VATFLOW · FCA programs
Issue & manage RDY times
Pick what you are working. Each path covers only what you need for Flow Constrained Area (FCA) releases — not airport arrival-rate programs. Start with Reading an FCA strip if the times are new to you.
Reading an FCA strip
Same strip layout in FCA Builder; IDST shows Flights to Work tables instead of strips. Example: an airborne aircraft locked to the line, then a ground departure waiting for RDY.
Sequence # / drag handle
Order in this FCA. Editors can drag to force MANUAL sequencing. Everyone else treats this as the current planned order.
Phase badge — AIR / CFR / RLSD
AIR = already flying (crossing time is fixed). CFR = ground, advisory only — no slot owned yet. RLSD = you pressed RDY; wheels-up is frozen.
Callsign & type
Who the strip is. Type is informational only.
Route · altitude · speed · nm to line
Dep → dest, FL, and groundspeed (or depart if still on the ground). nm to line is distance remaining to the FCA crossing along the filed route.
cross HHMMZ (ground only)
Scheduled crossing time at the FCA line (CTA). Wheels-up is backed out from this using estimated transit. On AIR strips the big time on the right is the crossing time, so “cross …” is not repeated on the info line.
Cyan gap line
AIR: spacing to the line or behind the previous airborne aircraft (nm).
Ground: minutes behind the previous aircraft at the crossing (here EVA585 is ~57.7 min after ACA503’s 1545Z crossing → cross 1642Z).
Big time (right)
AIR → crossing time (ACA503 1545Z).
Ground (Builder) → proposed wheels-up (EVA585 1550Z) so they make their cross time. In IDST the CFR column stays empty until RDY so you do not read an advisory number to the pilot by mistake.
Status under the big time
on time / air +… for airborne. no delay / hold +… / released for ground. Hold means metering is pushing wheels-up later than “ready now.”
What the times mean (quick ref)
| Crossing / CTA | When the aircraft is scheduled across the FCA line. Airborne: fixed by ETA. Ground: the slot the release is trying to meet (cross 1642Z on EVA585). |
|---|---|
| Wheels-up / RDY | When they should roll so transit time hits the crossing. Frozen only after RDY. Until then it is a projection (Builder may show it; IDST hides it until RDY). |
| Gap (min / nm) | Spacing behind the previous aircraft in the sequence — at the line for ground (minutes), or in trail for air (nm). |
| nm to line | How far they still are from the FCA along the filed route. Not the same as airport distance. |
On a CFR (not yet RLSD) strip, the big time in Builder is a proposal. Issue RDY from IDST (or FCA Overview / Builder) before you clear a wheels-up time. Airport TMU does not issue a time.
What are you working?
TMU — run the FCA
You own the program: draw/enable the line, set scope and rate, choose auto or manual sequencing, and keep the sequence honest when traffic outside your ARTCC is not on VATFLOW.
FCA Builder for create / edit / sequence / enable. Controllers issue RDY from IDST. Use FCA Overview for the ARTCC map picture. Staff setup: FCA How-To.
Auto vs manual sequencing
This is the biggest TMU decision after the line is live. It changes who “owns” order — the ETA engine, or you.
AUTO (default)
Airborne by ETA (fixed). Unready ground is advisory only and holds no slot. The first aircraft you RDY claims the earliest open gap.
- Use for normal metering.
- Best when pilots call ready in a sensible order.
- Leave here unless you need to force a sequence.
MANUAL
Drag a strip → manualSeq locks your order. Times chain along your sequence, not the global earliest gap. UI shows ✋ MANUAL · ↺ auto (Builder) or AUTO to return.
- Use to force taxi / runway / coordination order.
- Example: keep A before B even if B’s ETA is earlier.
- Return to auto when the special order is no longer needed.
Default for most events. Ready aircraft naturally fill gaps; unready projections do not steal slots. Less babysitting, fewer “why did my time jump?” moments when someone RDYs out of taxi order.
Go manual only when you must enforce an order the ETA engine will not: runway config, gate preference, a specific tower request, or protecting a priority flight. Tell the positions you flipped — they will see different proposed times. Click ↺ auto / AUTO when done so the board does not stay stuck in a stale hand order.
Scope — who gets metered
- ARTCC tag (owning ARTCC) — who may edit the program. Access control only.
- Scope (ARTCCs) — which aircraft are included in metering. Blank = everywhere the route crosses the line. Listed centers = only aircraft inside those FIR boundaries (ground judged at their departure field; air at present position).
A tight scope keeps your sequence about your problem set. A blank or wide scope pulls in distant departures that cross the line on paper — including traffic you cannot see issuing CFRs. Match scope to the centers that should actually participate in the program.
Traffic outside your airspace (not on VATFLOW)
VATFLOW only knows aircraft that appear in the VATSIM feed and match your FCA filters/scope. Controllers upstream or in an adjacent ARTCC may not be issuing RDY at all.
- Airborne is fixed. Jets already flying toward the line keep their ETA. You cannot “delay” them in the tool — conflicts between air are flagged, not rewritten.
- Watch the air picture (vATIS/vNAS/VATSpy/map layers) for aircraft that will cross your line without a VATFLOW release. They still consume spacing in the real world.
- Do not assume every ground strip will RDY. If a neighboring facility is not using the board, their departures may roll when ready and show up as air — your frozen releases can only bump later when air encroaches.
- Coordinate early with adjacent TMU/Center: share the FCA name, scope, and whether you are in AUTO or MANUAL. One shared sequence beats two parallel guesses.
- Rate / MIT honesty: if a large share of the stream is outside VATFLOW, the in-tool sequence understates demand — tighten verbally or widen participation, don’t just stare at green RLSD times.
