AIRSHIPS, YES, BUT WHY THE ARCTIC ?

There's enough hyperbole and good wishes to go around, when it comes to sound reasons to reach out to all the places that people have settled around the world. How about sound humanitarian or --- dare we say it without sounding heartless -- economic reasons to connect ALL the scattered dots all over the world.   

Why not make it easier to reach all the disconnected places in the world that could bring new, critical natural resources to the marketplace, at the same time that we bring the many benefits of healthy food, clean water, and decent sanitation to isolated settlements worldwide ?

Dr. Barry Prentice, of the University of Manitoba, launched (what began as) a one-man crusade called "Airships to the Arctic" some years back to improve supply-chain logistics to the very isolated Inuit and First Peoples settlements that lie far north of the "End of Track" signs and the Ice Roads that depend for their very limited access on the ice forming atop the lakes and tundras of Canada's Far North.

This hardening of the road surface took place only during those times that temperatures drop low enough to cause ice to form on the water's surface along carefully designated routes from the logistical End of Transportation to supply permanent settlements in two critical ways : providing food and newly available benefits of modern civilization and technology to the settlements and --- at the same time --- provide emergency medical and transport services to those indigenous people.

This is not to be taken lightly ! It's true that these First Peoples have survived for thousands of generations without outside help. However, once the benefits of decent health care were recognized, and the advantages of fishing from fast, modern small craft equipped with outboard motors, using machine-sharpened hooks, and requiring precious fuel oil to power the boats quickly and effortlessly out to the hunting and fishing grounds they had been exploiting for thousands of years, and the services of modern, highly educated medical personnel were demonstrated, the settlers cheered loudly AND the Canadian government felt -- and took over --- the humane obligations of continuing service.

Well, as pointed out very nicely in the TV reality series "Ice Road Truckers" , for years truckers drove their tractor-trailer rigs on the treacherous icy surfaces that froze enough to support their huge weight, bringing supplies up to the settlers, supplies that included, once the possibilities came into being, drilling and mining supplies to the hardy work force that made it possible to develop the rich supply of oil shale, rare earth minerals, and other resources available in rich supply up there.  

... And then the problems occasioned by global warming arose. The warmer climate no longer froze the water surface hard enough to support the trucks. How to continue the services northward, and the transportation southward with no roads, ice or otherwise?

Dr. Prentice, whose academic field is Supply Chain Logistics (it all makes sense now, doesn't it?) founded and directed a series of  "Airships to the Arctic" conferences to focus the world's attention on this nexus of problems. They succeeded on every level, and continue with the support of a non-profit organization called     "ISO Polar". We trust that they will continue to flourish and produce results for many years to come. Interest and support for these programs grew year by year, by both academics, by the Canadian government, and by interested military and commercial businesses.

BUT, Canada's northlands, while unique in its supplies and demands, is not unique in its isolated condition. A visit to any of the TV channels that have programs on the wild and isolated places in the world will change anyone's mind rapidly .

Couple that with an understanding of the benefits and possibilities of bringing vast areas of the world the benefits (and, make no mistake, the liabilities) of contact with the "outside" world, and the concomitant availability of very desirable natural resources, and --- suddenly --- there are millions of hectares of resources to exploit (not always an evil word) and human beings deprived of the many benefits that we take for granted.

AND YOUR POINT IS ...

Dr. Prentice quickly saw that a powerful transportation advantage existed in the use of Airships --- yes, those same aircraft that had been reviled and exiled ever since the (admittedly terrible) disaster of the Hindenburg Zeppelin, inflated to its fullest with hydrogen as a lifting gas, thanks to hydrogen's extreme lightness (very low molecular weight) and unwillingness of the U.S. to sell the rare and inert gas helium to the then recently Nazified German government. Helium doesn't burn, but on the other hand, doesn't provide as much lift as hydrogen. However, the Germans had racked up such a successful history of safe, comfortable --- even luxurious -- air travel over the preceding several decades using hydrogen, that they felt the game was worth the risk.

For whatever reason, and whatever the chain of circumstances, chemical reactions, and even weather, the Hindenburg Zeppelin burned just before landing at the Lakehurst Naval Air Station in New Jersey, causing the death of a total of some 34 passengers and crew, and the subject matter for an ultimate viral video ---who can forget tghe infamous "Oh, the humanity" comment by a distraught news commentator who witnessed and broadcast the disaster and reported live from Lakehurst on that paradigm-changing day in 1937 ?

