Originally, TransDigm manufactured and marketed a small group of aircraft components, such as batteries, pumps, and fuel connectors. TransDigm expanded its range of aircraft component products over time through acquisitions of other aerospace component manufacturers, growing in revenues by about 25 percent per-year from 1993 to 1998. In 1998, Odyssey Investment Partners, a private equity firm, acquired TransDigm from Kelso &amp; Company. After the September 11th attacks, the aerospace industry declined temporarily, resulting in losses and layoffs for TransDigm.