Prof Prodyut Das on ‘Appropriate Technology Regional Transport Aircraft’

Unlike the design of military aircraft which is led by the “latest” (even if unproven) technology, the design of a successful civil aircraft is more hard headed; it is very closely defined by alternate surface transport speeds, availability, the density of population, distance between  population nodules, condition of the economy, connectivity between the airport and the city centre and so on. These factors are quantifiable. The other factors, such as expectations in terms of punctuality, regularity, tolerance to noise, comfort and economy and their relative priorities go beyond statistics and slip into the realms of culture and philosophy. If the ‘East is East’ then its air transport options should also be ‘Eastern’. 

However, the air transport scene has, for a century, been dominated by the Western paradigm. Asian countries have used western equipment to solve part of their air transport needs, there being no ‘perfect’ equipment to provide an end-to-end transport solution and V/STOL aircraft, for instance, are infeasible to the point of being ‘exotic’. Western designs, whilst acceptable, are definitely sub optimal and in fact an imposition on Asian conditions.

The India of the 21st century is evolving, with changing economic conditions now opening up new opportunities. This is becoming a ‘new’ rather than a ‘competition’ area and the prospect of collaboration with the West does make commercial sense. New aircraft designs will be needed not only to meet the expected growth of what the Soviets called the Selskoe Khozaistanni (Rural Economy)  but also to replace the present genre of Western-origin aircraft which would soon enough be phased out. The market is massive !

Such an emergent market can also be an opportunity for foreign entrepreneurs to invest in India. The cost of skilled labour is the single largest factor in development and production of aircraft. The technology of civil aircraft is considered “lower”, indeed the basic technology almost a century old and well within the existing capability of India’s Industry, which however still lacks some ‘know why’ of certain aspects. In the mid-20th century, Europe had one or more aircraft manufacturer for every letter of the alphabet, from Avro to Zlin ! However, famous names slowly began to disappear as the cost of aircraft development became prohibitive for most medium and small scale enterprises of Europe. However the ‘seeds’ of that genius still exist. The ‘natural’ Indian enterprise and low labour costs plus exchange rates of the Rupees, together with Western aviation know how would spur investments to ‘multiply’ in effect, …  the future is exciting !

Whether such potential can be realised will depend on the way the Government of India’s policies evolve. There has been some positive change in recent times but still much remains to do, as has so far been done. Since Independence, India’s political leaders followed policies on strategic industries (weaponry and aviation), that were akin to those of  ‘a colonial power’ !  Just as the then Imperial Government did not allow Lala Walchand to set up his aircraft company on Imperial territory, the blinkered Industrial Policy of 1956 forbade the manufacture of aircraft by India’s private sector. 

At the end of World War II, many leading German aircraft companies including Dornier and Messerschmitt moved to Spain and Argentina as the Allied Control Commission forbade the design or manufacture of aircraft in Germany. The vision of Nehru and Nasser resulted in German involvement respectively in the HF-24 and HA-300 fighter programmes. However, India’s ‘liberalisation’ era which began in the early 1990s, sidestepped the aviation sector. So recently, when one of India’s leading industrial houses wanted to enter the light aircraft sector, they found a better opportunity to start in Australia – and Australia is hardly the best example of a nurturing Government in this arena. 

 Evolution of Civil Aviation

The foundations of today’s civil aviation industry are based on the development of strategic, intercontinental jet bombers following World War II. Amusingly, such technology proved quite amenable transportation of tycoons and the glitterati who previously had voyaged on luxury ocean-going ships, Cunard or P&O ! Whilst the laws of physics restricted aircraft maximum speed to Mach 0.82, advances in engine technology then tempted designers to move into the mass transportation market, thus changing the entire concept of air travel from the earlier one of ‘speed and grace’ (passengers were even gifted overnight bags on booking their flight) to becoming today’s ‘max pax’, airliners with cramped cabins.

