SAE ARP4102-9B-2021 PDF

Full title and description

SAE International — Recommended Practice ARP4102/9B-2021: Flight Management System (FMS). This document provides recommended criteria and functional requirements for Flight Management Systems used on transport-category aircraft, covering lateral and vertical navigation, performance management and associated human‑machine considerations for a fault‑tolerant design.

Abstract

This recommended practice (ARP4102/9B, revised January 14, 2021) defines the functions, performance expectations, human factors considerations, and fault‑tolerance objectives for on‑board Flight Management Systems (FMS) for transport aircraft. It describes required navigation functions (lateral and vertical navigation), performance and time‑of‑arrival management, and interfaces to navigation sensors and databases to support safe, predictable flight operations.

General information

• Status: Revised / Active (revised document).
• Publication date: January 14, 2021.
• Publisher: SAE International (Society of Automotive Engineers).
• ICS / categories: Aerospace / Avionics / Navigation and guidance systems / Flight management systems / Human factors.
• Edition / version: ARP4102/9B (Revised — 2021).
• Number of pages: 34 pages.

Key bibliographic details and revision history are recorded on SAE’s standards listing for ARP4102/9B (revised 2021).

Scope

This document recommends criteria and requirements for the design and performance of Flight Management Systems for transport aircraft. The scope includes functional definitions for lateral navigation (LNAV), vertical navigation (VNAV), performance management (including speed and thrust schedules), and optional time‑of‑arrival control; operator interface and display considerations; requirements for fault tolerance and failure modes; and interfaces to navigation sensors and navigation/performance databases necessary to support those functions. The guidance is aimed at providing consistent, predictable FMS behavior suitable for transport operations.

Key topics and requirements

• Functional definitions of lateral navigation (LNAV) and vertical navigation (VNAV).
• Performance management: speed, climb/descent profiles, and arrival scheduling (time‑of‑arrival control where provided).
• Navigation database and data interfaces (integration with sensor inputs and navigation databases commonly referenced in FMS design).
• Human factors and crew interface requirements for controls, displays, and modes to reduce mode confusion and support situational awareness.
• Fault tolerance, failure detection and annunciation, and guidance degradation procedures.
• Mode logic, alerting/annunciation strategy, and guidance/flight director integration.
• Performance monitoring, accuracy requirements, and expected operational behavior for transport aircraft FMS.

Typical use and users

Primary users include avionics manufacturers, aircraft original equipment manufacturers (OEMs), systems and certification engineers, airline engineering departments, human factors practitioners, and test/verification teams. The recommended practice is used to guide FMS design, validation, pilot interface design, and to harmonize supplier and operator expectations for FMS behavior.

Related standards

Related documents include other parts of the ARP4102 series covering flight‑deck displays, communications and navigation equipment, windshear systems and related avionics guidance material. FMS design and certification work also commonly references ARINC navigation database standards and avionics software/hardware airworthiness guidance (for example, industry software assurance standards). Examples from the ARP4102 family include ARP4102/6A (Communications and Navigation Equipment) and ARP4102/11B (Airborne Windshear Systems).

Keywords

Flight Management System; FMS; ARP4102/9B; SAE; avionics; lateral navigation; vertical navigation; VNAV; LNAV; performance management; human factors; navigation database; fault tolerance.

FAQ

Q: What is this standard?

A: This is SAE International Recommended Practice ARP4102/9B (2021), titled "Flight Management System (FMS)". It provides recommended functions, performance criteria and human‑machine requirements for transport‑class FMS.

Q: What does it cover?

A: The document covers FMS functional requirements (lateral and vertical navigation, performance management), operator interface and display considerations, fault tolerance and failure annunciation, and interfaces to navigation sensors and databases to ensure consistent, safe FMS behavior in transport operations.

Q: Who typically uses it?

A: Avionics manufacturers, aircraft OEMs, airline technical and operations engineering groups, certification and verification engineers, and human factors specialists use the ARP as guidance in design, testing and operational integration of FMS functions.

Q: Is it current or superseded?

A: ARP4102/9B was revised and published on January 14, 2021. It is the revised 2021 edition of the ARP4102/9 series; users should consult SAE International for any later revisions or reaffirmations beyond 2021.

Q: Is it part of a series?

A: Yes — ARP4102/9B is part of the ARP4102 family of SAE recommended practices that address flight‑deck equipment, displays and related avionics systems for transport aircraft. Other parts cover displays, communications/navigation equipment, windshear systems and more.

Q: What are the key keywords?

A: Flight Management System, FMS, navigation, VNAV, LNAV, performance management, avionics, ARP4102/9B, SAE, human factors.