ICAO Flight Plan Item 18 (Field 18): Codes, Subfields, PBN Requirements and Navigation Data Guide

When filing an ICAO flight plan, Item 18 (also referred to as Field 18 in some documentation and older references) might seem like just another field, but it is actually one of the most important parts of the entire form.

What is ICAO Flight Plan Item 18?

ICAO Flight Plan Item 18, labeled as “Other Information,” is a field in the ICAO flight plan form used to include additional details that are not covered in the standard items of the form. It allows operators to specify important supplementary information such as emergency equipment carried, search and rescue details, navigation or communication capabilities (e.g., “NAV/RNP10”), surveillance details (e.g., “SUR/ADS-B“), and special handling requests (e.g., “RMK/Medical Flight”). This item uses specific indicators and abbreviations defined by ICAO to ensure clarity and standardization across international air traffic services.

Item 18 Subfield Codes: Quick Reference Table

What is typically entered under Item 18 depends on the flight type and the capabilities declared in other items. The following table covers the main Item 18 (Field 18) subfield codes defined in ICAO Doc 4444 PANS-ATM:”

Note: Field 18 (also called Item 18) uses these codes in upper case, with a slash immediately following the code. Multiple entries appear sequentially in the same field. ICAO Doc 4444 PANS-ATM is the authoritative source for the current list of valid codes and their syntax rules.

 

Item 18 in Business Aviation Operations

Business aviation frequently relies on Item 18 to convey nuances of a charter or corporate flight. For example, if a large-cabin jet (e.g. Gulfstream G650) departs an unlisted private strip, the dispatcher enters DEP/ with coordinates. If the call sign is generic (e.g. corporate flight number) but the registration matters for CAR/EASA release, the REG/ element provides clarity. High-end business jets often hold multiple PBN/RNP approvals and extra FMS capabilities; these must be carefully encoded under PBN/ and NAV/. For instance, a Dassault Falcon 8X might have Satellite Based Augmentation System (SBAS)-enabled GPS (EGNOS) and an inertial system: the dispatcher could file PBN/A1B2 and NAV/SBAS INS to fully declare the equipment.

 

Business operators must also be mindful of special items: e.g. TALT/ (takeoff alternate) is often mandatory for IFR dispatch on twin-engine jets departing remote airports. DOF/ is used when filing days in advance (common for repositioning flights). ORGN/ can supply the dispatch office contact in case ATC needs clarifications. When Item 18 is incomplete or inconsistent, business jets can face tangible impacts: an incorrect PBN/ or missing RMK/ may lead to an ATC clearance that the crew is not qualified for, or even an automatic rejection by flight plan processing systems. Just Aviation’s flight and route planning service ensures that Item 18 entries are correctly completed and consistent with the aircraft’s certified equipment and approvals before every flight.

 

Item 18 entries flow from Doc 4444 (PANS-ATM) procedures; for example, ICAO explicitly notes that failure to include required PBN details after marking Item 10A with ‘R’ will cause a flight plan rejection. Likewise, if an alternate airport is specified as “ZZZZ” in Item 16, the ALTN/ name must appear in Item 18. In practice, professional flight operations personnel ensure all relevant codes (PBN, NAV, STS, etc.) are present to avoid back-and-forth with ATC or FMS loading errors.

PBN/RNAV Requirements and Item 18

Performance-Based Navigation (PBN) is central to modern flight planning. Business jets typically carry RNAV-1/2 and RNP-approach approvals, so the ICAO flight plan must reflect this. Under Amendment 1 to PANS‑ATM (2012), the meaning of the Item 10A code ‘R’ became “PBN approved,” and the specific RNAV/RNP codes must be “amplified” in Item 18. In other words, if a flight plan includes an ‘R’ suffix in Item 10A, the dispatcher must provide a PBN/ entry in Item 18. For a complete explanation of Item 10 (Equipment and Capabilities) and how it links to Item 18 PBN declarations, see Just Aviation’s guide to flight planning and schedule management.

