Appendix B: Acronyms
MSAW—Minimum Safe Altitude Warning
MSL—Mean Sea Level
MTA—Minimum Turning Altitude
MTR—Military Training Route
MVA—Minimum Vectoring Altitude
N
NA—Not Authorized
NACO—National Aeronautical Charting Office
NAS—National Airspace System
NASA—National Aeronautics and Space Administration
NAT—North Atlantic
NAVAID—Navigational Aid
NCAR—National Center for Atmospheric Research
NDB—Non-Directional Beacon
NextGen—Next Generation Air Transportation System
NFDC—National Flight Data Center
NGA—National Geospatial- Intelligence Agency
NM—Nautical Mile
NMAC—Near Mid-Air Collision
NNEW—Next Generation Network-Enabled