A strange paradox has thus unfolded : the early ‘inefficient’ jetliners were profitable enough whereas the latest ones  with incredible fuel efficiency, regularly result in many airlines going  ‘belly up’. Fuel prices have been identified as  the main reason for unprofitability but the underlying reason  is actually that the earlier specifications are being used as ‘template’ for the mass transportation market. An undeniable truth is that fuel burn is exceedingly sensitive to speed. A fifteen percent increase in speed requires fifty percent more power and burns thirty percent more fuel over the same sector. Are airliners for the mass transportation market actually flying a little too fast to be profitable ? In the West, there is little choice because of the ground conditions but in Asia, we can certainly dare to be different.

The Indian Paradigm

These factors remain today and are  the cost of an aircraft; cost of amortisation and financing; fuel bill; airport charges; wages of the crew; cost of maintenance; cost of sales, marketing and passenger handling.

These factors are as relevant and significant in shaping the design of our Asian Regional Airliner, a relatively simple aircraft, flying at two hundred knots (360 km.p.h) to be considered, with the probability of significant savings in each of the above areas, resulting in virtually halving the costs of development.

The ‘price’ of speed

The optimum cruising speed of such an aircraft is dictated by that of surface transport, with a rule-of-thumb calculation giving us five to six times the average surface speed (including chai breaks) for a journey. My experience in shuttling between Baroda and Nashik – and similar city pairs – gave me a ground speed of 50 km.p.h.  Thus to be competitive, the aircraft cruising speed must be between 250 and 300 km.p.h. In the lands of autobahns and freeways, that would be closer to 500 and 600 km.ph. The sky will not fall if a 550 km.p.h aircraft is operated on the Baroda-Nashik sector but it will be burning four times more fuel. The circumventing trick of course is to fly at higher altitude but then the aircraft will need pressurisation, which results in increased weight (the fuselage becomes a large pressure vessel, which is the worst in terms of weight) and then there are maintenance problems, seals, barometric units and so on. All this is manageable but the idea of a simple large turbine-engined Dakota concept of aircraft is lost and puts up the costs on Mr Hillman’s list.  An interesting fallout is that optimum ‘low speed’ shapes are more ‘blunt’ and compact which leads to significant weight savings for the same ‘cargo/pax’ volume, exemplified by the Dornier 228, designed by Munich-based engineers and continuously since produced by Kanpur-based technicians (more or this anon).

The airports

Much of India has many landing strips largely a legacy of WW2, with West Bengal and Assam literarily having scores of them. The Government has initiated a programme to update and upgrade some of these airfields. It would be wise not to rely on such plans, but better to carry out a survey of all the airstrips in the country to assess where matters stand. I am reminded of Ed Heinmann’s approach to the US Navy’s request for proposals for a nuclear-weapons capable bomber for their planned 100,000-ton super carrier to replace the Forrestal-class. Heinmann chose to examine what could best be done within the limitations of the Forrestal-class and came up with the iconic Douglas A-4 Skyhawk. As foreseen by Heinmann, those super carriers never came about and the USN learned that whilst the customer has the privilege of always being right, they lose nothing by listening to another person’s point of view.   

STOL is KING

STOL fairly complements max cruising speeds. The West has produced some remarkable STOL aircraft in the mid-20th century, beginning with the Fiesler Storch and the Westland Lysander. Post war, Dornier produced the Do 27 and the Do 28 Skyservant (above) which were particularly noted for their STOL performance, as was the Polish PZL Wilga. The Hunting Scottish Aviation Twin Pioneer is also  interesting because, despite heavy radial engines, it could lift 16 fully equipped troops off a ground run of 80 metres from jungles strips in Borneo and the hills of Nepal ! In India where even expansion of existing airstrips may run into local agitations, we should look at STOL capabilities very seriously. 

The Fairey Rotodyne of the 1950s gave VTOL capability to airliner sized (40-70 pax) machines and was simpler than the present Osprey whose civil version is yet to be marketed. The Rotodyne project needs a re-look at, as noise is less critical in Asia and collaboration or even purchase of its data could be well examined.

