Service B Message Formats

ICAO Supplementary Flight Plan (SPL) Message. The ICAO supplementary flight plan message is sent from an addressee with information additional to that already transmitted in a flight plan (FPL) message. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(SPL' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO DEST is the destination. The format is four alphabetic characters.

ETE is the estimated time en route. The first two digits are 00 to 99 and the last two digits are 00 to 59.

ICAO ALT DEST is optional. If present, ICAO ALT DEST is a space character followed by four alphabetic characters or four alphabetic characters followed by a space followed by four alphabetic characters.

ICAO REMARKS is other information and is 1-325 displayable characters. It may include embedded EOL sequences.

SUPPLEMENTARY INFORMATION is the endurance, persons on board, emergency radio, survival equipment, jackets, dinghies, aircraft color and markings, remarks, and/or pilot‐in‐command; each separated by a space. It may include embedded EOL sequences. The format is:

E/ followed by four NUMERICS giving the fuel endurance in hours and minutes

P/ for outside the NAS the format is followed by 1, 2, or 3 NUMERICS giving the total number of persons on board, or “TBN” (to be notified) if the total number of persons is not known at the time of filing, when so prescribed by the appropriate ATS authority. For inside the NAS the format is followed by 1-30 alphanumeric, space, and backward slash (\) characters giving the total number of persons on board, when so prescribed by the appropriate ATS authority.

R/ followed by one or more of the following, without spaces:

U - if frequency 243.0 MHz (UHF) is available,

V - if frequency 121.5 MHz (VHF) is available,

E - if emergency locator transmitter (ELT) is available

S/ followed by one or more of the following, without spaces:

P - if polar survival equipment is carried,

D - if desert survival equipment is carried,

M - if maritime survival equipment is carried,

J - if jungle survival equipment is carried

J/ followed by one or more of the following, without spaces:

L - if the life jackets are equipped with lights,

F - if they are equipped with fluorescein, followed by space followed by

U - if any life jacket radio is equipped with UHF on frequency 243.0 MHz,

V - if any life jacket radio is equipped with VHF on frequency 121.5 MHz

D/ followed by one or more of the following, separated by spaces:

Two NUMERICS giving the number of dinghies carried,

Three NUMERICS giving the total capacity, in persons carried, of all dinghies

C if dinghies are covered,

The color of the dinghies (for example, RED).

A/ followed by 0 to 500 A/N, space, and colon (:) characters indicating the color of the aircraft and significant markings (this may include the aircraft registration)

N/ followed by 0 to 500 A/N, space, and colon (:) characters indicating any other survival equipment carried and any other useful remarks

C/ followed by 0 to 201 alphanumeric, space, and colon (:) characters indicating the pilot information

Proposed ICAO Modification (CHG) Message. The proposed ICAO modification message is sent from an addressee when any change is to be made to basic flight plan data contained in a previously transmitted FPL message. If this message is sent to an ARTCC, this message requires either an ICAO Acknowledgement message or an ICAO rejection message. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(CHG' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

ICAO DEST is the destination. The format is four alphabetic characters.

ICAO REMARKS is other information and is “DOF/” portion if available, else “-0”.

AMENDMENT is the amended data. It may include multiple fields separated by oblique strokes. It may include embedded EOL sequences. The format is [a]/[b] where:

a – One or two numeric characters representing the type number of the field to be amended two

b – The complete and amended data of the field indicated in (a), constructed as specified for that field.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

Active ICAO Modification (MOD) Message. The active ICAO modification message is sent from an addressee when any change is to be made to basic flight plan data contained in a previously transmitted FPL and/or DEP message for an active flight plan. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(MOD' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

ICAO DEP PT is the departure point. The format is four alphabetic characters.

ICAO DEST is the destination. The format is four alphabetic characters.

AMENDMENT is the amended data. It may include multiple fields separated by oblique strokes. It may include embedded EOL sequences. The format is [a]/[b] where:

a – One or two numeric characters representing the type number of the field to be amended.

b – The complete and amended data of the field indicated in (a), constructed as specified for that field.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO Arrival (ARR) Message. The ICAO arrival message is sent from an addressee when a flight, for which basic flight plan data has been previously distributed, has been closed. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(ARR' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is for receipt only and is optional. If present, it is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO Cancellation (CNL) Message. The ICAO cancellation message is sent from an addressee when a flight, for which basic flight plan data has been previously distributed, has been cancelled. If this message is sent to an ARTCC, this message requires either an ICAO acknowledgement message or an ICAO rejection message. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(CNL' is the ASCII text string used for an ICAO cancellation.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the estimated departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

ICAO DEST is the destination. The format is four alphabetic characters.

ICAO REMARKS is other information and is “DOF/” portion if available, else “-0”.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO Departure (DEP) Message. An ICAO departure message is a notice of an inbound ICAO flight to an airport associated with an addressed FSS. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(DEP' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

ICAO DEST is the destination. The format is four alphabetic characters.

