Avionics

This is a five-part series on Active Noise Reduction in General Aviation. It came about because hundreds and hundreds of you have been asking good questions about ANR technology and its advantages in airplanes. This series is intended to provide G.A. pilots with a fairly technical and thorough understanding of this technology and the important […]

NOTE: Dr. Jim Yates provided substantial contributions to this section of ANR 101. Dr. Yates is Professor and chair, S.P.A. of John A. Burns School of Medicine, University of Hawaii, and principal of Audiology Associates Hawaii. Previous sections of this series have discussed active noise cancellation and the technical issues associated specifically with general aviation […]

In this section, we’ll be looking at the comfort and human-factors issues associated with ANR headsets. The ergonomics of the human head demand a wide range of adjustments to deliver comfort over hours of use. Optimizing the physical headset for pilot use Active pilots have been searching for ways to improve the physical aspects of […]

Looking at actual cockpit noise profiles, and how well aviation headsets cope with it In Section 2 of this series, you learned how engineers measure effectiveness of active noise canceling systems in the laboratory. But since we don’t fly in the lab, our emphasis will now shift to studying the actual noise spectrums in various […]

Understanding and comparing cancellation specifications Section 1 of this series dealt with the variables and complexity involved in canceling the repetitive and random aspects of airplane noise. It explained that although the basic elements of all active noise reduction systems are pretty much the same, the details of how they are designed and implemented has […]

A good place to start is with one of the most-asked questions that we receive from pilots: Don’t all active headsets work the same way…or do the same thing? The answer is a simple “yes”…and a much more detailed “no.” It’s yes because the principles of additive cancellation with out-of-phase sound is several decades old […]

According to my computer database, Cessna/ARC nav-comms fail 83% more often than theKing KX-155. Think about that next time you’re plowing through a cloud on approach. Sureyou have two radios, a hand-held, and perhaps a Gideon Bible you stole from the hotel. Butthat still might not be enough to keep you out of the rocks. […]

There are two FARs that dictate the biennial checks for most general aviation aircraft:FAR 91.413 for the transponder and encoder, and FAR 91.411 for the static system andaltimeter. First, notice that I didn’t mention the pitot system. While any sane pilot would liketo know that his airspeed indicator is reasonably accurate, the FARs do not […]

If you walk out across just about any aviation ramp, you’ll notice few noticeablechanges in the aircraft in the last decade or two. If you open a cowl or two, you alsonotice the powerplants haven’t changed much, either. But look at a few radio stacks andyou’ll see a dramatic progress. In the last couple of […]

VHF Comm Many years ago it was decided that civil aircraft communications radios would use the118-137 MHz band, and would use amplitude modulation (“AM”). Like many otherthings in aviation, this has remained unchanged for many decades. It’s a pity, because ourair-ground communications would have much better audio quality if we could switch tofrequency modulation (“FM”) […]