Monday, June 8, 2009

Weather and Maneuverabilty

WEATHER: past blimps and zeppelins have all been constructed out of flimsy materials such

as doped canvas, and rubberized or plastic coated synthetic fabrics. All are susceptible to tearing, and all degrade in ultraviolet light. This has resulted in craft that had little structural strength to begin with, and lessened the more they were flown.

Even though these could fly in virtually any kind of weather, they are not. The difficulty is not the wind, rain, snow, fog or what have you; the difficulty is the ground handling. Because these past airships are so flimsy and cumbersome, landing or taking off while being hauled about by a ground crew, or docking at a mooring mast, or moving in and out of a protecting hangar, becomes a nightmare as the airships are tossed about in varying air currents.

Historic losses of large airships were generally due to flight in extremes of weather; ie: thunderstorms. In the early years of lighter-than-air aviation, there were no modern weather prediction methods such as radar or satellites; and airships were flown in hazardous conditions, often by sight alone. Upon encountering severe weather, an airship (then) could not move quickly enough to avoid it if need be, nor aware in most cases that weather conditions were to severe for the structural integrity of the airship.

HOW TO SOLVE THIS PROBLEM:

(1) Construct airships of aluminum and carbon fiber. These materials are light enough to replace historic materials, yet they can be made extremely strong and weatherproof. They do not degrade in ultraviolet light.
(2) Cease docking airships at mooring masts and using ground crews for assistance in landing or take off. Instead, design airships to land directly onto the surface, land or water. This necessitates a change from the "rounded belly" shape of all past airships. It is an easy and common sense solution.
(3) Cease placing airships inside of hangars. Building airships out of sturdy weatherproof materials enables this change; just as a lightweight geodesic dome is used as a primary building.

MANEUVERABILITY: Past blimps and zeppelin type airships only have rudders/elevators at the stern of the craft; whilst engine thrust has been placed far in front of those to the center of the airships' hulls. This makes them extremely cumbersome to steer, much like a sailboat. The only steerage available is at speed; when the airship slows down to land or take off, it cannot readily be steered or controled. This is one reason why ALL past airships have needed to be literaly "man handled" into position by large ground crews.

Flight characteristics of past airships have been adversely effected by this rudder/power arrangement as well. Because of the long lag time between rudder or elevator commands and actions of the airships; they tend to "porpoise" in flight, or swerve off course repeatedly.

Because all past airships have been constructed of flimsy materials, they have been unable to use heavier, more powerful engines that might be employed to reduce the buffeting or force of winds in poor weather conditions.

HOW TO SOLVE THESE PROBLEMS:

(1) By constructing airships of strong materials, they can be made larger and carry much more powerful engines; even jet engines. This will enable them to avoid, or reduce the effects of varying winds and poor weather conditions.
(2) Building rigid airships with interior framing allows engines to be placed away from the center bottom location as in the past. This can permit thrust to be directed to ANY direction; thereby making the airship much more stable and able to counter variable air currents.
(3) Constructing airships out of very strong materials, and proper design of framing members, allows the airships to carry multiple engines, some dedicated to primary propulsion, some dedicated to maneuver.
(4) Use of directed thrust, and placing elevators forward on the airship as well as at the stern allows for more control in flight.

Q: How would they fly safely in any weather?
A: Turtle airships use multiple engines, all of which can direct thrust to any direction. Sensors placed throughout the airship measure forces brought about by varying air currents many times each second; and computers then determine where to apply compensating thrust in order to maintain stability during flight. Of course, the Turtle airships' hull is strong enough to allow it to withstand poor weather conditions. First rule of airship flight....simply avoid bad weather. Airships can do so because they do not have to fly in a straight line from point A to point B in order to conserve fuel, as do airplanes.

11 comments:

Anonymous said...

Hello Campbell, Thank you for posting your ideas concerning weather. I can see much of what you are saying. If we assume from your comms on ID an 300' long 180' dia in a turtle type for 20 ton payload configured for specific mission, we would have to weigh pros and cons carefully. For patrol, survalence etc against pirates your ship would be ideal with the possibility of installing a large enough passive array to intercept their sat phone commo and track them by that. many other apps come to mind.
As for weather new materials and designs help but cannot overcome what was faced by shenandoah. The updrafts carried her far above her altitude tolerance causing the venting of so much gas that even if she had not been torn apart she would have crashed. Can your turtle tolerate being lofted to 20,000 feet in a few minutes? Your only practical option is to avoid severe weather which is not always an option. Thank you
Larry Schumacher

Anonymous said...

Campbell as for combat I really must disagree with your assertions. From what you have publisher concerning your turtle I have seen nothing to enable it to stand up to tank fire or to a pass by an SU25 armed with 3omm and rocket pods(russian A10) As for locating it I agree that it is stealthy in regards to radar but it is also a huge target for the MK1 eyeball. Akron, Macon and Los Angeles were always located and shot down in excercises, much to the dissapointment of their advocates. And if we put a radar onboard as soon as we emit everyone will know right where we are. Thank you
Larry Schumacher

campbell said...

