Section 11. Flight Path Format Components

4-11-1. INTRODUCTION

This section supplements paragraph 4-10-2, Format. It contains detailed instructions on the format of flight path components and provides examples of properly formatted ALTRV APREQs.

4-11-2. DEFINITION

A flight path is defined as a consecutively listed set of fix/time/event groups in which the fixes in the set will be successively overflown. A route of flight may be composed of any number of flight paths; aircraft may merge or separate at various points along the route of flight.

4-11-3. FORMAT

Flight paths are separated by the phrases defined in paragraph 4-11-4, Components, which begin and/or end events along the route. The repetition of previously listed fixes is to be avoided. When flight paths merge or separate, the last fix listed in a flight path should be the point of merger or separation. Accordingly, the first fix listed in a flight path should not repeat the point of merger or separation. ALTRVs operating within US domestic airspace must file a minimum of one en route fix for each ARTCC through whose area the mission will be flown. Fixes must be no more than 200nm apart.

  1. Fixes should be used in one of the following formats:
    1. A two to five letter NAVAID identifier, location identifier, or fix name.
    2. A fix/radial/distance; specify the NAVAID, the radial in degrees magnetic, a slash “/” and the distance in nautical miles, expressed in three digits.
    3. A latitude/longitude expressed in degrees and minutes with the appropriate “N,” “S,” “E,” “W” suffix.
  2. Altitudes should be in one of the following formats:
    1. Below 18,000 feet - expressed in hundreds of feet.
    2. Flight levels - “FL” followed by the three digits of the altitude/flight level (18,000 feet and above).
    3. Block or range of altitudes:
      1. Below 18,000 feet - the lower limit, “B,” then the upper limit expressed in hundreds of feet.
      2. Flight levels - “FL,” the lower limit, “B,” and the upper limit expressed in three digits of altitude/flight level.
  3. Airways should be in one of the following formats:
    1. Victor airways - “V” followed by the one, two or three digit number of the airway.
    2. Jet routes - “J” followed by the one, two or three digit number of the route.

4-11-4. MOVING ALTRV COMPONENTS

The following phrases are to be used in Item D when filing an ALTRV APREQ for a Moving ALTRV. Unless otherwise noted, these phrases refer to events that occur immediately “following” the specified fix/time. The exceptions are LVLOF BY, cross; begin branch route, begin alternate route, begin partial route, join common route and exit at. Only certain listed phrases are known to the CARF computer. Any use of nonstandard phrases in Item D, unless contained within brackets [ ], will prevent timely processing of the ALTRV. The use of brackets for nonstandard phrases will cause the CARF computer to skip over the phrase and not utilize it for plotting or conflict detection. As used in this order, the phrases set forth below must have the meaning indicated.

