| # | Company name | Role | # of projects |
|---|---|---|---|
| 1 | Dekra Industrial - Vern-sur-Seiche | Check engineering | 1 |
| 2 | Dipl.-Ing. Heinz Deutsch | Check engineering | 1 |
| 3 | Dipl.-Ing. Rainer Gräfe | Check engineering | 1 |
| 4 | DMJM Aviation, Inc. | Check engineering | 4 |
| 5 | Dr. Ing. Helmut Kupfer | Check engineering | 2 |
| 6 | Dr. Kinkel | Check engineering | 1 |
| 7 | Dr.-Ing. Deutsch | Check engineering | 1 |
| 8 | Dr.-Ing. H.-H. Klein | Check engineering | 4 |
| 9 | Dr.-Ing. Jörg Erdmann | Check engineering | 2 |
| 10 | Dr.-Ing. Markwig Kordes + Partner | Check engineering | 1 |
| 11 | Dr.-Ing. Peter Henke | Check engineering | 1 |
| 12 | Dr.-Ing. W. Vogel | Check engineering | 1 |