Slashdot Mirror
Linux Takes Flight on Northwest Simulators
Rewbob writes "Northwest arlines is spending $34 million to convert its flight simulators to linux. "
Nifty practical applications. Normally when neat toys like this
come along, I beg for someone to send me one, but for some reason,
I don't expect NW to ship an airplane simulator over to the
Geek Compound. But the best part is that there will be one less
Fortran program out there *grin*.
Real FORTRAN programmers can write FORTRAN in any language
Ugh. I know this to be true. Back in the mid 80's I had the misfortune of seeing some code written by an old Fortran programmer that was purportedly C code... What it really was, was FORTRAN code that was just marginally close enough to C that it would pass through the compiler without errors (although prodigious warnings). Lint positively went postal at the sight of that code.
Imagine this: All the code was in the main(), no other functions were used (so sometimes the main was 20 or 30 pages of code). Flow control consisted mainly of liberal use of 'goto' to mostly numeric labels (like 'L010030'). Instead of using #define for constants, the programmer used global variables set to the value of the constant. The programmer didn't seem to understand C looping functions, so mostly did things with do and while loops instead of using for loops where appropriate. Things that should have been done with real data structures such as trees, linked lists, etc. were all done with arrays (apparently the guy didn't understand pointers). The programmer didn't seem to understand printf() very well either, so the way that he did output was abhorrent.
What a horrible, wretched mess. It segment faulted and bus errored right and left. I was glad I wasn't the guy who had to maintain that stuff...
Back in my days in uniform, we had the AN/ALQ-T-4 simulator. It simulated a B-52 Electronic Warfare cockpit. It ran FORTRAN. Before I touched the T-4, I was trained on the T-5 simulator, lovingly known as "HAL", at the USAF Electronic Warfare School. It too, ran on FORTRAN. Eventually, both were replaced by the B-52 Weapons Systems Trainer, and the SECT (Simulator for Electronic Combat Training). The WST ran FORTRAN, and the version of the SECT that I was on the design team ran FORTRAN.
.
I guess it just goes to show, nothing TRULY obsolete. . .
http://www.flightgear.org/ is an open-source flight simulator that has a port to Linux.
They describe on their website:
I work in a combat simulations group, and every sim has FORTRAN at its core, either for the entire structure except for UI, or at least for the aerodynamic sections of code. I don't think that FORTRAN will ever be done away with, there is too much heritage with it out there. Modern Aerospace Engineering Degrees require FORTRAN (at least mine did), but C/C++ are all electives for the CS majors.
We are planning on porting one of the sims from IRIX to linux, but thats been planned for awhile. I'll just have to see what happens...
-- toolie
Anyone who is a CS-type that thinks FORTRAN is dead just needs to talk to a mechanical or aerospace engineer. FORTRAN is still the primary language of engineering. Anything that is real-number math intensive is done in FORTRAN: CFD, simulations, etc. Granted, the FORTRAN code is often linked to other written in C or C++. The one person who said he was told in an interview "nobody progams in FORTAN anymore" was obviously not interviewing for an engineering position at Boeing, Ford, or Sverdrup.
Also a major jet engine manufacturer in the US has successfully compiled FADEC (Full Authority Digital Engine Control) software on Linux.
I know of at least one Unmanned Air Vehicle project which uses RTLinux.
Linux is nowhere close to flight certification but it could turn out to be a very useful system for flight systems development.
which analyst/columnist it was a month or so ago that issued a challenge looking for any mission-critical usage of Linux by a Fortune 500 company? I remember reading it on the web, some analyst going on about how no one was taking Linux seriously. Would love to be able to forward him this story.
Just another rabid Linux evangelist.
- jon
Ganymede, a GPL'ed metadirectory for UNIX
The article says that they evaluated several different operating systems. Also, it would seem that developing a flight simulator would be a costly proposition. I think the cost of OS licensing would be a fairly small percentage of the whole.
;)
I'm really not trying to stand up and say, "See how great Linux is?" I titled the post "Impressive" because, well, _I_ was impressed when I read the article. (It was also a nod to Darth Vader in ESB)
No, I don't know the first thing about commercial flight simulators. All of my assumptions could be completely wrong. I would love for someone who knows something about this stuff to correct me, so I'll know if this really IS impressive.
Finally, despite what one moderator thinks, this was not meant as a troll. I was genuinely impressed that Linux would be chosen for such a task. I understand that probably no one else is interested in whether or not I'm impressed. I'm also sure that slashdot would be no worse off if I kept my little opinions and comments to myself.
I apologize if the original post was troll-like, but I promise that it was not my intent. You can tell when I'm trolling, because I'll log in as Anonymous Coward.
Save the whales. Feed the hungry. Free the mallocs.
One of my previous jobs was working with a quantum physics group that had a program to simulate quantum interaction... sort-of a chemistry lab simulator that does the reactions atom by atom.
They started writing the code back in the late 60's, and are still writing it today. Of course, it's written entirely in FORTRAN. They still have a copy of the first version of the program... stored on punch cards. The original programmer (who's still working with the project) once gave me this prophetic quote:
"I don't know what computers will look like 20 years from now, but I know they will run FORTRAN."
I think he's probably right.
--Mid
I know both NWA and Opinicus. The rehost from Vax/VMS to Linux makes sense to me, actually the
OS is not real critical as a Sim tends to use almost NO OS features in operation. Flight Sims run a realtime dispatcher on top of whatever OS they boot from, and newer Sims are distributed computing systems with the host OS doing little during operation. just for reference the new A320 and 777 Sims from Thomson use 15-25 Motorola VME CPU cards spread in cages both on the Sim and in the computer room, and one of those runs Mot SYSV unix and talks to the "host" Sun workstation , the rest all run a custom RTOS.
dave
you guys seem to think "Fortran" means fotran 77--F90/F95 is a pretty slick language. You have operator-overloads, pointers, built-in level 1 and (partially) 2 BLAS, derived types, etc. Check out Imagine's no-cost F translator (it's a subset of f90).
rot13 the email address.
Here is a company that probably could/would use ANY operating system they wanted. They apparently did some real comparisons and chose a free operating system.
-- This part of my post left blank for note-taking --
Save the whales. Feed the hungry. Free the mallocs.