Forecasting the future of technological advance has always been an uncertain business. The common error is to take today's limitations and project them into the future. So, in 1929 Neville Shute Norway - no lay commentator, but an aircraft designer who later in life would write visionary novels as "Neville Shute" - said that the ultimate commercial aeroplane would have a speed of 130 mph, a payload of four tons and a range of 600 miles. This point would be reached in 50 years, or round about 1980.
In fact, by that time Concorde was in service and the 350-ton Boeing 747 was routinely flying non-stop from London to Singapore (6,700 miles). But perhaps the more interesting thing is that when this prediction was made, an RAF officer with even greater vision, called Frank Whittle, was already working on what, within 10 years, would become the jet engine.
For many years the headlong drive was for aircraft that would go faster and further. Now, we're reaching the point where planes, at least for the immediate future, go as fast and as far as the passengers need. In the words of Professor Ian Poll, director of the Cranfield College of Aeronautics: "The issues now are cheaper, safer and cleaner."
The giant gamble
One way of making air travel cheaper is to get economies of scale by building bigger planes. Powerful new engines and lighter construction materials (plastics, composites) make this possible.
The gains, though, are won at the expense of huge development costs that take years to pay back. Anyone starting on a big plane today is going to spend up to pound;10 billion before anyone pays for a seat.
It's a big risk. In 1971 Boeing had gone $2 billion in the red developing its 747 Jumbo jet and was on the brink of bankruptcy. But now, so many 747s have been built (nearly 1,300 - and it's still in production) that Boeing's investment was repaid long ago, and each aircraft not only makes a tidy profit but helps the firm sell its other planes at competitive prices.
Now, the same big gamble on a giant plane is being enacted in Europe as the European Airbus consortium moves towards the first flight next year of its Airbus A380. Eighty metres long and the same across the wings, it will carry 550 passengers on two decks, as opposed to the Jumbo's capacity of just over 400. If you want to buy one it will cost you pound;260 million, and the firm won't break even until 250 are sold.
Its selling point is that it promises costs per passenger 15 to 20 per cent less than the biggest 747, and in the highly competitive world of air travel that's a lot.
If the decision to go ahead with the A380 was bold, so will be the decision to buy it and fly it. We live in a fast changing world. Who knows what economic and political time bombs are ticking? So all over the world there are people sitting in boardrooms looking into crystal balls and wondering whether or not to see the bank manager about buying A380s at a quarter of a billion pounds a throw. The decision either way could bring triumph or disaster, not least for thousands of workers with mortgages to pay, and there's just not enough data to make an easy decision.
Boeing, for their part, are sticking for now with updates of existing planes. So, for example, they're working on a long-range version of their existing twin engined 777 that will fly 17,000 kilometres (10,500 miles) non-stop. They feel it's likely that instead of flying on giant planes between huge airports, we may want to fly from smaller airports nearer home.
Whatever the success of the super-jumbo Airbus, it might be the last example of what we think of as the "normal" aircraft shape - load-carrying body, a wing each side, and a tail perched at the back. Aircraft settled into that pattern very early, and give or take some experimental variations they've stayed like it.
Always, though, there's been the dream of doing away with the body. It doesn't contribute to flight, in fact it detracts from it by adding air resistance. So why not just have a huge wing with enough room inside to carry cargo or passengers? That way every bit of the plane would be involved in the work of flying, which would make it more fuel efficient and, therefore, cheaper to run. It's another seductively attractive way of attacking basic costs and making it cheaper to fly. And because such a plane would use a lot less fuel, it would be more environmentally friendly too.
Consequently, various manufacturers have experimented with the "flying wing" - in the 1940s, for example, the American plane maker Northrop tried out a flying wing bomber. The trouble is with basic stability - a flying wing has no stabilising tail, and some early examples killed their test pilots. Computer controls can react more quickly than a human to deviations from stable flight. So the aviation world is looking at what it calls the "blended wing body". Effectively it's a flying wing with a wide, thickened middle section that still contributes lift but also has space for the passengers or cargo. Such an aircraft, it's claimed, might use a third less fuel than its conventional counterpart.
Various design studies are going on, including one at Cranfield College of Aeronautics here in the UK. It's a big leap, calling for huge investment in research and manufacture, with no certainty of payback, so here, too, is a decision of a magnitude that will make highly paid directors and managers earn their keep. Quite simple things might tip the balance - the fact, for example, that with such a wide passenger section very few people will have window seats. Just that, together with its alien appearance, might turn off the travelling public. Or maybe everyone will love it, as they loved the Jumbo jet. Who'd like to gamble on the outcome?
In the 1960s, France, Britain, America and Russia intended to introduce supersonic transport planes (SSTs) that would cut long-haul flying times by more than half. The economics were always doubtful. America never built its plane. Russia's crashed before it went into service. France and Britain pooled their efforts and built Concorde, which has been a technological triumph and an economic failure even though fares are in the super-luxury bracket. Professor Poll says: "It was conceived before package holidays, when flying was assumed to be expensive."
If the idea is ever revived, the airlines' demands will be daunting - higher speed than Concorde, longer range, greater capacity, cheaper seats, quieter engines. It may happen, but it's a long way off. For the moment, the demand is for cheap mass travel.
'George' at the controls
Computerised management systems are now ubiquitous. We have them in education, so headteachers can now fly the school from their desk, using the MIS (management information system) installed on the network.
