Max Kingsley-Jones/LUTON Guy Norris/LOS ANGELES
Roger Lecomte, Airbus Industrie's vice-president of engineering support, says: "The introduction of the A330-200 was like that of the A321 [after the A320] for us. We were able to benefit from the lessons we learned with the introduction of the A330-300 and A340."
Lecomte says that the design of the A330-200 for longer-range missions than its A330-300 sister did not pose problems. "System-wise, the new model is essentially the same as the [long-range] A340 - in fact, the aircraft's utilisation is comparable to the A340's," he says.
Airbus says that the A330-200 fleet is being used on average around 10-15h a day, which is similar to that of the A340 fleet, and somewhat greater than that of the A330-300. The larger model, which tends to be used more on regional services, averages 6-10.5h daily utilisation.
The difference in the two A330 models' roles is highlighted more by the average flight-sector times, which, on the A330-200 is 3.5-8h (similar to the A340), compared to 1.7-3.5h for the A330-300. Lecomte says that the A330-200 fleet is showing an hours-to-cycles ratio of 4:1, compared to the -300's 2.2:1.
Canada 3000 and Monarch have the hardest-working fleets, topping the A330-200 utilisation figures with 15h a day. The worldwide A330-200 fleet is recording a dispatch reliability (departure within 15 min of schedule) of 98.9%.
For Airbus, the two most serious issues during the A330-200's first phase of service have been the nosegear steering limitations and leaking shock absorbers.
A 60° limit on the turning angle of the nosegear was imposed on all A330s and A340s following a landing accident involving a Sabena A340 at Brussels in August last year. The Sabena incident, in which one of the attachment fittings on the aircraft's Messier Dowty-built main landing gear (MLG) failed, was found to have been caused by excessive side-loads placed on the gear during taxiing.
Originally the type's brake/steering unit was programmed to allow a maximum 78° of deflection. Operators were also permitted to use differential thrust and braking during turning manoeuvres, but these can no longer be employed.
The limitation can cause problems at airports that do not have full-length taxiways because the aircraft has to be able to make a 180° turn at the end of the runway. The 60° limitation means that an A330-200 requires a minimum runway width of 51m, although the average runway width is around 45m.
Lecomte says that Airbus is aware of the problems imposed by the steering limitations, and expects these to be resolved early next year. "We have undertaken detailed studies of the loading and stresses on the undercarriage, and have a solution being prepared for the authorities. The limit should be lifted in January," he says.
Airbus has conducted a study of the world's airports and A330/A340 operator requirements, and has deemed that restoring a steering angle of 72° (6° lower than the original maximum) will "meet customers' expectations". Although some earlier A330/A340s will need modifications, aircraft with the latest "G" standard MLG will be approved for the 72° limit without modification. All A330-200s in service are equipped with the "G" specification MLG, and Airbus says that the introduction of a 72° limit will allow the aircraft to meet operators' requirements of being able to make a "U-turn" on a 45m-wide runway.
Airbus is known at one point to have considered approving greater maximum turn angles on an airline-by-airline basis, depending on individual requirements, with a commensurate reduction in main undercarriage life limits. However, Airbus says it is not now considering this.
Lecomte says that the failure of double seals in the main landing-gear (MLG) shock absorbers has been the new model's most serious problem. After two or three fixes failed after introduction, Airbus is being more cautious before it authorises its latest solution.
"We are about to begin an in-service evaluation trial with various operators, including Swissair," says Laurie Alder, A330/A340 product support programme manager. "We want to make sure that this fix will work." The trial is expected to last six months, but "we will not wait if we get good results", says Lecomte.
Intense competition between the engine makers, plus lower than expected life-cycle endurance on CF6-80E1 powered A330s, prompted General Electric to push forward with development of the more powerful -80E1A3 variant.
The move followed an incident in May 1998, when Canada 3000's first A330-200 made a precautionary diversion on its inaugural flight because of an oil leak in the number four bearing sump.
Rated at 72,000lb (320kN) thrust, the new -A3 incorporates a high pressure "boltless" turbine and is expected to raise life limits back beyond GE's original target of 15,000 cycles.
GE plans to offer the upgrade, including new three-dimensional aerodynamic designs in the turbine, to all CF6/A330 operators in a two-year programme beginning next year. Pratt & Whitney, meanwhile, reports "excellent" service reliability of the PW4168A-powered A330-200 fleet. According to PW4000-100 model manager, Steven Adamski, in-flight shutdowns and unscheduled engine removals were at zero by the end of October. Dispatch reliability for the engine was 99.98% and 99.99% for the nacelle for the same time period. The P&W-powered fleet has accumulated around 51,000h and 17,000 cycles.
Rolls-Royce took the opportunity to introduce a new Trent 700 production standard with the A330-200's debut, delivering the first Trent 772B engine on an Air Transat A330-200 in February.
The company says that the latest engine has recorded zero in-flight shutdowns, and no unscheduled engine removals or aborted take-offs since introduction. The in-service 772B/A330 fleet has completed 40,000h and 11,000 cycles, with dispatch reliability running at 99.6%.
The 71,200lb-thrust 772B incorporates Trent 800 technology to provide performance and reliability improvements, primarily in the high pressure system, says the manufacturer. The changes typically provide more thrust at higher altitudes, or equivalent thrust at higher ambient temperatures.
Source: Flight International
