"The aircraft's fuel gauges were inoperative because of an electronic fault which was indicated on the instrument panel and airplane logs (the pilots believed flight to be legal with this malfunction)."

Dudes, wtf? Unless Canadian regulations differ from US ones, you're not even allowed to fly a single-seater in day VFR without a fuel gauge.

this story is longer, I think: http://www.damninteresting.com/the-gimli-glider/

it explains why they flew without a fuel gauge. tl;dr - they knew the gauge was broken, but regs allowed the flight if the maintenance crew did a manual sounding of the tanks and the measured fuel was enough. they sounded and measured, but converted incorrectly between pounds and kilos. I think the pilots were severely disciplined for that failure.

They were disciplined by Air Canada as Air Canada held the pilots and ground crew at fault even though the Aviation Board found Air Canada at fault.

Their disciplinary action was later overturned and "the pilots were awarded the first ever Fédération Aéronautique Internationale Diploma for Outstanding Airmanship."