Aviation Programs



#17

I have written two programs for aviation use. I like to send them to Datafile to be published, but I want to make sure I have them optimized, and also that my English is good in article. May I post them here first and get feedback before I send to them?

Also, must you be member of Datafile to submit, as I am not yet.

If okay to post here, I will post tomorrow, as programs are done, but I need to clean up wording of document so it is well written.


#18

Hello!

Quote:
If okay to post here, I will post tomorrow...

If you ask me: Yes it is OK to post them here! I am always interested in aviation programs and because I do not receive this datafile thing, I would miss them otherwise. Of course I can also have have a closer look at them and give you some feedback if necessary. As for the language, I can be of no much help though, because I could only replace Hungarian-English by German-English ("Denglish" we call it)...

Greetings, Max


#19

Will do once I get the wording all fixed up.

What type of equipment do you fly? I see from user info you are a pilot.


#20

Hello!

Quote:
What type of equipment do you fly? I see from user info you are a pilot.

I started this flying thing quite late and do it part-time besides my engineering job, so I never aimed for the big airlines. As a flying instructor, I mostly teach future airline pilots in the simulator and on single- and twin-enined airplanes the "art" of instrument flying. Myself, I do air-taxi/company flights in twin-engined piston airplanes (Cessna 421 Golden Eagle and Piper Seneca), express cargo with a Cessna 404 Titan Courier and just started my conversion course on the Fiarchild/Swearingen Metro 23 twin turboprop (had my first 2 1/2 hours training yesterday, what a machine :-) !) that my company also uses for express freight. And sometimes I also spray silver iodide into thunderstorm clouds to prevent the formation of hailstones (but don't tell this my wife).

Regarding your programs: I had a quick look and as was already stated by someone else, without text prompts, they are very difficult to use, especially when one is in a hurry and has more important things on his mind (as is always the case once in the air). There should also be a provision for using default values (especially for wind and true air speed) when calculating different legs of a flight, because otherwise you have to re-enter the same values many times. This is exactly the reason why dediacted hardware (like the ASA pathfinders, Jeppesen Techstars or Sporty's electronic E6Bs (I have all of these in my collection :-) ) have replaces programmable calculators long, long ago.

This distance-between-coordinates thing is a nice excercise, but of no real use to a pilot, because every aircraft (at least every one I know) has a GPS reveiver with a navigation database that will do this for you without the need to enter co-ordinates manually. And in the office, we have dedicated flight planning software (our company uses PPS by the Danish company Air Support http://www.airsupport.dk/productsandservices.htm ) that will provide you with a complete flight briefing (including real-time wind and weather data) in less than two minutes, that even with the best pocket-calculator software will take you more than an hour to produce :-(

But what I really miss in my daily routine is a universal conversion program, not just the (useless!) mm->inch conversion that some calculators offer, but something like Pounds (fuel) -> Litres, that is always difficult to calculate and error-prone, when you are in a hurry.

Happy landings, Max


#21

I thought Sporty's E6B had that built in? I don't have mine here so I can not check. That easy calculation in states with standard airplane fuel. 6lbs per gallon. (or about 6.7lbs for jet fuel I believe.)


#22

Hello!

Quote:
I thought Sporty's E6B had that built in? I don't have mine here so I can not check. That easy calculation in states with standard airplane fuel. 6lbs per gallon. (or about 6.7lbs for jet fuel I believe.)

The E6B has a quite arbitrary marking at 0,77 kg/l that is neither correct for AVGAS (0,72 kg/l) nor for JetA1/Kersosene (between 0,75 and 0,84 kg/l). The most popular aviation slide rule in our part of the world, the Aristo (now Pooleys) Aviat has two dedicated subscales for the whole range of densities encountered with different fuel and oil types, both in kilograms and in pounds (see this foto here that I found through google (I would show you a photo of my own Aviat, but I have no idea where I have it, last time I used it must be over ten years ago) http://personal.telefonica.terra.es/web/jcvilchesp/reglas/imagenes/139_aristo_617_a.jpg ).

