The Future of General Aviation

The fate of the PAT programme has been left in the hands of Helen Piper (Pug’s widow) and Pug’s partner Lea Griswold. Hopefully, for the sake of aviation technology, it will continue and that certification be eventually completed.

There is little need to dwell on the state of the general aviation marketplace, particularly as it applies to personal flying and flight training. Manufacturers, distributors and dealers are all having a torrid time making ends meet, wondering whether they will be in business at year’s end. Personal flying is down and only the more efficient and larger flying schools are able to hang on. Sounds like gloom, doom and disaster! However, all will not be lost provided reason prevails and a solution evolves.

What are the prospects for the future?

The industry, and its customers, can continue in the current state of uncertainty and end up in bankruptcy, or it can take a good, long, hard look into its mid-term and long-term future. The clock can either be turned back to a point where flying training and personal flying is carried out in unsophisticated low-cost aircraft, cheap to buy and maintain and operate, or it can be wound even tighter with the end result of increased costs.

As it relates to flight training and private flying, AOPA in the United States has petitioned the Federal Aviation Administration (FAA) to amend US Federal Aviation Regulations to permit certification, operation and maintenance of a new classification of aircraft to be termed A Basic Airplane.

They define A Basic Airplane to mean ‘an aeroplane with a single engine of not more than 200 horsepower and a seating capacity of not more than four occupants. ‘

However the reason for mentioning the AOPA submission is not for the purpose of evaluating their petition, but more to illustrate that someone over there is alive to the situation and is doing something to bring it before the regulating authorities.

The problems of the Western World and of the USA are no different to those ‘Down Under’. Aircraft prices are too high, not so much for what you get for your money, but what you need to outlay for a flying machine in which you can fly privately.

In Australia as in the US, both aviators and would-be’s have turned to the home-built or ultralight. It is becoming not only cost-saving but fashionable to fly an ultralight. The most unlikely ultralight known to the writer to date is the Homo Avis, meaning Man Bird and not what else the reader may dream up.

Popular Mechanics describes the Homo Avis as a ‘foot launchable’ device designed by Igor Dmitrowski of Elmhurst, New York. The craft straps to the pilot’s back and leave both hands free to operate a pair of pistol-grip controls. Takeoff and landing is vertical, with levelling into horizontal flight as flight speed increases. The Homo Avis is designed to cruise at 100 mph, powered by twin, 25 hp ducted fan engines. The designer claims that it can be hung on a garage wall when not in use.

To the other end of the scale, there is the twin-engine ultralight born out of computer design and space-age technology, the LAZAIR. Designed in Autumn 1978 by Dale Kramer of Ontario, Canada, the LAZAIR has consistently won awards for excellence in design and workmanship. The safety of two engines is a feature.

The Distributors say that the LAZAIR is an aircraft. It does everything a full-size aircraft does except at slower speeds, consequently, it is important that the pilot of a LAZAIR should at least have a student pilot licence and have gone solo in a conventional aircraft. As a matter of interest, kit price is quoted at around $4400 in Australia.

So far this article has touched on the high cost of training and personal flying which can and is to some extent, keeping people away from and therefore out of flying. It has discussed the possibility that an alternative to this is to look to ultralights or homebuilt for recreational and training use; the attempt by AOPA (US) to introduce a new category of certification to provide for the class under discussion; possible new techniques for the building of airframes, and has asked the question ‘what are the prospects for the future?’

Before leaving the reader to ponder over what has been written it seems appropriate to draw some kind of conclusion about the lower end of the market. Could it be that the wheel has turned full circle and that the authorities, the manufacturers, the distribution system and the aviators must accept the fact that learning to fly in a simple Taylor Cub with minimal equipment was not all that bad?

It certainly appears that it could be a solution! Why not go back to square one and get the thing going again? There is no doubt that before long someone would want an ADF, then an autopilot and so on and the wheel would start to turn again, but at least it would be a start.

So much for the lower end of the market. Now to the professionals!

