There was a time when all that was required to use the office copier, printer or fax machine was the ability to fish out paper jams and a knack for percussive maintenance — known in layman's terms as a good hard thump.

Technical things on a small scale can be just as capricious. I heard a good one the other day — an expression for a phenomenon which had previously been unnamed, as far as I know. It's "percussive maintenance", which happens when your piece of electronic wizardry — television, computer, etc — won't work, and you give it a sharp unscientific whack to revive it — it often works, too.

The plan had been to let the media and various hangers-on go out for a ride in the big white six-seater, but technical woes kept the number of five-minute tours down to five out of more than 40 that were scheduled.

Early trips reported trouble that seemed to be fixed by using a wrench to apply repeated doses of percussive maintenance.