Ed Williams' Aviation page.

My 182

My aviation formulary contains a fairly complete collection of great circle and rhumb line navigation formulae. It also contains standard atmosphere properties and E6B functions. A pure Ascii version is available for ftp download. Some of the functions have been programmed into a Javascript on-line calculator, some into an Excel spreadsheet.

A Mercator (rhumb-line) calculator for WGS84 is here. A beginning on a (mathematical!) primer on navigation on an ellipsoidal earth is here. I'm planning on getting this finished sometime...

A discussion of compass errors, with formulae is here.

I've written software that computes magnetic variation anywhere on (or above) the earth's surface, using either the WMM or IGRF reference models. There are Mac , DOS , linux , and Java executables available by ftp. A web calculator is here . C source code released under the GPL is here , in Visual Basic (courtesy Ian Billing) here .

Francisco Bernal has adapted the code to make a Windows version with an interactive map interface here . It comes with source code and a dll. 16bit version .

My favorite weather briefing links. (I open a collection of them in tabs, using the Mozilla browser. Try it. You'll like it, provided you have a fast Internet connection.

Some reading matter:

Some other files that may be of interest are available in my ftp directory

A fairly comprehensive quiz for an IFR flight test or ICC (updated May 2004)
A mountain flying quiz.
Some FAA legal opinions on the logging of PIC time.
Text of recommended flight instructor endorsements.
An Excel spreadsheet relating relative humidity, dewpoint and wet bulb temperature.
An Excel spreadsheet implementing a simple model of a constant speed prop.
Pressure altitude vs. mbar pressure. I use it to get freezing levels (FRZ) from RAOB skew_T plots
An Excel spreadsheet that creates a "road-map" style table of distances and bearings between airports. Created by another pilot using the Formulary! Enter your own airports.
An Excel 2000 spreadsheet by Glen Denning, with a user-friendly interface. It has a variety of great-circle navigation functions and interacts with a database of navigation fixes (VOR and Intersections supplied). Look under "downloads".

Miscellaneous links

An (ex-) IFR student's checkride story.

Joe Campbell's IFR diary -in which I also feature!

Ed Williams is a 4200+ hr ATP-MEL Comm-SEL CFII. He owns a C182 based in Livermore CA. He developed and taught weekend ground schools for Aviation Seminars. He specializes in IFR instruction out of HWD and LVK.