Despite the substantial investments by firms such as Day Jet, other aviation professionals remain skeptical on whether we can expect this mode of travel to flourish due to the decreased cost of personal air travel. The primary obstacles being that aircraft utilization is the largest limiter in reducing costs of operation (fixed overhead) not necessarily advancements in technology.
The most notable evidence / example of this problem is the fact that direct operating costs of VLJs are not substantially lower than existing turbofan and turboprop technology that can carry larger loads, greater distances, and in some cases for a smaller initial investment.
