IAH Airspace Boundary (0)
IAH Airspace Terrain (1)
IAH Airspace Tier Terrain (2)
Hobby Airspace Boundary (3)
Elignton Field Airspace Boundary (4)
Elington Field and Hobby Airspace Terrain (5)
Elington Field and Hobby Airspace Tier Terrain (6)
All Airport Tiers (7)
| Ellington-Tier 1 |
| Ellington-Tier 2 |
| Ellington-Tier 3 |
| GBIA Tier 1 |
| GBIA Tier 2 |
| GBIA Tier 3 |
| Hobby Tier 1 |
| Hobby Tier 2 |
| Hobby Tier 3 |
| <all other values> |
|
