Engineering in the field of aeronautics; Consulting in the field of aeronautical engineering; Engineering design services in the field of aeronautics; Quality control for others in the field of aeronautics; Research and development of new products for others in the field of aeronautics; Testing, analysis and evaluation of the goods and services of others to determine conformity with certification standards in the field of aeronautics; Testing, analysis, and evaluation of the goods of others t...