ICAO REMARKS is other information and is 1-325 displayable characters. It may include embedded EOL sequences.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

Proposed ICAO FPL Message. A proposed ICAO flight plan message is a notice of a proposed ICAO flight that is departing outside of the flight plan area of the originating facility. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(FPL' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is for receipt only and is optional. If present, it is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

TYPE FLT is the type of Flight. TYPE FLT is one or two alphabetic characters. The first character is V, Y, Z and the second is S, N, G, M, X.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO ACTYPE is the aircraft type. The format is two to eight alphanumeric and slash characters.

EQUIP is the equipment. The format is up to 76 alphanumeric and slash characters. It may include embedded EOL sequences immediately prior to EQUIP and/or between the Comm/Nav and Transponder portions of EQUIP.

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

AIRSPEED is the true airspeed. It is the alphanumeric character ʻM' followed by three numeric characters, or the alphanumeric character ʻK' or ʻN' followed by four numeric characters.

ALTITUDE is the requested altitude. It is three to seven alphanumeric characters. The format is:

Fddd

Sdddd

Addd

Mdddd

VFR

VFR/ddd

where d – numeric character.

SP is a single ASCII space character.

ROUTE is the route of flight and is a string of 0 to 558 displayable characters. It may include embedded EOL sequences.

ICAO DEST is the destination. The format is four alphabetic characters.

ETE is the estimated time en route. The first two digits are 00 to 99 and the last two digits are 00 to 59.

ICAO ALT DEST is optional. If present, ICAO ALT DEST is a space character followed by four alphabetic characters or four alphabetic characters followed by a space followed by four alphabetic characters.

ICAO REMARKS is other information and is 1-325 displayable characters. It may include embedded EOL sequences.

CLOSURE POINTS is the closure points field address(es). It is appended to the end of the ICAO REMARKS preceded by the “RMK/” indicator. The format is xx=address(es), where xx is ʻCP' address(es) is up to 16 8‐character addresses with no embedded spaces.

ICAO FPL Message (Proposed‐Inbound). The ICAO flight plan message is a notice of an inbound ICAO flight to an airport associated with an addressed FSS. If this message is sent to an ARTCC, this message requires either an ICAO acknowledgement message or an ICAO rejection message. This message does require an acknowledgement within the NAS and Canada. If this message is sent to any other facility outside the NAS, an acknowledgement is not required.

ʻ(FPL' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is for receipt only and is optional. If present, it is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

TYPE FLT is the type of flight. TYPE FLT is one or two alphabetic characters. The first character is V, Y, Z and the second is S, N, G, M, X.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO ACTYPE is the aircraft type. The format is two to eight alphanumeric and slash characters.

EQUIP is the equipment. The format is up to 76 alphanumeric and slash characters. It may include embedded EOL sequences immediately prior to EQUIP and/or between the Comm/Nav and Transponder portions of EQUIP.

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

AIRSPEED is the true airspeed. It is the alphanumeric character ʻM' followed by three numeric characters, or the alphanumeric character ʻK' or ʻN' followed by four numeric characters.

ALTITUDE is the requested altitude. It is three to seven alphanumeric characters. The format is:

Fddd

Sdddd

Addd

Mdddd

VFR

VFR/ddd

where d – numeric character.

SP is a single ASCII space character.

ROUTE is the route of flight and is a string of 0 to 558 displayable characters. It may include embedded EOL sequences.

ICAO DEST is the destination. The format is four alphabetic characters.

ETE is the estimated time en route. The first two digits are 00 to 99 and the last two digits are 00 to 59.

ICAO ALT DEST is optional. If present, ICAO ALT DEST is a space character followed by four alphabetic characters or four alphabetic characters followed by a space followed by four alphabetic characters.

ICAO REMARKS is other information and is 1-325 displayable characters. It may include embedded EOL sequences.

ICAO Acknowledgement (ACK) Message. The ICAO acknowledgement message is sent from an ARTCC to indicate that the receipt of a message has occurred.

ACK ID is the character string ʻACK'.

SP is a single ASCII space character.

MESSAGE TYPE contains the characters ʻFPL', ʻCHG', or ʻCNL'.

MSGNUM is only present if the original FPL message contained a message number. If present, MSGNUM is ʻ/' followed by that message number in the format of three numeric characters in the range 001 to 999.

ORIGIN is three or four alphabetic characters which identify the origin of the message.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

ICAO DEST is the destination. The format is four alphabetic characters. For messages originating from Honolulu ARTCC, the ICAO DEST is optional.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO Reject (REJ) Message. The ICAO reject message is sent from an ARTCC to indicate that the receipt of a message has occurred but rejected.

ACK ID is the character string ʻREG'.

SP is a single ASCII space character.

MESSAGE TYPE contains the characters ʻFPL', ʻCHG', or ʻCNL'.

MSGNUM is only present if the original FPL message contained a message number. If present, MSGNUM is ʻ/' followed by that message number in the format of three numeric characters in the range 001 to 999.

ORIGIN is three or four alphabetic characters which identify the origin of the message.

