The two years between Paris air shows is an arbitrary period, but for Boeing the 2007 and 2009 shows almost perfectly bookmark a dangerously turbulent period in its long and storied history. Finally - some might say mercifully - the 787 really does look like it will make its maiden flight this month. But unfortunately for Boeing it may take more than flawless test flights to repair the damage done to the programme - and the airframer's credibility - by the last two years of delay.

Striding about confidently and buoyed by announcements for 125 aircraft orders at the 2007 show, Boeing declared that the first 787 would be structurally complete at the time of its roll-out. Then-programme manager Mike Bair said it would fly by the end of summer.

We later learned that this falsehood was rooted in an unprepared supply chain, an immature design and a neglectful awareness of the situation. Now, after two years of delay, the patience of Boeing's airline customers has worn thin. Expansion plans are shelved and fleet renewals on hold, and all the while they are wondering whether promises of delivery timetables are realistic.

Paris 2009 turned into a graphic illustration of the impact of Boeing's badly damaged credibility as Boeing had to absorb two heavy blows.

Airbus as usual ran away with the big orders - but then it still plays the air show game while its US rival makes a point of not storing up announcements. So while that may not have been of concern to Boeing, alarms bells must surely have begun clanging back home in Seattle and Chicago came from a key customer, who held back no punches. This from Qatar Airways chief executive and important 787 buyer Akbar Al Baker: "Boeing doesn't realise how much they're hurting their customers' plans. They're very much mistaken if they think we're going to give them much more time on the issue."

The aggressiveness of its test and ramp-up plans suggests Boeing brass understand the scale of discontent among their 56 787 customers. Unfortunately, many don't share Boeing's confidence that it has set out a realistic schedule to get the programme back on track.

And, even if Boeing's 787 progress now runs to plan, it is going to have to deal with the dismay of customers who are suffering without an aircraft whose fuel efficiency was supposed to be their secret edge in a downturn.

So, when the 787 flies, the world will be monitoring more than Boeing's efforts to develop an airliner. It will be watching it try to reconstruct its credibility.

Source: Flight International