Saturday, 14 December 2013

BAC One-Eleven Short Haul Airliner

BAC One-Eleven Short Haul Airliner :

Introduction :

The BAC 1-11 story began in the 1950s as Vickers Armstrong and Hunting Aircraft commenced work on two separate design studies for a short haul jet airliner. By 1961 the newly formed British Aircraft Corporation decided to proceed with the project and on the 9 May 1961 the public launch took place as the first order was announced by the company for 10 aircraft from British United Airways. On 23 October Braniff Airways placed a firm order for 6 aircraft. Other orders soon followed from Mohawk Airlines for 4 aircraft, Kuwait Airways for 3 aircraft and by Central African Airways for 2 aircraft. Braniff Airways subsequently doubled it's order to 12 aircraft while Aer Lingus ordered 4 aircraft. Western Airways ordered 10 aircraft but later it was cancelled. The biggest breakthrough came when American Airlines ordered 15 aircraft on the 17 July 1963. 60 orders had been received by the time the first 1-11 was rolled out.

History :

Back in the mid-1950s, jet power was beginning to make its mark in the commercial airline world. The DeHavilland Comet and the Boeing 707 designs were progressing and picking up orders in the long-haul four-engined jet market, and with passengers enjoying the smoother jet experience manufacturers were beginning to turn their attention to the short-haul market. Sud Aviation of France led the way with the SE-210 Caravelle, but Douglas (preparing a design that would become the DC-9) and the British aircraft industry were also moving in the same direction. Two British designs were put on the drawing board - the 14--seat Vickers VC11 and the 32-seat Hunting 107. The latter, powered by Bristol Orpheus engines, was aimed at the Viscount replacement market, but after market research and input from a British European Airways (BEA) design paper that was aimed at procurement of a short-haul jet, the proposed capacity was upped to 48 seats and Bristol Siddeley BS.75 engines introduced. The 1960 amalgamation of several of the U.K.'s airframe manufacturers into the British Aircraft Corporation (BAC) brought the Hunting and Vickers design teams together, and after a careful examination of the market the BAC.107 design was seen as a more commercially viable proposition than the VC11. Initial design work saw the capacity upped again to 59 and the airframe reconfigured with a T-tail, but feedback from U.S. airlines led to a further capacity increase to 80 seats, this being achieved through an increase in fuselage diameter that allowed for five rather than four abreast seating. Engines were changed again to a pair of Rolls Royce RB-163 Speys, and the aircraft was designed with a great degree of self-sufficiency in mind (including an APU and internal air-stairs) to again accommodate the demands of the U.S. market. These changes led to a designation change to BAC.111. The BAC board gave the go-ahead for the One-Eleven in March 1961, approving the construction of an initial batch of 20 aeroplanes.

Initial Orders, First Flight and a Major Setback :

The first order for the BAC.111 came on 9th May 1961 when the project was formally launched in public it was announced that British United Airways (BUA) had committed to ten. Ozark Airlines and Frontier Airlines in the USA also made commitments at the launch, but problems with the import of foreign jets led to both orders being dropped. Braniff Airways however did place an order for six in October 1961, and this order was fulfilled - it was the first time a US airline had ordered a non-American design off the drawing board. 1962 saw orders from Mohawk Airlines in the USA (4), Kuwait Airways (3), and Central African Airways (2), whilst 1963 saw a still-born order from Hawaiian Airlines (3), Braniff upped its order to twelve, and Aer Lingus committing to four. Whilst these initial orders were for the base series-200 aircraft, in 1963 BAC announced heavier series-300 and series-400 variants with uprated engines - American Airlines ordered 15 400s in July.

On 28th July 1963, the first BAC.111 (curiously given manufacturers serial number 005) rolled out of BAC's factory at Hurn in BUA's colours. G-ASHG took to the air for the first time for a 27 minute flight on 20th August 1963, just five months after the competing DC-9 had been launched. With 60 orders for 111s on its books at the time, BAC had taken more orders before first-flight than had been taken for any other British airliner.

By October, over 70 hours had been flown by the prototype and all of the initial general handling tests had been completed. On 22nd OctoberG-ASHG - the only prototype to have flown - crashed near Cricklade in Wiltshire with the loss of all onboard. The loss was attributed to a condition known as a "deep stall"; during a stall the disrupted airflow over the wings impinges on the high-mounted T-tail, resulting in it losing effectiveness and making recovery from the stall impossible. BAC modified the wing leading edge design and incorporated a stick pusher that would force the nose of the aeroplane down before the stall became too developed, and the test program resumed on 19th December 1963 when the second One-Eleven flew for the first time. The loss of the prototype wasn't the only set-back during the test program however - the third aircraft was written off following a heavy landing 18th March 1964 just a month after it first flew, and the fifth aircraft made a forced landing on Salisbury Plane on 24th August but was dismantled, moved back to Hurn and subsequently rebuilt.

None of these issues seemed to affect the 111 though, and on 9th April 1965 the type received its UK Type Certificate of Airworthiness. FAA approval for the type came one week later. 

