problems into existing regulations. As is often the case, by the time new policies are formulated, a new threat has arisen. Global aviation firms should adopt a philosophy of thinking like the terrorist, rather than relying upon yesterday’s doctrine to meet future attacks. In the realm of cybersecurity, firms must enhance their understanding of threats by testing their systems by in-house or outside consultants, tailoring their systems to meet the threats. Firms should cooperate on both cyber and physical security threats, as cooperation makes everyone stronger. Any would be hacker will always probe for the weakest link. Real and potential vulnerabilities should be shared between companies. Finally, airlines need to rethink border security, in the digital sense. While the number of remote attacks has increased in recent years, air safety is improved by a thorough knowledge of passengers – an area in which more capable programs are needed.
Civil aviation is a key element of the global economy and any event, whether accidental or intentional, has a direct bearing on the media. With new technology promoting the rapid transfer of information, it will continue to be a likely target for those who want to cause maximum disruption.
Pretend you’re the pilot of a large jetliner. You’ve completed pre-flight checks, both inside and outside, and are ready for takeoff. As you climb, the plane begins to vibrate and then pitch to one side. The number two engine then separates and you are faced with a decision – jettison the remaining fuel on the aircraft or make a heavy landing with fuel on board. While engine separations are not frequent occurrences of air travel, they can have tragic consequences for both the plane and the surrounding area. During the course of this blog, we’ll review two key cases involving such incidents.
In May 1979 a McDonnell Douglas DC-10 (Flight 191) was making a regularly scheduled passenger flight from O’Hare International Airport in Chicago to Los Angeles International Airport. Moments after takeoff, the aircraft plummeted downward, killing all 258 passengers along with the crew of thirteen and two on the runway. A subsequent investigation by the FAA revealed the number one engine separated from the left wing, flipping over the top and then landing on the runway. During the separation from the wing, the engine severed several hydraulic lines which locked the leading edge wing slats into place, as well as damaging a three-foot section of the wing. As the plane began to climb, it experienced a state of uncontrolled aerodynamics, in which the left wing provided minimal lift compared to that of the right wing while the engine was at full throttle. This condition caused the aircraft to roll abruptly to the left, reaching a bank angle of 112 degrees before crashing.
While the cause of the DC-10 engine loss was later determined to be due to a damaged pylon structure connecting the engine to the wing, several other factors also played a role in the crash. The hydraulic system powered by engine number one actually failed but ran from motor pumps connecting it to the engine three systems. While hydraulic system three was also damaged, it continued to provide pressure until the crash in spite of leaking fluid. Electrical problems were also a factor in the crash of Flight 191. The number one electrical bus, attached to the number one engine, failed, resulting in several electrical systems going offline including the flight captain’s instruments, stick shaker and wing slat sensors. As a result of the partial electrical failure, the flight crew only received a warning about the number one engine failure – not its loss. Though the crew had a closed circuit television screen behind the pilot from which to view the passenger compartments, it too was subject to the loss of power from the engine. After the Flight 191 incident and three other DC-10 crashes during the 1970s, a number of major airlines began to phase out the DC-10 in the early 1980s in favor of newer and more fuel- efficient jetliners such as the Boeing 757 and 767. While the phaseout had more emphasis on fuel efficiency, the safety of the aircraft cast a cloud over its service.
The DC-10 wasn’t the only wide-body jet to experience engine separation. In October 1992 an El Al Israeli Airlines Boeing 747-200 cargo plane (Flight 1862) with three crew members and one passenger on board, began a flight from John F. Kennedy Airport , New York to Ben Gurion International Airport, Tel Aviv with an intermediate stop at Schiphol Airport, Amsterdam. Weather conditions were favorable at the time of departure with all pre-flight checks performed, with no defects found. About ten minutes out of Schiphol, the flight data recorder indicated both engines 3 and 4 and their connecting struts had left the aircraft. The co-pilot transmitted an emergency call to Schiphol, requesting a return to the airport. However, the aircraft could not make a straight-in approach, due to both altitude and proximity to the airport. Therefore, the air traffic controller had to vector the El Al plane back to the airport by flying a pattern of descending circles to lower the altitude for a final approach. About five minutes into the flight pattern, the flight crew informed the controller of the loss of engines three and four and were beginning to experience flap control problems. The controller directed a new heading to the flight crew, but noticed the plane was taking 30 seconds to change headings. About three minutes later, the flight crew informed air traffic control they were receiving audible warnings indicating a lack of control and low ground proximity. Approximately twenty-five seconds later, the aircraft crashed into an eleven-story apartment building, about seven miles from Schiphol Airport.