Actually, Western  aircraft designs have come with relatively narrow cabins so as to reduce drag and as a result, these designs have a tendency to “cube out” i.e they can lift the load but which cannot be fitted inside the cabin. India being an agricultural country and with increasing stress on ‘exotic fruits and flowers’ type of agriculture, not cubing out may become a significant selling point.

“Is nothing sacred” ?

Decades ago, a Japanese liquor company applied modern analytical methods, including allegedly gas chromatography, to analyse Scotch whisky and come up with a Japanese equivalent, indistinguishable from “the real stuff. “The Scotsman printed such news with a very plaintive “Is naethin’ sacred” ?.

No, nothing is sacred  in the matter of strategic technology development, and the way it is marketed. One must review certification norms for Asian conditions.  Are the existing US/European civil aircraft certification agencies being scrupulously – and  impartially – fair ? Or are there various hidden agendas ? Consider the following:

• In the late ‘sixties, there was a huge “to do” on the HAL-built Avro’s inability to meet phase II of the climb out requirements. That this requirement is a safety issue is indisputable. Given India’s high ambient temperatures, that the engine’s power and the wings lift both suffer by about 7%, is also indisputable. However, this resulted in pressure to reduce the MTOW of the Avro 748 which had direct impact on profitability of the type. I can understand that in Switzerland that requirement would be absolute considering the terrain. But in India? Could not the restrictions  have been applied only to select airports, say in mountainous areas ? Or was this an effort to open the market for imported types (also given HAL prices ? ).

• Western regulations have for long insisted on twin engines for any aircraft carrying more than nine passengers and we have nodded in synch. Statistics however show that there were more fatalities when twins lost an engine because the pilot, under stress, often feathered the surviving engine and the aircraft then went in! They say more Canberra crews died practicing engine out approaches then during actual engine out emergencies. 

It is interesting to compare the Russian experience with their Antonov An-2 biplanes. The DOSAAF would allow the single-engined An-2 to amble off with a crew of two plus two jump masters and ten parachutists, each with two parachute packs plus the odd ‘observers’, which was a load equivalent of perhaps 18 passengers. So were the Russians being callous in terms of air safety ? The possible logic is that the An-2 had a controllable minimum speed of 45 kts and so when lost in fog in mountainous terrain, the SOP was just to fly at minimum speed as the impact energy of an An-2 crash was less than half that of Western types ! Secondly the very capacious fuselage of the An-2 meant that getting out was quick and, lastly, Russia being sparsely populated and terrain quite flat, chances of a successful emergency landing, were quite high. 

Now for a twist in the tale ! After  collapse of the Soviet Union, many An-2s ended up in the USA. Given their safety record, one would have thought that they would easily get US certification. I heard they did, but it was so restrictive (the aircraft had to return to the takeoff airfield at the end of each sortie! ) that commercial use except for parachute jumping became ludicrous ! People say that it was done to protect the US light aviation interests but the  point I really want to make is that before we quote anybody’s flight safety rules  as a Father’s unalterable curse,  let us examine the relevance and applicability of such rules. 

The Dakota Genre

The Douglas DC-3/C-47 Dakota is a necessary reference point on the subject. The Dakota was successful not because, as has been suggested, it was so modern that it stayed relevant for another eighty years but because it was superbly appropriate for the 300 kmph cruise speed. Wherever that speed was relevant, the Dakota earned its living. 

The Junkers Ju-52 (above) and the Curtis C-46 Commando were worthy contemporaries and need more study. The Ju-52’s demise can be attributed to the German collapse and the consequent lack of spares.  The C-46’s relative obscurity underlines the need to study the needs of each customer closely. The C-46 carried sixty percent more at fifteen percent higher speed then the C-47 but required eighty percent more power (note this well !)  but had only fifty percent more fuel : the design’s capabilities was less “harmonised ”. The C-46 initially also had a reliability problem. The lack of wing fuel tank drain vents meant leaking fuel vapourised and after accumulating, sometimes even exploded. This led to unexplained loss of aircraft which were blamed on the fuel drums being transported, usually ‘over the hump’ from Assam to China. Little design details mattered.  

