FLTDOC.DO FLTCMP.BA was written using admittedly inaccurate assump- tions, as discussed below. I make no warranties of any kind, including warranties of merchantability and fitness for a partic- ular purpose. This program was written for my own entertainment. Since I cannot prevent its change by some unknown person before it gets to you, since I know that it relies upon approximations which are not totally accurate, and since, in fact, I cannot even be sure that garbage won't sneak in from the phone lines as you download it, I cannot know if it will work for you, but would be willing to bet that it won't. FLTCMP.BA (checksum 1222469) was written for the TRS Model 100 to take the place of the slide rule type flight "computer". I wanted it do everything the slide rule can do, plus a few things a slide rule can't, like weight & balance. I ran out of steam before I wrote the code to do time and distance to a radio station. You are welcome to modify FLTCMP to add this function, which is listed in the menus. FLTCMP pretty much runs itself. You move through the menus using the up and down arrow keys. The data for ident to ident navigation should be stored in NAVAID.DO, an example of which is included at the end of this documentation. The data fields are Ident, Description, Latitude North, Longitude West, Compass Variation. Latitude and longitude data are included in NAVAID.DO as decimal numbers, but the number to the right of the decimal is not fractional degrees, but rather the minutes of latitude. Thus, 35 deg. 30 min. latitude would be included in NAVAID.DO as "35.30", and not as "35.50". Compass variation, on the other hand, is in degrees and fractional degrees. Thus, 10 deg. 45 min. east variation would be stored as "-10.75", and not as "-10.45", if you want to get that exact with the variations. The program will append new idents to your NAVAID.DO, so you can add idents that way. I have found it convenient to put the lat. and long. for enroute checkpoints and other locations for which I do not have an ident into NAVAID.DO using an ident of XXXX. Note, however, that XXXX is the only ident that the program does not expect to be unique. For that reason, for VORs which have the same ident as an airport, but which are not located at the same lat. and long., I add "V" at the end of the ident (e.g., LAX would be the airport, and LAXV would be the VOR). The program does not require you to use "V", and you can develop your own method of dealing with similar idents. Use the up and down arrow keys to scan through your NAVAID.DO idents. The program is huge (necessary for all the screen printing and menus), and therefore is not something you would want to leave stored in RAM on a permanent basis. Also, you should probably download it into something besides an M100, and then transfer it to your M100. I have not really tried to optimize the code to reduce its size, although I do run a packed version which I have packed with TOOLKT.BA from the M100SIG on Compuserve. Actually, I have modified TOOLKT to run on my Tandy 1000, and have compiled it, so that it runs a lot faster and I don't have any memory problems. It also makes it much easier for me to store the program in ASCII on a floppy, and download it to the M100 when I want to use it. Being able to run the checksum on both machines makes it easier to tell if I have gotten a good ASCII download to the M100. And being able to renumber and pack M100 programs on a PC clone with much higher speed and much larger memory is convenient. I recommend TOOLKT.BA for anyone who has not downloaded it. If you like this program, or have suggestions on modifying it, let me know by leaving me a message in either the AVSIG or the M100SIG on Compuserve. My Compuserve ID is 73337,2600. I may or may not acknowledge your message, as I get on Compuserve irregularly. And, I may or may not make modifications based upon suggestions I receive. And, if I do make the modifications, I may or may not upload the modified version. In fact, if you think of good modifications, please make them and upload a new version of this. To make this easier, the version I have uploaded is not packed. Suggestions for improvement: 1. Code actual formulas for pressure and density altitude, instead of approximations derived from charts. 2. Combine the navigation and wind triangle functions to give a screen more like the standard Pilot's Navigation Log/Flight Plan form. 3. Rewrite the weight and balance portion to use data for the plane you fly, or even several planes from which you choose, stored in a .DO file, rather than having to be keyed in each time. 4. Rewrite the entire program to make the various func- tions separate program modules called from a menu program. You could then load a particular module or not, depending upon whether you will use it for a particular flight. Sometimes you don't really need density altitude, sometimes you don't really need weight and balance, and you may not want the calculator function at all. 5. Modify the navigation module so that it averages the compass variations for the origin and destinations, rather than using the origin variation for the entire leg. As regards modifications, the only thing I can guarantee from this end is that if you manage to find out my telephone num- ber, I WILL NOT provide "support" for this program. What you see is what you get. The formulas for the following quantities were derived as linear algebraic (and not differential) equations from the answers to problems in either the Private Pilot Test or the E6B instruction manual. For that reason, the answers this program gives for many of these values are only approximate. At least some of these values are not linear. For example, pressure alti- tude does not decrease at exactly 1000' (or even 910') per 1" Hg. The decrease changes as the pressure changes, and as a result the difference between the correction factors for 28.0" Hg and 29.0" Hg is greater than the difference between the correction factors for 30.0" Hg and 31.0" Hg. Note lines 103 - 108 of the program give six different formulas for calculating the correction fac- tor, depending upon the altimeter setting. The formulas I have derived are those for the following unknowns: 1. Pressure Altitude-see lines 103-108. PA = Altitude + ((29.92 - Altimeter Setting) x 910) + 46.8 + (60 x (28.5 - Altimeter Setting)) if Altimeter Setting is less than 28.5. 2. Density Altitude-see line 114. Density Altitude = (Pressure Altitude x 0.9075) + (66 x Outside Tempera- ture - Standard Temperature)) + 256 3. Standard Temperature - see line 114. Standard Tempera- ture = 59 - ((Pressure Altitude x 3.5)/1000). If someone has more accurate formulas for these values, I would appreciate getting them. Please leave them in a message to me, along with where you got them. Of course, any values which depend upon these numbers (such as True Airspeed which depends upon Density Altitude, which in turn depends upon Pressure Altitude and Standard Temperature) will also be only approximations. And since some of the vari- ables used to compute the values in these derived equations are themselves computed using derived equations, the inaccuracies may very well compound each other. What does this all mean? IF IT IS CRITICAL, CHECK IT USING A METHOD OF KNOWN ACCURACY. If you don't, you will be courting disaster. This program uses code adapted from NAV Ver. 4.4, by Lance Quinn, which is available from the M100SIG on Compuserve as NAV100.V44. It also uses code adapted from FCALC.LAP and FPLAN.LAP, both of which are available from the AVSIG on COMPUSERVE. NAVAID.DO Example ABQ,ALBUQUERQUE NM,35.03,106.36,-11.34 AUS,AUSTIN TX,30.18,97.42,-7.1 FLG,FLAGSTAFF AZ,35.09,111.40,-12.87 PHX,PHOENIX SKY HARBOR,33.26,112,-12.41 XXXX,DEL RIO TX,29.22,100.55,-8.43