Control in bad weather. The common view is that airships are easily blown around, even in light wind, and very hard to control when landing and on the ground. This is true of ALL aircraft but airships, with their large volumes and surface areas and small propellers are particularly affected.
Most airships flying today are under-powered and are cigar-shaped with a defined front and long body on the sides. They use fins and tails to control the pitch and roll. When stationary or moving slowly there is less airflow over these surfaces so control can be lost. And when moored or tethered to the ground, current airship designs connect via a single-point nose cone. This puts a lot of airframe stress in one point and allows the other parts of the aircraft to move freely and uncontrolled.
SkyLifters are uniquely different. It is vital to make an air-lifting device that delivers a useable hook in the sky in weather conditions beyond the operational limits of land cranes and helicopters. And an air-crane that can be parked safely in all weather without having to fly home to base.
To supplement the table below, here are some other points to have in mind:
• Rain, hail, ice, snow, sun, and changes to temperature and pressure are items that ALL aircraft have to be certified to manage safely, SkyLifter included.
• Body of SkyLifter is omni-directional and therefore it is always facing front-to-wind, so when the wind changes direction it does not turn the SkyLifter.
• Thrusters are omni-directional and have a high power-to-aircraft mass ratio.
• Payload is centered below the SkyLifter, giving natural balance for flight stability.
• Flight control is 100% aerostatic and via thrusters, so no airspeed is required in any phase of flight; no fins no tail.
• Upright flight. SkyLifter has a very low centre of gravity and a high centre of buoyancy, so during flight, pitch and roll become heave and tow, promoting a naturally stable flying attitude.
A comprehensive detail of SkyLifter performance in various weather types is simply too complex to be explained in a short note. Instead, the table below summarises the 4 primary operational phases of a SkyLifter’s life and how they can be designed and operated to ensure safety and performance.
Optional scenario | Description |
1. Moored for extreme weather or large maintenance | SkyLifters have a Smart Hangar system. The Hangar includes strong ground anchors that hold the hull close to the ground and an ingenious fabric skirt that extends from the circumference of the hull to the ground. This configuration creates a domeshaped hangar as a safe refuge protecting from extreme weather while moored |
2. Moored, waiting for next job, crew change or short-time re-supply | SkyLifters have endless flight endurance, so when they need to be near the next job, it will be more common to ‘park’ them free-floating in the sky. When they do come to the ground for a short time, for example to refresh crew or supplies, this can be done with the aid of landing the ballast pods which are also used for hook operations. |
3. Free flight, A to B | Air can be turbulent and gusting, with large temperature and pressure gradients. It is a complex and mostly invisible to the eye. SkyLifters have many air sensors and forecasting systems to enable pilots to make safe decisions. Most other aircraft try to fly quickly away from bad weather, but SkyLifter pilots have the option to float with the wind and therefore endure inside a storm with minimal stress. |
4. Free flight, lifting on hook | SkyLifter’s airspeed capability far exceeds the maximum allowed by authorities for land crane hook lifting. |