For example, a Gulfstream G650 with standard RNAV 5 and RNP 1 authorizations (plus WAAS/LPV) might file:

• Item 10A: /R-SDFG1Z (where R=approved PBN, S=RVSM, D=GNSS, F=GPS, G=GLONASS, 1=GBAS, Z=other)
• Item 18: PBN/B1C2 D2L1 NAV/SBAS

 

Here “B1”=RNAV 5, “C2”=RNP 1, “D2”=Advanced RNP AR approach, “L1”=Lateral deviation 0.1 (example codes), with SBAS added in NAV/. Such detail tells ATC exactly what routes and approaches the aircraft can fly. If these items are inconsistent (e.g. R in Item 10A but no PBN/ line), modern ATS processing will reject the flight plan. Operators are therefore required to tie their actual onboard capabilities (including database currency and approvals) to the codes in Item 18.

Regulatory Context: ICAO and Data Integrity

ICAO standards underpin these practices. Annex 15 requires that any significant aeronautical data change be propagated through the Aeronautical Information Regulation and Control (AIRAC) cycle, with Aeronautical Information Service (AIS) ensuring data reaches users at least 28 days before it is effective. If data is not ready, AIS must issue precautions (e.g. “NIL” by 28 days prior) to warn operators. For example, when a new fix is not in the published AIP cycle, a Trigger NOTAM alerts pilots and flight planners. NOTAM interpretation and weather data integration are covered in detail in Just Aviation’s guide to strategic weather planning.

Doc 4444 (PANS-ATM)

Specifies the Flight Plan format (including Item 18) and encourages uniform filing. It explicitly links Item 10 (equipment codes) to Item 18: e.g., under PANS-ATM, filing ‘R’ in 10A without the proper PBN/ entries is noncompliant and causes rejection. PANS-ATM also details standard prefixes (DEP, ALTN, EET, etc.) used in Item 18.

Doc 8168 (PANS-OPS)

For aircraft operations reinforces data currency: before flying any RNAV or RNP procedure, the crew must verify that all required navaids and database content are correct. Crucially, it states that a procedure must not be flown if the navigation database lacks it. In effect, outdated or missing data translate to “no-go” for an RNAV approach.

 

On the operator side, authorities require a data chain and database LOA (Letter of Authorization) for RNAV/RNP usage. In business aviation, failing to meet these integrity requirements (for example, by installing a chart that conflicts with the FMS data) can violate airworthiness or operations rules.

Case Study: Business Jet at Dubai Al Maktoum Airport (OMDW), UAE – Falcon 8X (Jet)

Dubai’s Al Maktoum International Airport is equipped for RNAV and RNP operations. A Dassault Falcon 8X inbound from Europe may plan an RNP AR approach to runway 31L. The flight plan item 18 must include, for example, PBN/A1B2 (RNAV 5, RNAV 2) and equipment NAV/GPS if using GPS-based RNP. If a new waypoint (e.g. ALICE, a SMAP) was added but not yet in the Airbus/FMS navdata, the FPL might be flagged. Annex 15-compliance means the UAE AIS should publish any critical fix by AIRAC, but if late, ATC would have to issue a NOTAM (which the crew reads via DMAN (departure manager) or briefing).

 

The result: the Falcon’s dispatch may reserve extra fuel to hold if vectors replace the RNAV arrival, and file an alternate like DXB with ALTN/DUBAI INTL. In extreme cases, without current nav data, an 8X cannot legally fly RNP AR (per PANS-OPS) and must revert to simpler procedures. Mastering fuel efficiency in such scenarios becomes critical—not just for cost control but also for maintaining compliance and operational flexibility when routing uncertainties arise.

 

In conclusion, understanding and correctly completing ICAO Flight Plan Item 18 is vital for safe, efficient business aviation operations. Just Aviation’s trip planning service manages the full pre-departure documentation process, including Item 18 accuracy verification as part of every international mission plan. From accurately filing PBN and NAV capabilities to managing delays in navigation data, Item 18 ensures compliance, clarity, and effective communication with ATC. At Just Aviation, we prioritize precision in maximizing business jet flight planning to minimize disruptions and support seamless operations—because every detail matters when delivering exceptional aviation service worldwide.