4. Ground Control: Noting that the flight is IFR, receive taxi instructions. 

5. Tower: Pre-takeoff checks complete, receive clearance to takeoff. 

6. Departure Control: Once the transponder “tags up” with the ARTS, the tower controller instructs the pilot to contact Departure to establish radar contact. 

7. ARTCC: After departing the departure controller’s airspace, aircraft is handed off to Center, who coordinates the flight while en route. Pilots may be in contact with multiple ARTCC facilities; they coordinate the hand-offs. 

8. EFAS/ Hazardous Inflight Weather Advisory Service (HIWAS): Coordinate with ATC before leaving their frequency to obtain inflight weather information. 

9. ATIS: Coordinate with ATC before leaving their frequency to obtain ATIS information. 

10. Approach Control: Center hands off to approach control where pilots receive additional information and clearances. 

11. Tower: Once cleared for the approach, pilots are instructed to contact tower control; the flight plan is canceled by the tower controller upon landing. 

A typical IFR flight, with departure and arrival at airports without operating control towers, would use the ATC facilities and services in the following sequence: 

1. FSS: Obtain a weather briefing for departure, destination, and alternate airports, and en route conditions, and then file a flight plan by calling 1-800-WX-BRIEF. Provide the latitude/longitude description for small airports to ensure that Center is able to locate departure and arrival locations. 

2. FSS or UNICOM: ATC clearances can be filed and received on the UNICOM frequency if the licensee has made arrangements with the controlling ARTCC; otherwise, file with FSS via telephone. Be sure all preflight preparations are complete before filing. The clearance includes a clearance void time. Pilots must be airborne prior to the void time. 

3. ARTCC: After takeoff, establish contact with Center. During the flight, pilots may be in contact with multiple ARTCC facilities; ATC coordinates the hand-offs. 

4. EFAS/HIWAS: Coordinate with ATC before leaving their frequency to obtain inflight weather information. 

5. Approach Control: Center hands off to approach control where pilots receive additional information and clearances. If a landing under VMC is possible, pilots may cancel their IFR clearance before landing. 

## Letters of Agreement (LOA) 

The ATC system is indeed a system and very little happens by chance. As a flight progresses, controllers in adjoining sectors or adjoining Centers coordinate its handling by telephone or by computer. Where there is a boundary between the airspace controlled by different facilities, the location and altitude for hand-off is determined by Letters of Agreement (LOA) negotiated between the two facility managers. This information is not available to pilots in any Federal Aviation Administration (FAA) publication. For this reason, it is good practice to note on the en route chart the points at which hand-offs occur. Each time a flight is handed off to a different facility, the controller knows the altitude and location—this was part of the hand-off procedure. 