Both number 3 and number 4 engine struts were recovered from Naarden Harbour, just east of Amsterdam with both engines attached to the struts. Remaining parts of the aircraft were located within a thousand foot radius of the impact. From an analysis of the parts and their placement, investigators were able to determine the number 3 engine separated first, traveling in an outboard direction, striking engine 4 and causing it and the supporting strut to separate from the plane. The engine struts or pylons are designed as two-cell torque boxes absorbing vertical, horizontal and torsional thrust loads to the wing, acting as an aerial shock absorber. The Boeing 747 pylon was supported internally by five fuse pins, which provide enough strength to hold the pylons in place with the exception of extreme loads, in which the pins fail, allowing the engine to break away without damaging the wing fuel tanks. This philosophy was adopted by Boeing from experiences with the earlier 707 and 727 models, in which a number of incidents of both in-ground and mid-air engine separations occurred. The crash of the El Al jetliner was attributed to a failure of a center fuse pin in the number 3 engine strut. The pin cracked due to metal fatigue and was a bottle bore design. The FAA issued a directive in 1979 requiring airlines to conduct inspections of the fuse pins every 2,500 flight hours as the bottle design was prone to fail at that point. The El Al 747 was one of a few aircraft which had not replaced their bottle pin units. As a result of the El Al crash and two other 747 crashes, the FAA mandated a retrofit of all Boeing 747 wing struts in 1995. The new strut design offered increased protection in the event of an engine separation, while still using fuse pins to protect the wing tank from damage during ground impact.
As the two previous cases indicate, engine separations may result from a number of problems. Sometimes it’s a matter of faulty parts, while lack of proper maintenance plays a role in others. The overall design of the aircraft itself may be a factor. However, the safe operation of an aircraft requires a continual interplay of aviators, air controllers, engineers and the flying public to promote flight safety.
While the United States was a pioneer in aviation development during much of the twentieth century, many of its airports border on a state of decay. During the course of this blog, we’ll examine the current state of the nations airports, as well a number of proposed solutions.
Though many complain about airports, often as a result of troubled airline experiences, perhaps comparing major air hubs in the United States to their more modern overseas counterparts is unrealistic. Each airport has its own unique history in relation to the communities they serve. Aviation development in the US increased dramatically after World War II with airport construction complementing that effort. Many of the prime airports in the United States were conceived in an era before the proliferation of both foreign and domestic air routes. Most airport renovation efforts over the last 30 years have involved a limited patchwork process, since many of the hubs are surrounded by urban areas – unlike the modern air hubs of Asia and the Middle East, which serve emerging markets and emphasize architecture and aesthetics over serving large volumes of passengers. For example, Dubai’s main airport covers an area of about 7 million square feet, designed to serve from 25-30 million passengers per year, while the Jet Blue terminal in JFK airport serves approximately 22 million passengers per year in an area less than 1 million square feet. Post 9/11 security and related requirements have also placed additional stress on US airports. The financial and environmental costs of airport construction often make such proposals a political liability. The ownership and control of airports in the United States, a landlord-tenant model between the airlines and the municipalities, also serves to inhibit progress.
