As a student nearing graduation, I want to work in the aerospace field. The problem is, I’m not so well-versed with all the positions and opportunities available. I’d like to know more about what specific positions entail. For example, I’ve heard a lot about avionics engineering, but not enough to understand it well. Experts, what is avionics engineering?
There are many separate disciplines within the field of aerospace engineering. One specific field, avionics, generally concerns the electronic systems used to ensure safe and managed flight. Whereas other engineers are responsible for the design of the aircraft, avionic engineers are responsible for the electronics and computer systems within. Avionics engineers are responsible for the electronics, computers, and wiring that ensure safety.
Avionics is a term created by combining aviation and electronics, and, as stated, this discipline concerns the electronic guts of the airplane. This field includes all aviation electronics including, for example, radar, autopilot systems, flight recorders, ground communication, and collision avoidance systems. To ensure a safe and manageable flight, these electronics must be strictly evaluated and tested to ensure flawless performance during use. Many of the crucial electronics are designed with redundancy to ensure continued flight following the failure of a single device.
As aircrafts become more sophisticated, much of the flight is reliant on computers including the autopilot systems. According to the FAA, many manual controls are now automatically controlled by technologically advanced avionics systems. Computers run software programs which are designed to ensure a safe and comfortable flying. As with the electronics, it is imperative that all of the software systems are rigorously tested and evaluated. The avionics engineer is responsible for the creation and programming of the varied electrical and computer systems within the aircraft.
How are these systems regulated?
DO-178c or “Software Considerations in Airborne Systems and Equipment Certification” is the document used by certifying agencies to evaluate the software designed for commercial aviation. The DO-178c guides the establishment of software levels or Design Assessment Levels (DAL) which assess the potential risk following a software failure. There are five Design Assessment Levels each with accompanying requirements for certification.
Level A is Catastrophic and indicates that software failure would most likely result in passenger deaths and loss of the aircraft. Level B or Hazardous indicates that compromised software would lead to a loss of aircraft controls and severe or fatal injuries. C or Major level indicates safety concerns and an increased amount of work for the crew. Minor or Level D is represented by increased crew work and possible passenger discomfort. Finally, Level E or No Effect has no impact on safety, amount of crew responsibility, nor passenger discomfort. All of these levels correspond to the effects of software failure on the functions of the aircraft.
As a result of these safety concerns, each Design Assessment Level requires a specific amount of testing to ensure the efficacy and reliability of the software at each level. The number of assessments required are in proportion to the level of threat. Many of these assessments must be made “with independence,” meaning that the creators of the software cannot be involved in the assessment evaluations.
This independent testing is delineated by how strict the assessments in proportion to the DAL. At Level E, no testing is required, as a failure in the software has no effect on safety, crew workload, nor passenger comfort. Minor DAL levels require an assessment of high and low level requirements, and additional review of high level requirements. All of the following levels require the testing of the previous level plus additional testing. Therefore, Level C or Major DAL requires all the testing of Level D, plus a review of the design and code, testing of both high and low level requirements, assessment of the data and code coupling, and assurance that each source statement is covered. Level B requires all the testing of C and D plus target testing, code decision/condition coverage, and independence of code coverage activities. Finally, Level A or Catastrophic includes all previous reviews and the inclusion of proof of code modified condition coverage and source to binary correlation.
Avionics concerns the electronics and computer systems of air travel. Early on in aerospace technology, these systems were fairly rudimentary, but modern aerospace technology is reliant on computer technology. The DO-178c guidelines delineate what is required to assess and certify aircraft software. Adherence to these guidelines, will ensure comfortable and safe air travel.
