History shows that people globally have dreamt for thousands of years about ships floating
in the Earth’s atmosphere serving aerial transport and other needs in a way that Sir
George Caley (known as the father of aeronautics) explained in the 19 th Century. Indeed,
he recognised that the atmosphere isn’t just thin air. Rather, it’s a fluid substance with
several layers blanketing the whole world as an ocean that airships may ply in similar ways
to fish in water.
In fact, people today concerned with astronautics have considered this possibility as a way
after travel through space to then enter the atmosphere of other planets in the universe as
ships for initial aerial exploration and possible controlled descent onto firm surfaces below.
This is a dream of people who reach for the stars but are bound by gravity to Earth’s
surface. New airships today already fly at record heights in the stratosphere, which
balloons also do!
Yet gravity is what causes both weight and buoyancy, which are opposite forces and may
be of equal magnitude, enabling flotation. Gravity in the first place draws matter together,
causing weight when free fall is opposed. This occurs when standing on the Earth’s hard
surface, as Sir Isaac Newton before Caley explained in the 18 th Century through ‘action
and reaction’, which people feel through their feet and legs – also from the effort to climb
stairs or hills. People also know what happens if free fall is arrested abruptly, which may
be fatal without adequate ways for shock absorbance under the dynamic effects to arrest
motion of the mass system.
Buoyancy (aerostatic lift) in the atmosphere isn’t so easy to explain or understood despite
Archimedes’ explanations about 2,300 years ago, as this is a secondary effect that’s hardly
felt and usually ignored from being weak due to low air density. However, it is felt in water,
a different fluid substance that, by comparison with air, isn’t compressible and has greater
effect from the amount displaced by our body being near to our own weight – so has much
greater density. Indeed, some people float without effort in it, as ships do – pushed up to
the surface by the water they are in (if not flooded).
What this means is that the fluid vessels are immersed in must be prevented from entering
them, unless needed onboard in small amounts for different reasons, because it’s buoyed
externally by it and where any taken aboard only adds weight to the vessel, helping it to
sink. This is what submarines do, which take water in to sink and later expel it to rise. It
can work the same way in the atmosphere, although there are other things to also
consider.
This is where understanding of the way buoyancy works in the atmosphere becomes
difficult to explain. Also, because people have been taught incorrectly for a long time that
an airship’s vessel (a balloon or aerostat) and used to get sufficient buoyancy for flight as
useful aircraft, is filled with a ‘lifting gas’ to buoy them. This term perhaps stems from
aeronautical people who lost touch with physics and the nautical side involved (i.e.
pertaining to ships), which marine people do understand properly how buoyancy works.
It also was complicated in the past by aero people who perhaps thought that aerostats
were not aerodynes able to get lift from airflow, which they naturally do (depending on
design and operation). They also invented the term ‘lifting bodies’ for aircraft that can’t float
in air, such as the space shuttle, which doesn’t have wings to get aerodynamic lift – using
body shape instead, as airships usually do (depending on form).
However, the main complication for airships is finding the right way structurally to resist
atmospheric pressure, a challenge that submariners also face but against hydrostatic
pressure. Both marine hydrostatic and the atmosphere’s aerostatic pressures increase as
the respective vessels sink or descend and is the reason why gravity enables buoyancy.
Buoyancy results from the weight of fluid on a vessel immersed in it reducing from the
surface the fluid is supported on (i.e. the sea bed or, for air, hard and mushy land or the sea’s surface) to the edge of space. The absolute static pressure of a fluid or gaseous
substance thus is greater below the vessel in it than it is overhead.
The vessel (or body immersed) therefore gets differential pressure across its height,
buoying it up against total weight. All that’s needed is for the vessel’s outer surface to be
impervious to the fluid it’s immersed in and be able to displace it without collapse or loss of
form against the fluid’s absolute pressure tending to crush it. This more or less is the way
submarines work (treating the air they contain as nothing).
It was the conundrum Francisco de Lana faced 1670, believed to be the first person to
propose an airship method with potential to work based on Archimedes’ principle. What he
proposed was attachment of a sailing boat with lines to several metallic shell spheres
(balls) that would be evacuated, thus displacing the air they held. However, what he didn’t
recognise was that his balls were heavier than the weight of air they contained and (made
very-thin) would fail from structural instability of the shell, so would collapse in the way that
submarines do when diving too deep.
The trick he didn’t realise, which Prof. Charles 1783 did, was that, instead of evacuating
the vessel, to first make it with coated thin high tensile strength lightweight fabric as an
impervious, foldable balloon. Then inflate it with a lighter-than-air (LTA) gas to pressure
stabilise the balloon against atmospheric pressure. This combination reduces overall
weight below that of the displaced air’s weight – so buoys it up with ability to carry
payloads. The LTA gas thus is not a lifting substance! Rather, it’s an essential structural
element to get useful aerostatic lift applied externally on the balloon (or aerostat) to buoy it
up.
