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Comment by disordinary | Hacker News Reader

I was on a Cathay Pacific flight a few years ago and was looking at all the games they had in the in flight entertainment system. This was an older plane with really bad games, one of which was a number guessing game. I was bored and so wondered what would happen if I entered a negative number as my guess. The entire in flight entertainment system on the plane was down for a couple of hours until the crew figured out how to restart the system properly.

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I love testing things like that.

I was a caller for my University's Phonathon. Somebody realized that the software had never been tested, so they asked a number of the frequent callers to test the system. I wondered what would happen if I put a negative number in for a pledge. The system accepted the input, but the systems it was tied in to did some really weird things with it. The pledge was automatically marked as completed, because the amount paid (0) was larger than the amount owed (a large negative number). Recognition for gifts isn't based on paid amount though, it's based on amount "credited" to the donor. This makes sure that people get recognized for matching gifts from their companies, but the companies get the tax documents, etc. The recognition amount was stored as an unsigned integer with 4 decimal places. When a negative pledge was entered, an integer underflow occurred and you suddenly were the largest donor to the university by a huge margin. Funny thing was that anybody could have messed the system up, because you could also enter a negative number on the online pledge page as a donor.

That being said, professional fundraisers are very familiar with the largest donors at an organization. Somebody would have caught the error immediately, and there wasn't any way to screw up the financials/bank statements, but it was a fun little error to uncover.

I think you mean Cathay Pacific?

Edit: Glad to help! I was going to delete after you corrected, but it looks like I can't :/ Interesting note: Google doesn't even give me the "Did you mean" option when I tested "cafe pacific". Must be a pretty common mistake.

I've always wanted to fly Cathay Pacific, as I've heard the service is fantastic. Never had the opportunity yet, though.

I do indeed :)

A lot of those big airlines are a mixed bag. If you get one of their newer planes they are world class, but we were on an aging 747, it creaked and groaned, had the aforementioned in flight entertainment system, and the toilets stunk up all the rows near them. But some of their planes are beautiful and the service is top notch. This was a few years ago but even in economy they gave everyone a little pack with toothbrush, ear plugs, travel socks, and those masks you put on to sleep when it's light.

I've had a similar experience on Lufthansa where one flight was an amazing plane with a bar downstairs, and all the mod cons, and then I had a flight from Frankfurt to LA which was 12 hours without any back of seat in flight entertainment (it just had a few screens hanging from the ceiling). This was only three years ago.

That's why I try and fly Air NZ wherever I can, it's not the best airline in the world but it's consistently good across the whole fleet.

Funny enough, a few months ago I passed a value to a WordPress function, a function that evidently wasn't checking what was sent to it, and got something wonky back. I open a bug report. The reply was, "Well, you're not supposed to do that." My reply was, "NO. You're not supposed to let me do that." I believe the code went unfixed. Crazy.

I was worried you where going to say it took the plane offline

There was that story a year or two ago about someone who took control of a plane through the in flight entertainment systems. I don't know if it was scare mongering or not but you'd expect that the entertainment system and flight control computers were on separate networks.... wouldn't you?

I don't just expect them to be on separate networks - I expect them to be fully air-gapped!

Entertainment systems typically can show flight info. They receive it through something like ARINC one-way serial link.

Air-gapped might get in trouble too in case of depressurization. It'll be almost vacuum gapped then.

This reminds me of the (possibly urban legend) story of the F-16 navigation system that turned upside down on crossing the equator.

https://catless.ncl.ac.uk/Risks/3.44.html

There is another one that is not an urban legend, in 2007 a group of six F-22 completely lost their navigation and partially lost communication when crossing the international date line. They had to visually follow their tankers back to Hawaii.

http://www.dailytech.com/Lockheeds+F22+Raptor+Gets+Zapped+by...

Pretty certain this isn't an urban legend. I was stationed at Hahn in 1983, the first base in USAFE to get the F-16, and it was related to the troops by a General Dynamics technical guy. This was found in the simulator during testing, and the pilot had flown south of the equator and the plane inverted. He said "Huh, that's strange." and flew back into the northern hemisphere, and the plane corrected itself.

Would the speed of the inversion have killed a pilot? That wasn't mentioned, but given that humans have different G tolerances depending on the direction ... maybe.

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