Boeing ( BA) has some questions to answer. The aircraft maker, which will announce second-quarter results Wednesday morning, said a month ago that its once-vaunted 787 program faces more delays, a result of higher-than-expected stress at about three dozen points where the aircraft's wings are jointed to its body. Boeing promised to update financial guidance when it announces earnings and to provide a new 787 development schedule "in several weeks." Expectations are not high. Broadpoint Amtech analyst Peter Arment says it remains unclear whether the company will provide a new 787 schedule. "It's a big uncertainty whether there has been enough time since the delay announcement for them to have an accurate schedule," he says. "Enormous complexity is involved in these (stress) tests, and there's a sense we may not hear for a few more weeks. In trading Thursday morning, Boeing shares were up 1.3% to $42.76 a share. "Their future is certainly tied to the success of this program," Arment adds. Even after 60 cancellations this year, the 787 remains a showpiece product and accounts for 850 of Boeing's 3,469 outstanding orders. Even with delays, deliveries are likely to begin years before deliveries of its principal competitor, the Airbus A350XWB. A second question is whether Boeing will reduce full-year earnings guidance of $4.70 to $5 a share, which it provided at the end of the first quarter. "Odds are they will lower it," says Gradient Analytics analyst Brent Miller. "If they don't lower it, it will be a challenge to meet it." Analysts surveyed by Thomson Reuters obviously agree: they estimate full-year 2009 revenue to be $4.52.