It should be noted that total weight includes the air or gas contained! However, aero
people generally neglect this as well as the buoyancy aircraft do get without an aerostat,
relying on aerodynamic lift alone to fly and using net weight instead of true weight in their
calculations. In other words, they use the aircraft’s weight as weighed in still air.
Aero people know very well that an aircraft’s basic weight must be minimised to maximise
payload weight carriage ability and that total weight (referred to as ‘All Up Weight’ – AUW)
must be sustainable throughout flight. This is not different for airships. However, it’s not an
easy thing for aeroplanes to do, as they don’t become airborne until reaching a critical fast
airspeed (needing a runway for that). The airspeed then must increase to climb and gain
sufficient lift in thinner air to maintain lift at altitude with adequate ability to manage the
effects of high airspeed in all weather that may be encountered.
This high airspeed is not a simple nicety for air transport purposes. Rather, it’s a necessity
to be maintained for safe flight of aircraft without flotation ability. The recent Dreamliner
incident emphasises the dangers involved when aerodynamic lift isn’t sufficient –
particularly after initial take-off to then reach a safer altitude with all critical systems
functioning properly!
Although aeroplanes may glide to some extent, helicopters and other rotorcraft, while
useful for ‘point to point’ duties without runways, more likely would fall and crash
catastrophically after power or rotor failure. However, both types are power hungry
needing copious amounts of fuel (or stored energy) to fly, which has had a significant effect
(also from what people do to get, transport, process and manufacture materials for
systems needed) causing climate change and the pollution issues we face now. Frankly,
they’re not ‘Dream Ships’ with ‘Net Zero’ or sustainable ability having near maxed out –
unable to further serve duties desired.
What one should ask is, “why don’t most aircraft developers use ‘aerostatic lift’ to safely
become and remain airborne against AUW?” After all, buoyancy is a gift of nature
supporting many life forms, including humans, to do things that often are considered
mundane, such as ships that transport most of the world’s cargo economically – also with boats or barges plying lakes, rivers and canals. They also can still use sailing methods in
judicial ways that is free and have exceptional endurance, range and payload carriage
ability.
The general answer to this largely is marketing speak to say that customers (passengers)
want the high speed and that it is necessary to minimise ticket prices. So, what do the
majority of customers say who have difficult, often long, journeys and high costs to reach
or leave busy airports, are kept waiting at them for many hours, herded like cattle through
various security checks, boarding/disembarkation and so forth airport procedures and then
put in packed seating provisions with little ability to move for many hours in aerial transit?
All this just for high speed between 2 points that for many destinations needs further
aircraft flights to reach airports not near to major hubs. Then there’s transport of goods,
often in older repurposed aircraft that involve similar issues at each airport to get to, be
managed at them and then continue on to reach the goods’ final destination – somehow.
This is where helicopters or rotor craft have been used for point to point operations without
runways, able to transport people and goods between small locations that also function as
aerial cranes for construction or rescue and recovery purposes. However, their ability for
this is at slower airspeed between points as well as being limited in both range and
payload weight due to fundamental physics that don’t scale up to do what ships are able
for.
This inability has led to a plethora of odd arrangements yet to prove they can be managed
safely in operation combining helicopter or rotorcraft and aeroplane methods that are
excessively power hungry with little evidence for reliable scale up to sizes able for longer
distance flights or to carry much heavier payloads safely on a regular basis. Also, that
exacerbate climate warming from the processes to produce them, causing further
environmental destruction that upsets the world’s ecosystem.
Frankly, the situation is out of control today careering on a dangerous course from panic
that speeds with huge costs the existential threat of climate warming faced instead of
mitigating it. This stems from people who control Aerospace finance by concentrating only
on prolonging the existing outgrown airline industry with its abnormally high airspeed
needs, without considering how buoyancy from the atmosphere can help to solve ‘Net
Zero’ requirements.
A fair percentage of the Aerospace budget (currently zero) should be allocated to the
sector for Buoyant Aircraft (BA) i.e.: balloons, tethered aerostats, airships and partially
buoyant types using both aerostatic and aerodynamic principles of flight. This is needed to
meet Net Zero requirements more easily and enable new services. It also includes other
new ways for automation, sustainable energy, control and point to point logistics anywhere
in the world.
After all, BA are proven air vehicles that were developed before aeroplanes and other non-
BA types but have had a chequered history for various reasons. However, one could
hardly say that they contributed to climate warming and, in this respect, as they have
natural ability for sustainable flight with least environmental harm, which cannot be said for
non-BA types.
Instead of aircraft that only try to defy gravity, a shift is proposed to instead harness it for
Dream Ships that are possible in the near future based on technology from the past that
fell from grace in favour of non-BA types quicker into service, preferred for war purposes.
Small airships today, quick to develop under model aircraft rules, are showing significant
potential now for such services. Also, although airships have yet to prove reliable point to
point services, they now have easier omni-directional ways to use that are quicker to
develop with safe ways that manage difficult weather.
Author: Charles Luffman
LBA Founder and CEO