Weather: True, Shannandoah was lost to severe turbulance and updraft, as you say. The single most obvious answer is that they had no idea what kind of weather they were facing, at night. They merely tried to fly between thunderstorm cells as revealed in lighting flashes. Of course, we now have technology that is light-years beyond that; radar and satellites, etc. Comparing then to now is very much like comparing the Wright Flyer to a Concord.
One thing though, the size of an airship allows it to carry a very large radar array, enough to employ Doppler; which can highlight varying, potentially harmful air currents, even in seeminly empty or still air.

COMBAT: Again, comparing 1930's airships' shortcomings in combat testing is not truly applicable to today.
A modern airship would pass overhead in total silence. At night, it is unlikely to be seen. At speeds of 150-200 mph, it is hard to "shoot down"; even if seen. Shooting it down pre-supposes that it has no ability to defend itself; or, that it is not accompanied by other defensive/offensive platforms.

Indeed, radiate, and they know where you are. Much less need to do so on an airship by the way, it can slow down enough to pick it's way through air, flying nap of the earth, or landing if wanted.

Survivability of an airship will always be dependant upon the size of weapon employed against it. The huge size and redundant or multiple helium cells makes it far more "survivable" after damage than other aircraft. that huge size also almost absolutely requires a huge weapon....something like a fuel-air explosive on top of it. Not totaly impossible of course, but hardly likely.

Anonymous said...

Campbell, I must say that it is nice to discuss this in a forum that is not hostile to airships where cries of hindenburg reverberate.
Agreed that we have weather avoidance tools which would enable us to keep from exposing the Turtle to extreeme conditions. The only scenario I can think of offhand is if our airship ended up pinned against hostile airspace by a typhoon. Unlikely at best. If used properly our airship would never encounter weather bad enough to destroy it.
With modern materials and design the loss of Macon due to the fin puncturing the rear cells would never have happened. Kevlar and carbon fiber give us options the designers at goodyear could only have dreamed of. Thank you
Larry Schumacher

Anonymous said...

As for combat these craft are very large. 300' by 180' (or 1300' by 250' like I dream of) are remarkable objects to be flying. People in the area will comment and those listening can localize our craft and intercept it. At night we are much harder to detect but still not invisible. As for total silence that is hard to attain, perhaps we could have a few C130s flying around to draw attention from us.
Battle damage: Accounts from german zepplins ww1 tell of battle damage causing loss of bouyancy forcing a landing. Later missions were above a cloud layer with an observer lowered through the clouds in a small car. From reading your proposals nothing on the turtle can withstand tank fire and a target as large as the turtle could be hit at long range with optical sighting. At night IR would reveal engines and control cars etc and 3rd world nations could hire mercernaries equipped with them to direct a tank platoon protecting an LZ. for reasons like this I hesitate to use an airship for a tactical lifter. Thank you
Larry Schumacher

Anonymous said...

Airships have so many things going for them, I do not wish to dwell so much on the negatives. For Litorral ASW a flying frigate would be much better than LCS, equipped with sonobouys, fixed wing UAVs, a huge MAD array etc. and with decoys in case the enemies object is just one of the uses I envision. Well gotta go. Thank you for your time
Larry Schumacher

campbell said...

Should you come here once again to see what I've written, just this:

thank you. You interest in airships is appreciated; your comments welcome both negative and positive. That's how we learn!

Please feel free to communicate by email at any time.

Anonymous said...

Campbell your airship has many intriging aspects. I hesitate to actually land an airship on the water, many modifications would have to be made for it to do it well. How about a modification of the sea anchor. If we were to lower two large bags, one forward and one aft, and fill them with sea water, then drop ballast to tension the cables this might hold our craft in a stable condition allowing lighters to recieve cargo from underneath the airship. Just a thought. Good luck with your ideas.
Larry Schumacher

campbell said...

Please see the picture. Unlike past blimps or zeppelins, the Turtle is constructed ENTIRELY out of materials that are rigid, strong, weatherproof and waterproof. The bottom of the Turtle is more like a trimaran boat. It can set down directly onto the water. Water ballast is then taken on board to keep the airship stable on the water surface. At take off, this ballast is dumped; the airship, again lighter-than-air, simply rises. Engine thrust is used to supplement this.

when on the water surface, the airship moves up to, and ties to, a pier just as a marine vessel. depending on the size of the airship, cargo may be loaded with normal forklift, or even driven directly onto the airship (ro-ro)

Anonymous said...

Hi, as for airships landing on water...... i seem to remember a British design called Skycat that was an airship/slash hovercraft, that used the hovercraft skirt to 'suck' itself onto whatever surface it had to land on. Sorry, can't remember where i read about it. May be worth researching though. Hope this helps. Had a good read of the sight and thinks its great!. Cheers. Andy.

Darrell Campbell said...

The "hovercraft" landing system is a seriously flawed idea. A hovercraft works because the weight of the craft being supported forces the craft against the surface, while the air being blown underneath it is allowed to escape via a skirt. The weight of the craft is a critical necessity. To use a hovercraft on a LIGHTER-THAN-AIR craft is impossible; the craft has to be weighted down. Doing this defeats the entire purpose of the Lighter-than-Air craft.

Reversing the hovercraft apparatus so that it "sucks" the craft down onto the surface, allows for objects to be sucked into the machinery as well. Not a good thing.

Adding in the weights of the hovercraft systems and controls, it becomes an untenable way to operate an airship. It will inevitably prove a failure.