Anyway, the real-life task is not just a simple conversion, but a little bit more complicated and error-prone:

After landing, we are usually met by the refueller, who wants to know how much fuel we need to uplift. And in a hurry, because there are other customers waiting for him... To compute the required amount in the unit he uses, usually litres, rarely imperial gallons, we need to start from the fuel remaining on board (displayed either in pounds, gallons, litres or kilograms, depending on the aeroplane), the expected flying time to the next destination, an average fuel consumption (again in lbs/hr, gals/hr, l/hr or kg/hr, sometimes not even in the same units that are shown on the fuel gages!) and the fuel type (Avgas or Jet, at 0,72 kg/l or around 0,8 kg/l). Many of these inputs are constants for a certain aeroplane, so it would be an unnecessary complication to re-enter them every time.

Real-life tasks like the one described above really require a calculator with a multi-line display and a menu-system, because they have to be programmed in a fool- and error-proof way that allows for real quick data entry. Also one must be able to see at a glance, if _all_ his inputs are correct (especially the units!). Therefore, tasks like these are now ususally performed with notebook computers or tablet PCs running dedicated software. I once programmed this into my hp-71B, but found that it is not user-friendly and safe enough for the job. It might be different for a private pilot who flies once per week and can spend the rest of the week playing around with his toys, but in commercial operations with multi-sector flights and quick turnaround times, programmable calculators really have become a thing of the past just like everywhere else, I'm afraid.

Greetings, Max


#23

See difference between you and me is that you fly commercial planes, and I fly private. My plane has many of the features built in as well, but I wanted challenge of programing calculator to do.


#24

Hello!

Quote:
See difference between you and me is that you fly commercial planes, and I fly private. My plane has many of the features built in as well, but I wanted challenge of programing calculator to do.

What are you flying? Anyway, the tasks are always the same, no matter if you pay for it or someone else is paying you :-)

Here is my one-minute-implemention of the above stated problem on one of the best pocket calculators built so far (not from my collectors point of view, but strictly in terms of functionality and usability):

A user-friendly, idiot-proof interface with all input and output values labelled and visible all the time. And, as I said, implemented in less than two minutes thanks to the bulit-in spreadsheet application.

Greetings, Max


#25

Max, great screen shot! How easy it is to read the spreadsheet at regular size? My major disappointment with the 89 Titanium is its very small font size. It is so small that it us frequently unreadable to my eyes.

I seem to recall an incident in Canada years ago that resulted from a mixup of refueling units. I forget if it was liters/gallons or pounds or whatever, but the plane ran out of fuel because of the mixup. It did land safely, though, as I recall. On an unused dragstrip!


#26

Hi Don,

Quote:
Max, great screen shot! How easy it is to read the spreadsheet at regular size? My major disappointment with the 89 Titanium is its very small font size. It is so small that it us frequently unreadable to my eyes.

I could have transferred the screen content alone with the Ti-Connect software and cable, but I wanted to show the name&brand of the calcualator, so I took a photo with my digital SLR camera and macro lens.

I have no Ti-89 for direct comparison, but the pixel count is 160x100 for the 89 and 240x128 for the 200. The physical screen size of the 200 is 89mm x 49mm (or 3.5in x 1.9in), you would have to measure the size of your 89 screen in order to calcualte the relative pixel sizes.

I find the spreadsheet font very easy to read, but when I try to read equations in the normal calculator mode, subscripts and superscript are very hard to read. But overall, the Ti200 has a far better (by orders of magnitude!) display than a classic hp-48.

Quote:
I seem to recall an incident in Canada years ago that resulted from a mixup of refueling units. I forget if it was liters/gallons or pounds or whatever, but the plane ran out of fuel because of the mixup. It did land safely, though, as I recall. On an unused dragstrip!

Yes, this is the famous "Gimly glider" (an Air Canada Boeing 767 that landed on a disused military airfield called Gimli) where they messed-up kilograms and pounds upon refuelleing. But then, aviation has made the biggest imaginable mess of units over the years, that it really is a miracle that this kind of incident dosen't happen more often! (See e.g. here: http://www.wadenelson.com/gimli.html )

Greetings, Max

#27

That very cool. Interesting that it has built in spreadsheet. I have never seen TI voyager calculator.

I own a Columbia 400 SL with E-Vade. In fact I was to fly to Virgina this weekend, but plans change and I never went. I am thinking of upgrading plane to have climate control as well and my family and I go to some warmer areas, and it would be nice when on the ground or at lower levels to have less humid cockpit. It is no rush though.


#28

Hello!

Quote:
I own a Columbia 400 SL with E-Vade.

