Right at the beginning of the adventure, the PCs are supposed to stop the engines of their shuttle from exploding. This requires two tech-use tests first at +0, then at -20, with 4 Degrees of Failure (failing by 30 or more) triggering an explosion.
A starting enginseer likely has an intelligence value somewhere in the low 40s. He has a combi-tool and probably either a servo-arm servitor or a straight +10 skill bonus.
Thus, he has a chance of about 40-45% to make the test and will blow up everyone on a roll of 70-75 or above.
If the group hasn't got an enginseer, the Operator will have to do. Assuming he's not busy with moving his vehicle against the orkish buggies, he might at least put his tech-use to good, well, use. Sooo… let's go for a 35 intelligence, no +10 and no tool. 15% chance of making the test, 45+ means blowing everyone up. Though it might be argued that he could simply use his comrade's Put That Out! to skip the whole thing, but presumably, that's not intended.
Considering that for many groups, this will be the second roll in the entire game, those chances seem rather harsh to me.