TEXT is a set of ASCII characters that contains the reason that the message is being rejected and the contents of the original message. TEXT may contain embedded EOL sequences. For messages originating from Honolulu ARTCC, TEXT is the following set of fields:

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

ICAO DEP PT is the departure point. The format is four alphabetic characters.

TIME is the departure time. The format is four numeric characters. The first two characters representing hours from 00 to 23 and the last two characters representing minutes from 00 to 59.

ICAO DEST is the destination. The format is four alphabetic characters.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO Logical Acknowledgement (LAM) Message. The ICAO LAM is sent from an addressee to indicate that the receipt of a message has occurred. The reference data (RD) contains the reference number, which is the message number (MN), of the message being responded to.

ʻ(LAM' is the ASCII text string used for an ICAO flight plan.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ICAO Logical Rejection Message (LRM). The ICAO LRM is sent from an addressee to indicate that the receipt of a message has occurred but contained an error and has been rejected by the receiving system. The reference data (RD) contains the reference number (i.e., message number (MN)) of the message being responded to.

ʻ(LRM' is the ASCII text string used for an ICAO logical rejection.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ICAO REMARKS is from the other information field and the format is RMK/code/field/text, where:

Code. Two numeric characters comprising the error code.

Field. Two numeric characters comprising the field in error or “00” if the error is not field specific.

Text. The contents of the message that caused the error when the error is field specific. When the error is non‐field specific, a descriptive error message must be included.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed. EOL is a string of 1 carriage return followed by a line feed or 2 carriage returns followed by a line feed.

An LRM received on the SPL example transmitted above if the SPL was bad.

ICAO Search and Rescue (SAR) Messages. An ICAO SAR message consists of three different alert types: the INCERFA, the ALERFA, and the DETRESFA. These messages are similar to the QALQ, INREQ, and ALNOT messages. This message can be forwarded between domestic facilities, which is the case for MBO and AMOC. This message does not require acknowledgment.

ʻ(ALR' is the ASCII text string used for an ICAO SAR Messages.

MN is the message number. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

RD is the reference data. The format is a(a)(a)(a)/a(a)(a)(a)ddd, where:

a - alphabetic character

d – numeric character

Parentheses indicate optional character.

ALERT PHASE

INCERFA

ALERTFA

DETRESFA

ORIGIN is eight alpha characters.

FILLER is a string of characters with the size dependent on the alert type; not to exceed the line length of 69 characters.

EOL is a string of one carriage return followed by a line feed or two carriage returns followed by a line feed.

ACID is the aircraft ID and is defined to be one alphabetic character followed by one to six alphanumeric characters.

SSR is the beacon code and is optional. If present, the format is /adddd, where:

a - alphabetic character

d – numeric character; may contain a value from 0 to 7 (note: all zeros are not allowed)

TEXT is a string of characters including embedded EOL sequences. The number of characters between each EOL will not exceed 69 characters. SAR messages are limited to 20 lines of text separated by EOL sequences.

Additional ICAO SVC B Messages Examples.

ICAO FPL

FF KZOAZQZX DTG KOAKYFYX (FPL-N12345-IG -SR22/L-S/S -KSEA1414 -N0220F090 DCT -PAEN0600 -DOF/170428 RMK/DO NOT POST) FF PAENYFYX DTG KOAKYFYX (FPL-N12345-VG -SR22/L-S/S -KSEA1414 -N0220F095 DCT -PAEN0600 -DOF/170428 RMK/DO NOT POST)

ICAO supplementary flight plan (SPL)

FF PAENYFYX DTG KOAKYFYX (SPL-N12345-KOAK2100 -PAEN0500KSEA -DOF/170448 RMK/DO NOT POST -E/0600 P/3 R/VE S/P J/V D/03 005 C YELLOW A/RED WHITE N/SPOT GEN3 SISTER IN FRESNO 559-555-5555 C/JOE PILOT 555-555-5555)

Change proposed time (P-TIME)

FF PAENYFYX DTG KOAKYFYX (CHG-N12345-PAEN2315-KOAK-0-13/PAEN2350)

Cancel proposed flight plan

FF PAENYFYX DTG KOAKYFYX (CNL-N12345-PAEN2200-KOAK-0)

Change estimated time en route (ETE) for proposed flight

FF PAENYFYX DTG KOAKYFYX (CHG-N12345-KOAK2330-PAEN-0-16/PAEN0130)

Change route for proposed flight

FF PAENYFYX DTG KOAKYFYX (CHG-N12345-KOAK1800-PAEN-0-15/KOAK-KSEA-PAEN)

Departure message

FF PAENYFYX DTG KOAKYFYX (DEP-N12345-PAEN1500-KSEA-0)

Change of destination for active flight

FF PAENYFYX DTG KOAKYFYX (CNL-N12345-PAEN2200-KOAK-0)

Change estimate time of arrival (ETA) for active flight plan

FF PAENYFYX DTG KOAKYFYX (MOD-N12345-KOAK-PAEN-16/PAEN2350)

Arrival/Closure message

FF PAENYFYX DTG KOAKYFYX (ARR-N12345-KOAK1900-PAEN2350)