Winner: Richard Wolf
Location Knittlingen, Germany
Achievement Combining grinding and borescope tools to allow compressor-blade repairs without engine removal. Like many of the best innovations, this year's winning entry in the Maintenance category is a relatively simple concept, but one which could save the aviation industry millions of dollars. Richard Wolf's idea was to combine a borescope - the instrument used for internal engine inspections - together with the blending tool required to perform compressor-blade repairs. The result is that engines can be repaired on the wing, without expensive unscheduled removals.
Borescopes have long been used for inspecting damage to compressor blades and other engine inernals. If the damage exceeds the allowed limits, the next step was to disassemble the engine and replace or repair the damaged blade. In many cases, the compressor blades can be reshaped or "blended" back to a smooth profile in the maintenance shop and re-installed.
The cost of removing the engine from the wing in the first place can be extremely high, however, not least because of the requirement for a test-cell run before the re-assembled powerplant is allowed back into service.
Wolf's Blending Scope for the first time combines a borescope with a rotating grinder which allows the compressor blades to be inspected and, if necessary, repaired in situ.
The tool costs less than $30,000 and fits into a small suitcase, but the potential costs savings are massive. The unscheduled removal of a modern turbofan can take around a week and cost an operator well over $100,000. By contrast, on-wing blending can generally be completed in a one-night stopover. One operator of a medium-sized aircraft fleet already estimates that the tool is saving at least one unscheduled engine removal each month. Carriers such as American Airlines are now also able to use the tool to carry out blending at the very first sign of blade damage before it has a chance to become serious.
In August 1996, the Blending Scope helped General Electric to avoid pulling a GE90 engine out of its time-critical certification effort.
After pioneering work with Lufthansa and GE, Wolf launched the tool in 1996, and was quickly included in the Boeing 747 manual for maintenance of the GE CF6. Use on the CFM International CFM56 was approved at the end of the year and approval is due to follow shortly at Pratt & Whitney and Rolls-Royce.
Source: Flight International