Given the constraints on space in many urban areas, airport designers are forced to move up rather than out. In a practical sense, any airport restructuring begins with the check-in process. By placing security and check-in on separate levels, traffic flow is segregated between the two functions. Such an organization divides passengers into two categories – those who are able to check in with the aid of mobile devices, and those who use the more traditional (paper) approach and may require assistance to board their flight. Both groups must pass through security before boarding . Such an arrangement could cut pre-flight processing time by as much as 40 per cent. As mobile technology becomes more dominant, it offers air carriers both the convenience and flexibility to book flights outside the confines of an airport. Satellite check-in sites at hotels, restaurants and shopping centers allow airlines the option of verifying and staging passengers from remote locations, requiring less staff and processing time. Delta airlines, for example , has set up its own security service at a major airport from which to process passengers. This concept provides both security and marketing benefits.
A recent trend in airport check-in procedures is the use of self-service technology. Miami International Airport purchased approx. 45 automated kiosks, to reduce customs and immigration processing time. These automated kiosks can process a passenger within two minutes, making what was once a grueling check-in process a relatively seamless one. Several major air hubs are embarking on outside improvements to enhance the passenger experience. For example, Chicago O’Hare began a $15 billion capital investment program in 2005, transforming the current system of intersecting runways to a series of parallel ones, which will increase capacity by 60 % while substantially reducing delays. An additional control tower, runway and cargo center are under construction at O’Hare and are slated to be operational in about three years. Los Angeles International began an $8.5 billion expansion program in 2006, with construction completed on the New Tom Bradley International terminal in 2013 with new dining, gates and retail areas designed to meet the needs of international tourists. Related projects include the updating of Terminal 6 to meet the needs of large scale aircraft, such as the Airbus A380. LAX is also building a new Central Utility Plant, as well as taxi and runway improvements.
Understanding how the above innovations affect terminal operations will be the key to the future success of the nations airports. As air traffic continues to grow despite economic and other setbacks, passengers will continue to demand more control over their travel experience. Airport planners must continue to emphasize key passenger services such as transit, parking and baggage claim to remain competitive, while focusing on the core mission of airports as gateways to the world.
While watching the recent movie Sully, I was amazed at the sophistication of current flight simulators available to the major aircraft producers. During the course of this blog, we will trace the development of flight simulators from mere mechanical devices to the virtual reality electronics of today.
A flight simulator is a mechanical or electronic device, which attempts to duplicate both aircraft flight and the environment in which it flies. Current simulators can replicate factors such as flight controls, wind, moisture and electronic system interaction. While flight simulation is used primarily for pilot training, it may also be used to design aircraft, as well as identify effects of aircraft properties.
The earliest flight simulators were used during World War I to teach gunnery techniques. This involved a static simulator with a model aircraft passing in front to aid both pilots and gunners to develop correct lead angles to the target. This was the only form of flight simulation for nearly ten years. The Link Trainer, developed by Edwin Link in the late 1920′s, capitalized on the use of pneumatic devices from player pianos and organs from the family musical instrument business. The first trainer was patented in 1930 with an electrical suction pump boosting the various control valves operated by stick and rudder action while another motor simulated the effects of wind and other external disturbances. These actions could be manually adjusted to provide a variety of flight characteristics.
While the Link Trainer provided a quantum leap in capability over previous flight simulators, many in both the military and civil aviation communities believed the live flight experience offered a better training environment. However, by the early 1930′s, the United States Army Air Corps had a need for flight simulator applications which could train mail pilots to fly by instruments for long distances. An enhancement to the Link Trainer was a device called the course plotter, in which a self-propelled tracker could remotely trace the trainer position from an inked wheel with communications between pilot and instructor facilitated by the use of simulated radio beacons.
It was during the late 1930′s, when flight simulation began to be based on electronic applications. The Dehmel Trainer, developed by Dr. R. C. Dehmel of Southwestern Bell, coupled a Link Trainer with an advanced radio simulation system, which could accurately duplicate navigation signals transmitted to a receiving aircraft, providing a state of art simulation of radio navigation aids. The Aerostructor, developed by A. E. Travis, utilized a fixed base trainer with a moving visual presentation, as opposed to radio and electronic signals. This presentation was based on a loop of film which depicted the effects of course changes, pitch and roll. While the Aerostructor was never mass produced, a modified version of it was in service with the US Navy.