The most modern passenger jets have their own equivalent in the flight management system (FMS). FMS is going to make it a lot cheaper to operate a big passenger plane. Crucially, it'll make it safer, too. The computer never gets fatigued, doesn't misread the altimeter or confuse one control knob with another, isn't distracted by chatting to the flight attendants and isn't afraid to interrupt an autocratic senior captain who's clearly doing the wrong thing, all of which have caused disasters in the past. Ian Poll says: "80 per cent of commercial aviation accidents have a human component. If we can remove that, flying will be even safer."
FMS in effect is an extension of the old "automatic pilot" (always known as "George") that's been around since the1930s. But whereas George basically just kept the aircraft on course, FMS in its most advanced form makes flying 300 passengers from London to New York as easy as getting getting 20 quid from a cash machine.
In a plane fully equipped with FMS the captain, sitting in a "glass cockpit" (display screens instead of instruments with dials), punches in a code that calls up the appropriate programme for the forthcoming trip. The FMS then handles the take-off, the flight and the landing. It will keep in touch with air traffic control's own computers, and with global positioning satellites. It will make minute changes to the controls in order to get the most economical performance, and it knows the vagaries of the approach to the destination airport.
Meanwhile, the flight crew look out of the window, eat lunch and keep radio contact as necessary. They might doze, trying not to go to sleep simultaneously - at which, according to myth, they aren't always entirely successful.
In theory, passenger planes of the future won't need anyone on the flight deck at all. It could even be safer that way. Except, of course, that people probably aren't going to buy seats on a plane with an empty flight deck. The industry joke here is that in the future if you visit the flight deck you'll find there a man and a dog. The man is there to feed the dog, and the dog is there to bite the man if he tries to touch anything.
The more realistic hope was that the plane of the future could be if not pilotless, then operated by less skilled - for which read "cheaper" - crews. Life, though, has a habit of being unfair to technological dreamers, and it's arguable that the industry, in quickly trying for a high degree of automation, has made some of the assumptions that we've all grown to be wary of. In all areas of life, including classrooms and school offices, when IT has arrived we've had a touching faith that it will work perfectly from the start, going on to rely on it beyond the point where common sense ought to have intervened.
For example, there have been aviation accidents caused, not by the computers themselves, but by aircrew entering the wrong data and then being too slow to realise that the aircraft was doing the wrong thing (the old "rubbish in, rubbish out" principle well known to computer buffs). On one occasion a passenger plane, its FMS, wrongly set up, flew into the ground short of its destination airport in good weather and broad daylight. The crew assumed, until it was too late, that the computer knew what it was doing.
Such events, it's important to emphasise, are extremely rare and will not ultimately affect the march towards safer and cheaper highly automated flight. They do, though, have the effect of reminding us of the principles that we're always at pains to emphasise to our pupils and colleagues in their use of ICT - that we need to be sure of the quality of the data we enter, that we should use knowledge and common sense in interpreting what the computer tells us, that we shouldn't automatically use the computer without being sure it's the best tool for the job. And, most importantly perhaps, that a computerised management system doesn't compensate for inadequate management skills.
Piston engines were reckoned to fail in flight once every 4,000 hours of operation, and any frequent traveller in the 1950s was likely to tell you of arriving with one engine shut down.
A modern gas turbine, though, is calculated to fail every 200,000 hours.
The drive to improve this is continuous, and involves, for example, probes and sensors in every part of the engine, detecting the slightest deviation from normal working - yet another IT application that's making flying safer. In future, engines won't be routinely serviced according to a schedule, but will be tackled as and when problems are reported by the IT systems on board. This, of itself, will be safer, because routine servicing can bring its own problems of human error.
So what will we see in the sky?
The technological answer is that we'll see huge new airports and runways, responding to an apparently limitless increase in the demand for air travel, driven by falling costs and the business requirements of a global economy. Our government estimates that the demand for air travel will more than double by 2020. That's the expectation that's currently driving them to consult on a big airport expansion programme - one option includes a big new airport in the Warwickshire countryside. Flying in and out will be futuristic-looking blended-wing passenger and cargo planes of at least double the capacity of today's jets.
That's the dream. But there are factors standing in the way, not least a groundswell of concern about airport expansion, noise, the burning of fossil fuels, and upper atmosphere pollution. (The upper atmosphere is a delicate environment. It seems that gases put there just stay and don't descend. And because it's very dry, even hydrogen burning engines will make it more humid, with unpredictable results.) The issues are serious and worthy of research by our pupils. Aviation is a major contributor to the UK economy - it employs 180,000 people directly, and many more indirectly, and aircraft carry 20 per cent of all our exports. Through institutions such as the Cranfield College of Aeronautics, the UK is a world leader in research. On the other side of the coin are all the environmental concerns. Many of these are having immediate effects on our communities - huge areas of the country are directly affected by airport expansion proposals, for example, and local feelings run high. It's a live issue, and our pupils will be directly affected as they grow up.
Gerald Haigh wishes to acknowledge the help of Professor Ian Poll, director of the Cranfield College of Aeronautics, in researching this article.
Two major manufacturers of commercial aircraft
News of opposition to airport expansion www.airportwatch.org.uk
Cranfield College of Aeronautics www.cranfield.ac.uk