Wow! This is on my shopping list once I win the lottery :-)
Does the E-Vade system work well? This really is a big advance over de-ice boots and TKS!

Quote:
One other thing, I glad I not own plane you fly in that program as at 700 lbs an hour, that a lot.

The 700 lbs figure is typical for the Metroliner, but that carries 19 passengers at around 280 knots. A more modern design (with modern powerplants) should be able to do the same with less than 500 lbs/hr, but there are no modern aeroplanes in that category.

Quote:
It would be nice to be able to have solver...

The fuel calculation above could indeed be handled by a solver, because there is always only one value to be computed. I have played around with different HP calculators with solvers on this (48, 28, 33s, 17bII). The advantage of using a solver is that you have to enter your constants (like fuel flow, conversion rates) only once, yet they do not become part of the formulas and can easily be changed when necessary.

The more interesting (in terms of formulas involved) wind calculations can hardly be done with solvers though, because there is always more than one resulting value.

A good calculator for this kind of thing is the hp-28 (C or S does not matter much) because it is nearly indestructible (good when carrying it around in the flight bag), can handle long variable names and as many variables as there is memory, has a proper alpha keyboard and a multi-line display. And since nobody likes them, you can find them very cheap on eBay (usually under 20 Euros). But they have one big disadvantage: The RPL programming language, that makes them almost unusable. I think I could quicker learn Hungarian or Irish Gaelic than RPL ;-)

Greetings, Max

Edited: 19 Aug 2007, 3:53 p.m.


#29

I have only had to use the E-vade a few times because I purchased the unit in June, and have not flown in too many bad situations. Living more up north though, I felt that would do myself and family better than the climate control. It is a lovely airplane with glass cockpit and all. Very nice to travel in.

I do have a 28C, but I have not yet figured out how to use it much. You are right that it is very rugged. Only problem I have is corrosion in battery compartment. I have been meaning to fix that, but have not had time yet. It is no big deal though as my plane provide most information that I need, and I have a old E6B that I could use, and PDA with Sporty's E6B on it as well.


#30

Greetings,

I have been following this thread. That Voyager screenshot was nice, but do either of you own an hp 50g? I do not own an hp 35s yet, but based on my experience with my hp 50g, I know nice aviation programs may be written. (RPL though).

In fact, while I was writing this post I thought to search hpcalc.org and found this:

http://www.hpcalc.org/details.php?id=167

It was ported to hp 49g (I assume from the hp 48xx series), so it should work on the hp 50g. Also, the person who ported it is a *very* active contributor to comp.sys.hp48, where there is much discussion regarding hp 35s and hp 50g. I would assume fuel calcs could be added easily.

comp.sys.hp48:

http://groups.google.com/group/comp.sys.hp48/topics?lnk=gschg


Cheers,
Pal


#31

Thank you very much my friend. No, I do not have HP50, but I do have HP 48GX, I just get actually, well not long ago. The program look very nice, but I have no idea how I would load that onto the 48. It has connector on unit, but I no have cable for it. Someone tell me old serial mouse cable can be used somehow, but he does not know how.

I wonder if someone here may know how that work?

#32

One more thing. I'm not sure I follow the formulas that you have to equate the values you have. It say you have 800 lbs remaining, with a burn rate of 700/hr. How is it you have 2.7 hours left of flying? Or is that something you key in and then it compute values below.

Either way, I would be interested to see formulas, as this looks very nice.

**EDIT** Never mind, I see what you are doing. You are calculating the B5 = B3 * B2 - B1, and then apply weight to litre conversion. Very nice.

This is where I wish 35s could handle variable longer than one character. It would be nice to be able to have solver, or program work like Pioneer series where you could make variable name longer. When I play with 17Bii emulator, it nice that you can do this as it could handle the fuel components. I guess, if you make program though, you could do a line that say EQN Fuel Remaining, EQN Flt Time, etc. It be pain though as you would have to enter fuel flow each time, unless you fly same equipment all the time, and then that could be hard coded in. Still, TI Voyage look very nice. I never see one before. I would think PocketPC could do same thing, but not have QWERTY keyboard on PocketPC.

One other thing, I glad I not own plane you fly in that program as at 700 lbs an hour, that a lot. Mine only do about 105 on average. Sometime less, sometime more.

Again, thank you for sharing Max, it very enlightening.

Edited: 19 Aug 2007, 1:24 p.m.


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