Hehe Lou I wish I had you as my teacher in the early 60's..
I am pretty sure that I would have end up in a Russian space station or something similar to that..  8-)
Your teachings are legitness, if you understand my bad term..  ::)

Now lets see how the boys answer on this tricky question...

One advice guys:
*Most stuff on a aircraft, can be used for more than one thing only!*
*Those stuff will operate both positively and negatively, at the same time  :D*

So make sure that you give Lou more than just one answer, "Why"...
Trust me he will not be satisfied with it  ;D´
Give the whole story, "pro's/con's/why/how/when"
And then I promise you! He will say to you, that you have answered correctly with great extend to it as well...  ;)

Hope this doesn't confuse you guys who want to answer Lou's tricky question...