Feedback

After reading your February 2001, Avionics Magazine articles on ultra-wide band (pages 20 and 28) and Aeronautical Telecommunications Network (page 16), I felt compelled to write to you to express my concerns.

As an avionics engineer for an airline that recently made a three-generation jump in systems technology with the B717, I have been thrust into this "new" world of digital avionics. This has proven to be a double-edged sword. Now, throw in the addition of UWB, ATN, ADS-B, Free Flight, etc., and some very interesting questions arise.

Who pays for all this new technology? And what is of greater concern to me is how does general aviation (GA) fit into the grand scheme? How many GA aircraft owners can afford the latest in avionics? Probably few.

I am also involved in GA as an experimental aircraft builder. To equip my aircraft with only basic IFR capabilities, a VHF nav/com, a GPS/com, and a Mode C transponder will cost me somewhere between $8,000 and 10,000.

We forget that without GA, we wouldn’t have the aviation industry we so often gloat over. We wouldn’t have many of the pilots now flying commercial aircraft. How loudly will GA’s voice be heard next to the needs of commercial aviation?

If the aviation industry and the FAA feel compelled to create all these wonderful new systems and technologies, every potential user must be included in the design and implementation process. Product liability nearly killed GA in the 1980’s. If we’re not careful, avionics could do the same in this decade.

Regarding your article "Product Focus: Air Traffic Control Switches" in the February issue (page 26), I was surprised by two aspects. Firstly, that you did not mention QSIG as the adopted signaling protocol for networking ATC switches in the digital age, and secondly, by your implication that VoIP (voice over IP ) technology will quickly gain hold in ATC switching.

Over the past five years, considerable effort has been expended by ATC organizations and manufacturers on the study and implementation of the digital signaling system known as QSIG for networking of ATC switches (see www.pqmconsultants.com/qsigats.htm). This has culminated in a soon-to-be-published ICAO recommendation that will significantly assist the transition from today’s essentially point-to-point communications network for ground telecommunications towards a fully switched integrated digital network–something that is lacking in ATC telecommunications today.

In our view, it is unlikely that voice over IP technology will find application in ATC networks for some years yet. The issues concerned with quality of service and reliability have hardly been addressed, and so far, there is little evidence of switch manufacturers having adapted their products to use IP routing instead of circuit-switching.