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. 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. 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. 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: Letters of Agreement (LOA) 2-15