I was wondering why there aren't more helicopters using the notar system.
You are talking about NOTAR popularity. I believe, in this case, one needs to look at the environment within which NOTAR is produced - a firm which has battled with some fairly fundamental challenges for the better part of the past 20 years and which struggles to attain steady growth in terms of sales.
Had this
not been the case, and say the NOTAR patent sold to a manufacturer with a significantly higher product throughput, one
might have witnessed the progressive refinement of the technology resulting in improvements in its operational effectiveness and further boosting its popularity.
I don't understand how after 20 years people still think engine exhaust is used in the NOTAR system.
Because early publicity surrounding NOTAR technology intimated that exhaust gases would be integrated with accelerated ambient air to pressure the boom. When this option was not selected the corresponding publicity was considerably less (.. one can understand how a front page heading in the Herald Tribune "Hughes Backs Down From Integrating Exhaust Gases in Newfangled Helicopter Technology" might have limited readership appeal) .. and, consequently, those lacking proximity to NOTAR development and operations did not appreciate that this strategy had been altered.
PPRuNe's Rotorheads and other mediums are doing a great job of educating (well, most of the time
) those who are interested in these things.
S.