Perhaps the most interesting and to some extent controversial new technology project in recent years has been the Lear Fan – the ‘all plastic’ aeroplane that has captivated the imagination of even the sceptic. Somehow it seems to read trouble, not so much from a theoretical or functional viewpoint, but from an organisational and funding aspect. At the time of writing, news came from Belfast, where this twin-turboprop business aircraft is to be built, that manufacture is to be delayed until the middle of 1983. The delay has again raised the question of the viability of the venture. The project, which started in America, was transferred to Belfast after being heavily backed by the British Government. Last October, Lear Fan was refinanced by a Saudi Arabian and American consortium through a new holding company, registered in Delaware, US, with the British Government stake reduced to five per cent.

What this does of course, is to add to the speculation that the project may never get off the ground, not so much because it is not a great idea, but due to the enormous problems associated with highly technical commodities, particularly in relation to certification, product liability and the capital outlay needed to see the project through to fruition. Even if all of these things went well we still have the question of ‘viability’, such as was the case with the Concorde.

These comments are not intended to suggest that there is not a dire need for improved and new technology or new techniques to be worked on and developed for future applications. Projects such as those conducted and/or organised under the auspices of the National Aeronautics and Space Administration (NASA), must be continued with industry participation. This is most desirable from a long-term aspect.

Continuing improvements in efficiency, safety, environmental capability, and utility are the broad goals of the general aviation programmes conducted by NASA. More than a dozen contemporary production and prototype general aviation aircraft have been designed with the aid of new technology gained from NASA programmes of the past decade. They range from twin-jet business aircraft to single-engined trainers.

In the past, general aviation aircraft technology has lagged technically behind commercial airliners and military types. The majority of today’s general aviation fleet is built on the aeronautical science that was driving the aircraft industry before World War II. Except for some new concepts developed by innovative experimental aircraft homebuilders, and applications of advanced production techniques by some manufacturers of a new generation of business aircraft, today’s general aviation aircraft would not have looked out of place in the 1950s.

Much has been previously written on the subject of NASA and the research carried out at Langley, Ames, Lewis and Wallops Research Centres, but suffice it to say that general aviation has a lot for which to thank those experts.

So far the inference may have been gained that the major research necessary for general aviation aircraft has been directed towards the airframe and perhaps avionics. However, that is indeed not so!

The bulk of general aviation aircraft today are fitted with larger internal combustion engines that must burn aviation gasoline. What can be done to improve their efficiency?

This question was addressed by scientists and engineers at NASA’s Lewis Research Centre, Cleveland, Ohio, the focal point of propulsion research for decades. Two major truths have been driving the programmes at Lewis for the past several years. First, most contemporary propulsion systems are expensive to operate. Second, most are generally noisy and emit undesirable exhaust emissions. Consequently Lewis investigators are studying ways to provide a new technology base for propulsion systems, specifically for advanced intermittent-internalcombustion engines. Ideally, these engines should be able to use any of a number of fuels, primarily jet fuel; they should burn less of it more cleanly and in a powerplant of lower weight.

Portions of this programme are being handled by industry and universities. The industry is building and testing engine components; the universities are involved in mathematical modelling of the complex combustion process and in research on advanced component technologies.

One phase of NASA’s propulsion research effort concentrates on two different types of engines. The first is an advanced, high-speed, liquid-cooled, rotary-combustion engine, familiarly known as the Wankel after its inventor’s name. The second is a two-stroke, stratified-charge piston engine. Both types are being tested in prototype form and both have shown significant performance advantages when compared to the conventional production internal-combustion engines.

Air-cooled general aviation powerplants dissipate much of their heat by radiation from multiple fins formed as part of the cylinders. Not much fundamental investigation has been done on the performance of engine cooling fins since World War Two, and NASA’s Lewis researchers thought it time to re-examine the problem. As would seem obvious, they found that major improvements in heat dissipation could be achieved if the cooling fins were designed to optimise their size and spacing.

