The first footage - That machine was at Camarillo Airport around the mid 80s and slung a blade during a hover.
That system was mounted on several airframes the latest was on a yellow Rotorway body and named Pegasus still flying today
and some other names are the same bunch, followed their work and the only thing changes is the body style - no other improvements
pressure jets rotor lag in regulation and bad fuel economy. A Robinson uses 124 hp to fly these tip jet compressors are using 200 hp
When the concept of the Air Pressure Jet was conceived, fuel was inexpensive, and the increased cost of a higher fuel burn was still cheaper than the associated hourly maintenance costs of complex transmissions and associated accessories.
Someday there will be a turbine engine that is powerful enough with more effecient fuel burn than the predicessors to bring the hourly fuel cost down and make this design more attractive.
I'm just uploading these links to these videos just for pure viewing enjoyment.
Those engines exist today, even with the weight of the main gearbox the transfer of energy is what brings economy to the table.
It's just a few bucks on the reserve for time life components
As an operator the expenses are
Fuel - bulk sales, and supplying the locals reduces costs
Insurance - fleet policies and training requirements reduce costs - even changing aircraft types-
crew- hire the minimum to get the job done, "Outside Contractor" VS Employee
aircraft spares - Become a dealership - fleet training, discounted spares, sales, fleet rates through manufacture, direct support, advertising.