Wright Brothers...........What if?

[Broomstick]

*Originally posted by Xema *

*Originally posted by Broomstick *
(…scratching head…) So… if it’s all about passengers… how do FedEx, DHL, Airborne, UPS, etc. manage to make enough money to stay in business?

When carrying freight, compare ton-miles per day. (Surely you’re aware that an index of efficiency doesn’t become invalid because you offloaded the passengers in favor of freight??)

Sue, I was just tugging your leg there - it’s a pet peeve of mine that a lot of folks think “aviation” is only about hauling tourists and the military. Cargo is probably just as big, if not bigger, than the people-hauling airlines.

If we’re talking about what matters (fuel per passenger- or ton-mile), this is true at low speed, but wrong at high speed (something for which many customers will pay a premium).

But not all cargo has to be hauled at high speed. Lightweight, bulky non-perishable cargo that is not needed overnight would fit the bill. In some cases, low price is more important than speed. I deal with this at work, where some items I ship overnight, and sometimes I tell shipping “Whatever’s cheapest, as long as it get there in three weeks or less”.

*Originally posted by Xema *

*Originally posted by Broomstick *
It’s possible that for freight this might make more sense than a high-speed aircraft. If we didn’t already have an extensive network of railroads filling that niche we might have blimps and zepps instead.

Dubious - LTA craft are less efficient than HTA for time-sensitive cargos, and hopelessly behind railroads (and trucks and ships) for heavy hauling.

Again, not all cargo is time sensitive, and not all cargo is heavy. Certain times of food, for instance - bulk grains, boxes of saltines. Crates of bubblewrap. Crates of toilet paper.

Unlike trains and trucks, LTA does not require extensive ground-based infrastructure, so routes can be quickly and easily changed.

While LTA can’t haul as much weight, efficient delivery doesn’t always require that - otherwise FedEx would use semis to deliver christmas presents to residential neighborhoods and they don’t, they use panel vans.

LTA is also quieter than conventional aircraft.

Now, it may be that, given our current circumstances LTA does not make economic sense, but I wouldn’t say they would NEVER make sense.

*Originally posted by Xema *

*Originally posted by Broomstick *
cruise ships are terribly inefficient means of transporting people.

Howzat? They have lost the intercontinental routes due to the speed and cost advantages of HTA craft, but ships still haul millions (e.g. on ferries). I guess it’s possible to argue that cruise ships are marginally less efficient due to have been tarted up a bit.

I suspect we’re defining “efficient” differently.

Cruise ships are inefficient because they aren’t particularly fast, cost a lot more than alternative forms of transportation, and sometimes don’t even take people anywhere - just out into the ocean and back without touching any other land. But then, a cruise on a ship really has nothing to do with transportation in the usual sense - it has to do with vacation, fantasy, and relaxing. Taking the trip is the point, not the destination (if there even is one).

There is no reason LTA couldn’t fill the same niche - particularly since at one time it did. I think it would largely be a matter of marketing and a big initial captial outlay. True, the number of passengers you could carry at any one time would be limited, but since you won’t have an enormous demand (at least initially) that wouldn’t be a problem. You just have to carry enough people at a price at which you can make money. How many and how much? I don’t know.

*Originally posted by Xema *

*Originally posted by Broomstick *
But then, transport isn’t really the point, is it? Zepps could have a niche in the leisure travel industry (as a matter of fact, in their heyday they did occupy this niche).

Now yer talkin’. This is what LTA might work for, though it obviously depends on novelty, so the market may be limited. Here’s a link to the new Zeppelin company, which is trying to get going in the tourist ride business. Note that at 335 euros for a 1-hour flight, it ain’t cheap.

And the Concord was what, $10,000 a ticket? Granted, it never made a profit, but if you could make a profit at 335 euros in LTA, and enough folks would pay it, yeah, you could do it. That’s the question - are there enough people willing to pay a ticket price high enough for you to make a profit from?

*Originally posted by Xema *
This has been alluded to previously. But what is the development that capital will finance and that will make LTA transport efficient and practical? If it’s a competitive idea, why won’t it work on a small scale first? Why do we need dozens or hundreds of airships before the first of them become practical?