The Baasler BT 67 was a  turbine conversion of the Dakota and its acceptance proved correctness  of the Dakota concept, plus the advantages and problems of ‘turbinising’. Its PT 6A-67Rs were almost a tonne lighter than the Wrights they replaced, which resulted in CG problems, but this was simply restored by putting a 40 inch plug in the fuselage ahead of the leading edge. The changes resulted (as the Table shows) in a more capable aircraft which nevertheless was still a compromise. It had too much wing area : a modern aerofoil would have saved 60kW.h/hr at cruise and the not quite fully circular fuselage cross section precluded pressurisation should the customer have wished that.  A new design based on the old Dakota would have been a formidable contender.

Assessing the aircraft

There was an advertisement clip on TV some years ago which depicted the press conference of a pioneering aviatrix (looked like Amelia Earhart and her Lockheed Orion) and then someone in the audience asked ‘Mileage kitna deti ?’ (How much mileage does the aircraft give ?) We value different things. The aircraft has to be assessed not for speed or comfort or ability to operate in Cat III weather but on profitability, utility, versatility, ruggedness and how much money it would make. Never mind if air services are irregular during the monsoons, the passengers will put up with that if the tickets are affordable for rest of the year. (Table 1 gives a comparison of the operating economics).

Our Regional Transport Aircraft (RTA)

Our RTA 70 project is planned to compete with the ATR and Q400 (both above). A snowflake in hell has a better chance !  Suppose your fairy Godmother (mine has indignantly refused) were to give us the entire drawings, tooling and the civil certification, would we  then be in a position to become a respectable supplier of such class of aircraft ? Immediate questions would arise about the cost of production, delivery rates and their certainty, after sales service and a host of such issues. Would Jet Airways/SpiceJet/IndiGo place big orders? Could we stand the price war that the fully depreciated ATR would probably then unleash? Another example : if the Saras II happens, will this then stand up to the Beechcraft 1900D for private operators ?

Instead of going bald headed into such (mis) adventures, we should look at the niches and the gaps in the product range and develop products that are not possible to be economically developed or produced by the West  : simple, labour intensive, appropriate technology aircraft which would break their bank if they tried to compete. India has some ninety cities of between three million and half a million populations and another hundred with populations between half a million and two hundred thousand, all with rich agricultural hinterland, the mean distance between the nearest two being around 190 kms. This market is ideal for a series of (relatively) high capacity, mixed freight /passenger, near STOL rugged transport aircraft, quite different and not competing with any Western product. 

These could be :

• A  small 12-15 seat/two-and a-half ton single engine utility aircraft sized between the Cessna Caravan and the Dornier Do 228, with emphasis on unprepared field/ high altitude STOL capability. About 3000 kms. of our northern frontiers are around 6000 feet above mean sea level.  A biplane, with its large light weight wing area and docile handling in confined airspaces, might surprisingly prove to be the best choice. Figure 1 shows two configurations.

• The second niche exists for a 40 seater, sized between the Dornier Do 228 and the ATR 42/72 series, and  we are looking at a kind of a “turbine Super-Dakota”. 

• The third niche exists as a 6-abreast seating 100-150 twin turboprop – say using the cabin of an Airbus 320 or a Boeing 737 but the entire design optimised for a cruise speed of 400 kmph on 200 km sectors. Indian Airlines once used to operate a Boeing 737 on the Calcutta-Ranchi-Patna–Lucknow-Delhi sector. The many stops meant advantages of jet speeds were simply not realised. A large turboprop – partially pressurised, if at all – would  certainly have been more closely matched to the profile and would be significantly more economical. The target customers are those people who now travel such sectors by Indian Railways AC sleepers. Much of Asia  -  but not the West – has such a market.

