Boeing’s 787-9 is nearing entry into service with launch customer Air New Zealand, and is on schedule for a mid-year start of operations.
So far the programme has been seemingly unscathed by the developmental and testing breakdowns that plagued the introduction of the 787-8 – more than three years late – in 2011.
Functional and reliability testing – the last step in the certification process – has started on a 787-9 in All Nippon Airways livery, after the flight-test team accumulated 550 flights and 1,300 flight hours since first flight in September 2013.
As a group of journalists were allowed to tour one of the four 787-9 test aircraft for the first time on 29 April, at Boeing Field in Seattle, company officials again emphasised how the painful lessons from the 787-8 should lead to a smoother path to certification and a reliable start to operational service for the 6m (20ft)-longer variant.
Most of the reliability improvements added to the 787-8 since entry into service with All Nippon Airways in October 2011 have been rolled into the first 787-9 on the production line, says Mark Jenks, vice-president of 787 development.
“Air New Zealand is going to have essentially all of the improvements that we’ve driven from the -8. In addition, where we’ve made changes on the -9 where something is unique, we’ve taken additional steps to make sure we don’t have reliability issues with those unique components,” Jenks says.
For example, the 787-9 introduces a hybrid laminar flow control system embedded in the vertical fin. Boeing is keeping details of the invention a closely guarded secret, but the goal is to reduce drag significantly in cruise flight by preventing the airflow around the fin from transitioning to a turbulent stream.
Although the system is a first on a commercial airliner, Boeing is confident it has found a practical design that will meet reliability goals at the start of operational service.
“It’s very elegant,” Jenks says. “So we really don’t expect to have any issues with respect to the basic reliability of the system.”
Boeing officials acknowledge airlines may feel wary about the prospect of introducing a new variant of the 787. The 787-8 is still struggling to meet the industry standard – a 99.5% dispatch rating – more than two years after entering service. Two battery explosions in 2013 grounded the fleet for four months.
Although the overall programme schedule remains on track, the 787-9’s development has involved challenges. Most challenging has been the design of the mid-body fuselage section. A bottleneck developed on the production line in Charleston, South Carolina, as workers struggled to seamlessly add the stretched mid-body section into the production flow with the 787-8. Boeing officials have since said the issue is under control, and the bottleneck almost cleared.
Jenks acknowledges that side-of-body join – a section that caused a major redesign and delay on the 787-8 – also posed problems on the 787-9.
“There were a few frankly really minor adjustments we made through the process on the lower side of body for the -9,” Jenks says. “But nothing major. That’s why we were able to pretty much meet our schedule.”