 |
| accident investigation: 56 phrases in 19 subjects |
| Airports and air traffic control | 1 |
| Astronautics | 4 |
| Automobiles | 1 |
| Aviation | 9 |
| Aviation medicine | 5 |
| Caspian | 1 |
| Diplomacy | 1 |
| Ecology | 1 |
| Electricity | 1 |
| Energy industry | 4 |
| General | 8 |
| Law | 1 |
| Military | 10 |
| Nautical | 2 |
| Oil / petroleum | 3 |
| Oil and gas | 1 |
| Production | 1 |
| Rail transport | 1 |
| Trade unions | 1 |