For starters, there no such thing as a small LTA. A local man in my area actually owns a two-seat blimp. Flies it around the neighborhood. It’s 100 feet long and contains 20,000 cubic feet of helium (this via my husband, who has talked to the man and tried to mooch a ride). That’s about as small as they come. Looks pretty big to me. The small airports, by the way, are able to service it without special equipment - you don’t need hundreds to ground crew it, and it can be fueled by the same trucks that fuel the HTA’s. But while a two-man blimp doesn’t require an extensive outlay of capital for ground infrastructure it’s practicaility is very limited (aside from pleasure flying, aerial photography, ground observation, and possibly hanging advertising banners on the side of it are all that come to mind right now). The bigger the airship the bigger the infrastructure required. For money-making purposes, be they pleasure cruises or frieght-hauling, you need a BIG airship and that’s where the expenses really start to pile up - costs for the physical ship itself, lift gas, storage facilities…

*Originally posted by Xema *

*Originally posted by Broomstick *
but yes, I think that the HTA aircraft have in part bullied them out of the arena

In what way (other than demonstrating much greater efficiency)?

The crash of the Hindenburg basically scared everyone off LTA long enough for the HTA’s to take over. Also, while zepps were used effectively in warfare for a brief time, once HTA’s caught up with them as far a reliability they were sitting ducks, so the military abandoned them. There’s no way the military is going to go back to them, but I think that if the Hindenburg hadn’t blown up in New Jersey they might still have a civilian niche.

*Originally posted by Xema *

*Originally posted by Broomstick *
(for that matter, it’s questionable just much economic sense HTA travel makes).

Several hundred million airline passengers a year might possibly quarrel with this. What’s a more economically sensible way to travel from, say, Chicago to London?

How can you call something economically sensible given that so many companies in the industry have filed for bankruptcy?

If you’re traveling to another continent, air travel makes a lot of sense. If your trip is under 500 miles, though, it doesn’t - a good passenger rail system is arguably cheaper and it is far less likely to be stopped by bad weather. Even though I live fairly close to two major airline hubs, even though I myself am a pilot with access to planes, when I visit my parents 300 miles away I either drive a car or take Amtrak (Yes! Amtrak riders really do exist!). Why? Well, last time I checked the train ticket was cheaper. Also, it’s not just about flight time. There’s a considerable hassle involved in getting to the airport and boarding these days. Measured from door-to-door, it is faster for me to take the train, AND, as I pointed out, the train is much less affected by weather. But - short haul air travel is growing. Lack of passenger rail in the US has a lot to do with that.

(Before you bring up rail subsidies - aviation and highways are both heavily subsidized by the Federal (and in many cases, local) government as well)

Just because were doing something a particular way does not mean it’s the most efficient way of doing it (however you define efficient)

[Bosda_Di_Chi_of_Tricor]

*Originally posted by Sam Stone *
Your idea that there was no ‘vision’ or ‘leadership’ in the aviation industry seems to suggest that the decision to keep open airports was made by some central body. This is not the case.

By no means do my remarks suggest that. Investors stampede after trendy new stocks without prior agreement or central control. Businessmen read about new approaches and pursue them, often because they observe their competitors doing the same thing. Sometimes, without genuinely assessing whether or not it is productive. They fear “being behind the curve” so much, that they don’t stop to ask where things are going. This is not leadership. Sometimes “central visions” produce the same result. Witness the fact that Capitalist, Socialist and Communist aviation industries had their share of screw-ups. Most “Industry Leaders” act more like cattle than leaders.

If Zeppelins were more efficient at hauling general cargo, Fed Ex would buy them. If there was a side benefit of giving them the ability to moor closer to destination customers than an airport would allow, so much the better. They’d lease some property on the outskirts of the city and set up their own landing zone.

No, they wouldn’t. Zeppelins were unavailable in mass produced format. And even an individually efficient vehicle couldn’t compete with the advantages found from mass production. If mass produced Zeppelins were available, things might have been different. But they weren’t available.