From that day forward, it would have been easier to purchase a textbook on tropical diseases in Nunavut, in Northern Canada. than to find regular commercial transportation by Zeppelins, which had become the generic word (like Aspirin and Kleenex in those early decades of the 20th Century) for airships.

THROWING OUT THE BABY WITH THE BATHWATER

BUT the many advantages of airship transportation also were lost, with the exception of some far-seeing personnel in the U.S. Navy, and --- perhaps --- some nations that used blimps in various highly specialized circumstances.

Then Dr. Prentice revived hope for the Airship again with his Conferences ... and did a remarkably fine job of stirring up interest again. Probably through the focus of this interest on the Canadian Arctic, he succeeded ---  probably better than even he might have dreamed.

BUT, at a price. In many political circles today, Airships means Arctic. ... and yet there are arguably many other countries and specific locations that suffer from the same isolation and contain the same concentrations of (different) valuable resources, with no decent (or indecent) or traversable roads or navigable inland waterways as Northern Canada. Let me just very briefly outline some possibilities and allow you to add others in the Comments section of this Blog from your personal knowledge.  

Think Brazil and its wealth of minerals and arable land.

Consider Central sub-Saharan Africa with its seemingly endless supply of terribly undernourished people, without even potable (drinkable) water, and certainly no dependable supply of electricity.

Think of the many times we have seen images of isolated areas of Borneo or other locations in the Pacific or Indian Ocean with --- even in this day and age, NO WAY TO GET THERE aside from primitive canoe and foot pathways hacked machete-stroke-by-machete stroke through otherwise impenetrable vegetation and unimaginable hazards.

Consider the vast stretches of the Siberian dual barriers of desert and frozen tundra.

... and a brief final commentary video segment broadcast on The Animal Channel that focused on the new threat by exploding populations of several seriously dangerous species of jellyfish that routinely kill people (and critters) that venture into their territory; that brought the latest giant American aircraft carrier to a halt by swarming by the tens of millions into the water intake tubes, that provided cooling water to the carrer's power plant; that have actually adapted to fresh water from their native coral seas to a lake in Florida, to the utter astonishment of marine biologists.    

... and then think of Dr. Prentice and his tireless band of advocates trying to link all these wastelands --- and many others --- together and bring to them the benefits of modern comfort and technology .

We wish you well, Professor Prentice ! .. and maybe ISO Polar is indeed a much more descriptive, more inclusive  name than "Airships to the Arctic". We suggest to all our readers that this is an effort totally worth supporting.

"AIRSHIPS AND SPECIFICATIONS CREEP", OR "HOW TO KILL A CONCEPT"

Picture this : It's 1914 (or so) and the United States -- unknown to itself, but crystal clear to the Allied General Staff --- is about to embark on a major war in aid of the Allies.

A General Staff meeting has been called to plan the design and construction of new weapons to stop the powerful aggression of the  Central Powers.

General Farseer : "Our troops can't throw a grenade nearly as far as we would like, and the amount of explosives don't produce much of an effect. Training the men to throw farther is not an effective solution. What we need is a weapon that can fly like a bird over the enemy troops and drop grenades on them from above".

Colonel Sachenwisser : "First, that still wouldn't solve the strength-of-explosive issue. Second, as you know, we are developing the aero-plane, and some of them apparently can remain aloft for an hour at a time, carrying a man and some equipment".

The General Staff nodded agreement in unison. "But", spoke up one mid-level officer, "It would be nice if they flew faster than the 58 miles per hour that ours can. If only we could build some that got up to 75 or --- even better --- 80 miles per hour, and perhaps carry two men, one to operate the aeroplane and one to drop the grenades over the side at the targets; that should handle the problem."

"Excellent idea, Fotherington", said the Chief of Staff, "Let's add those requirements  to the specifications. "

"Yes", added Colonel Rockridge, "And let's make sure that what we're throwing has at least ten pounds of high explosive."

"Ten pounds, be dashed ! Let's make it a really massive 25 pound super-grenade ... if an aero-plane can even lift that much off the ground".

"Unrealistic !"  "Fantastic nonsense" "Can't be done or our boys in aeronautics would have done it by now". Comments cascaded around the room.