• Finally there is that heavy lifter (which can be imagined if you are old enough) as a Blackburn Beverly clone), or just a Globemaster II but redesigned for its ability to through load a MBT (T-72/90) or a S 400 system and transport that from Babina or Ambala to Leh or vice versa and designed for sub continental rather than intercontinental ranges. International air freighting is growing and it makes little sense to air freight equipment from, say the US only to truck it thereafter across the sub-continent. There will be a need for  matching heavy (but short range) air freighting capability.

Since the profitability of an operator will depend on how exactly we can meet his needs, an approach for the design team would be akin to that of a lego brick model with various fuselage cabin lengths, wings areas and undercarriage options available so that the design could be tailored to the needs. The customer will have options of pressurised/partially pressurised and un- pressurised fuselages and retractable or fixed undercarriages which would mean hard – but  repetitive – work at certification. Here, a ‘pod and twin boom’ layout is a very strong contender.

Nec Quis quam Nisi Ajax

The heading actually means “only Ajax can replace Ajax” or “you can do nothing till Ajax comes along”. The Aviation Industry is a high risk high profit but ‘full time’ business and requires all the time, dedication, energy attention, knowledge and efficiency that such business needs. The Soviet Union had it absolutely organised. Their political leaders had seen frontline war service; their military held cabinet ministerial rank and their top engineers held military ranks as also senior party positions. It was cohesion, teamwork knowledge and passion at their productive best. No time was wasted in trying to ab initio educate an intelligent, powerful but sceptical ignoramus ‘team member’ which explains the excellence and rapidity of Soviet aircraft development. Despite professions of equality the performers had no pay bands; all of General Designer Andrei Tupolev’s cheques were unconditionally honoured by the Soviet state  (apoplexy epidemic in North Block !).

In such a totalitarian state,  it was possible for “the man in charge” – for  example Admiral Gorshkov, regarded as  father of the Soviet Navy’s renaissance – to stay at the helm for thirty years (he was retired only at his own request at the age of 75.). As a senior ‘cabinet minister’ and political leader, Gorshkov combined job knowledge, national policy and clout all in one person. The result was that  the Soviet Navy became a challenge to the mightiest Navy, that of the United States. The magnitude of the achievement can be gauged by the following story. In  1956, the year he took over and  seeing Nikita Khrushchev observing some Morskoya Flota sailors in a rowboat on the River Moskva, said half jokingly, “That is our Soviet Navy”. The Russian Navy was then at one of its periodic declines. Gorshkov went about to build it up to its present size in twenty years, with the pioneering move to also export Soviet naval equipment helping to finance part of his own formidable vision.  

Such continuity is not possible in Western Democracies so they, recognising reality, as have handed over the knowledge, passion, and day to day dedication required to run such business to the private sector. An example would the firm founded by Marcel Bloch, known today as GA Marcel Dassault . Marcel Block Dassault (1892-1986) started off as a propeller manufacturer in 1913 and went on to manufacture aircraft during the 1920s. Renaming himself as Dassault during the Second World War (being in the French Resistance) he went on to head General Aeronautique Marcel Dassault, which continually achieved brilliant results for its shareholders – and France – by using fairly basic technology with great élan.  Dassault’s passion was so great that as long as he was alive, he apparently did not allow his worthy successor and son, Serge, to run the company ! Between the two, father and son, we have seen a century of continuity, job knowledge and passion. From many possible names I have deliberately chosen Dassault and France because France was the European country most affected by leftist ideals and communism and yet the French Communists were knowledgeable enough, pragmatic enough and patriotic enough to realise that certain areas were inviolable even to politicians. When they nationalised the French aviation industry they still left Marcel Bloch (Dassault) in charge of his company. 

