But if anything is going to push it over the edge of going off (for whatever reason it has finally decided it's time), it's going to be a plane driving over the top / near it.
The reason it detonated now is probably corrosion eating away for decades. Which also has made it incredibly dangerous to defuse WW2 bombs, because their behavior is so unpredictable.
If you look at the photo in the article, the bomb seems to be at the very edge of the taxiway, where a plane is unlikely to drive directly over it. If it would have been a little bit closer to the center, it might have happened just as you described...
I wasn't referring to the damage the explosion might have done to the plane, I was thinking about the explosion being more likely to be triggered if the landing gears of taxiing planes pass directly overhead rather than at a certain distance. Then again, since the ground under the taxiway is already compacted, any mechanical effect that reaches a buried bomb is probably vibration rather than direct pressure, and that also has an effect at some distance (but it's probably still stronger directly underneath)
Just watched a blurb from NHK's hourly news programme and they mentioned a plane carrying 96 passengers and crew had taxied down that taxiway just minutes prior to the bomb going off.
I reiterate this was sheer dumb miraculous luck that nothing and nobody was harmed or killed.
