Introduction

This website provides the technical specification for the Flight Simulation Data Link Protocol (FSDLP). FSDLP is designed to enable first-class, realistic text-based communications between pilots, controllers, and virtual airlines when engaging in networked flight simulation activities.

Historically, this niche has been filled by third-party software operating independently of flight simulation networks. However, the increased complexity of virtual aircraft and the general rise in popularity of flight simulation has demanded a solution with improved availability, realism, and ease of implementation.

The idea behind FSDLP is to decentralize the role of exchanging messages with virtual aircraft. To ensure compatibility with existing authentication and data exchange schemes the protocol remains network-agnostic, and only requires that a common interface is made available to aircraft. It is entirely up to networks, virtual airlines, and any other providers to determine how messages are uplinked to and downlinked from pilots.

Documents Referenced

The following documents have been referenced when designing the specification. Access to these documents may or may not be limited.

• ICAO Doc 10037, Global Operational Data Link (GOLD) Manual, First Edition, 2017
• EUROCONTROL Specification on Data Link Services, Edition 2.1, 2009
• DCIT End-to-End Procedures for CPDLC Operations in the US NAS, Version 2.2, 2023

Conventions Used

The key words “MUST”, “MUST NOT”, “REQUIRED”, “SHALL”, “SHALL NOT”, “SHOULD”, “SHOULD NOT”, “RECOMMENDED”, “MAY”, and “OPTIONAL” on this website are to be interpreted as described in RFC 2119 🔗.