But with even the most efficient in patterns achievable, engine cooling can be very difficult if the cowling which encloses the powerplant is poorly designed. A quick glance at almost any of today’s light single-engine aircraft indicates that the cowlings were designed for considerations other than those of optimum aerodynamic efficiency. By properly designing the external and internal shapes of an engine cowling, the drag caused by the flow of cooling air through the engine and cowling can be minimised.

NASA propulsion programmes also address the environmental impact, real and perceived, of the two engine-propeller combinations that typify general aviation.

The rekindled interest in turboprop engines, spurred by the fuel crises of supply and price, has driven a resurgence of studies of propeller performance. NASA is analysing and testing new propeller shapes, new airfoil sections for the blades, and new materials such as composites, in order to build a base of technology for the design and production of a modern generation of more efficient, quieter propellers. Low-speed propeller investigations are being conducted simultaneously.

Separately to the NASA research programme into propellers, European manufacturers, such as Aerospatiale, have been working on and in fact have in current production, composite rotor blades such as those used on the Ecureuil helicopter, or as it is more popularly known in Australia, the Squirrel. Such has been the success of the Aerospatiale composite, that they announce for it an infinite life. Dropping down several octaves, we find that the LAZAIR homebuilt, referred to earlier in this article has ‘computer designed 28 inch propellers made from carbon fiber-filled nylon – strong and extremely efficient. ‘

Conventional metal construction has dominated in the aviation field because of the industry’s long experience with it. Recently composite materials – essentially woven cloth impregnated with fibres of carbon or other high tensile strength materials – have found increasing use in military and transport aircraft. Their advantage is a great strength for lightweight. Research and perhaps to a certain extent, courage, as mentioned earlier in this story, resulted in the design and prototype construction of the Lear Fan, the production of the Squirrel and the use of similar materials in the propellers of ultralights. So dramatic is the end result, that one wonders just how long it will be before polycarbons and the like will be finally perfected for the motor racing world and from there on to the aircraft engine.

The NASA studies reported on, included taking into account the various fuels that are used in other forms of power supply, such as diesel and liquid methane. One such study was in conjunction with Beech Aircraft Corporation’s Alternative Energy Division, which has converted vehicles to operate on liquid methane and other applications of LM technology. Mike Neuberger, Beech’s Senior V. P. in charge of the Division said ‘Our studies and operational experience show that the use of liquid methane significantly reduces the cost of operating automotive fleets – by 40 to 60 per cent on an annual basis. ‘

Cessna Aircraft Company is another that has been working effectively with NASA. Evaluation of the results of one series of studies placed heavy emphasis on low fuel consumption and direct operating cost and on high operating efficiency as well as acquisition cost, noise, multi-fuel capability and ease of installation. The results indicate that the highly advanced rotary engine offers the best all-round performance and features for future general aviation aircraft. The diesel was the next most effective.

The other engines studied, although showing worthwhile advances relative to today’s engines, did not appear to be as promising as these two powerplants. In particular the turboprop, they felt, should be viewed primarily as a replacement for the baseline engine (conventional piston engine), offering market appeal rather than improvements in efficiency or costs.

The Big Two US engine manufacturers, Teledyne-Continental and Avco Lycoming appear to shudder when one mentions ‘all-new’ technology and for one, your writer doesn’t blame then one iota. The Continental Tiara was a project that looked promising and had the Big Three airframe manufacturers all hepped up flying the Tiara in various airframe configurations. One might say that Piper lost and was the first to use it in a production aircraft. Sad thing was that the Tiara concept was great and no doubt still is, but where is it today? Continental did not have it on their own, for Lycoming spent countless hours, and dollars, trying to get more and more out of their standard production models.