  1. Beginning events.
    1. An ALTRV which starts from the departure point must have the following components:
      1. It must begin with an altitude.
      2. A SID or RAVEC may be specified.
      3. A LVLOF point must be specified.
    2. If an ALTRV does not begin from the departure point, a beginning event must be used to start the ALTRV. BEGIN PARTIAL RTE or ((PR or ((... are used when it is desired to start the ALTRV en route. There are four types of partial route formats:
      1. A PR may be used when the pilot does not desire the ALTRV to begin from the departure point or if the departure point must not be disclosed.
      2. A PR may be used for an ALTRV coming from an international departure point inbound to U.S. airspace.
      3. A PR may be used for an aircraft recovering from special use airspace and returning back to destination on an ALTRV.
  2. Aircraft Joining/Leaving an ALTRV
    1. JOIN (call sign). Point and time at which the specified aircraft merge with the ALTRV routing being defined.
    2. LEAVE (call sign). Point and time at which the specified aircraft are to separate from the ALTRV route being defined.
  3. Increasing and Decreasing area/track Events.
    1. BEGIN ALT DPRT RTE or ((AR. Specifies two or more alternate routes from the same point of departure. This should either be the first phrase of Item D or immediately follow a previous alternate departure route. The phrase should be followed by:
      1. Alternate departure route description enclosed in square brackets “[ ].”
      2. Call signs of the aircraft that will utilize the route; all of the aircraft specified in Item A must be accounted for.
      3. Altitude
    2. BEGIN BRANCH RTE or ((BR. A branch route always starts from a point on an existing ALTRV. It is a track of an ALTRV defined from the breakaway point on a common route to the next fix or final destination. The phase should be followed by:
      1. Call signs of aircraft which will utilize this route.
      2. Altitude held prior to splitting off.
      3. FROM (fix). Indicates the point at which aircraft taking the branch route separate from the main body. The phrase “FROM” is followed by the name of the breakaway fix and all remaining fix/time events.
    3. BEGIN CMN RTE or BEGIN CMN RTE or ((CR. - Defines a route formed by the merger of two or more flight paths when “JOIN” is not used. This phrase should follow all of the branch routes which merge into the common route. It should be followed by:
      1. Call signs of all aircraft merging into this route at its starting point.
      2. Altitude.
      3. FROM (fix/time). (optional) Indicates the point at which the aircraft merge; the phrase is followed by the name of the fix and the time.
    4. Join RCVR CMN RTE Timing/Altitudes to (fix). Defines a route formed by the merger of two flight paths. Typically used in a support ALTRV where the tanker is joining the RCVR ALTRV and assumes RCVR route/timing and altitudes on the RCVR ALTRV. Note: At the join up point, the altitude of Tanker must be the same altitude as the RCVR Altitude.
    5. END CMN RTE. Point at which the aircraft will separate into two or more routes.
    6. BROAD FRONT EVENT. BEGIN (number) NM FRONT (number) NM EITHER SIDE OF A CENTER LINE (fix/time)...(fix/time) FRONT ENDS. Describes an event which occupies a frontal width, measured perpendicular to the direction of flight, which is greater than normal. The broad front event is the specified number of nautical miles wide and is centered on a line of the specified fixes; two or more fixes should be specified.
    7. CELESTIAL NAVIGATION (CELNAV). This may be filed for use in a Broad Front.
    8. ENTER STATIONARY RESERVATION or ENTER MANEUVER AREA or ENTER TIMING TRIANGLE. Utilized whenever it is desired to reserve a stationary volume of airspace within a moving ALTRV for some period of time; point and time of entry are indicated by the fix/time which precedes the phrase. The phrase should be followed by:
      1. Definition of the vertical altitude range of the stationary reservation; may be omitted if the range is the same as the altitude held prior to entry into the reservation.
      2. Definition of the boundary of the stationary reservation. One of the following phrases should be utilized:
        1. (number) NM EITHER SIDE OF A LINE BETWEEN (fix)...(fix). Defines a corridor of the indicated number of nautical miles wide centered on the line segments which connect the specified fixes; specify two or more fixes.
        2. BNDD BY (fix)(fix)...(fix) or WITHIN AN AREA BNDD BY (fix)(fix)...(fix). Defines an area bounded by the line segments which connect the specified fixes; specify three or more fixes.
        3. WITHIN (number) NM RADIUS OF (fix). Defines a circle with a radius of the indicated number of nautical miles centered about the specified fix.
      3. EXIT AT (fix/time) or EXIT STATIONARY RESERVATION AT (fix/time) OR EXIT TIMING TRIANGLE AT (fix/time). Point and time of exit specified by the fix/time which follows the phrase.
    9. ORBIT W/I (number) NM RADIUS DPRT ORBIT AT (time). Utilized to orbit aircraft within the specified number of nautical miles about the fix which precedes the phrase and to have the aircraft depart the orbit at the specified time; the use of “W/I” and/or “AT” is optional.
    10. IBASF (number). Point and time at which aircraft will initiate a stream formation with the formation aircraft separated by the specified number of minutes.
    11. IBACF (number). Point and time at which cells will initiate a stream formation with the cells separated by the specified number of minutes.
  4. Altitude Changing events
    1. CLMB. Indicates that the new altitude range extends above the old altitude and does not include all of the previous altitudes. A level-off point (LVLOF) is required.
    2. CMPS. Indicates that the new altitude includes some of the previous altitude range but does not extend above or below the old altitude range. A level-off point (LVLOF) is required.
    3. CROSS (fix/time) AT (altitude) OR ABOVE/BELOW. Restricts the climb or descent to an altitude so that the ALTRV will be within the specified altitude range when passing over the specified fix. A level-off point (LVLOF) is required.
    4. DSND. Indicates that the new altitude range extends below the old altitude range and does not include all of the previous altitudes. A level-off point (LVLOF) is required.
    5. LVLOF or LVLOF BY(fix) or LVLOF W/I. Altitude transition is to be completed “by the fix following LVLOF or LVLOF by or,” within the specified number of nautical miles of the fix which precedes LVLOF W/I; this phrase is not needed when the new altitude contains all of the previous altitude.
    6. XPND. Indicates that the new altitude range extends above and/or below the old altitude range and includes all of the previous altitude range.
  5. Descriptive Events. Used to describe or clarify certain mission activities.
    1. ACCELERATE TO SUPERSONIC. Supersonic speed will commence at the fix/time which precedes this phrase. (See End Supersonic.)
    2. END SUPERSONIC. Point where supersonic speed will cease. (See Accelerate to Supersonic.)
    3. AIRFL BEGINS or BEGIN AIRFL. Point at which air refueling begins.
    4. AIRFL ENDS or END AIRFL. Point at which air refueling ends.
    5. ARCP. Point at which the receiver arrives in the observation/refueling position with respect to the assigned tanker.
    6. ARIP. Point at which the receiver enters the refueling track, initiates radio contact with the tanker, and begins maneuver to join up.
    7. DRCT. Utilized to eliminate doubt as to when an action occurs. It is generally used for clarification in association with multiple events.
    8. ENCAN or EXCAN. Point and time at which aircraft will enter or exit Canadian airspace. These fixes may be defined as either a fix/radial/distance or a latitude/longitude.
    9. Point at which the aircraft will exit CARF jurisdiction and will cease to be defined.
  6. ALTRV ENDING EVENTS
    1. END RTE or )). A general terminator for routes; the fix/time which precedes this event is the final point of the route (LAND, IFPFP, END CMN RTE, JOIN CMN RTE (in the case of a Support ALTRV), or “...” may be substituted for this phrase. It does not indicate the disposition of the aircraft at the point of termination.
    2. IFPFP (Individual Flight Plan From Point). Point and time at which aircraft will proceed to their destination on individual flight plans. This event is used to allow the controller to pre-plan clearances prior to the break-away fix. Most foreign nations mandate IFPFP information. File all IFPFP routing information to and from the ALTRV:
      1. To join the ALTRV.
      2. When receiver(s) and/or tankers leave ALTRV en route.
      3. When receiver/tanker buddy launch and terminate ALTRV en route.
      4. When receiver/tanker join the ALTRV en route and terminate the ALTRV en route, IFPFP routing information is required for both receiver and tanker to and from the ALTRV.
      5. When receivers file air spares. The project officer is required to file IFPFP routings for air spares from the break-away FIX back to destination.
    3. JOIN CMN RTE TO (fix). Point at which aircraft will join a route described on another ALTRV. The phrase is followed by:
      1. Fix/time at which aircraft leave the common route, or,
      2. “END” when the aircraft will proceed with the other ALTRV to destination, or ALTRV ending point.
    4. LAND. Point at which aircraft will land.

