Data furnished by Boeing since last week reveals just how thin is the margin for error for completing the compressed 787 flight test schedule on time for a mid-May delivery to launch customer All Nippon Airways.
Randy Tinseth, Boeing’s vice president for marketing, disclosed on his blog last week that the 787 flight test schedule will require 3,100 hours of flight tests and 3,700 hours of ground tests.
Mike Bair, Boeing’s vice president and general manager for 787, told analysts and journalists on 5 September that the six flight test aircraft will be delivered in two-to-three week intervals, and that each aircraft will fly about 120 hours per month during the test period.
To extrapolate from this data, Flight calculated the maximum utilisation of the fleet if the first 787 starts flying in mid-November and the five remaining aircraft follow in two-week intervals with no interruptions.
Based on these parameters, Boeing’s flight test fleet would have a maximum utilisation of about 3,420 hours, or only a 320-hour cushion to maintain schedule if any surprises arise.
Although not a precise measurement, Boeing’s data offers a revealing glimpse of how little room for manoeuvre is left to the flight test team if there are delays of any kind.
For example, the first flight launch window stretches from mid-November to mid-December. If the 787’s first flight occurs at the end of that window, Boeing’s utilisation of the flight test fleet drops to 2,700 flight hours, or 400 hours less than the programme requires.