"Can't we add a little length to the wings to provide the additional lift required; if we need to add a few hundred feet to the length of takeoff (Is that the right word?) , that should do it."

 LATER THAT WEEK :

Colonel Peltier : "Are we comfortable with all that refined petroleum they carry about ? I hear that it's highly explosive and all it takes is a spark to produce a massive explosion and fire. Second of all, the propelling substance is difficult to come by, all the way from the area east of Egypt. There's none of that stuff in either the United Kingdom or the French Republic, and it requires a complex refining process. It looks to me as though our lads will be exposed to terrible dangers in the event that one of those rough landings they're always making triggers a powerful and destructive explosion. Maybe we should cancel the whole project completely"

"Well, that settles it for me"; "Let's table the idea for more study !"

"Agreed . Also, studies indicate we'll need a larger crew than even the two that have been proposed.

"We would need one to steer the vehicle, to keep the curved aerial wing surfaces aligned properly with the lifting forces, and to keep watch all about to avoid hazards to flight such as other flying machines, the ubiquitous industrial smokestacks, and the flock of birds one of those flying machines ran into last week ;

"... one man to continually take magnetic compass readings and sextant sights to determine the air-ship's position;

"... and the Grenadier to actually sight, aim, and launch the explosive device". Speaking of which, the ferrous metal in the grenade plays havoc with the magnetic compass, rendering navigation almost impossible. I think we're chasing a chimera, men ! I strongly believe that we should pursue other avenues of new weaponry".

"General Buff-Orpington, did you see the requirements report regarding the need for heavy metal armour to encase the aeroplane to prevent stray bullets from piercing the (what's that bloody new French word?), ah, fuselage.  Place three men in those vehicles --- assuming the things would even fly with all that weight --- and they are all in grave danger, up in the wide open sky like they are, subject to the effects of both stray and aimed fire"

"Surely, not even the vicious Huns would deliberately aim at a fellow flyer or his vehicle ! The carnage would bring a complete and sudden end to war as we know it. It's not clear which side would yield first".    

"Can't we just increase the specifications : mandate a heavier overall total weight, with a carrying capacity of, say, the three men previously discussed, effective shielding for the fuselage, and perhaps a couple of dozen super-grenades."

"The 16 grenades alone (actually the men in the field are now calling them "bombs"), at 25 pounds each, yield a weapons weight of 400 pounds.  I'm afraid that's beyond our capacity, General. We're already up to 2000 kilograms total weight  ... converting to the French metric measure.  It can't even lift itself off the ground. These limits are imposed by the immutable laws of gravity and engineering".

One of the junior officers, still exhilarated from his first flight in an aeroplane, chimed in,  "That's easy to remedy ! Specify a heavier total carrying capacity, and the ability to stay in the air for two hours."

"Impossible, lad. We're already stretched beyond our capabilities." Turning to the Director of Planning, "That's what comes of permitting the publication of those scientific-fantasy stories available in the popular libraries. It encourages too much foolish speculation."

"But, General", up chimed Sieur Phillipe de Battenbourg, the young Duke of Elysee, "We must be bold ! Someday, aeroplanes will fly at over 100 miles an hour, and carry hundreds of pounds of destructive chemicals. We will rain devastation on the King's enemies."

"That does it !" The face of the Chief of Staff turned a bright choleric crimson. "I'll have no more of this foolish speculation. Next we'll be going on about those foolish moving-pictures-in-every-home fantasies. The project is cancelled, effective immediately. We've wasted many thousands of pounds sterling and hundreds of staff hours on this, and I refuse to throw good money after bad ; I don't want to hear any more about it !"

... and that was the end of the aero-plane !

It is particularly ironic that a similar scenario could be written about the ups and downs of airship research and production. No one ever reasonably expected that the first models of the "aero-plane" would emerge fully developed, and with no problems. Yet we expect that of our airships.

It is also ironic that the single catastrophe of the Hindenburg, with a loss of life of just over 30 people completely stopped airship development cold in the mind of mankind in 1937, while these days one mid-size passenger aircraft accident kills many times that, several times a year; yet we continue to trudge off optimistically every year to the airports of the world, by the millions, with no fear.

Mission creep *** is the term that describes the way we start off with small expectations and goals, whose boundaries become stretched further and further throughout the development process, a little at a time, until the goal recedes unattainably far into the distance.

