Hydrogen fuel cells that generate electricity, powering all onboard systems and 6 quiet electric outrunner motors.
6 rotors, designed for low noise and low RPM.
115 mph. Average speeds for local trips will likely be around 85mph, in a straight line and with no traffic.
We believe the everyday “sweet spot” will be between 10 and 150 miles. However, when you count the time and stress involved in getting to an airport, going through security and other delays – longer distance on-demand travel with Skai is highly appealing.
Up to 4 hours, though most flights will take just minutes. For specialized applications, auxiliary fuel tanks can increase flight times based on mission needs.
Liquid hydrogen onboard tank. Refueling takes less than 10 minutes.
Up to 1000 lbs.
Fault tolerance is about eliminating potential points of failure, by reducing complexity and adding redundancy – i.e. backup systems. For example, a helicopter’s rotor system uses a highly complex transmission. Many failures occur here, and there’s nothing to back it up.
Each of Skai's six rotors uses a brushless electric motor, with no complicated gearbox or tail-rotor connection. It’s a simple, redundant system that can tolerate one rotor failure for continued safe flight and landing. Even if it loses two rotors, it will land safely.
In fact, Skai’s three primary systems – rotors, fuel cells and flight computers – are redundant to ensure peace of mind on every ride.
Even if multiple systems fail, the vehicle will still land safely. Should a catastrophic situation occur, Skai has an additional fail-safe redundancy – an airframe mounted parachute.
While any single failure is rare, true safety is about being prepared for worst-case scenarios.
Airframe & Cabin Safety
In addition to proven technology and redundant systems, even the fabrication of the vehicle chassis was designed with a safety-first approach.
The carbon composite airframe and landing skids are built to flex and reduce the effects of a hard landing.
Inside the cabin, the impact-absorbing seats are FAA-certified, with a 4-point seat belt system to keep passengers safe and secure.
Mounted to the airframe is a fail-safe parachute system. Should the failure of multiple redundant systems occur, the parachute will deploy from the roof, and gently lower the entire vehicle to the ground. This proven system has been in use for decades, and has been installed on more than 35,000 aircraft.
Technology & Expertise
Skai is equipped with advanced fly-by-wire technology, which has been proven over hundreds of thousands of commercial aircraft flight hours.
In addition to better signal redundancy and speed, the system is protected against electromagnetic interference, e.g. from lightning strikes or transmission towers.
Key avionics include a triple-redundant autopilot system that helps maintain smooth, stable flight when piloted, in addition to flying the aircraft autonomously.
The next-generation Automatic Dependent Surveillance Broadcast (ADS-B) system provides tracking, weather data, increased air traffic awareness, and reduces the risk of collisions with other aircraft.
Like any modern vehicle, Skai is equipped with a suite of sensors to ensure safety and maintain persistent, proactive awareness of any potential risks.
Key systems include a combination of LIDAR (Light Detection and Ranging) and camera sensors that can detect large and small objects in the vehicle’s path.
There are a number of fuel system sensors that ensure efficiency and safe ongoing performance. For example, there are multiple hydrogen leak detectors on board, tied into an annunciation system for the pilot, and available as telemetry to the ground during flights. When the vehicle is stationary on the ground, the sensors remain active to detect any possible leaks.
Designworks of BMW Group
Alaka'i teamed up with Designworks, the design innovation studio of the BMW Group, to develop Skai’s design. The forward-thinking company is known for “designing systems that improve the world we live in”. Their extensive work on BMW vehicles, in the mobility sector and a brand range of industries made them the perfect partner for Alaka'i. Designworks brought their expertise to bear in this new Skai Craft.
Initially, Designworks determined the vehicle architecture and configuration, which included the layout of components such as fuel cell tanks and seating. This was done with consideration to key criteria that included safety, passenger experience and performance, which were evaluated and optimized to arrive at the best solution.
For example, the majority of components were positioned as low as possible in the vehicle to reduce the structural load on the airframe. They were also positioned in relation to the seats to create a balanced center of gravity, which has a direct effect on the stability, performance and handling of the vehicle.
One of the largest components that Designworks had to accommodate into the vehicle was the hydrogen fuel tank. This was positioned laterally behind the rear seats to create the widest point towards the rear of the vehicle. This provided an opportunity to shape the exterior with a elongated “boat tail” at the rear to minimize drag by delaying airflow separation and allowing it to remain attached throughout the length of the vehicle.
One of the final steps was to refine the passenger experience.
The modern cabin design offers a clean aesthetic with ambient LED lighting to add a warm, calming touch. Well-appointed seats are upholstered with premium materials and stylish accents. The glass canopy windows deliver 180º sight lines for exceptional aerial views.
If there’s work to be done, 5G-powered WIFI keeps passengers connected the whole flight through. Using the Skai app, passengers will even be able to take AR-enhanced selfies to share their experience.
Skai’s rotor system was designed to deliver a smooth, quiet ride with maximum safety and capability.
The rotors are mounted on 6 boom arms that are attached to the airframe independently of the cabin enclosure. This minimizes cabin noise and vibration, while at the same time reducing weight and improving the stability, handling and performance of the vehicle.
The 6 rotors are designed for low noise, and are powered by counter-rotating pairs of brushless electric motors. The motors are in turn controlled by 6 motor controllers – these control the voltage, current, RPM and torque to each motor and monitor system status and performance.
Finally, the motor controllers are all overseen by the flight computers, which manage the entire system and maintain flight stability and smooth performance.
As noted, keeping the rotors (and the entire Skai experience) as quiet as possible was a key consideration. Noise pollution is a major problem that affects millions in the US, particularly in urban areas.
The vehicle’s 6 rotors spin at lower RPMs to significantly reduce decibel levels – we believe it will be by far the quietest air mobility solution in the air. This will allow air-taxi, medi-vac and cargo services to operate in populated areas with minimal impact.