Airline Service and Airframe Development :

British United Airways put the One Eleven into service the same day as the CofA was granted - G-ASJJ (aircraft number 14) flew from London Gatwick to Genoa in Italy. Braniff followed on 25th April 1965 with its first revenue flight from Corpus Christi to Minneapolis. Orders continued to be confirmed in 1965 too - Mohawk added two more, Aloha AIrlines and TACA of El Salvador both ordered two, British Eagle took two and Philippines added one to its previous order for two. 1965 also saw the first flight of the series-400, destined for American Airlines - the variant flew for the first time on 13th July 1965 and was certified in November 1965. So successful was the BAC 111 becoming that by 1966, as well as receiving further orders from Mohawk, Aloha, LACSA of Costa Rica, Lanica of Nicaragua, Laker Airways, Channel Airways and Bavaria, BAC had set up a second production line at Weybridge - 46 aircraft were delivered in 1966 alone.

By the end of 1967, 100 One-Elevens were flying with airlines. Earlier in the year on 27th January, BAC had launched the 13' 6" stretched 111-500 on the strength of an order for 18 from BEA, and had flown a stretched series-400 as a -500 prototype on 30th June. The -500 could accommodate 20 more passengers than the earlier series and featured uprated Spey engines and an improved wing design to help preserve take off performance. The first production aircraft for BEA flew on 7th February 1968 and the variant was certificated on 15th August the same year. A higher-weight variant of the -500 flew in 1969 and was delivered to Caledonian Airways later the same year.

120 111s were delivered between 1968 and 1971. With sales beginning to wane BAC looked at a further stretch that would have given the 111 a similar capacity to the Douglas DC-9 and Boring 737 variants being offered to airlines. However, with Rolls-Royce struggling following its bankruptcy, the Spey engine had reached the limit of its development and further stretches of the 111 were seen as non-viable without a change of engine. In order to stimulate sales BAC developed the series-475, a short-bodied 111 with the uprated wings and engines of the -500 series and other design modifications that were aimed at making the 111 suitable for rough, hot and high airfields but only 12 were sold. A further stretch powered by CFM-56 engines was also proposed in the late 1970s, but by that time BAC was involved in developments with Airbus and the design was not progressed. Only 35 111s were produced in the last 12 years of UK production, and One-Eleven production was eventually transferred to ROMBAC of Romania. The first One-Eleven built at Baneasa flew in 1982 - by that time, the last two 111s built in the UK had rolled out of the factory at Hurn but had not been sold. Despite supplying kits for 22 aircraft, only nine were built in Romania. BAC built 235 111s, of which 232 were delivered to customers - 56 series-200s, 9 series-300s, 69 series-400s, 12 series-475s and 86 series-500s. Adding the Romanian aircraft to these totals, the One-Eleven sold 241 - a major success by British airliner manufacturing standards but falling massively short of the production totals for the rival Douglas DC-9 and Boeing 737.

The One-Eleven in 2013 :

August 20th 2013 is the 50th anniversary of the One-Eleven's first flight. Only two remain in service, both airframes used by Northrop Grumman to test new systems and sensors. A third aircraft in V.I.P. configuration is potentially airworthy but by the time of the type's 50th birthday had been stored in Dallas, Texas. Whilst the One-Eleven achieved some notable early sales successes and achieved a good production run by UK standards, sales of the type were ultimately thwarted by its lack of capacity growth potential. BAC had an early sales lead over the rival Douglas DC-9 and later the Boeing 737, limited sales after the first few years resulted mainly from a lack of power increase potential from the Spey engine which was an issue that did not challenge its American rivals powered by Pratt & Whitney JT-8D engines. That far fewer 111s remain flying than its rivals is also testament to the limited potentially for 'hushing" the type's noisy Speys. Many observers and passengers will fondly remember the 111 with its shrieking Spey engines, but few will get to see one flying beyond the type's half century in the air.

Variants :

- BAC One-Eleven 200 
    Initial production version, 10,410 pounds-force (46.3 kN) Spey Mk 506 engines.; individual customer designations within this series. 56 built.

- BAC One-Eleven 300 
    Uprated engines (11,400 pounds-force (51 kN) Spey Mk 511s), more fuel for longer range; individual customer designations within this series. 9 built.

- BAC One-Eleven 400 
    Series 300 with American instrumentation and equipment; individual customer designations within this series. 69 built.

- BAC One-Eleven 475 
    Series 400 body with Series 500 wing and powerplant plus rough-airfield landing gear and body protection. 9 built, including 3 for Oman.

- Rombac 1-11-495 
    Planned Romanian-built version of the Series 475. None completed.

- BAC One-Eleven 500 
    Extended body version with up to 119 seats and longer span wings. Fitted with more powerful engines (12,550 pounds-force (55.8 kN) Spey 512s); individual customer designations within this series. 86 built.

- BAC One-Eleven 510ED 
    Variant of the 500 series built for BEA/British Airways. Size and engines same as other 500s, cockpit modified to provide more commonality with HS.121 Trident and required a different type rating from all other 500 series One-Elevens.

- Rombac 1-11-560 
    Romanian-built version of the Series 500. Nine completed.

- BAC One-Eleven 670 
    Series 475 with improved aerodynamics and reduced noise; one converted from Series 475.

BAC One-Eleven Short Haul Airliner.


Preeti Bagad [BE(CS)] 
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