mark@anwar.UUCP (mark) (11/30/84)
Last Sunday I decided to visit a couple of local FBO's at Republic Airport on Long Island NY in search of a good aviation computer. In my quest I had a predetermination to buy an electronic type because of its convenience (push buttons) v.s look up the data (slide rule style). Another reason for my prejudice is that the flight manual Im currently using has the flight computer chapter set up to teach the student with an electronic calculator (note: of course the electronic type they use throughout the chapter is manufactured by the same company as the book). By the end of my search I ended up with a slide rule type (jeppesen CR5) despite the use of the electronic type in the flight book. This was due to several reasons. First, the electronic type was not available in any of the FBO's I visited. Second, All the "locals" I spoke to said the slide rule type is perfectly fine, reliable, and less expensive. And third, I assumed (with my very little statistical data) that most pilots must prefer the traditional type since no one knows about the modern replacement for the traditional slide rule. -> Do you flyers out in netland have a preference ? Is the modern marvel really available at FBO's ? Do new pilots have a different preference than older pilots ? Finally, Is one easier to use than the other ? :-) Mark Nickson HHB Softron 1000 Wyckoff Ave Mahwah, NJ 07430 201-848-8000
ron@brl-tgr.ARPA (Ron Natalie <ron>) (12/02/84)
Having grown up with slide rules I have no problem with the wiz-wheel calculator. Mostly my calculations don't require absolute precision and it's nice to be able to visualize the wind and other calculations rather than punching little buttons while flying along. Mostly though, I think it's because I bought a friends spare whiz wheel when I was in pre-private groundschool and never bothered to shell out any more money on a new one. -Ron
dmmartindale@watcgl.UUCP (Dave Martindale) (12/03/84)
Well, I know the Avstar is available at my local flying club. I don't own one, though every once in a while I think about it. Basically, the idea of a specialized calculator where I could just key in wind speed, direction, true track, and true airspeed and get out true heading and groundspeed appeals to me - that's how a flight-planning calculator should work. I already do the other calculations involved in flight planning with a calculator, and I've written a program for my HP-10C to do the typical wind-drift calculation (though it is awkward to use). So for me, buying a specialized calculator would get me a better "user interface", but I'd lose Reverse Polish Notation for input, which I like, and probably lose the HP's nice floating point too (I haven't looked closely at the Avstar - I don't know if it really has scientific notation). Also, the HP doesn't know how to handle TAS/CAS conversions, pressure/density altitude conversions, and that sort of thing. But I definitely don't like the old-fashioned slide-rule type of flight computer, for the same reason that I prefer a digital calculator to a slide rule - it's simply easier to use, and more accurate. I still carry the slide-rule type though, for the functions that my calculator doesn't provide, and as a backup (no batteries!).
cfiaime@ihnp4.UUCP (Jeff Williams) (12/03/84)
An aviation computer is a very personal thing. I still have a soft spot in my heart for the big, old, aluminum E6-B that I bought from my first instructor for a whopping $5. However, even though it will not warp in the sun, I find that I don't use it as much as I used to. Enter the Jeppeson Avstar electronic flight computer. This thing is fantastic for preflight calculations. Lets face it, the density altitude computations alone are worth the $50 that the calculator costs from the discount houses. I used it for my ATP written with good results. But, in the air it is, in my opinion, worthless. Consider, oh fellow aviators, just what it takes to enter a simple time, speed, and distance problem into one of these marvels of modern technology. One keystroke for each digit. One keystroke to define what the data is that you just entered. One keystroke to let the beast know that you are ready to see a result. While in flight, that is a lot of time with the head in the cockpit punching buttons. In flight, to keep tabs on myself, I use a Jeppeson CR-2 shirt pocket circular computer. You can set it once, and then check ground speeds just by looking at your clock and glancing at the computer. It doesn't need total recalculation for every checkpoint. Sure, a tweek of a knot or two, but that is a one-hand operaton. Oh indeed I tried my trusty Avstar in flight. In such machines as a King Air, a Funk, and even the Valmet Pik-23. The only machine it was really useful in was the Valmet, because I could easily convert IAS in Kilometers to Knots, then take that and convert the whole mess to TAS. It could be done on the CR-2, but what a pain. Of course, for the simplest flight computer, a watch with a "tachymeter" on it used to time the section lines... Jeff Williams AT&T Bell Laboratories ihnp4!cfiaime
doug@terak.UUCP (Doug Pardee) (12/03/84)
[I'm being the Devil's Advocate -- been on retainer for some time]]
My view is not to be confused with the popular view... I know of few
pilots who agree with me... but...