And, why do you assume a businessman would make this all-wise decision? :dubious: The image of the corporate executive as a short-sighted idiot is becoming ubiquitous. The businessman today is almost exclusively incapable of seeing beyond very short-term intrests and short-term profits. Hell, he often can’t see beyond the next quarterly report!

If they truly made extra profit from that, they would begin to under-price their competitors, and the competitors would also have to move to airships to stay profitable.

Correction–the senior executives & CEO would vote themselves bonuses that would be large enough to effectively eliminate the extra profit. Their competitors might emulate them–or they might downsize, force the remaining workers to labor for less pay & longer hours, & then pocket the increased profits as a bonus. You seem to assume that businessmen have an intrest in improving their industry. You are wrong. They are only intrested in enlarging their personal incomes, and often don’t even care about the stockholders intrests. If they can more easily get money by working their employees harder, rather than by innovating, then they will not innovate. Innovation requires investment.

If enough did that, and enough passengers desided to go that way, then the old airports would become underused, and eventually would fade away.

But none of that happened, because airships were seen as more expensive, slower, harder to manage, or more dangerous than an equivalent traditional cargo plane.

No. Let me introduce you to the idea of sunk costs. Sunk costs are assets that can be used in only one very narrow application. Most of the post WW2 aviastion industry is heavily tied up in sunk costs. Much of it is inapplicable to Zeppelins.

Let me introduce you to the idea of Government Intrests. Developement of fixed-wing aviation was seen as being in the intrests of governments across the glode, as they reali8zed that modern air forces were a military necessity. Ever since the 50’s, the Feds have back commercial fixed-wing aviation, because it’s existance helps provide personnel, facilities & an industrial base to support combat aviation. Most airports are owned by governmental or quasi-governmental agencies, as is the one I work at.

Zeppelins have no current military use. So, there will be little encouragement for them by the government. Fixed wing aircraft, especially jets, do have military use, so they get tax breaks, subsidies, loans, etc.

No conspiracy, just governments & private industry acting short-sightedly. Happens all the time.

In conclusion, you talk about how well things are run in theory, and fail to admit how poorly they are run in practice. Most business do not even approach the standards you suggest.
BTW—if fixed wing aircraft are so darn efficient, & businessmen are so wise, why do airline go broke so often, so fast? As far as I know, most of them never make a profit. :dubious:

[ElvisL1ves]

That’s the miracle of free markets with perfect information and perfect ease of entry and exit, which the airline industry approximates more than most industries do. In the long term, it drives profits to zero.

[Broomstick]

*Originally posted by Ale *
As much as it could be descrived as a toy the fact remains that it flew on the same principles a full scale plane does; and the Planophore had control surfaces, the stab and rudder were adjustable, as well as the wing incidences which could act, roughly, as warping; granted it was a static 3-axis control, but the model could be trimmed to flight left, right, up and down. You can think of it as a test model, “let´s see how could I turn a big plane to the left”, add a bit of incidence to the right wing, and/or some left rudder, the model will tend to dive so a bit of up elevator should be set. I do thi all the time; free flight models have control surfaces (not all though), and those surfaces have to be adjusted to make the model fly in the desired path; I don´t see what´s different to a 3-axis control system then, barring the blindingly obvious that there´s no live input.

Speaking as someone who sits in cockpits fairly often, I have to say that the “live input” aspect is extremely important.

What you’re talking about in the Planophore are things that are now called stability and trim. They’re important, but they are not control.

Stablility is a good thing - in moderation. A perfectly stable aircraft would be very difficult (if not impossible) to steer. A highly stable aircraft is less manuverable. Whether that’s good or bad depends on the purpose of the aircraft and flight. The most manuverable aircraft, though - the fighters and airshow stunt planes - are UNstable, or with strong tendencies towards instabilities.

