Posted on 02/26/2007 2:47:19 PM PST by SubGeniusX
Six Lockheed F-22 Raptors have Y2K-esque glitch of their own over the Pacific
Lockheed’s F-22 Raptor is the most advanced fighter in the world with its stealth capabilities, advanced radar, state of the art weapons systems and ultra-efficient turbofans which allow the F-22 to "supercruise" at supersonic speeds without an afterburner. The Raptor has gone up against the best that the US Air Force and Navy has to offer taking out F-15s, F-16s and F/A-18 Super Hornets during simulated war games in Alaska. The Raptor-led "Blue Air" team was able to rack up an impressive 241-to-2 kill ratio during the exercise against the "Red Air" threat -- the two kills on the blue team were from the 30-year old F-15 teammates and not the new Raptors.
But while the simulated war games were a somewhat easy feat for the Raptor, something more mundane was able to cripple six aircraft on a 12 to 15 hours flight from Hawaii to Kadena Air Base in Okinawa, Japan. The U.S. Air Force's mighty Raptor was felled by the International Date Line (IDL).
When the group of Raptors crossed over the IDL, multiple computer systems crashed on the planes. Everything from fuel subsystems, to navigation and partial communications were completely taken offline. Numerous attempts were made to "reboot" the systems to no avail.
Luckily for the Raptors, there were no weather issues that day so visibility was not a problem. Also, the Raptors had their refueling tankers as guide dogs to "carry" them back to safety. "They needed help. Had they gotten separated from their tankers or had the weather been bad, they had no attitude reference. They had no communications or navigation," said Retired Air Force Major General Don Shepperd. "They would have turned around and probably could have found the Hawaiian Islands. But if the weather had been bad on approach, there could have been real trouble.”
"The tankers brought them back to Hawaii. This could have been real serious. It certainly could have been real serious if the weather had been bad," Shepperd continued. "It turned out OK. It was fixed in 48 hours. It was a computer glitch in the millions of lines of code, somebody made an error in a couple lines of the code and everything goes."
Luckily for the pilots behind the controls of the Raptors, they were not involved in a combat situation. Had they been, it could have been a disastrous folly by the U.S. Air Force to have to admit that their aircraft which cost $125+ million USD apiece were knocked out of the sky due to a few lines of computer code. "And luckily this time we found out about it before combat. We got it fixed with tiger teams in about 48 hours and the airplanes were flying again, completed their deployment. But this could have been real serious in combat," said Shepperd.
thanks look forward to it
Control, Alt, Delete!
All the code reviews in the world won't catch something like this. Someone just forgot to list this detail as a specific requirement and something that needed testing. Happens all the time and you just have to catch it in the field.
I think it is a larger problem of America becoming more politically correct. You cannot say or do anything without someone getting p*ssed !
Sorry, your son won't be returning from his deployment, he was shot down by an ace computer programmer...
And 1.2 million of the purchase price will go to the RIAA in case any pilots decide to listen to "pirated" music while in the air. Plus, if you beam your music or data to any other Raptor, it expires in three days or three uses. So make sure you hit the target the first time and soon or your new targeting data will have a "Would you like to buy this targeting data from the Microsoft store?" placeholder instead of letting you hit the target.
Sounds like the Tacoma Narrows Bridge in WA
True, but compared to what they built it up to be, it was a non event. Wonder if the daylight savings change will screw some things up......
It's probably about data checking. A subroutine should never trust the data it gets, but still programmers make the mistake of trusting it. "The data is coming from the system itself, so why not trust it?" Big mistake. Let's say the navigation system uses local time data for its operation. Suddenly the date on the time jumps forward by one, the subroutine freaks out due to the unexpected change and crashes. What I don't understand is why the system isn't built modular so that the navigation system could just be restarted.
True story: Recently a guy was using the in-flight entertainment system of an airline, setting up a game of Tetris which allowed you to set the number of future pieces you can see. The maximum allowed value of 4 using the arrows on the screen. Then he used the seat phone, and it accepted an input of 5 from there (but nothing above 5). Looks like a programmer wrote "It's okay if it's less than or equal to 5" instead of "It's okay if it's less than five."
Not too big of a problem, except the the guy was able to use the up arrow keys to then go higher, where he was normally stopped at 4. Looks like the programmer wrote "Don't go higher if it equals 4" instead of something like "Don't go higher if it's greater than 3."
So, having bypassed the initial bounds check and unrestrained by another poorly written one, he kept hitting the up arrow until it hit 127, and next after that in a signed byte is -128 (it rolls around to negative). A negative value where a positive is expected down the line can have serious consequences, like out of bounds or data type mismatch. He hit up again, it briefly showed -128, and *poof* went the entire in-flight entertainment system. Everyone's screen went blank.
It's amazing the consequences a small bug can have.
These kind of flight essential systems go through an incredible level of code review. Including a third party review.
However, they are reviewed and tested by human beings, and human beings are ultimately fallible creatures.
This bug somehow slipped through.
They will figure out how it slipped through and rewrite their code verification procedures and make sure this mistake doesn't happen again.
They're going to be spending a lot of time convincing the Air Force and the FAA that they've fixed the flaw in the process that allowed this bug to slip through.
Thankfully this didn't result in loss of life, or even the loss of the planes.
There is a way to help that, but most people don't want to do it anymore. You write the system highly modular and mathematically prove (not just test, prove) each small module for correct operation. A program is just a big algorithm, and algorithms can be written to be provable. Then with those proofs you prove the interaction of the modules. It takes a long time, it is tedious, and it takes people very knowledgeable in higher math do to it, but it can be done.
Thank you, thank you very much. I like being splattered with the paint of a thousand insults, but I am pond scum, not just scum.;-)
SZ
Not to mention max longitude is 180, not 190.
Not exactly. A program is code+data+environment which is based on usually many algorithms. There is no way to test in a lab all permutations of data and environments. That being said, automated testing is still way undervalued. We need to do a lot more of it.
And you prove that each of those algorithms works as designed no matter what data it receives. It's not the whole way there, but it gives you a solid, proven foundation for the whole system that you can test as usual. For the in-flight entertainment example, the module should have been proven not only like "For values 1-4 as the input" (the valid values) but as "For any value X as the input."
Rumor has it that the lowest bidder had SCADS of surplus Y2K software he gave 'em a great deal on.....and some vacuum packed lentils thrown in for free....!!!
The story is in the mainstream now. So no subtrifuge needed. Plus...none of the planes they flew F-4 and 727/767, hopefully had this problem so they likely don't have experience wit it.
It doesn't matter unless you are a corporate or institutional functionary. Of course that is most of us.
LMAO! Stolt
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