During World War II advances in aircraft design such as retractable landing gear, variable pitch propellers and higher speeds created a demand for more realistic forms of flight simulation. In response to this, the Hawarden Trainer was developed, which used a cutaway center section of a Spitfire fuselage, which allowed training in all aspects of operational flight. In 1939, the British were in need of a simulator which could train it’s navigators who were ferrying US aircraft across the Atlantic. The navigator was supported by a number of radio aids, as well as a celestial dome corresponding to changes in the position of the stars relative to changes in time, longitude and latitude. The Celestial Trainer, designed by Ed Link and P. Weems was also modified to train bomber crews, in which simulated landscapes gave the bomb aimer target sightings as they would appear from a moving aircraft. Redifussion (Redifon) produced a navigation device in 1940, which simulated existing radio direction equipment allowing two stations to take a fix on an aircraft’s position. By the end of the war, aircraft crews were trained by the simulation of radar signals to acquaint them with new types of radar developed during the war.
While the science of flight simulation had progressed dramatically over the past thirty years, they were unable to accurately duplicate performance characteristics of a plane. This changed with the arrival of subsonic jetliners in the 1950′s. Aircraft manufacturers began to produce more complete data and extensive flight testing. This data was stored on analogue computers, making the data transferable, but requiring more hardware as aircraft testing became more sophisticated. By the early 1960′s, digital computers began to replace the aging analogue units due to the increased data capacity and speed of the digital units. The most successful of these, the Link Mark I, operated with three parallel processors functional, arithmetic and radio selection, using a drum memory for data storage. By the 1970′s the majority of computer systems could be adapted for flight simulation.
During that decade computer image generation or CGI technology became available for flight simulation models. This technology, adapted from the space program, used a ground plane image, supplemented by three dimensional graphics. This technology became more sophisticated in recent years, mating it to advances in digital computers – a far cry from the rolling ground plane pictures of the 1940′s. Today, flight simulation is a colossal industry, spanning the globe with a wide range of high tech applications for both aircraft users and producers, enhancing the safety of both crew and passengers.
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.
The recent grounding of 128 planes of the Southwest Airline fleet along with a number of private aircraft accidents have placed a renewed emphasis on aircraft inspections. During the course of this blog, we will examine the inspection process, as well as the human factor.
While many processes in today’s aviation are performed electronically, the inspection of an aircraft is still largely done by visual observation. An aircraft inspection may range from a casual walk around the plane to a detailed inspection involving a complete removal of aircraft components, utilizing complex inspection aids. The first step of conducting an aircraft inspection involves collecting the required forms and reference materials from which to document the inspectionThe aircraft log books must be reviewed to provide background information and a maintenance history of the aircraftChecklists are utilized to ensure all items are included, appropriate to the scope of the inspection. Additional publications provided by the aircraft manufacturer and the Federal Aviation Administration are useful guides for inspection standards. Conceptually, aircraft inspections may be planned on either a flight hours or a calendar basisAircraft functioning under the flight hour system are inspected when a specified number of flight hours are accumulated. The flight hour system requires more documentation than the calendar inspection, as well as placing limits on the number of hours an aircraft may be flown. Different parts and operating systems on a plane may also have varying hour limits between inspections. The calendar inspection system establishes a regular interval between aircraft inspections, specifying a given number of weeks between each inspection. The calendar system is both simple and efficient, with scheduled replacement of components with hourly operating limits replaced on the date nearest the hourly limit.
The criteria governing the airworthiness of a plane is specified by the Code of Federal Regulations, which prescribes maintenance and flight operations standards. Title 14 of the CFR establishes the requirements for annual and 100 hour inspections. Private aircraft with less flying hours are subject to annual inspections while commercial planes must have a complete inspection every 100 hours. While both inspections are identical in detail, there a few differences. A certified air frame and power plant maintenance technician can perform a 100 hour inspection, while an annual must be performed by a certified air frame and power plant maintenance technician with inspection authorization. Also, the 100 hour inspections are more rigid in their maintenance schedules, allowing only a 10 hour overflight beyond the 100 hour limit to the inspection site. Since annual inspections may be quite extensive and detailed, the progressive inspection program was developed. The progressive inspection program divides the inspection process into four to six phases, the completion of which amounts to an annual inspection. Under the progressive program, an inspection phase is usually completed within a couple of days – minimizing the downtime of an aircraft. If the required phases are not completed within a twelve month period, the remaining phases must be completed before the end of the 12th month from when the first phase was completed. Owners and operators contemplating a progressive inspection program must submit a written request to the FAA Flight Standards District Office having jurisdiction over where the applicant is located.
