MAX KINGSLEY-JONES / LONDON
The A318 enters service next month with launch customer Frontier, marking the culmination of a difficult development programme
The Airbus A318 may have been a problem child for its loving parent during its formative years, but it is now full speed ahead for the smallest Airbus model. Since its launch four years ago, the 107-seater programme has suffered major development delays, an internal row over assembly workshare arrangements, and a raft of order cancellations. But with certification in place and service entry with Frontier Airlines round the corner, Airbus is confident the programme is back on its feet.
Born after the collapse in 1997 of the 100- to 120-seat AE31X regional aircraft programme planned with China, the A318 was conceived as a "cut and shut" derivative of the A319 to give Airbus a rival to the smallest Boeing 737, the -600, and the Boeing 717, which had just been renamed from the MD-95 after Boeing's takeover of McDonnell Douglas, and was pushed as the US manufacturer's primary 100-seat offering.
The A318 programme was unveiled at the Farnborough air show in 1998 as a hybrid aircraft featuring much airframe commonality with the larger A320 family members, but being offered with a single, unique powerplant - the Pratt & Whitney PW6000.
By its launch in April 1999, the A318 had accumulated 109 orders and commitments from six customers, including Air France, EgyptAir, International Lease Finance and TWA. Service entry was set for late 2002.
In July 1999, CFM International came aboard the A318 as part of the deal with Air France, offering a derated derivative of the CFM56-5B that powers the larger models. This move later allowed the General Electric/Snecma joint venture to come to Airbus's rescue when the P&W engine ran into major development problems.
The A318 was the last major derivative to be launched by Airbus under its old consortium structure, and before the creation of EADS. With A320 family final assembly divided between Hamburg (A319/A321) and Toulouse (A320), there was some dispute between the old Aerospatiale and Dasa over who should have responsibility for the new model. In the end, it was allocated to the German partner (now Airbus Deutschland) and an agreement reached for offsets to the French plant with the promise of A319 overspill production - although this is yet to happen because of production cuts.
Reduced seating
The A318 is 4.5 fuselage frames shorter than the A319, reducing overall length to 31.44m (103ft 2in) and two-class seating by 17 passengers to 107 - similar to the 737-500/600 and the 717.
During development it became clear the P&W engine would not meet its performance guarantees and the engine programme was delayed by three years. Airbus "didn't want an aircraft that couldn't perform as advertised out of the box", says A320 family director product marketing Stuart Mann. The programme was reorganised with the CFM56-powered version as the lead variant. Although the PW6000-powered version was still the first to fly, in January last year, the CFM56 programme was accelerated to enable first deliveries in July 2003, about seven months later than the P&W version's original in-service target.
The delay was caused by an engine redesign after it failed to meet fuel consumption targets, resulting in the original five-stage high-pressure compressor (HPC) being replaced by an MTU-designed, six-stage HPC. It came as a blow as most A318 customers had specified the P&W engine. Although 129 A318s were ordered, the orderbook has shrunk to 84 due to switches to other A320 family aircraft, and TWA's financial woes which led to its takeover by American Airlines. Frontier, an early customer for the PW6000-powered A318, switched to the CFM56 and will be the first to take delivery of the aircraft, in July. Air France's first aircraft will follow in October.
Four A318s for Frontier and five for Air France are due for delivery this year. Seven A318 deliveries are planned for 2004, and 23 in 2005. Up to 45 aircraft could be delivered in 2006, including initial PW6000-powered A318s.
Of the original PW6000 customers, only America West and ILFC remain, and America West has slipped deliveries to 2006-8 as part of its restructure. Air China, British Airways and EgyptAir switched their A318 orders to the larger A320s (but kept the P&W link by specifying the International Aero Engines V2500).
The second A318, also PW6000-powered, began flight tests in June 2002, when the first aircraft was grounded for re-engining with CFM56s. This aircraft returned to the air with new engines in August. The two aircraft accumulated 850h and 350 flights during the 17-month test programme, which culminated in European Joint Aviation Authorities certification of the CFM56-powered version on 23 May. US Federal Aviation Administration approval is due this month.
Flight testing covered the performance of the aircraft in all phases of flight, including an evaluation of handling qualities. Tests included flight envelope definition and fly-by-wire protection parameters; flutter and ground effect; climb performance; braking and auto-land performance; noise measurement (for the CFM56 version); engine-out take-off performance; and the performance of the CFM56-5B at the A318's thrust ratings - 21,600lb (96kN) and 23,300lb.
Rejected and abuse take-offs with the aircraft operating outside normal parameters, including minimum unstick speeds (VMU), were undertaken at the French national flight test centre at Istres in December with the CFM56-powered aircraft. Hot and high demonstrations were also carried out at Mexico City (elevation 7,341ft) in March when the aircraft flew to North America for an air show in Acapulco.
"Overall, there were no big surprises during flight testing, and the aircraft generally performed as predicted," says Airbus. Meanwhile, the reconfigured PW6000 began initial test runs in early 2003, and three test engines have now accumulated 370h of testing and 271 full cycles. All three test engines either "meet or exceed" the HPC efficiency improvement target of 5% relative to the Block 2 configuration of the earlier five-stage HPC engine.
Looking ahead
P&W says six test engines will be running within two months and flight tests on its Boeing 747SP are still expected to start on schedule in the third quarter of 2003 for FAA certification in November 2004. First flight on the A318 is now due in the first quarter, with entry-into-service expected to occur in the fourth quarter of 2005 to "suit the delivery timescale of ILFC and America West", says P&W.
When the new PW6000 is approved, the first A318 will be re-engined and will undergo about 100h of engine performance-related testing for certification of that variant. This will take place in 2005, with certification targeted for November that year.
So despite its bad start, the A318 is poised to start earning money for its customers. Airbus is confident the future is now brighter for its smallest model. "The A318 extends the family for A320 customers," says Airbus vice-president marketing Colin Stuart. "We expect to sell the majority to existing A320 operators."
Frontier will be the first to put the new baby to the test, and will introduce the aircraft next month alongside its fleet of 17 132-seat A319s from its hub in Denver, Colorado. The airline says the 114-seaters will replace its similarly sized 737-200s on its thinner routes, and could also be used on lower demand longer-haul flights.
Source: Flight International
