Short-haul Jet Airliner B.A.C. ONE-ELEVEN IS NOW WELL AHEAD OF THE FIELD

Press, Volume CIII, Issue 30452, 28 May 1964, Page 14

Short-haul Jet Airliner B.A.C. ONE-ELEVEN IS NOW WELL AHEAD OF THE FIELD

IBy

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MICHAEL DONNE.

Air Correspondent of "F'nancial Times ”/ hti arranaemciit 1

Production of the One-Eleven short-haul jet airliner is now mounting rapidly at four major factories of the British Aniiraft Corpoiiition to meet an order book which already stands at /•> over £73m„ and which seems likely to rise to at least the It ( -mark In the end of this year. The One-Eleven may well become one of Britain s best-selling aeroplanes ever, although whether in numbers it will exceed the Viscount—production of which has now ended with -tooth aircraft —remains to be seen.

Many airlines throughout the world are now seriously thinking of replacing their piston-engined and turboprop fleets with jets, and their choice lies between the One-Eleven; powered by two Rolls-Royce Speys, and its American rival, the Douglas DC-9, powered by two Pratt and Whitney jet engines. The two aircraft are- similar in design, with the engines at the rear of the fuselage. Airlines which are known to be considering short-haul jets, at present include United, Trans World and Western in

the United States, Alitalia. K.L.M., Lufthansa and Swissair in Europe, and Trans Australia ' and Saudi-Arabian, among others, elsewhere. Vast Market It is already clear that the short-haul jet has a vast market potential, spread over nany years. The only developnent which seems likely to upersede it is the vertical >r short take-off airliner, but his is still in its earliest tages in the military field, md is unlikely to reach the ■ivil market at least until the nid-70’s. Furthermore, over 50 per cent of all air travelers go on journeys of 500 miles or less, and the passenger traffic curve continues to rise. Accordingly, many hundreds of short-haul jets of the One-Eleven/DC-9 category are likely to be ordered over the next decade. The Dutch Fokker F-28 will also become a contender for the market soon, and it is not beyond the bounds of possibility that some other manufacturers may try to get into this lucrative field over the next few years. So far, however, the OneEleven has a long lead over the DC-9, which will not fly

until early next year, and an even longer lead over the F-28. The serious blows dealt by the loss of two of the first five One-Elevens to fly. are being overcome rapidly, and the total delay to the programme' may be cut to just a few weeks. One-Elevens are now coming off the final assembly line at • Hurn, near Bournemouth, at the rate of two a month, and this will be maintained throughout this year. By December, 20 should be flying. By early 1965, production will be at the rate of four aircraft a month, and

tooling is already well under, way for a rate of six’ a month in 1966. Work is so far forward that at Weybridge, another of the four main factories involved (the others are at Filton and Luton), machining is already in progress on the forty-fifth set of wing panels. Five Flying The latest aircraft to fly was the fifth aircraft for British United Airways. Fuselages have been completed for the next five One-Elevens for Braniff and for the first of the heavier Series 300/400 development aircraft (a “Family” of One-Elevens for wide variety of roles is planned. Unconfirmed reports suggest that a West German store owner has ordered a One-Eleven as an executive aircraft). Components for the four Aer Lingus One-Elevens, the first two for Mohawk Airlines of the United States, and the first for Central African Airways, I are in an advanced stage of I construction.

Along with the mounting production programme, the extensive testing programme, both on the ground 'and in the air, has also got

.into its stride. The reasons for the loss of the first aircraft have now been analysed, land the necessary engineering j modifications arc being incor jporated on aircraft on the i production line. The loss of another One-Eleven recently was attributed to pilot error, not to any structural or mechanical faults, and does not require any further modilica tion programme. Ground Tests The ground testing is based on achieving a safe life for the aircraft of at least 40.000

i flights. Averaging 45 minutes each, this means 30.000 hours flying, which, at an annual utilisation of 3000 hours a year, in turn means a safe life of at least 10 years for every aircraft. The . ground test programme inchides the now customary water tank fatigue test undertaken on all new airliners. At Filton, near Bristol, tests on a com plete fuselage began last December. based on simulating flights of short duration but high frequency, in fact I achieving on the ground the precise conditions the OneEleven will experience tn the air. Each flight is simulated by a 90-second cycle of applied loads at various pres sure differentials to represent taxi-ing, take-off, climb, cruise and landing. Each cycle is repeated 40 times an hour for 16 hours a day, five days a week. The aim is to reach 100,000 simulated “flights" by mid-1967. Long before this however, the One-Eleven's safety will have been deter mined to the satisfaction of the Air Registration Board land the aircraft will have been certificated to both British and American standards and will be in airline service. But the testing programme will go on, for it is important to discover exactly what sort of life an aircraft’s structure can expect, since it may remain in service for many years. The long-term ground tests also help to show up quickly troubles that might occur later in an aircraft’s life, thereby giving the manufacturer a chance to forestall them.

Along with these fatigue tests, a vast programme of small-scale tests on a wide range of components, such as those involving major structural joints, is under way. A 100-ton testing machine is subjecting specimen components to two million applications of the specimen’s design loading, at the rate of 500 applications a minute—and this test is being repeated on three separate specimens of each component to be tested. All Aspects Studied i In the air, the flight test programme to date has been concentrated upon a preliminary study of all aspects of the aircraft. The aim is to find out early any items which may need special attention, thus leaving adequate time for them to be dealt with. The investigations so far have included preliminary handling and calibration, assessment of control forces, structural load measurements, single-engine handling, flapless take-offs, and landings, and autopilot tests. The total flight test programme for the Series 200 One-Eleven is planned to take about 1600 hours, and by the I middle of last week over 263 hours had been logged in over 160 flights. For the later Series 300 and 400 aircraft there will be additional certification flying, which will be undertaken on (two 8.A.C.-owned aircraft due I to fly towards the end of this pear. One of these aircraft lis also scheduled to undertake the development flying 1 on the Autoflare system, the preliminary stage towards I ultimate fully automatic or /’blind" landing, which could Ibe one of the One-Eleven’s most useful assets in the years ahead. In the meantime, most of the test flying has been done by the first aircraft for British United, G-ASJA, which Is primarily the systems testing aeroplane. This OneEleven has also made the first flights outside Britain to Zurich and Rome. To date, more than a score of pilots from over a dozen airlines have flight tested the OneEleven, and some of these have been from airlines which have not yet ordered. It may well be that they will do so soon.

Dr. M. A. F. Barnett, of Wellington, has been elected president of the Royal Society of New Zealand.—(P.A.)