Both stable and unstable aircraft, though, use the same controls (with a few variations). You have a yoke/stick and rudder with which to steer the thing through 3 dimensions. Some designs incorporate funky things like “ruddervators” and “elevons” but even those terms tell you what conventional controls they’re emulating and which axes they control:

rudder - yaw
elevator - pitch
aileron - roll

ruddervator - yaw and pitch (these are the steering bits on a V-tail planes)
elevon - pitch and roll (you see these on flying wing designs, and some tailless delta wings)

Something like the Ercoupe, in which the pilot controls only ailerons and elevator, still has a rudder (controlled by a coupling to other controls). The 2-axis no-aileron system used by some ultralights utilizes dihedral to control roll, but the system is limited. Some of those designs incorporate spoilers, which are sometimes called 2-1/2 axis control.

“3-axis control” is equivalent to the steering on your car, which is controlled by the steering wheel. “Trim” is equivalent to the tire alignment, which can help or hinder steering. The Planophore has great tire alignment, but no steering wheel. I would not drive such a car (nor fly such a plane)

[Broomstick]

originally posted by Xema
I agree with much of what you say, though I’m skeptical that there’s any inherent advantage to weight-shift control when the goal is lightweight, low, slow, economical flight. And I know of several 3-axis control aircraft where wings (or parts thereof) can be swapped to suit conditions.

If you’re flying without any instruments at all, or just the bare minimum (airsped and altimeter, or as we used to say, the “how fast” and “how high”) weight-shift can give a very intuitive feel to the steering, which can allow for some very precise control with an experienced pilot.

The advantage is that the hardware for weight-shift is much less bulky and complicated than for 3-axis control. 3-axis controls require running cables out along the fuselage and wings, bell cranks for the ailerons, hinge attachments, and so forth. Weight and complication, all of it. The control bar used in weight shift does not require cabling, has much less hardware, and is much simpler from a construction viewpoint. If you’re talking about Part 103 ultralights in the US, where the legal weight limit for a man-carrying aircraft is under 254 lbs, you start worrying about ounces and how thick the layer of paint is on various parts. The sum total of parts for 3-axis control will always be bigger and heavier than the equivalent weight-shift parts for any given size of aircraft.

The less weight the smaller the engine required - and the more performance you get out of any particular engine. A smaller engine weighs less and burns less fuel - and therefore costs less to run.

Then you get into things like unpowered ultralights (gliders, basically) which have to weigh under 155 lbs (gosh, that’s only 5 lbs more than me! And big honkin’ 240 lb guys fly those!). There’s a reason you see more rogallo-wing (that is, weight-shift) gliders in that category than standard 3-axis. It’s very difficult to build a 3-axis glider to meet those standards.

The smaller you go, the more practical weight-shift steering becomes.

originally posted by Xema

originally posted by Broomstick
I’m not convinced it [negative dihedral on the 1903 Flyer]was a good idea at all. Bluntly, I think it was a mistake, one they corrected in later models.

Consider that the Wrights were planning to use the Flyer at low altitude in a place with strong gusty winds. Dihedral does make a plane more susceptable to gusts (as their correspondence notes) so it would have been questionable on a plane to be used at Kill Devil Hills. And for dihedral to have its roll-stabilizing effect, the plane must sideslip a bit, which isn’t a great thing when flying at an altitude of a few feet. So it made sense to avoid this approach in 1903.

In 1904 they were flying at Huffman Prairie in Ohio. Winds were much lower there, and they eventually flew much higher. Accordingly, they took out the negative dihedral. They were smart guys.

Gosh, maybe you don’t want to see me land at my home field in brisk 15 kt crosswind - which we get all too frequently around here.

Anytime there’s gusty winds, crosswinds, or both I have to deal with flying low in those conditions - on takeoff and landing. I’ve landed a C150 in a full 20 kts of crosswind with gusts. Then again, I have a LOT more training and experience than the Wrights (or anyone else) did in 1903. And that counts. You can sideslip all the way onto a runway - you just land first on one wheel, then on another, then the third makes contact The alternative is a crab (angle into the wind) that you take out just before touchdown with a sharp jab to the rudder. The big trick is to have the tires lined up properly with the pavement.

When done properly, positive dihedral causes the wing to seek a level attitude. Sure, it may catch a gust, but it will also right itself without pilot input. As opposed to, say, a C150 with its HUGE one degree of dihedral which will happily fly canted to one side much longer than pilot and passenger may like. And these tendencies hold true not just at 1000 feet above ground but also 10 feet above ground.

