VATSIM, IVAO, and PilotEdge — what controllers expect

Published 3 June 2026Reference article

VATSIM, IVAO, and PilotEdge are the three online networks where home flight simulator pilots fly with human air traffic controllers. The networks share the same fundamental expectation — real-world ATC phraseology — but differ in scope, pilot client, controller training, and what a pilot encounters on first connection.

What the three networks have in common

On all three, controllers are volunteer (VATSIM, IVAO) or paid professional (PilotEdge) air traffic controllers using a controller client to staff sectors that match real-world airspace. The pilot uses a pilot client connected to a flight simulator (MSFS, X-Plane, P3D) and communicates with controllers by voice (preferred) or by text.

The phraseology expected is the real-world phraseology of the airspace being controlled — FAA in the US, CAP 413 in the UK, SERA in Europe, TC AIM in Canada. The networks are venues for practising real-world radio procedure, not separate phraseology systems with their own conventions. A controller staffing London Control will issue clearances exactly as a real London controller would.

Source: VATSIM Pilot Resource Centre; IVAO Documentation Library; PilotEdge Pilot Resource Center.

VATSIM

VATSIM (Virtual Air Traffic Simulation Network) is the largest of the three and has the broadest global coverage. Membership is free; controller and pilot training are run by volunteer regional divisions. The controller rating syllabus runs from S1 (Tower Trainee) through C3 (Senior Controller) and on to I3 (Instructor); the pilot rating syllabus (P0 through P4) is optional but mandatory for controllers.

Pilot clients in the VATSIM ecosystem include vPilot, swift, and xPilot. A VATSIM pilot client cannot connect to IVAO and vice versa; the networks operate independent infrastructure.

Callsign conventions: real-world airline callsign with airline telephony (BAW123 spoken as “Speedbird 123”) or general-aviation registration (N534CT spoken as “November Five Three Four Charlie Tango”).

IVAO

IVAO (International Virtual Aviation Organisation) is a separate network with similar goals but distinct infrastructure. Membership is free; training is run by national divisions on IVAO’s own syllabus. Controller ratings use different letters than VATSIM — the progression is AS1, AS2, AS3 (ATC Student stages), then ADC (Aerodrome), APC (Approach), ACC (Area), and SEC (Senior Controller).

IVAO publishes its own pilot client (the current generation is Altitude); a VATSIM client will not connect. Accounts are separate from VATSIM. Some regions have stronger IVAO coverage, others stronger VATSIM coverage — pilots who fly extensively in Europe often hold accounts on both.

Callsign conventions match VATSIM: airline callsign with telephony, or GA registration.

PilotEdge

PilotEdge is the smallest of the three by membership but the most concentrated. It is a paid subscription service offered in several tiers — including standalone Los Angeles ARTCC and broader Western US plans — staffing roughly half of the contiguous US (the Seattle, Oakland, Los Angeles, Denver, Salt Lake City, and Albuquerque ARTCCs) with professional controllers, many of whom are current or former real-world ATCs. The network targets serious training: students working toward real-world pilot certificates often use PilotEdge as a procedural-training environment.

PilotEdge publishes a graded series of CAT (Controller Assisted Training) ratings, from CAT-1 (basic VFR radio) through CAT-11 (instrument procedures in busy airspace). These ratings provide structured progression that the volunteer networks do not.

Callsign conventions: same as the volunteer networks. PilotEdge is FAA-only by coverage, so all phraseology is FAA.

What controllers expect

Standard initial contact.

Identify yourself, state your location, state your request. Don’t over-volunteer information — the controller will ask for what they need.

Region-appropriate phraseology.

FAA constructs in US airspace, CAP 413 in the UK, SERA in Europe, TC AIM in Canada. A controller working London Control will not switch into FAA phraseology because the pilot is American.

Readback discipline.

Altitude assignments, heading instructions, frequency changes, runway assignments, hold short of, line up and wait, cleared for takeoff, cleared to land — all require full readback. “Roger” alone is not acceptable for any of these.

Voice over text.

Voice is preferred on all three networks where the pilot’s setup supports it. Text is acceptable as a fallback for new pilots, broken microphones, or shared-housing late-night flights, but voice puts the pilot inside the experience the network is designed to recreate.

Choosing a network

For a pilot starting out, VATSIM has the broadest coverage and the most active controllers worldwide; this is the default choice. IVAO has stronger coverage in some European regions and a different community feel. PilotEdge is the right choice for pilots who want concentrated US West Coast staffing and structured CAT training, and who can justify the subscription cost.