Airlander is designed to undertake multiple roles, including for Defence and Security applications, in which the aircraft’s Susceptibility, Vulnerability and Survivability are of paramount importance.
The term susceptibility refers to the ability of an aircraft to avoid threats. Airlander's susceptibility relative to conventional and unpiloted aircraft is considered to be low by design, due to the following:
- The hull (or envelope) is constructed largely from fabric and filled with helium. This will result in a relatively low radar return from the large hull.
- Airlander's engines will have relatively low infrared radiation compared to the gas turbine engines often used on other aircraft. They are spaced widely apart, further reducing Airlander’s apparent heat signature.
- Airlander is relatively quiet.
- Airlander can operate at altitudes above the range of small arms fire and most man-portable air defence (MANPAD) systems.
- Airlander is not dependent on runways or airfields and can remain airborne for days at a time, so it can be operated from unexpected or unusual places.
Vulnerability is defined as the ability of an aircraft to withstand damage caused by man-made threats. Aircraft using lighter-than-air technology, like Airlander, are very difficult to disable and even harder to bring down completely. Airlander's vulnerability to threats is considered to be less than that of conventional aircraft and UAVs because:
- The pressure differential between the internal helium space and the external atmosphere is very low. Punctures to the hull therefore result in very slow leakage and a gradual, controlled descent.
- The aircraft can continue controlled flight, continue its mission, return to base, and land using any two working engines.
- The four engines, fuel lines and control lines are widely dispersed, meaning that a single damage event is relatively unlikely to cause loss of the aircraft.
- The aircraft flies relatively slowly so damage caused will not be made worse by the effect of airflow.
The term survivability refers to the capability of an aircraft to avoid or withstand natural and man-made hostile environments, including lightning strikes, mid-air collisions, and crashes.
There has been significant research carried out into the survivability of lighter-than-air aircraft which has been conducted over a period of time and within a variety of environments. These airship findings will be applicable to hybrid aircraft like Airlander. Key points of note within this research are that airships are “highly survivable against conventional threats” because:
- Gas leaks slowly, even from multiple holes in the envelope (live-fire testing of airships by agencies in the US and the UK has confirmed this).
- Recovery of an airship to the ground is likely even after severe damage.
- Missiles are unlikely to fuze or initiate on contact with the hull.
- Lighter-than-air aircraft have low acoustic, IR and RF signatures.
- Airlander is also designed to withstand lightning strikes, High Intensity Radiated Fields, extremes of temperature and icing conditions.
For more information, get in touch with our team.