5-4-10

En Route Fourth Line Data Block Usage

JO 7110.65BB, Change 3, effective July 9, 2026 · Official text on faa.gov

The fourth line of the data block must be displayed. When using the fourth line for forwarding control information, only messages specified in this section, a facility directive or LOA are authorized. Any additional control information must be forwarded via other communications methods. Free text may be used by individual sector teams for recording information the team deems appropriate for managing the sector, but must be removed prior to initiation of identification transfer.
Reference

FAA Order JO 7110.65, Para 5-4-5, Transferring Controller Handoff, Subpara b.
FAA Order JO 7110.65, Para 5-4-8, Automated Information Transfer (AIT).
The en route fourth line data block area must be used for coordination purposes only in association with radar identified aircraft.
When automated information transfer (AIT) procedures are applied, en route fourth line usage for transfer of control information must be specifically defined within facility AIT directive.
Reference

FAA Order JO 7110.65, Para 5-4-8, Automated Information Transfer (AIT).
FAA Order JO 7210.3, Para 4-3-10, Automated Information Transfer (AIT).
Coordination format for assigned headings must use the designation character “H” preceding a three-digit number.
Example

H080, H270
Aircraft assigned a heading until receiving a fix or joining a published route must be designated with assigned heading format followed by the fix or route.
Note
1. The notation “PH” may be used to denote present heading.
2. The character “H” may be omitted as a prefix to the heading assignment only if necessary due to character field limitations, and it does not impede understanding.
Example

H080/ALB, 080/J121, PH/ALB
Coordination format for weather deviations must use the designated characters:
D-deviation
L-left
R-right
N-north
E-east
S-south
W-west
/F-direct next NAVAID/waypoint in the flight plan
D(heading)-(heading)–deviate between two specified headings.
Note
1. Two digits specify turns in degrees and must include direction character(s). Three digits specify heading(s).
2. The inclusion of /(NAVAID) or /(waypoint), when preceded by the designated characters for weather deviations, indicates that a pilot has been authorized to deviate for weather and rejoin the route at the specified NAVAID or waypoint. The use of /F, following the designated weather deviation characters, indicates that a pilot has been authorized to deviate and rejoin the route of flight at the next fix in the route in accordance with paragraph 2-6-4.
Example

D90L/ATL, DL/KD75U, D090/F

Note

3. The absence of /NAVAID, /waypoint, or /F after the weather deviation designated characters indicates that the pilot has been authorized to deviate for weather, and the receiving controller must provide a clearance to rejoin the route of flight in accordance with subparagraph 2-1-15 c.

Example

DN, D20L, D30R, D180-210
Coordination format for specific assigned airspeeds must use the designation character “S” preceding a three‐digit number. A three-digit number followed by a “+” must be used to denote an assigned speed at or greater than the displayed value, or followed by a “-” to denote an assigned speed at or less than the displayed value.
Example

S210, 250+, 280-
Aircraft assigned a Mach number must use the designation “M”, “M.”, or “.” preceding the two‐digit assigned value. The displayed Mach number must also be followed by a “+” to denote an assigned speed at or greater than the displayed value, or a “-” to denote an assigned speed at or less than the displayed value.
Example

M80, M80+, M80-, M.80, .80, .80-
Coordination format for aircraft authorized to conduct celestial navigation training within 30 NM of the route centerline specified within the en route clearance must use “CELNAV.”
Coordination format for aircraft requesting an altitude change must use the designation characters “RQ” preceding a three‐digit number.
Example

RQ170, RQ410
Coordination format for aircraft requesting a route change must use the designation “RQ/” preceding a specific fix identifier.
Example

RQ/LAX, RQ/NEUTO
The acceptance of a handoff by the receiving controller must constitute receipt of the information contained within the en route fourth line data block.This information must not be modified outside of the controller's area of jurisdiction unless verbally coordinated or specified in a Letter of Agreement or Facility Directive. It is the responsibility of the receiving controller to advise the transferring controller if any information is not understood, or needs to be revised.
Note

Due to system and character limitations the usage of these standardized entries may require additional support via facility directive in order to provide complete coordination.
All other control information must be coordinated via other methods.