Off-hand, I can’t recall hearing about ANY aircraft other than the 1903 flyer that has a negative dihedral. If you can name one, please do - I’d be curious to know about it.

Negative dihedral, promotes instability. And that’s true at both altitude and in ground effect. It doesn’t “make sense” at any altitude or at any speed. In short, the negative dihedral of the 1903 flyer was a mistake, pure and simple, which they corrected in all later aircraft. Sure, they were smart guys - they learned from their mistakes. But because they were on the edge of human knowledge and experience they did wander into some blind allies.

originally posted by Xema

originally posted by Broomstick
The instance where weight-shift will probably work best in a small GA aircraft is in elevator failure.

Using the pitch effects of power is also valuable in this (mercifully) very rare event.

Not if you have a pusher engine. Rear-mounted engines have the opposite effect on pitch that a tractor/front-mounted engine does. If you throttle up a pusher you pitch down, not up, and if you throttle back you pitch up, not down. They do try to design pushers to minimize these effects but it’s hard to eliminate entirely. And pusher engines do have their uses.

Also - if the emergency is that dire you shouldn’t assume the engine is working, or if it is, that it will continue to keep working.

But maybe I’m nitpicking

originally posted by Xema

originally posted by Broomstick
Would I willingly start a flight in a 3-axis airplane and fly it weight-shift? Nope. But if I had to I think there’s a decent chance of it working. Hey, if things are THAT bad I don’t care if I trash the plane - I’m trying for ME to survive!

A sound plan. OTOH, keeping the plane intact will tend to ensure that you stay that way.

Quite true - an intact aircraft virtually guarantees intact occupants. But if I have no choice about landing, need 800 feet to stop the airplane, and only have 500 feet of “runway”, I’ll take it because I’ll be much slower than last 300 feet and will most likely survive the impact. The airplane, however, will take significant damage. This sort of “flight planning” isn’t a lot of fun, but it’s necessary sometimes.

[Sam_Stone]

As much as it could be descrived as a toy the fact remains that it flew on the same principles a full scale plane does;

Same principles, yes. But not the same aerodynamics. A small scale model will not behave the same aas a full-scale aircraft, because at smaller scales the air behaves differently. The model sees it as being more viscous, which changes the way the airfoil behaves, the stability, and a bunch of other things.

When NASA does small-scale wind tunnel testing they try to compensate for these factors, but it’s not perfect - which is why so much money is spent build really large wind tunnels you can put full-scale aircraft into.

Negative dihedral, promotes instability. And that’s true at both altitude and in ground effect. It doesn’t “make sense” at any altitude or at any speed. In short, the negative dihedral of the 1903 flyer was a mistake, pure and simple, which they corrected in all later aircraft.

It’s impossible to say this without knowing why they chose the anhedreal. The Wright brothers were well aware of the effects of the anhedral at that time - I remember seeing some correspondence somewhere in which they discussed whether they should remove it to increase stability. They may have had anhedral to improve performance in ground effect, or for structural reasons, or possibly because they thought that they had too much stability in roll, and were worried about the ability of their wing warp mechanism to provide enough authority to roll the plane. So maybe they put the anhedral in to make it just marginall stable so the controls would be more effective.

[Ale]

Sam, that´s why I said principles to begin with…
It´s quite true that a plane can´t simply be scaled up or down without affecting the aerodynamic properties of the airframe; however, the differences between a Planophore and a Flyer, for example, wouldn´t be so great, since the flight speeds were not so different (10/15 Km/h versus, what? 45/55?). The viscosity of the air plays a role, but against the smaller plane.
In such a situation the most noticeable difference comes from the great difference of wing loadings between a model and a full scale plane; for example, a plane with 20 sq. meters wing area weighting 200 Kg if reduced by a factor of 2 would weight 3.76 Kg (the cube root of the original weight) and the wing area would be 4.47 sq meters (the square root); so the big plane has a wingloading of 10Kg per sq. meter, while the small plane has 0.82Kg per sq. meter!