Chapter 1 — IFR Operations in the National Airspace System
Today’s National Airspace System (NAS) consists of a
complex collection of facilities, systems, equipment,
procedures, and airports operated by thousands of people
to provide a safe and efficient flying environment.
The NAS includes:
- More than 690 air traffic control (ATC) facilities with associated systems and equipment to provide radar and communication service.
- Volumes of procedural and safety information necessary
for users to operate in the system and for Federal Aviation Administration (FAA) employees to effectively provide essential services.
- More than 19,800 airports capable of accommodating
an array of aircraft operations, many of which support instrument flight rules (IFR) departures and arrivals.
- Approximately 11,120 air navigation facilities.
- Approximately 45,800 FAA employees who provide
air traffic control, flight service, security, field maintenance, certification, systems acquisitions, and a variety of other services.
- Approximately 13,000 instrument flight procedures
as of September 2005, including 1,159 instrument landing system (ILS), 121 ILS
Category (CAT) II, 87 ILS CAT III, 7 ILS with
precision runway monitoring (PRM), 3 microwave
landing system (MLS), 1,261 nondirectional beacon
(NDB), 2,638 VHF omnidirectional range
(VOR), and 3,530 area navigation (RNAV), 30
localizer type directional aid (LDA), 1,337 localizer (LOC), 17 simplified directional facility (SDF), 607 standard instrument departure (SID), and 356 standard terminal arrival (STAR).
- Approximately 48,200,000 instrument operations logged by FAA towers annually, of which 30 percent
are air carrier, 27 percent air taxi, 37 percent general aviation, and 6 percent military.
America’s aviation industry is projecting continued
increases in business, recreation, and personal travel.
The FAA expects airlines in the United States (U.S.) to
carry about 45 percent more passengers by the year 2015
than they do today. [Figure 1-1]
Figure 1-1. IFR Operations in the NAS.