ADF Basics »

Ever wonder how an ADF knows which way the NDB is? Why it needs both a loop antenna and a sense antenna? Or what that "BFO" mode is good for? AVweb's avionics editor takes you through the basics of one of the the most complicated avionics systems in your airplane, the lowly ADF. More

Transponder Basics »

There's a whole lot more to your transponder than a blinking light and an IDENT button. In this article, AVweb's avionics guru teaches you everything you need to to know about transponders and altitude encoders. Even the most grizzled veteran pilot is likely to learn a thing or two. More

DME Basics »

Distance measuring equipment is among the most valuable black boxes on the panel, especially for the IFR pilot. But there's a lot more to DME than turning it on and watching the numbers count down. AVweb's avionics guru explains how DME works, its inherent errors and limitations, and what to do if it stops working. More

ELT Basics »

In recent years, the FAA has made big changes to both the specifications and regulations covering Emergency Locator Transmitters. Now, your ELT must be tested annually and, if it flunks, it may have to be replaced with a new unit that meets all the latest requirements. The new ELTs are much better than the old ones, but installation can get complicated and costly. AVweb's avionics guru explains all these changes and what they mean to you. More

GPS Is Fabulous, but I'm Hedging My Bets »

GPS is the most remarkable navigation system that aviation has ever had, and it's going to get even better with the decomissioning of Selective Availability and the launch of a new constellation of L5-band satellites. But don't yank the VORs and DME out of your panel until you've read the cautions by AVweb's avionics guru about some of the limitations and problems associated with relying on GPS as your sole means of navigation. More

What Is Portable Equipment? »

With the growing popularity of handheld GPS receivers, notebook computers and the like, we get more and more questions about exactly what the FAA means by "portable" equipment, how and when portables may be used, whether they're likely to interfere with permanently-installed avionics, whether they should be turned off during instrument approaches, and so forth. AVweb's avionics guru answers those questions and more in this article. More

Avionics Master Switches »

If your aircraft was built before the late 1970s, the factory probably didn't include an avionics master switch. But if you've upgraded your panel to modern solid-state radios, you really need one maybe even two. There are several different kinds, and AVweb's avionics guru explains how they work, how they fail, what they cost, and why you'd be foolish not put one in. More

Dealing with Uncle Otto »

A 17,000-hour lightplane pilot offers some of the finer points of flying with an autopilot. In this article, we find that things aren't quite as "automatic" as we would hope, but with a little study, those little black boxes can make things easier and safer. More

Otto-Speak »

Nothing can be more exasperating to a pilot or aircraft owner than trying to get a balky autopilot fixed. But often more than half the battle is communicating the symptoms accurately to your avionics technician in language he'll understand. Autopilot wizard Gary Picou gives you an arsenal of autopilot terminology that you'll need to talk the talk. More

GPS Explained »

You don't have to be a rocket scientist to understand it, but it sure helps. For the rest of us, here's a step-by-step explanation of how all this new-fangled sat-nav stuff works from the editor of IFR Magazine . Read this and you'll be able to toss around terms like "ephemeris" and "clock bias" and "orbital perturbations" with the best of 'em! More