There are a number of ways to prevent this sort of problem:
1) Drive the bus up on blocks high enough that if the bags go to minimum possible
height (fully deflated), you still have plenty of room between the bus frame and the
2) If you jack anything up, use a SCREW jack so it can't collapse, or use an adequate
3) Get a pair of special jacks that work like a fork lift. You roll/slide them in around the
tire and a pair of extensions grab the tire and lift the bus. They have mechanical locks
on them that prevent them from falling. I've seen charter buses on a driveway with
four of these animals, one on each corner, and the bus was high enough to walk around
underneath. My only concern was what might happen if a heavy gust of wind came along.
Much safer inside, assuming you have a high enough (17 feet or more) ceiling.
4) [I think this is most practical] Build a service pit in the floor or your shop if you have
one, or create an equivalent outdoors so you can work under the bus with the wheels on the
ground. It's cheaper than a hospital stay or a funeral.
And if you use blocks or ramps, make sure they are wide enough and stable enough that
they cannot roll over or sink into the ground, and make sure you have them on very solid
soil, even when it's raining or wet.
If you are working on air bags, if you can find an appropriate place to do it, you could use a
length of 3-inch steel pipe (1/4-inch wall thickness) with steel plates on each end alongside
each air bag. Inflate them to raise the body high enough to insert the pipe between axle
assembly and a suitably solid point on the bus frame, then deflate the bag. Doing this all
at once all the way around the coach is "left as an exercise for the student" to figure out
Most injuries/fatalities boil down to somebody doing something really stupid (like falling
asleep under a bus? -- Were they out to late the night before? Why?). Sometimes
life can be rather unforgiving. I sometimes wonder who was silently protecting Ben
Franklin from himself while he was "discovering' electricity in lightning! That's a really
good way to get critically killed (or is it "become critically dead"?)...