Meanwhile, fortunately, our military services continue doggedly through the development phase into operational reality of some very nice machinery. Keep up the good work, lads !

*** SPECIFICATIONS CREEP" The Airship equivalent of 'Mission Creep'

The Resurgence of WALRUS and other HYBRID ULTRA-LARGE AIRSHIPS

The Walrus concept is of a heavy-transport Airship, capable of lifting as much as one or two million pounds ( 900,000 kilograms) . It was one of the projects that were being specified and seriously considered for both civilian and military uses within the last five to ten years as a faster  alternative to sea transportation, one that also offered a versatility that maritime transport could not .  DARPA ( the Defense Advanced Research Projects Agency)  funded exploratory efforts until about 2006. However, the advantages were so clear that the Walrus concept, or even a smaller adaptation of it, remained. A key issue is whether Walrus is dead or whether some version of it --- a Hybrid Ultra Large Aircraft (HULA) --- just might rise again? The need appears so great that, recently, re-arrangements and modifications of it continue to rise --- it might , like a giant ghost, continue to rise again and again in various guises . More tomorrow.

AIRSHIPS TO (NOT ONLY) THE ARCTIC

Professor Barry Prentice and his ISOPolar Group are to be commended for calling the attention of the world (or at least that part that pays attention to something beyond the latest sports scores). By naming his challenge "... to the Arctic", he has done a first-rate job of bringing the challenges of transportation in an area rich with a culture increasingly stranded without vital supplies as well as with increasingly important natural resources.

... and yet, Cable television is also doing an excellent job of reminding us of the many other areas of the world where geology and lack of infrastructure either hinder development or impose horrendous penalties of risk and difficulty on taking advantage of the possibilities.

We're talking about the South American Andes mountain range where a misstep of two feet (less than one meter) or a judgment call of similar size while driving supply trucks can precipitate disaster. Arguably the most difficult driving in the world, shipping supplies by motor truck remains an incredible challenge to skill and human nerve.

It also reminds us that there are other, similar, logistical challenges in the world. The Indian Sub-continent, bounded by the Himalayan mountain range on one side and the Indian Ocean on the other, effectively seals the boundaries of one of the most vibrantly alive, burgeoning economies in the world.

If truly wish to open boundaries, as our small efforts in open economic borders seem to indicate, carefully weigh the difficulties of supply and access by land routes to billions of people, not only rich in cultural heritage, but representing a major market. ... and we haven't even begun to think about sub-Saharan Africa.

We cannot just depend on surface transportation, and we must pursue the technologies that would permit us to fully expand our horizons to communicate to, engage in commerce with,  and supply the many forgotten peoples of the world.

MY CHOICE OF AIRSHIP IS ... and the Undisputed Winner is ...

After all the long dissertations that seem to stretch on about this wonderful new era in Airships ---- let's call it the Airship Renaissance ---- here's our firm's pick for the Airship of the Future, one that encapsulates all the best features of What's Coming Next, together with the rationale that dictated each aspect of the choice :

A Hybrid Craft --- where the lift is provided by a combination of
                     static lift --- lift provided by a lifting gas displacing an equal amount of heavier air , and
                     aerodynamic lift --- where some lift is provided by airflow over a suitably designed                        airfoil, using the Bernoulli Effect  

1. Unmanned (Shocked?)
Training of controllers is much shorter and less demanding than selecting only pilots of general aviation or military conventional aircraft and then training them in this entirely new skill. The necessity of the usual crossover from pilot has not been proven to our satisfaction, as demonstrated by current military requirements. The military services don't have the luxury of time, and the fact that their controllers are better than just good enough is good enough for us. Amusingly enough, one of the indicators of success as a controller --- NOT a requirement --- is that applicants for the training have previous experience as a ... hold it for this one ... radio-control model aircraft hobbyists. That tells us something !

2. Lighter-than-Air Dirigible --- that is, an aircraft that can be Directed (steered) rather than flown subject entirely to the winds

3. Lifted by Hydrogen, not Helium, as the lifting gas (now there's a surprise)

4. Powered by a Fuel Cell --- a relatively recent development in eenergy circles, converting the fuel which varies, directly into electricity throgh the use of catalysts and "dry" chemical processes

5. Providing electricity to the electric motors (rather than diesel or gasoline) very efficiently

6. Provided with the capability of snapping on the accessories that perform the mission, so that the airship has great flexibility in mission type

7. and Rented or Leased out (rather than sold) to the ultimate user so that, in effect, you sell the same product over and over --- a much easier accomplishment for expensive equipment, and ensure that the Operator is highly trained and experienced, and repossession of the asset is relatively easy, if necessary. 

