So It's Been 20 Years

Reminiscing has never been one of my greatest joys. In fact, for me, most of it involves waking up at some unusual hour only to venture back to the airport to check if in fact I did safety that connector, read the squawk correctly, or comply with all the required tests. So what exactly is noteworthy in the world of avionics over the past two decades?

One of the most obvious changes has been the gradual evolution of mechanics into technicians. In the eyes of many this change is nothing more than a play on words. The implication in my view is that our industry has now realized our profession involves significantly more than just mechanical knowledge and aptitude.

With virtually all the aircraft types certificated within the last 20 years it becomes increasingly more difficult to distinguish where the airframe stops and avionics begin. Almost all of us in an aircraft maintenance role have come to the realization that computer technology is in fact not a passing fad but another reality of the job. The concept of self-diagnostics has still not been fully comprehended by many of our colleagues and the thought of “Fly by Wire” evolving into business aviation as well as general aviation has been inconceivable.

Education and training
Perhaps the biggest challenge our industry faces is keeping the knowledge level of technicians in line with technological advancements. Another reality is that aircraft of today can not be learned in the same way as those manufactured prior to the 1980s.

Many initiatives are underway through the efforts of several professional organizations to improve the aviation maintenance profession followed with acknowledgement for the efforts of those willing and able to participate in continuing educational programs. Among the ones carrying momentum is The National Business Aviation Association (NBAA). It currently has significant thrust in advancing our quest for knowledge with an initiative called “Project Bootstrap,” www.nbaa.org/prodev/bootstrap. This plan creates an achievable set of goals intended to provide direction to technicians seeking a career path and in part provides guidance for becoming an effective avionics technician.

Within our 20-year time spectrum, the Federal Aviation Administration, along with several other airworthiness authorities, has implemented programs such as AMT Awards in an attempt to stimulate technicians to actively pursue education including human factors and regulatory content.

Increase in air traffic
Another significant challenge of the last 20 years has been accommodating the exponential increase in the world’s aircraft fleet. This has become a major issue in areas associated with high-density air travel. Several initiatives have been put in place and continue to evolve including reduced vertical separation minimums (RVSM) and reduced navigation performance (RNP).

The intent of RVSM is to enable more aircraft to utilize the most preferable and most efficient tracks while accomplishing their missions. This is done in much the same way as a highway department accommodates increased traffic without pouring more concrete. They take the existing lanes of traffic and make them narrower along additional lanes to be added in the existing paved area. This should automatically cause driver awareness to increase significantly as drifting in another lane becomes more likely. For aircraft to operate at Flight Level 290 to 410 in designated RVSM airspace both the crew and the aircraft have to be certified. This certification does impact maintenance practices. In some cases more frequent certification of altitude indicating systems is needed along with detailed geometric inspections of strategic areas of the airframe. Once the initial RVSM preparations are made and the aircraft performance is validated, application must be made to the RVSM monitoring agency (usually the local airworthiness authority) for the approval to fly within the designated airspace. This privilege does come with an impact on maintenance as certain required checks must be performed routinely to ensure continued airworthiness.

Navigation systems
Since it became fully operational on April 27, 1995, GPS has become a widely used aid to navigation worldwide. The global positioning system has become a mainstay of transportation systems worldwide, providing navigation for aviation, ground, and maritime operations. Disaster relief and emergency services depend upon GPS for location and timing capabilities in their life-saving missions. A space-based global navigation satellite system was the answer to providing reliable positioning, navigation, and timing services to worldwide users on a continuous basis in all weather, day and night, anywhere on or near the Earth.

GPS is made up of three parts: between 24 and 32 satellites orbiting the Earth, four ground-based monitoring stations, and the GPS receivers owned by users. GPS satellites broadcast signals from space that are used by GPS receivers to provide three-dimensional location (latitude, longitude, and altitude) plus the time.

Following in the footsteps of the October 2008 update of the GPS Performance Standard, the FAA has issued specifications for the wide area augmentation system (WAAS). During the following month the agency reported that it has now published 1,333 localizer performance with vertical guidance (LPV) approach procedures based on WAAS at 833 airports.

WAAS is the multibillion-dollar U.S. satellite based augmentation system (SBAS) developed under an FAA contract by Raytheon Corporation and designed to provide real-time differential corrections, integrity messages (satellite signal “health”), and ranging signals that WAAS-capable equipment can use to improve navigation.

The system includes two geostationary satellites and a network of ground reference stations that monitor GPS satellite signals. WAAS corrects for the GPS satellite position errors, ionosphere delays, and other disturbances in the GPS signals and in addition to warning pilots when the satellites are not functioning correctly it can also provide a greater accuracy in navigation computations.

Much of what has been mentioned above is a piece in a vastly greater initiative referred to as “Next Gen.” As the term infers, this is a program that will take us forward into the realm of “Free Flight” and involves improvements in communications, navigation, and surveillance as it fits into the air traffic management plan.

Switch to digital
Current analog radios at either 25 or 8.33 kHz frequency spacing have done well for us in our first century of flight. Future needs dictate that more information is better and therefore newer digital radios are part of the mix to enhance ground to air communications via digital data. In addition Automatic Dependent Surveillance Broadcast (ADS-B) is planned to replace the current ground-based primary and secondary surveillance radar (PSR, SSR) with a satellite-based system.

With ADS-B, both pilots and controllers will see radar-like displays with highly accurate traffic data from satellites along with displays that update in real time and don’t degrade with distance or terrain. The system will also give pilots access to weather services, terrain maps, and flight information services. The improved situational awareness will mean that pilots will be able to fly at safe distances from one another with less assistance from air traffic controllers. Synthetic vision will enable operation in conditions where visibility is close to zero and infrared sensors will provide significant enhancements to the prevention of runway incursion.

The technological advancements occurring in the next 20 years will undoubtedly impact the content of my 40th anniversary contribution to AMT magazine. I figure it will include hypersonic transport and possibly the Vulcan death grip and without a doubt phrases like “Beam me up Scotty.”

Nevertheless, we will continue to climb the endless mountain of knowledge and keep ‘em flying.

Jim Sparks has been in aviation for 30 years and is a licensed A&P. His career began in general aviation as a mechanic, electrician, and avionics technician. In addition to extensive hands on, Jim created and delivered educational programs for several training organizations and served as a technical representative for a manufacturer of business jets. Currently when not writing for AMT, he is the manager of aviation maintenance for a private company with a fleet including light single engine aircraft, helicopters, and several types of business jets.

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