4-11-5. STATIONARY ALTRV COMPONENTS

STATIONARY RESERVATION. This is the first phrase in Item D whenever a stationary ALTRV is being utilized. The phrase should be followed by definitions of the:

  1. Vertical altitude range.
  2. Boundary. One of the following phrases should be utilized:
    1. (number) NM EITHER SIDE OF A LINE BETWEEN (fix)...(fix). Defines a corridor the indicated number of nautical miles wide centered on the line segments which connect the specified fixes; specify two or more fixes.
    2. BNDD BY (fix)(fix)...(fix) or WITHIN AN AREA BNDD BY (fix)(fix)...(fix). Defines an area bounded by the line segments which connect the specified fixes; specify three or more fixes.
    3. WITHIN (number) NM RADIUS OF (fix). Defines a circle with a radius of the indicated number of nautical miles centered about the specified fix.
  3. Duration of the activation, by indicating “FROM (day of the month and UTC time, month and year) TO (day of the month and UTC time, month and year).”

4-11-6. MOVING ALTRV APREQ EXAMPLES

The following are a few common examples of formatted ALTRV APREQs.

  1. Example of an ALTRV in which the tanker buddy launches with the receivers and stays with them to destination.
  2. Moving ALTRV with tankers joining en route and leaving the ALTRV IFPFP:
  3. Moving ALTRV with tankers joining IFPFP and leaving via Branch RTE.
  4. Moving ALTRV with an accompanying support ALTRV:
    1. ALTRV MISSION
    2. SUPPORT AIRCRAFT WHILE ON ALTRV.
  5. Moving ALTRV as a partial route

4-11-7. STATIONARY ALTRV APREQ EXAMPLES

  1. Stationary ALTRV which includes aircraft:

    Stationary ALTRV which includes aircraft:

  2. Stationary ALTRV which does not include aircraft:

    ALTRV APREQ MISSION CORONET BLUE