So, what do we get for our Ajax? An IAS; a good student from St. Stephen’s or JNU with a degree in History or Economics with perhaps a stint at Imperial College or Cambridge; usually exposed to Leftist Economic philosophies. Who, as a “clod hopping collector”, did good work in Gonda district in the regime of rural indebtedness. Articulate, meticulous, hardworking and upright, he is up from a stint at the Ministry of Animal Husbandry where he tied up with the FAO for an important programme in Holstein/Zebu/ Illawarra cross breeds and this is his third year in the Ministry and now he is stamping his feet to move into the PMO which was always his lifelong ambition and with his abilities and experience, he deserves it ! He has a frequent flyer card with several airlines but prefers Air India. He can lean on his Defence Minister who usually has tenure countable in months not that it matters in any way because he is more interested in the politics of his home state. The passion of Krishna Menon, the stoicism of Yashwant Chavan or the intelligence of  Babu Jagjivan Ram happens but rarely. Courtesies apart it is – technically - entirely correct to call our Ajax as essentially ignorant. He certainly is no Churchill/Hitler or Stalin who were interfering busy bodies even in the matters of weapons design (the privilege of any comment is that of the readers !).  

Right path of the Buddha

American aims were identical to those of the British but their approach was much more “worldly wise”. The US Government was never under any compulsion to prove any political philosophy : it knew that it did not know the business. It trusted the US Industry to take the lead as it had ample faith that these people knew more about aeroplanes and would move mountains to do what was needed. The Government relegated itself to the role of being a Vigna Hanta (destroyer of obstacles) and provider of venture capital. The story of development of the Boeing 707 is a classic example of how this alternate approach worked. 

Having earlier developed the atom bomb, there now was need to move “the thing” across intercontinental distances. Of the four contenders who responded to the RFP, Boeing’s proposal formulated from 1943 onwards were for the models 424/432/448/450, the last being submitted in March 1945, hastily revised to incorporate German data on swept wings ‘captured’ during American advance to the Elbe and with six engines mounted under the wing on pylons, an aircraft which emerged as the XB-47.  

This new bomber had many technical problems : the slender high aspect ratio wing flexed almost two meters up and down from the datum in flight, unnerving the first crews and there also was reverse aileron effect. At certain speeds and altitudes the stalling speed and the critical Mach number coincided, so appropriately, was called the “coffin corner”. Nevertheless the structural and aerodynamic advantages of the B-47s podded engine and pylon approach were amply proved in operational service.

Having developed the B-47, Boeing then proposed development of  an aerial tanker, capable of matching the B-47’s speeds, thus making FR less of a hazard. The result of such marketing effort led to an order for hundred and thirty five tankers as the KC-135, whose prototype was the famous ‘dash 80’. The KC-135 allowed Boeing to reduce the launch costs and risks of the ensuing Boeing 707 airliner. However their hopes of using the KC-135 fuselage jigs were dashed because they now realised that the fuselage diameter had to increase by another 8 inches (200mm) if the customer was to be satisfied. 

Legend has it that the fuselage was just one inch more in diameter than the competing DC 8 but that one inch made a world of difference in the packing of passengers in a six-abreast seat layout. This required investment in new fuselage tooling and Boeing spent $ 16 million to do so. Boeing could take the decision to invest within the precincts of then offices, there was no need to educate anyone to get the sanction. The short decision chain helped Boeing to move at the rate demanded by the market.  

What then for India ?

Asian economics and demographics dictate larger airliner capacities, shorter stage lengths and more primitive field capable aircraft than is in the vision of Western manufacturers. These augur well for the economics of an air ticket. The civil transport market in India has the advantage of a shorter decision chain and so within the existing capability of our Industry. This can truly be the Great  White Hope : whilst we all wait for the Government to extract digit ( i.e. “finger”). 

A full discussion on the fascinating subject of appropriate technology air transport is not necessary here. Potential private sector operators and the private sector Industry are those people who use earned money and know their business and are both equally interested in coming to a successful result. Between them they know what is needed and how to do it. A comprehensive governmental liberalisation of India’s aviation industry is need of the day;  the time to continue with unworkable management is long past. The industry is too dynamic and knowledge-based to be effectively managed by the present system – as the results repeatedly – and wearifully – show.