The Economic Value of Airships

Yesterday's post began a critique of an article in ScientificAmerican.com, a usually sober and authoritative source . Quoting from the on-line article :

"In 1950, Theodore von Karman, one of the founding fathers of ... aeronautical engineering, published a paper entitled What Price Speed ? Specific Power Required for Propulsion of Vehicles.
[now updated by faculty at Imperial Colleege, London].
von Karman showed that if you take a vehicle's horsepower divided by its weight and speed , yoou can see how efficient that vehicle is compared to other vehicles."

The article goes on to argue, essentially, that the reason for the lack of progress in airship development is due to their comparative inefficiency as transportation.

Well, there's a lot more to that story than the author provides his readers. First, some brief background on the situation :

Dr. Barry Prentice, of the University of Manitoba, is to be strongly commended for his tenacity in pursuing vital North American concerns in the North circumpolar regions. He began his crusade to wake up international interest in the once-forbidding regions that stretch around the North Pole for such an enormous distance north of Canada, through areas which were once considered of no interest because they were so unnavigable, so difficult of traverse, and so seemingly bare of value, of resources, and of people.


BUT, time and paradigm shifts changes all things. Three critical variables shifted :


1. the brutal economic facts of the discovery of priceless mineral resources in that area,

2. the realization of the sudden accessibility of these areas because of the opening of the Northwest Passage attributable to climate change, and

3. the interest of the area as a geo-politically and strategically important region.


Travel requirements and political control exerted their inevitable influences. Suddenly, the Middle East, with its almost Biblical politics and its quasi-monopoly on oil, has begun to diminish in importance. Entrepreneurs in other countries began to dig their giant globes of the Earth --- with their three-dimensional perspectives on trade routes --- out of the executive offices where they had served as room decorations for centuries.

Suddenly, these peculiar-looking vehicles called Airships began to make a great deal of sense. Why?


1. They didn't need roads

2. They didn't need a complex infrastructure like long runways, often impossible to construct in the Northlands

3. They didn't require the huge initial cost --- in the billions --- to construct the spider web of access roads which ground travel appeared to require. Furthermore who would provide or finance them ?
That's a very large dollar figure that is rarely factored into developmental planning or assessment . Remember that mining companies are in the business of locating and extracting minerals, not in the business of building roads.

4. Airplanes --- even great ones like the DeHavilland Beaver ---- have limitations on the size and weight they can carry and require major construction of runways, landing strips, and airports, as well as refueling and repair facilities.

5. Can you say "broken truck axles"?

6. Native settlements, as they increased in complexity, have come to depend on external resources --- even to outboard motor parts for boats used in arctic mammal hunts

Where is the concern for Efficiency now?) .


The people who say, "Ice Roads? Why don't they just travel when they can?" must be living in an ivory tower world. Immediate need and unexpected emergencies constantly intrude into our Real World . It's a world in which, every day, conditions are evolving that force new realities upon development and support in the circumpolar regions, which in turn force the adoption of new modalities on the planners.


The hard-nosed, gimlet-eyed businessmen and investors associated with mining, logging, and natural gas exploration companies ask "What is the best way to do that?" and suddenly find themselves becoming strong supporters of airships to meet arctic heavy lift needs.


These questions must be answered, and sooner rather than later :


1. Who will pay for access roads?
2. Who will fund the initial capital costs?
3. ... with no clear Return On Investment? Who will wait the 10 to 15 years for this ROI ?
4. Who will own and control these part-time highways ?
5. Who will deflect the impatience of the shareholders?
6. Who will determine the priority of appropriating the building costs?
7. Isn't it the truth that the need for investment capital is often inversely proportonal to its availability, often with self-appointed naysayers arguing that it's all unnecessary and inefficient.


When you ask "Why is it taking so long to get flying, viable airships to market?" , please add to all those impedimenta the following major considerations :


1. The very long certification times for new modalities of air travel.
2. The uncertainty of the certification processes and requirements for these unfamiliar airships
3. The lead time to educate pilot operators in an unfamiliar operational process
4. The resistance and mind-sets of legislators and bureaucrats
5. ... and, finally, the opposition of theoreticians concerned with efficiency who can prove mathematically and (in Captain Queeg's memorable phrase) " beyond a shadow of a doubt that the strawberries were stolen".

