Shortages of airworthy fasteners and flight control software have forced Boeing to further compress the 787's flight test schedule from a maximum of nine months to as little as five months.
Although first flight has drifted from August to at worst mid-December, the company is sticking to its original plan to deliver the first aircraft to launch customer All Nippon Airways - with a capability for extended-range twin-engine operations performance standards capability - in May 2008.
The 787 now faces an eight-month deadline to resolve its fastener and software problems, assemble and fly the first aircraft, assemble five more flight-test aircraft, integrate two different engine types (Rolls-Royce Trent 1000 and General Electric GEnx), complete a long list of airworthiness and ETOPS tests and deliver the first aircraft.
Assuming Boeing's current problems are fixable by December, the airframer acknowledges that the new schedule provides almost no margin for error if surprises appear in 787's flight test programme.
Mike Bair, Boeing's vice-president and general manager for 787, notes that more buffer could be added by eliminating flight tests, but that's "not something we want to do".
The "schedule crunch" means Boeing is revamping the way it will run the flight test programme and will run higher flight hour rates than on past programmes. "We're essentially going to be running an airline, 24h a day, seven days a week," says Bair. "On the 777 we averaged around 70-80h a month per airplane, we're going to do around 120h a month or bit more that on the 787."
While the schedule buffer has dwindled, Boeing executives seem sanguine with the programme's financial health, even if new issues delay delivery to ANA until August.
"A one-to-three month delay scenario will have minimal financial implications for us in 2008," says Scott Carson, president of Boeing Commercial Airplanes.
Bair remains optimistic that the flight-test phase will validate his team's predictions and not turn up any major new issues. But he caveats this by noting that the point of flight tests is to discover the "unknown-unknowns" before the aircraft enters operations. The 787's technology advances mean Boeing's team must prove the airworthiness of an all-composite fuselage and a more-electric onboard power system.
Boeing also confirms that the first 787 will be delivered with ETOPS capability "out of the box", although airlines such as ANA must seek individual certification by regulatory agencies.
Boeing expects the 787's maximum ETOPS duration will be 330min, but "regulatory agencies will likely require the airlines to operate at ranges less than that at the beginning - most likely 180min", the airframer says.
More immediately, both issues that delayed the first flight date remain active problems, but are on track to be resolved in late September, Bair says.
Flight controls supplier Honeywell and Boeing are trying to fix glitches in the 787's six million lines of software code. Despite leasing a 777 as a software testbed, the system still hasn't been cleared for flight status.
"We expect to complete our software development in the next few weeks to support a mid-November to mid-December [first flight]," Honeywell says.
The company also is struggling to overcome the worldwide industrial fastener shortage, with a lack of documentation from subcontractors frustrating the efforts of mechanics at the final assembly to identify and replace thousands of temporary fasteners.
"Right now it's a horse race between the two [problems] to see which one is going to be the biggest contributor [to the delay]," Bair says, adding: "Right now I think we'll get them both healed up in the same timeframe."
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Source: Flight International
