The 777 has the most extensive in-flight test program of any previous Boeing model. Nine airplanes will be used with engines from all three manufacturers. Before the test program is completed, the 777’s will fly nearly 7,000 hours in more than 4,900 flights. The flight testing for each engine configuration will last about one year with customer involvement of flight and ground crews in the latter stages of the test programs. All of the 777’s involved in testing will carry large amounts of instrumentation and data recording equipment and will return to the factory after completion of testing for retrofitting before delivery to the airlines. One of the pleasant surprises that resulted from the flight testing was the lower than expected aerodynamic drag of the fuselage. The reduction in drag saves about 15-20 minutes on a typical flight between Seattle and London.
The full scale failure test of the wings on the #2 production airplane is quite impressive. Each wing was subjected to 500,000 pounds of force and the wing tips deflected 24 feet before failing at 154% of maximum flight loads, well above the 150% target. The applied force represents a factor of safety of 1.5 times the loads experienced during a 2.5 g dive maneuver. The right wing failed 0.020 seconds before the left wing. Over 2000 individual strain gauges were used to instrument the plane with 500 miles of cables relaying the data.
Originally developed by Shadd Shokralla