I say buy a cheapie all-plastic circular slide rule type, and then
throw it out after you pass your flight test. Aviation calculators
only multiply, divide, and do wind triangles. Any 10-buck calculator
can do multiplication and division plus a bunch of other neat stuff
like addition, subtraction, etc. Besides, anyone that is smart
enough to figure out how to run a calculator can figure out all of
the normal piloty stuff in his head (I'm being serious). All
except wind triangles, which are of no use unless you know what
the wind direction and speed are. And if you think that the
Weather Service knows what the winds aloft are, I've got some
land in Southern Arizona that I'd like to sell you.
The only aviation calculator that I've seen that would have
been worthwhile was made by Heathkit a number of years ago. It
included a clock, and would accept up to 9 checkpoints and
a flight plan. As you passed over each checkpoint, you punched
a button and the calculator would figure out how long the preceding
leg took. This information, combined with the heading that you
had to hold to get where you were going, allowed the calculator
to figure out what the wind must have been, and then would
extrapolate the following legs of the flight plan based on that
wind. Then it could give you neat info like ETA at each
checkpoint, groundspeed, fuel remaining, etc.
Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!dougmarcum@rhino.UUCP (Alan M. Marcum) (12/03/84)
I've been flying for a couple of years (~330 hours now). I
learned to use a slipstick during primary training, but do most
of my pre- and in-flight calculations with my HP-67, using some
programs I wrote. (I never did buy the slipstick!) My programs
don't have everything the specialized calculators provide, but I
can handle 'course + wind => heading' and density and pressure
altitude conversions. The ETA, fuel consumption, distances, etc.
I compute using the normal four-functions.
I do miss not having a great-circle computation facility, but I
just haven't gotten around to building that program yet.
And, yes, I carry a spare battery with me when I fly.
--
Alan M. Marcum Fortune Systems, Redwood City, California
...!{ihnp4, ucbvax!amd, hpda, sri-unix, harpo}!fortune!rhino!marcumherbie@watdcsu.UUCP (Herb Chong, Computing Services) (12/04/84)
I could be mistaken, but doesn't HP have a custom ROM for their 41C that does the typical navigation calculations required for aviation? This, of course, is probably the most expensive alternative available, but I thought you might want to know. Herb...
jlg@lanl.ARPA (12/04/84)
> The only aviation calculator that I've seen that would have > been worthwhile was made by Heathkit a number of years ago. It > included a clock, and would accept up to 9 checkpoints and > a flight plan. As you passed over each checkpoint, you punched > a button and the calculator would figure out how long the preceding > leg took. This information, combined with the heading that you > had to hold to get where you were going, allowed the calculator > to figure out what the wind must have been, and then would > extrapolate the following legs of the flight plan based on that > wind. Then it could give you neat info like ETA at each > checkpoint, groundspeed, fuel remaining, etc. That's easy. I programmed my HP-41CV to do that months ago, and I'm not even a pilot (yet). Of course, only 9 checkpoints won't make it past a cross country check ride. My instructor wanted checkpoints every five minutes!
dmmartindale@watcgl.UUCP (Dave Martindale) (12/06/84)
> Of course, only 9 checkpoints won't make it past > a cross country check ride. My instructor wanted checkpoints every five > minutes! Arghh. This seems a bit excessive. I'd rather spend my time looking out the window than recalculating groundspeed all the time.
