Celebrating Aviation History in the U.S.
Flying high in the sky, each day more than 45 thousand planes are crisscrossing more than 29 million miles of United States airspace. Flight might be commonplace now, but for hundreds of years the reality of taking to the sky was only a dream.
November is National Aviation History Month, a time dedicated to exploring, recognizing, and celebrating America’s great contributions and achievements in the development of aviation.
EMA has a long history of working to advance the use of simulation for certification of aircraft to electromagnetic effects. In fact, EMA was the first to use the 3D finite difference time domain (FDTD) technique for civilian certification of a complex transport aircraft.
Advancements in Aviation Technology
Figure 1: A short history of aviation in the U.S.
Powered flight first came to the U.S. in 1903 in Kitty Hawk, North Carolina. After making thousands of glides from atop a hill, Orville and Wilbur Wright became masters of the air. The brothers used what they learned from the glides about sustained lift to design a gas engine and the first efficient air propeller for their powered plane. On December 17, they completed the first four powered flights in the U.S., the longest being 852 feet in 59 seconds.
As planes and commercial flight developed, flight communications became easier in 1949 when the Civil Aeronautics Authority (CAA) inaugurated the first direct radiotelephone communications between aircraft and air traffic control towers. The technology was first used in Chicago and was rolled out to all air route traffic control centers (ARTCC) by 1955.
A computer was used for the first time at the Indianapolis ARTCC in 1956 to assess the value it could provide during the preparation of flight progress strips used to track planes. In 1959, the FAA, which took over for the CAA, commissioned UIVAC file computers for use in air traffic control towers in New York and Washington. United Airlines was the first airline to use a computer for automatic touchdown, that happened in 1964 on a Caravelle jet.
The United States headed into space when the first satellite was launched in 1958. In 1970, two-way air traffic control satellite communications were used for the first time. The full-time point-to-point satellite service was between San Francisco/ Oakland and Honolulu.
Technology continued to grow in the 1980s. The first aircraft to navigate across the Atlantic Ocean entirely using Global Positioning System (GPS) was in 1983. In the following years, the FAA put together a task force to look at the possibility of a Global Navigation Satellite System using GPS. Released in 1992, the report found that the system offered the greatest opportunity to enhance aviation efficiency and safety since the introduction of radio communications and navigation. The next year the FAA would approve the use of GPS for non-precision airport approaches in Aspen and Steamboat Springs, Colorado.
Electronics in Aircraft
Figure 2: Title page of Aircraft Generated Electromagnetic Interference on Future Electronic Systems
As aircraft got more high-tech, the FAA wanted to learn more about how electronic devices and their susceptibility compared to their analog counterparts. In the paper Aircraft Generated Electromagnetic Interference on Future Electronic Systems published in December 1983, FAA researchers were told to pinpoint equipment susceptibility, learn how to minimize the effect of the threat, and recommend test methods and criteria.
Researchers concluded that electromagnetic compatibility (EMC) is a concern to most levels of management. They said that the least expensive way to include EMC hardening into any system is to include it in the conceptual and early design stages. Figure 3 is from the original report and shows the trade-offs available in EMC control techniques.
Figure 3: Chart showing the trade-offs available in EMC control techniques from the 1983 paper Aircraft Generated Electromagnetic Interference on Future Electronic Systems.
Modeling EMC in an Aircraft
At the time that the study was published, researchers said that factoring in EMC at the design phase would not be easy because it “requires engineers who understand and can solve the problems, and, of course, requires that the necessary engineering time be budgeted.” Simulation tools have made this task easier.
EMA used the first known application of the FDTD technique for civilian certification of a complex transport aircraft on the McDonald Douglas MD-90. In the project, EMA3D® was used to determine the effects of indirect lightning strikes on the plane’s electronics including engine controls, navigation, communication, and fuel systems. The simulation approach was validated using existing experimental data obtained for certification of the MD-80 program.
The research group noted that the simulation approach was more cost effective than the traditional model of building physical prototypes and performing testing. Savings were estimated to be at least $1.5 million ($2.2 million adjusted for inflation.)
EMA has also played a role in the development of standards for the FAA, analyzing the risk of high-intensity radiated fields (HIRF) to fixed-wing aircraft. The report helped to determine the current HIRF certification requirements that were adopted in 2007. EMA scientists also helped the FAA with examining the HIRF requirements for aircraft to determine the optimal test level.
Today EMA continues to develop its simulation tools to support changing aerospace technology, including products launching to space. EMA’s Space Environment and Radiation Effects facility can recreate space-like conditions, allowing product developers a way to assess the performance of a product without ever having to send it to space. Along with Ansys Charge Plus (formerly EMA3D® Charge), EMA plans to make on-demand terrestrial space evaluations commonplace. These products deliver safe and reliable designs with proven performance in harsh space environments and are a true market differentiator.
With the U.S. planning to land astronauts on the moon no earlier than 2024 and with four billion people across the globe expected to travel on an airplane in that same year, the future of aviation is only going to continue to grow. It was more than 500 years ago when Leonardo da Vinci said, “Once you have tasted flight, you will forever walk the earth with your eyes turned skyward, for there you have been, and there you will always long to return,” and it’s a sentiment that seems to hold true to this day.