Why Do We Need This Training?

Actually, if one were to fly solely with all the automated gadgetry available today, it may seem that learning basic techniques is a waste of time; click a button or two and let the computers fly us happily to our destination, right? No, that's not right. Sometimes computers fail, programs have glitches, or pilots enter bad information. So pilots must be able to fly an airplane and navigate using basic skills and techniques. Flying an airplane with total reliance upon automation is...well, I suppose it's like drinking cheap Scotch; it just isn't done!

Many disagree with having to learn the basics of aviation and navigation, claiming that it's senseless to waste time on mundane tasks when there are simple programs that do it all for us with the click of a button. I won't make the slightest effort to challenge you...feel free to build your own airline and fly it however you like. But if you plan to fly with LewisAire, you'll have to learn how to use those needles and knobs on the instrument panel. As you can see...I tend to get mean and cranky when I run out of Scotch.

Magnetic North vs True North

There's much that could be said regarding this troublesome little anomaly, but we're not going to say most of it. We could go on and go on forever discussing The Great Circle, using navigational terms dating back well before Columbus' time, but we'll cover what you really need to know about the difference between True & Magnetic North, and let it go at that.

Most of us know there can be a significant difference between between True North and Magnetic North as we move around the globe, primarily because True North is based on the geometric system we use for measuring and plotting (and reading) the earth's surface, whereas Magnetic North is based on the physical location of the North & South Magnetic Poles...which, by the way, move around from place to place. The difference between True North and Magnetic North is called the Magnetic Variation (or Mean Declination), and the Magnetic Variation for our region of operations ranges from 25-32 degrees...the farther North you go, the greater the variation. If you're plotting a course using True North, the Magnetic Variation must be accounted for (and compensated for) when using just the magnetic compass, but now for the good news: Most (but not all) computations done in navigation radios and instrumentation are based on Magnetic North, so there's nothing at all for you to do with this amazing new bit of wisdom! The picture below shows the HSI heading and the Magnetic Compass in agreement...I rest my case, Your Honor.

Common Navigation & Instrumentation Terms

ADF - Automated Direction Finder

Bearing - The direction between two points; can be referenced to True or Magnetic North.
Compass Swing - Magnetic compass adjustment for Magnetic Deviation

Course - The bearing (direction between two points); generally referenced to a geometric grid (map)
using True North.

Course Heading - The aircraft heading required to follow a Course.

Glideslope - A radio beacon sent outbound from the approach-end of an ILS runway, rising upward at

a 3-degree angle, and is used for ILS approaches. Glideslope range is generally limited to

less than 25 miles.

Heading - The direction in which the aircraft is pointed, referenced to Magnetic North.

HSI - Horizontal Situation Indicator.

IFR - Instrument Flight Rules.

ILS - Instrument Landing System.

Inbound - Toward an airport.

KIAS - Airspeed in Knots as indicated on the airspeed gauge.

Localizer - A highly-directional radio beam sent outbound from the approach-end of an ILS runway,

used for ILS approaches. Localizer range is generally limited to less than 30 miles.

Magnetic Bearing - Often used as Heading.

Magnetic North - Top-center of the earth as referencd by the North Magnetic Pole.

Magnetic Variation - The difference between True North and Magnetic North.

Mean Declination - Same as Magnetic Variation: The difference between True North and Magnetic

North.

MSA - Mean Safe Altitude; the altitude which will clear any vertical obstructions en route by at least

1000 feet.

MSL - Mean Sea Level; the aircraft altitude above sea level, measured in feet.

Outbound - Away from an airport.

Radial - Often defined as: (A) A specific direction leading to or from a geometric compass rose, or

(B) A specific radio beam to or from a VOR station.

Track - Generally thought of as the Course, and often referred to in association with the GPS.

True Airspeed - Calculated airspeed as derived from Altitude and Indicated Airspeed

True North - Top center of the earth as calculated by geometric gridwork.

VOR - Variable Omnidirectional Radio; sometimes called VHF Omnidirectional Range

VSI - Vertical Speed Indicator; measures aircraft ascent or descent in feet-per-minute.

WCA - Wind Correction Angle; a calculated value that is added to (or subtracted from) the aircraft

Heading in order to compensate for the effects of wind, allowing the aircraft to follow a

specified Track or Course.