ron@brl-tgr.ARPA (Ron Natalie <ron>) (12/07/84)
Yes, actually, my first instructor was a physics prof at Johns Hopkins and the class was all university students. He pointed out that there was no point in buying a computer since we all had scientific calculators and we could do all that wind stuff with vector math (remember the law of cosines). I used a pocket TRASH-80 (which is unbearably slow) for a while. In addition to being able to do rudimentary math, part of its programming was to use the spherical law of cosines to tell me how far apart two points were given their latitude and longitude. Handy for getting rough distances between fields without unfolding a bunch of charts. Just look up the coordinates in the facilities directory. -Ron
gmm@bunker.UUCP (Gregory M. Mandas) (12/07/84)
> > Of course, only 9 checkpoints won't make it past > > a cross country check ride. My instructor wanted checkpoints every five > > minutes! > > Arghh. This seems a bit excessive. I'd rather spend my time looking out > the window than recalculating groundspeed all the time. That IS the point. You should spend the time looking out the window. Remember pilotage. If you are talking about VFR (which I am) having a checkpoint every fine minutes is seeing if the RR tracks below are the same ones one the map. I think today's pilots are caught up in the technology bit a little too much. Greg mandas ittvax!bunker!gmm
doug@terak.UUCP (Doug Pardee) (12/10/84)
> I used a pocket TRASH-80 (which is unbearably slow) for > a while. In addition to being able to do rudimentary math, part of its > programming was to use the spherical law of cosines to tell me how far > apart two points were given their latitude and longitude. Handy for > getting rough distances between fields without unfolding a bunch of > charts. Just look up the coordinates in the facilities directory. You must not live in the West. One doesn't fly a straight line between two points out here. If you try, you will a) pile into a mountain, b) bust an Airport Traffic Area, c) bust a TCA, or d) bust a restricted area. And that's just during the climb-out! AOPA keeps sending me literature on Flight Charts. One of these days they'll figure out that I've no use for charts where the "airways" are computer-calculated as straight lines between VOR's, and not based on the true airway alignment. In addition, VOR's out here tend to be affected by the mountainous terrain, so the radial as computed by Flight Charts is often as much as 3 degrees off the airway as flight-tested by the FAA. Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!doug
lgl@cbosgd.UUCP (Lionel Lynch) (12/13/84)
In article <737@watdcsu.UUCP> herbie@watdcsu.UUCP (Herb Chong, Computing Services) writes: >I could be mistaken, but doesn't HP have a custom ROM for their 41C that >does the typical navigation calculations required for aviation? This, of >course, is probably the most expensive alternative available, but I thought >you might want to know. >Herb... HP does make a special ROM for the HP41 and variations thereof. The price was about 60 dollars when last I checked.. -Lionel (cbosgd!lgl)
demillo@uwmacc.UUCP (Rob DeMillo) (12/13/84)
> By the end of my search I ended up with > a slide rule type (jeppesen CR5) despite the use of the electronic > type in the flight book. This was due to several reasons. First, > the electronic type was not available in any of the FBO's I visited. > Second, All the "locals" I spoke to said the slide rule type is > perfectly fine, reliable, and less expensive. And third, I assumed > (with my very little statistical data) that most pilots must prefer > the traditional type since no one knows about the modern replacement > for the traditional slide rule. > > -> Do you flyers out in netland have a preference ? > Is the modern marvel really available at FBO's ? > Do new pilots have a different preference than older pilots ? > Finally, Is one easier to use than the other ? > > :-) Mark Nickson HHB Softron 1000 Wyckoff Ave Mahwah, NJ 07430 > 201-848-8000 Perference? When the Christmas season is over I plan on getting the electronic version. (I currently have the slide rule.) My reasons are the same for buying an electronic calculator over a slide rule calculator...I DETEST fidgeting with the little knobs, slides, and fiddly things. I also am not too pleased with keeping track of the differences between 0.1 1.0 and 10.0 ... Just a personal observation... --- Rob DeMillo MACC ...seismo!uwvax!uwmacc!demillo
wtm@ihuxb.UUCP (Peter Fales) (12/16/84)
>> In article <737@watdcsu.UUCP> herbie@watdcsu.UUCP (Herb Chong, Computing Services) writes: >> >I could be mistaken, but doesn't HP have a custom ROM for their 41C that >> >does the typical navigation calculations required for aviation? This, of >> >course, is probably the most expensive alternative available, but I thought >> >you might want to know. >> >Herb... >> >> >> HP does make a special ROM for the HP41 and variations thereof. >> The price was about 60 dollars when last I checked.. -Lionel (cbosgd!lgl) HP41 ROM modules are down to about $35 (the price I paid for my aviation module) Peter Fales ihnp4!iwlc7!psfales