No matter what type of inspection program an airline or operator utilizes, human error is always a factor. Historically, human error studies have emphasized flight crew performance with a more recent emphasis on air traffic controllers. Air safety studies have largely neglected human factor issues affecting the performance of aircraft maintenance personnel. This has been a serious oversight, since human error in aircraft maintenance has had an equally dramatic effect upon the safety of flight operations as pilot or air controller error. Both aircraft maintenance and inspection tasks can involve a variety of duties, creating an environment for error. Maintenance personnel frequently work under time pressures, especially in high traffic segments, in which the carrier seeks to maximize profits while minimizing aircraft turnaround times. Aircraft maintenance technicians are increasingly servicing fleets which are increasing in age, with many planes in service for over twenty years. These aircraft require an intense inspection regimen to detect signs of fatigue, corrosion and general deterioration. Concurrently, new technology aircraft are entering service with the world’s air fleets, with features such as composite materials, environmentally friendly engines and built-in diagnostic equipment. The need to maintain air fleets of multiple technology tiers will require both a highly skilled and educated technical force to meet present and future demands of the aviation industry.
When one makes the decision to become a pilot, they first realize how many hours and how many dollars are involved in order to complete the training – a regimen not everyone can sustain. During this blog, we will explore current employment trends for commercial pilots, as well as the underlying causes for pilot shortages.
When the Airline Deregulation Act passed in 1978, the government no longer controlled airline industry scheduling, staffing or fares. With the market saturated with new airlines, the industry now controlled who they hired and how much they paid them. The airline segment entered a period of intensified competition between existing airlines with new ones entering the market. While these conditions created an increased demand for commercial pilots, flight schools were able to keep pace with the demand due to the expansion of the national economy. This growth began to slow in the 1990s, with a number of airlines such as Precision, Atlantic, TWA and North American either being absorbed into another airline or leaving the industry, creating a surplus of available pilots.
On the heels of the airline consolidation of the 1990s came another event which brought a drastic impact upon the industry – the terrorist attacks of September 11, 2001. These attacks brought about enhanced security measures and related costs to be borne by the airlines, in addition to creating a climate of fear, which devastated the industry as a whole.
Financial considerations are another factor affecting the supply of pilots. The major airlines (those serving international routes) currently require a pilot to have a Bachelor’s degree along with completion of their Airline Transport Pilot (ATP) certificate. The tuition required to complete both courses of study is easily in excess of $100,000, leaving entry level pilots saddled with debt for a number of years. To make matters worse, competition is keen for the relatively few openings at the major airlines, forcing many graduates to begin their careers working for the smaller regional airlines, subcontractors who operate smaller jets and turboprops on behalf of the major carriers. These airlines offer starting salaries in the $20,000 to $25,000 range, low by industry standards, with advancement to captain often taking at least five years. Pilot tuition further increased in 2013, to satisfy a new FAA requirement of 1,500 hrs. training for safety purposes. The previous requirement was 350 hrs. Starting salaries at the major carriers average between $35,000 to $40,000 per year. By comparison, a 2LT in the USAF, with flight pay and allowances, earns approximately $50,000 per year.