TMU checklist
-
1
Create & enable
Draw the line, set owning ARTCC, scope, rate/MIT, filters. Enable when ready. Aircraft join only when the filed route crosses the line.
FCA Builder -
2
Choose AUTO or MANUAL
Leave AUTO unless you need a forced order. If you drag, tell the positions and return to AUTO when the need passes.
Sequence panel · ✋ MANUAL · ↺ auto -
3
Monitor RDY from the field
Tower/APP/Center issue RDY from IDST with the matching filters. You can also RDY from Builder. Cancel returns the aircraft to advisory.
Builder · IDST · FCA Overview -
4
Watch the outside picture
Scan for non-VATFLOW / out-of-scope traffic that will still cross. Protect airborne; bump frozen releases later only when needed.
Map · adjacent facilities
Center — protect the stream
You work IDST with your ARTCC filter for RDY, and FCA Overview for the map. Airborne crossings are fixed; coordinate with tower/APP and do not invent delay the engine cannot apply to air.
IDST — add your ARTCC (and/or airports) in Working filters, sign in on position, issue RDY. Same FCA releases sync everywhere. Programs are built by TMU in FCA Builder. Map: FCA Overview.
Mental model
- AIR strips — already flying; ETA to the line is fixed. Spacing problems between air are flags for you, not times the tool rewrites.
- CFR / advisory ground — projected only. They hold no slot until someone presses RDY.
- RLSD — frozen wheels-up. That departure owns a crossing slot. Cancel (RLSD ✕) returns them to advisory.
What you do on position
-
1
Load your ARTCC
Open IDST → add ARTCC / airport / approach filters. Only metered FCA departures in scope appear.
IDST -
2
Sign in on a controller position
RDY unlocks when you are signed in with VATSIM and online on an ATC position. Check Settings if the board stays locked.
Sign in · ATC verified -
3
Coordinate RDY with the field
Prefer letting DEL/GND/TWR issue from IDST with their airport / approach filters. If you RDY for them on a center-wide IDST, confirm the pilot is actually ready — early RDY steals a gap.
RDY · optional HHMMz floor -
4
Watch air + non-VATFLOW
Upstream traffic may cross your FCA without ever appearing as a ground strip on this board. Treat airborne ETAs as hard; frozen releases only move later if air encroaches.
Sequence · air picture
Center best practices
- Don’t RDY a ground strip “just in case” — advisory projections free the slot for someone who is truly ready.
- If TMU is in MANUAL, honor that order; don’t fight it with random RDY timing.
- Optional HHMMz + SET before RDY when the pilot quotes a later wheels-up — never issues before that floor.
- Full control (ARTCC editor) can drag-reorder / return to AUTO — only do that with TMU awareness.
- One voice with the towers on a stream beats three people issuing the same callsigns — let the field own IDST RDY (airport / approach filters) when they can.
APP / TWR — issue the release
DEL, GND, TWR, and APP: issue FCA times for your departures in IDST with airport / approach filters. You do not need to build the program. Airport TMU is tools and monitoring only (AAR, MIT, recommended delay) — it does not issue a time.
IDST — add the airports, approach sectors, and/or ARTCC you are working (same filters as Airport TMU My Dashboard). Only FCA-metered ground departures in your scope appear. Sign in on position, then RDY. Airport TMU remains for AAR/MIT monitoring.
FCA PRGM — this departure is in an FCA; that program owns the release (not destination AAR).
Ready Time — pilot’s earliest wheels-up floor (HHMMz).
RDY / RLSD — frozen wheels-up for the FCA crossing. Until you press RDY, the time is only a projection (advisory).
Why one airplane is earlier than another
- Closer / earlier ETA to the FCA line.
- Someone pressed RDY on them first (they claimed the open gap).
- TMU put the sequence in MANUAL and dragged them higher.
- Rate / MIT spacing ahead of the next aircraft.
- They have an earlier (or no) Ready Time floor.
How to issue
-
1
Open IDST for your field
Add the tower airports, approach sectors, and/or ARTCC you are working. Filters match Airport TMU My Dashboard on this device, but RDY lives here — not on Airport TMU.
IDST · Working filters -
2
Confirm the flight is FCA-metered
Flights to Work only lists ground departures in an active FCA. If a flight is missing, it is not in a live FCA — Airport TMU dest AAR delay is informational only and is not a release.
IDST · Unscheduled -
3
Ask the pilot
When they call ready — or quote a later wheels-up — decide: next open slot, or a floor time.
Pilot ready call -
4
Optional ART floor
Enter HHMMz as ART. The release will never be before that time; spacing may still push later.
IDST · ART HHMMz -
5
Press RDY
Use RDY — ISSUE NOW (or SET after ART) to lock wheels-up. Tell the pilot that time. ART is prefilled with the estimated taxi time from the aircraft’s present position to its departure runway, including the departures queued ahead of it — overwrite it if the pilot tells you different.
IDST · RDY -
6
Fix mistakes
Cancel with RLSD ✕ to return to Unscheduled if they aren’t ready or you issued the wrong callsign. Re-RDY when they actually are.
Cancel · re-issue
APP / TWR best practices
- Work IDST with your airport / approach filters. Center can use ARTCC-wide filters. Airport TMU is monitoring only.
- Don’t RDY before the pilot is ready. Advisory rows don’t hold slots — freezing early steals from someone who can go.
- Issue in taxi / runway order when you can. If TMU is in MANUAL, follow that order.
- Use the Ready Time floor when the pilot says they’ll need 10+ minutes — don’t lock a “now” slot they’ll miss.
- One position owns RDY for a gate/stream when possible (usually GND/TWR). Don’t double-issue with Center.
- After cancel, times for others may improve — re-check the list before you brief the next pilot.
- Only treat FCA PRGM rows as FCA releases. No program / VFR / ground stop rows follow their own rules.