A Snecma Services team has fixed three low-pressure turbine blades on a CFM International CFM56-3 without removing the engine from under the wing of the Ukraine International Boeing 737-300. The team at Melun-Villaroche was able to undertake the on-wing repair without removing a single piece of the engine, except the borescope inspection plugs. The operation was followed by a dye check to verify for cracks in any of the parts, write Christina Mackenzie and Rob Coppinger.
The repair took about 12h with all parts manipulated through an access hole several millimetres in diameter under the engine.
Meanwhile, a new composite fan blade developed by Snecma is undergoing a demonstration programme following successful birdstrike and overspeed tests.
In trials since February the blades have survived the impact of a variety of bird weights. The blades have also passed "overspeed" tests, in which the blades are rotated beyond their design speed. Unlike with previous composite blades, the fibres are not wound in a parallel fashion. Instead, the form is built by weaving the fibres in three dimensions, with resin injected afterward. This production method is said to have the advantages of lower costs and fewer manual operations.
Serge Eury, Snecma Motors research and development vice- president, says: "They have a good resistance to impacts due to their 3D structure. These [bird] tests were carried out on a GE90 engine type fan blade."
Eury says a more complete demonstration programme is needed to qualify the technology.
Source: Flight International