Herein lies a problem of great magnitude! Imagine that you were a manufacturer of glass dolls’ eyes with one hundred million dollars invested in plant, equipment and glass-eye technology and/or technique and your customers started demanding plastic dolls’ eyes. There is little doubt that you would endeavour to impress on your customers that ‘glass is beautiful’. This does not necessarily mean that manufacturers such as TCM and Avco Lycoming are not aware of changes that are seen to be inevitable, and which one day will be with us. Development costs are staggering to say the least and the time needed for completion to the certification standard is quite lengthy. Ten years ago the diesel engine was the thing for development; now the water-cooled powerplant is ‘well on the way to certification’, so we are told. A Thunder water-cooled engine has been flying the Californian skies for some time on one side of a Rockwell Commander 680W. The Thunder engine is described as a new, lightweight, high-performance, liquid-cooled aluminium internal combustion engine. The prototype is a 700-horsepower unit of VS configuration.

The purpose of this article is not to go into too much detail about any one project, but to reflect on the state of current production technology and techniques and to ruminate about the future and what it holds for us. In the meantime, we have seen engines turbocharged, with intercooler systems added, thereby returning cooled air to the intake undercooling providing full cruise capability at higher altitudes, lower fuel consumption and higher TBO. Intercooler Lycomings power Piper’s new pressurised Mojave seven-seater twin which cruises at 234 kts.

Technology and technique are words that are thrown around with semi-reckless abandon during most discussions on aircraft manufacture and product groups. The dictionary says Technology – a. The application of science especially to industrial objectives. b. The entire body of methods and materials used to achieve such objectives. Technique – a. The systematic procedure by which a complex or scientific task is accomplished. b. The degree of skills or command of fundamentals exhibited in any performance.

Both apply in the case of Piper Aircraft Corporation Engineering Division, even if it is for the sole reason that they use CAD/CAM, a system of computer-aided design and computer-aided manufacture. The system, developed by McDonnell Douglas and designated MCAUTO CAD/CAM, enables progression from part concept to finished product in a single session.

It was in 1975 that Piper decided that computer-aided design and manufacture was in their future. After lengthy research and trial the CADD/DGS system of the MCAUTO programme was selected. Spelt out this means – computer-aided design and drafting with distributed graphics systems – as used in advanced aerospace projects.

The DGS at Piper is tied via computer and a dedicated landline to McDonnell Douglas’ large IBM mainframe complex in St Louis, Missouri. Through this time-sharing concept, Piper are able to make use of immensely powerful computers and software at a fraction. of the cost of developing, installing staffing and maintaining such a system. On a graphics display, Piper’s engineer can visually construct a design simply by pressing buttons and manipulating geometric entities with easy-to-use graphic controls. (As Piper’s Senior Vice President of Engineering, Marian Dees says ‘It’s kinda like flying an aeroplane, it’s easy when you know which buttons to push and what to do with the controls’.) The design can then be visually tested and analysed. Changes can be made quickly, or alterations can be tried. The final design forms a common database model that is used to electronically add drafting symbols, to produce an engineering drawing, and to generate numerical control machine tool tapes. All of this without an old-fashioned pencil lead being spread on paper. This process obviously frees up skilled professionals to work on other projects.

The Piper Malibu, reported on in the March issue of Australian Aviation, was Piper’s first complete aircraft designed and manufactured from scratch using their CAD/CAM capability; in fact, it was the first general aviation aircraft to be so designed and manufactured. The prime purpose of touching on it in this article is to let us appreciate the genuine efforts that the major aircraft makers are undergoing to take advantage of the benefits of advanced technology. It is in this way that they can make their real-term contribution, not only towards product refinement and excellence but towards combating spiralling production costs brought about by wage bills in what has in the past been a labour-intensive industry. Piper believes that by 1985/6 ninety per cent of all engineering drawings will be produced in an automated fashion and computer-controlled machining and manufacturing will increase drastically.

From what has been written is seems that there must be two considerations-one, to get the masses back into private flying and two, to improve technology and technique in production lines. A dramatic change in regulations as they relate to ‘Basic Airplane Certification’ could be the answer to problem number one as suggested by AOPA of the US, coupled with the use of ultralights for ab initio training. The number two problem is more complex. Not only does it involve the How, When and Where exercise, but the viability! Is it money well spent? If it was your cash, would you be in it? There you are left to ponder. Perhaps the answer will be evident in the 1990’s!