The sky maybe not a limit for humans anymore, but in the future may have some limitations for flight. 

Before the first flight on 17 December 1903 by the Wright brothers, only birds enjoy the blue sky. But today there are lots of different vehicles using the same zone for their flight. 

Commercial aircraft, Business Aircraft, Helicopters, Military aircraft, and recently eVTOLs and for higher levels spaceships and satellites. The total worldwide fleet size is almost around 30000, some around %15 grounded due to maintenance or spare parts, but still, there are almost 25,500 aircraft flying in certain frequencies. 

21 years ago RVSM was implemented as a means to increase airspace capacity and provide access to more fuel-efficient flight levels. The International Civil Aviation Organization (ICAO) and its member states first mandated the implementation of RVSM in the North Atlantic in March 1997, with other regions around the world to follow. The RVSM program transformed airspace usage above FL290, and was one of the biggest changes to airspace ever made. The aim was to implement a program to reduce the vertical separation minima between aircraft from 2,000ft to 1,000ft above 29,000ft (FL 290). This Implementation involved training and preparing controllers from 41 countries at the first phase, and pilots and flight planners from 2,300 airlines and operators. The RVSM program went live at 00:01 UTC on 24 January 2002 across the 41 States, with air traffic controllers allocating aircraft to the new flight levels. The six additional flight levels created by RVSM between 29,000 feet and 41,000 raised airspace capacity by up to 20% and helps to manage the higher traffic in the same airspace. Now we are celebrating the 21st year of RVSM's successful implementation, and feel that more challenges waiting for us in the near future regarding number of flying vehicles. 

After almost 20 years from RVSM implementation, Aviation again is on the edge of a new revolution, moving from turboprop and jet engines to electric motors, batteries and energy storages, lightweight composites, digital technologies, pilotless flights, and systems integration. To achieve the 2050 NetZero goal needs new class of electric and hybrid aircraft to introduce to the market. We’re on the way to an Advanced Aerial Mobility era. A solution of air transportation that makes passenger and cargo moveable to and from locations that were impossible by aircraft and uneconomical by helicopter to serve. 

The new generation of vehicles enables these flights to carry out, by electric motors, powered by batteries or green energy sources. They will be capable of Vertical Take-Off and Landing (VTOL) or Short Take-Off and Landing (STOL) area requirements. First-generation aircraft will plan to be piloted, following the way for increasingly automated and potentially autonomous flight in the near future. 

This new generation aircraft design, bridges the huge gap between communities separated by inconvenient public transport or impassable terrain and obstacle elements, facilitating new regional networks growing and new routes establishment which lead to economic growth.

The new generation aircraft is capable to offer emergency response and different logistics, business models, and solutions by improving the new technologies and having better economic forecasts. It also supports the industry decarbonization plan and cleaner infrastructure. 

Because, unlike helicopters, new aircraft seems more safe, clean, and quiet, while offering lots of benefits to busy and populated cities with limited lands to offer aircraft and helicopter operations. 

The market expectation is to see eVTOL operations begin over the next 2 years. And followed by Commercial passenger and cargo operations are expected to begin in 2026. This is the major reason behind the investment acceleration in recent years in the eVTOL manufacturers and related industries and solutions. The investment rate reaches a significant increase from USD200 Million in 2018 to almost USD 7 Billion in 2022. with at least US$6.5 billion of capital flowing to eVTOL aircraft manufacturers and infrastructure just during 2020 and 2021. 

We believe that eVTOLs offer a huge opportunity for the customers and support smooth transportation over the cities and access to difficult-to-reach locations, however, there are challenges to making this solution a reality in the world. Challenges like regulations, infrastructure, and environment. 

eVTOLs need to operate within a clear policy and regulatory framework including with the designated airspace, and strict rules. In such an environment, the safety of the vehicle and operations must be the primary concern to be addressed by the authorities, currently, some vehicles undergoing a type certification process by the EASA, aiming at showing compliance of the type to EASA’s latest SC-VTOL regulations. These advanced regulations and their complementary Means of Compliance are currently being used by EASA in the certification of several eVTOL aircraft. 

While the airframe, engines, and avionics are in the approval process by EASA and other authorities, policymakers in each country are yet to provide overarching guidance on establishing a flying ecosystem. The private sector tries to undertake much of the work to speed up the delivery and usage, but some areas do require public authorities to set, confirm or clarify the rules. 

By taking care of current operations in Civilian, Military, and helicopter, as well as risks, the authorities should update existing policy, legislation, regulations, and frameworks where possible, in order to establish procedures have the benefit of safety, familiarity, and predictability for all operations in a single sky. It reduces ecosystem complexity and is easy to implement between different stakeholders. Regardless of the required policy to operate the eVTOL in the current busy sky, the data coding method and data delivery format would need an extra working group. The EUROCAE already started to implement the first draft for such data exchange methods, aiming to help eVTOL fly safer. 

The biggest challenges for policymakers will be announcing the definition of electric aircraft classes and categorization, airspace management over urban areas and at larger volumes of flights, plus effective policies and processes for airspace evolution, security requirements for operation for both passenger and airframe security, pilot training and licensing arrangements, autonomous piloting frameworks, aerodrome licensing requirement and regulation, and flight Planning permission. imagine seeing all taxis operating in the sky. 

Another issue would be having new dedicated aerodromes for eVTOLs. New infrastructure must be developed to accommodate a growing fleet of eVTOLs. Despite analysts projecting tens of thousands of eVTOL deliveries over the next two decades, work on designing and building the required infrastructure need to be faster.

With the launching of eVTOLs, aircraft numbers in our skies will rapidly grow. Accommodating these aircraft while avoiding disruption to existing aviation, requires a new way of managing airspace. Conventional manned aviation is dependent upon Air Traffic Management services or a pilot’s ability to see and avoid other aircraft. Drones, air taxis, and very high-altitude vehicles perform very differently from conventional aviation. In some cases, these vehicles have no onboard pilot to see and avoid other aircraft. The challenge is to reconcile different modes of operation, enabling all aircraft to operate safely and efficiently. There are multiple efforts underway to modernize airspace management. The primary challenge is to modernize the airspace structure to accommodate today’s commercial and military aircraft and helicopter capability and tomorrow’s new airspace users. 

ATM service providers shall invest in Unified Air Traffic Management capabilities, such as modern surveillance and information exchange systems, to provide safe and secure air traffic control services and solutions to both old and newcomers. Enhanced communications allow air traffic controllers access to all real-time information about operations. This enables the delivery of a common information service to airspace users. Also, communications with aircraft will be via digital data exchange methods, like Controller Pilot Data Link Communications (CPDLC) or System-Wide Information Exchange (SWIM), and try to reduce the need for voice communications and keep the frequencies for situations such as aircraft emergencies. improving the ADS-B network will support the operation as well. 

By using adapted airspace structures and ATM procedures, ATM service providers could apply advanced modelling and simulation to demonstrate the feasibility to support new-generation aircraft operations in the cities while integrating with existing airspace users