No, I upset Dave Murphy (moderator) himself! Apparently my not regarding his site as a learned academic establishment, and posting this sort of thing really upset him. I noticed a lot of prof engineers disappear from that one - wonder why?
How many engineers does it take to change a light bulb?
Only one, but he has to develop a prototype.
How many heli pilots does it take to change a light bulb?
Again only one, but he has to safely ground the failing one first.
Mart