The aircraft maintenance professional's source for technological advancements, maintenance alerts, news, articles, events, and careers
Issue link: http://amt.epubxp.com/i/789984
GENER AL AVIATION 28 JANUARY/FEBRUARY 2017 AIRCRAFT MAINTENANCE TECHNOLOGY THE STAMPE SV4 IN THE AEROSPACE WORLD, THE procurement of spare parts is not always easy and is usually expensive, specially for older aircraft. At some point, when it comes to vintage aircraft, spare parts become rare, or in a worst case they simply don't exist anymore. A historically signifi- cant airplane disappears from the airfield and becomes in a best case a static exhibit in the museum. Today, with a help of reverse engineer- ing technology the active life of such an airplane or entire fleet can be extended at a reasonable price. Till just a few years ago the failure of an engine part in a vintage airplane often was its death sentence. Now, there is a way to prevent the aircraft from being wrecked and to get them back in the air, even if there are no spare parts available. Sheet metal parts are easier to recon- struct, engine parts, specially the big ones like engine blocks, are one much different and complicated story. This is mainly, because after decades casting molds don't exist anymore — usually the original manufacturer went out of business decades ago and a new series production is not feasible for reasons of cost. In this case, reverse engineering technology now helps to reconstruct parts. This process, a kind of reverse development, makes it possible to re-create a product, which exactly equals to the original part, using an existing (broken) part, a piece of it, or a blueprint. In doing so, reverse engineering must go through a certain process, which includes the strategic consideration of how this "restoration" has to happen — where a specific succession of steps is required. This reverse engineering has many simi- larities with the design of a new part. On the recovery path, from a damaged or no longer existing part, many prob- lems have to be solved, because such a process is not simply a copy of the origi- nal part. Thanks to modern technologies such as 3-D scanning and new designer software, almost everything has become "doable," even with much better properties than the original part. An improvement of the properties is usually not (always) desired in aviation, since the parts have to meet the original certification stan- dards. If reverse engineering is used for the commercial reproduction of parts, extensive industrial property rights and the corresponding licensing laws must also be observed. Parts for experimental aircraft can be reproduced in better qual- ity, can be lighter, and cheaper, since less legal standards have to be met. A certi- fied part has to be restored according to OEM (original equipment manufacturer) specification, as the original part was. It could, however, also be improved by more modern technology/materials, but this has to be coordinated by and with the OEM and the aviation authorities, otherwise the certification may be lost. In a concrete example, which I have discovered at the last AirVenture in Oshkosh, I would like REVERSE ENGINEERING: HOW TO RECONSTRUCT AIRCRAFT PARTS By Marino Boric