So, is there a current pilot shortage? Several criteria may be used to gauge current and future staffing levels. One indicator, additional air routes, would suggest a surplus of pilots in the near term. After 9/11, the airline industry went through a drastic reduction in staffing. While the industry has largely recovered from this, it has been a slow one with traffic still not at pre 9/11 levels. In 2012, Boeing conducted a study which forecast a need of 70,000 pilots by 2024. This is, in part, based upon a projected demand of new aircraft orders at an increase of 1.4% per year over the next decade. The results of this study are a mixed bag, suggesting a slow expansion at the major airlines with a corresponding reduction at the regionals. Flight school enrollment is another factor of pilot supply. While flight school enrollment has experienced a gradual decline over the last ten years, a recent General Accounting Office study indicated a demand of an additional 42,000 pilots between now and 2024. The study determined the projected pilot pool to be adequate to meet anticipated needs. However, the 1,500 hr. training requirement imposed by the FAA upon flight schools delays the certification of future pilots by an additional 12 to 18 mos., limiting the available pipeline of entry level pilots. The extension of mandatory retirement from age 60 to 65, approved by the FAA in 2007, will serve to reduce pilot attrition. This is partially offset by a reduction of former military pilots entering the airline force, which they believe has limited pay and growth potential. Furloughed pilots, whose positions were cut from their respective airlines due to unprofitable routes and other factors, are an ever present part of the pilot pool.
While the various studies and factors appear to offset one another, two problems remain certain. The cost of completing an Airline Transport Certificate coupled with a Bachelor’s degree now averages about $125,000, which could make an aviation career a domain of the wealthy. The other half of this problem is the relatively low starting salaries offered by the regional airlines. At the current levels, it takes entry level pilots ten years or more just to pay off the ATP training. Airlines and/or government assistance must be made available to insure the best qualified applicants serve as pilots. While the regional airlines have traditionally been stepping stones to careers with the majors, the regionals must seek to improve pay, benefits and overall working conditions to promote stability within their pilot force. A flight captain with ten or more years of service with the major airlines averages from $120,000 to $200,000 per year, the regionals about 60% of that. If these two problems can be addressed, we’ll not only have an adequate pilot supply but a highly capable one.
With the ongoing search for Flight 370, much attention has been focused on how such flights are monitored. During this blog, we will trace the history of flight recorders from their earliest days to the technology of today’s systems.
The earliest attempt to develop a practical flight recorder was the result of experiments conducted by two French engineers in 1939. This recorder utilized a photographic film media to record changes in the aircraft’s attitude, such as diving, climbing, banks, turns and other variances by a projected beam of light. Although the system was limited by changing film strips after each flight, it served as the forerunner for future research. The development of flight recorders received a low priority during World War II as a result of military technology applications. However, two British scientists produced a device in 1945 which used a copper foil to record flight data, with various styli indicating the application of various aircraft controls. This system was both more practical and survivable than the film device and was relatively crash-proof for its time.
By the 1950s, flight recorders were enclosing in fire-proof casings. While the foil recording media was believed to be indestructible at the time, several high-profile crashes of the BOAC Comet jetliner proved the media vulnerable to a crash. In 1965, the FAA mandated flight recorder boxes withstand a 1,000 g. crash, from the prior standard of 100 g. of the 1950s. Also during that year, cockpit flight recorders were mandated which recorded the last thirty minutes of flight crew conversation. Initially, two separate recorders were installed, but a large number of combination recorders became available within a few years. While flight recorder boxes were black, dating from the film technology days, they were mandated to be bright red/orange color beginning in 1965, to make them more visible to rescue crews. Recorder boxes also began to be located in the tail of an aircraft, as a result of a number of crash tests, which proved the speed of impact to be drastically reduced by the time it reached the tail of the plane.
Because of the limitations of the foil system, magnetic tape became available in the late 1960s, in which ever larger amounts of flight data could be more easily recorded and stored. In the 1970s, the magnetic tape system became enhanced by the application of digital technology, which increased the speed by which flight data could be retrieved. By 1990 all of the major airlines began to use solid state flight recorders. A solid state system is one in which data is stored in semiconductor memories or integrated circuits, rather than using the older technology of electromechanical data retention. The advantages of the solid state system were low maintenance costs, as well as speed of data retrieval and ease of storage. Within a few years, it may be possible to develop a solid state video flight recorder to monitor all flight crew activities from the start of a flight to its finish. While some in the aviation community may view this as an intrusion, others will be glad big brother is watching.