The clearest determinants for reality checks on aeronautical progress, customer acceptance, and widespread use are not mathematical equations for efficiency, but rather the purchasing practices of the military and paramilitary (police) services. They choose the best tools for the job, test them with infinite care, and back their bet with billions of dollars. For proof, just check the latest airship procurements; you'll find them under "Purchases" in Defense Industry Daily, NOT in 60-year-old theoretical engineering texts.

Helium Hokum Revisited and Ravaged

There is an on-line periodical named "ScientificAmerican.com" that I'm sure many hold in great regard. However, they recently published an article by an independent design and systems engineering consultant, which continues the history of bad reasoning and misguided information that has dogged airships ever since the days of Santos-Dumont and that, unfortunately, will furnish still more authority to those who oppose airships.

The article, Helium Hokum, is subtitled "Why airships will never be part of our transportation infrastructure".

It contains such vitriolic statements as that, during the author's lifetime, roughly five billion dollars (in today's dollars) have been spent chasing airships for transportation, money that could have been spent building a lot of road and a lot of track, of which the only result has been a vast mountain of paperwork --- most of which ended up in local landfills.

Whew !

He goes on to say that the Airship Renaissance has always been just around the corner since about 1945, but that the only result has been the employment of a bunch of engineers who just don't get the simple fact of engineering science that, in his words, the only true measure of the result is efficiency ---- how fast can you go for how cheaply you want to get there.


In Jan Huss's penetrating phrase, "O Sancta simplicitas !" ; in this article, what a gross oversimplification .


Judging all means of transportation solely on the basis of "efficiency" --- and a very narrowly construed expression of efficiency at that--- is equivalent to judging all vehicles solely on the basis of miles-per-gallon.

If you're a suburban housewife driving on average American roads, perhaps that is one criterion by which you might want to choose the best transportation for you.

If you're in an army tank under fire, assigned to destroy an enemy emplacemenet, NO.

If you're racing in the Indianapolis 500 , NO.

If you're driving the Queen of England to Parliament, NO.

If you're a teen-age boy trying to impress a girlfriend, NO.

... and on and on !

The British have a wonderful aphorism, "Horses for courses", that is, choose the tool to suit the job.

The presumption of the article, that all transportation can be judged by the single criterion of efficiency, borders on bad logic.

Let's consider the very real and present problems presented by the wide variety of missions undertaken by our military services, despite a wide variety of obstacles and environments.


1. They must anticipate that the transportaton infrastructure of the area to which they have been dispatched will be damaged or destroyed. The military unit might be required to carry and disembark a brigade-sized unit to the Point-of-Need in three-to-five days, with no facility prepared to receive it. .. and do it in the dark, silently, landing on uncertain terrain, land or water.

2.Consider the case where they encounter incompatible rail gauges, as in the Baltic States, or a single rail line that is blocked or destroyed.

3. ... or where access in mountainous regions is hampered by bridges and tunnels.

4. ... or if the transportation is over the untracked Arctic tundra


Clearly one could go on forever --- exaggerating for effect --- reciting the vast number of impediments that they may encounter, where the ONLY means of transportation is designated "advanced lift platforms that are not dependent on improved airports and seaports". Why on earth (literally) then, would one even begin to discuss efficiency. Cost per mile ??? Miles per gallon ?!?


OR consider the need for Intelligence, Surveillance, and Reconnaissance (ISR) of an area, as when the U.S. Coast Guard was assigned the task of persistent surveillance of our southern borders, often hovering in one spot for days on end. Efficiency ? A textbook engineer with little imagination would probably slide-rule it at INFINITY ... or ZERO .


Too military for you ? Stay tuned for discussions of the logistical support of oil and precious minerals exploration in the Arctic, an ongoing responsibility that Dr. Barry Prentice, of the University of Manitoba, has kept our eyes focused on for many years ... or the logistical and humanitarian support of people in the Arctic ... not just food and fuel, which can be determined in advance, but also the evacuation of injured or ill personnel in the event of a medical emergency.

These ---- and many other real world needs --- exist for which considerations of efficiency must be set aside . Stay tuned.