In a corner of Bordeaux-Merignac airport (south western France), facing the Dassault factory, an area is surrounded by walls insulating the rest of the world from the noise of blasts of air-flow generated by aircraft engine tests.
An obligatory passage for any aircraft having just rolled off the assembly line. This test area is dedicated to what are called “run-ups”; and it’s here that the engines of these Falcons have just been turned over for the first time.
Michel Malard, flight test reception manager - Dassault Aviation: watch the interview in the video.
Produced under the supervision of an inspector mechanic, with the help of two other mechanics, the run-up testing takes on average two to three days. With the plane stationery, restrained by chocks, engines and all aircraft systems will then be tested individually in a very specific order. Depending on the aircraft, from 40 to 50 pages of tests are carried out. The measurements registered by on-board or external instruments, are then recorded in the log.
Using a stopwatch, the inspector mechanic will check how long it takes for the engine to start, to switch off, and the transition time from low to high rev’s; measurements will also be taken of temperatures as well as for environmental vibrations to verify proper installation of the engines. Finally, visual checks, with engine covers open, are also on the list.
Michel Malard, flight test reception manager - Dassault Aviation: watch the interview in the video.
Facing upwind so that a maximum of air enters the engine air intake, and that exhaust gases are discharged into the opposite downwind direction, the run-up is normally done once only. But if significant changes are made to the aircraft during its life time, such as a change of certain equipment, connections or even engines, a new run-up must be carried out. A test that pushes the engines to their extreme, but for safety, never all at the same time.
It’s only after the next step, the safety inspection, that the engines are tested together, thoroughly, under full throttle during the rolling or taxiing tests, where the acceleration and braking will be tested on the ground. After which, the plane will then, finally, begin its first tests in the air.
