Can we drop the jetpack debate already?
From the site:
What Is A Jetpack?
There is some confusion over what a jetpack is/ was/should be.
Basically it comes down to a disconnect between what is science, what is engineering and what is ‘common usage’.
1. Science
Science says that a Jet is a ‘coherent stream of particles moving in a parallel direction’.
This is why we talk about the ‘jet stream’ in the upper atmosphere. This is why a jet ski is called a jet ski. This is why a jet boat is called a jet boat. This is why the Coast Guard call their water jet powered craft ‘jet propelled’.
This is why our device is a jetpack. There is a coherent stream, all the engineering calculations, control calculations etc. are based on the fact that there is a jet of air exiting the fanjets.
AND
So why call our device a ‘Jetpack’?
Well, by both common usage and science it is a jet. We already have jet ski and jet boat. I do not believe that an aviation engineer will be able to convince all those owners to start calling their devices a ‘water pump propelled boats’.
In the end we found that 95% plus of people call it a jetpack when they see it, so why fight that ?
If you have a very narrow view of what a ‘true jetpack’ is (i.e. that it is a pure jet) then none have ever been built. The closest would have been the Bell jet belt, but again this was not a ‘true jet’, it was bypass ratio gas turbine powered. In fact I cannot think of any ‘true jets’ in the GA industry, most are Fanjets.
Perhaps now you see that the ‘correct answer’ is far more complicated and debatable, so much so that normally it is not worth even starting the discussion, because the ‘correct’ answer relates to opinion not fact.