[Nexialist]

This is nothing. I work for an aircraft maintenance software company. Last week I fixed a bug where the system would silently delete a maintenance task if you clicked the X button on a confirmation dialog instead of "no". This had not been fixed for three years.

[rohit89]

Wow, I thought programs for critical systems went through stringent testing. Was this bug not fixed earlier because they figured that the probability of it being responsible for a fatal error was low ?

[Nexialist]

The actual on-board software of an aircraft is definitely given a lot of attention as far as testing is concerned, but unfortunately more indirect systems, such as maintenance tracking software, is treated pretty much the same as any other piece of software; which puts it down to the company that made it to judge how much testing they perform.

In my company, the management puts a higher priority on putting all available hands on rolling out new functionality than fixing bugs, in order to try and win new contracts from potential customers. Or at least that's their excuse, in my opinion there is no such thing as a low priority bug, no matter what industry you're in.

[d99kris]

The difference is that a pilot knows far more about an aircraft than the average driver knows about their vehicle.

[Nexialist]

That's probably true, but the potential for a severe, un-recoverable issue is about as high. An aircraft is composed of hundreds of individually tracked components with associated information about how old the component is, how much it has flown, etc. Most of these parts have a mandatory expiration date at which point it is swapped out or sent for repair. A failure in the system which tracks all this data (which is what I work on) isn't quite as directly dangerous as, say, a bug in the on-board navigational software. But you can still end up flying around with an engine way past its intended expiration date far too easily.

[sokoloff]

Agreed. I know a fair bit about what keeps my single-engine piston aircraft in the sky, and many of the possible faults are routinely checked/confirmed OK during pre-flight inspection and/or run-up.

Still, I don't want to inadvertantly miss a 500-hr magneto IRAN, a wing spar or bolt NDT inspection interval, run my dry vacuum pump twice as long as I planned, or several other possible faults that aren't easily testable by other than maintenance technicians.

[d99kris]

Point taken.