Devlog 02: COSYS, Single Sector and Multisector

Last week was about talking to aircraft. This week is about the controllers around you. In single sector you have the airspace to yourself. In multisector you work part of Schiphol approach, AUTO controllers run the rest of the FIR, and COSYS is how you make agreements with them.

That's also where the game name comes from. MultiScope is built around more than one scope: the sectors that AUTO controllers run today, like area control, are set up so we can make them playable positions in the future.

SINGLE SECTOR

Single sector is the easiest way into EHAM, and the place to start after you've completed the Academy Box (more on that next week). You work all four Schiphol approach positions on your own. Arrivals appear about 15 NM before their initial approach fix (IAF), and departures appear when they get airborne. There is no area control or tower to coordinate with, and no COSYS. You also set the conditions. You pick the runways and can change them during the session from the runway cards on the side panel. With custom traffic you set the shift yourself: a quiet one with a few arrivals an hour, or a busy one to see how much you can take. Real World mode runs a real offline schedule instead, starting at the hour you pick on the day chart, so you can test yourself against real-life traffic.

MULTISECTOR

Multisector covers the whole Amsterdam FIR. Arrivals cross the FIR boundary at one of 11 entry points, somewhere between FL280 and FL320, and the AUTO area controller brings them down towards the IAFs. Departures climb out through approach and are handed to area control, which takes them to their exit point. On the New Game screen you choose which of the four Schiphol approach positions you work: Feeder East, Feeder West, Arrival 1 and Arrival 2. The feeders take the arrivals over from area control and work the departures' climb-out. The arrival positions bring the traffic onto final. Every position you don't take is run by an AUTO controller, and so are the five area control sectors and Schiphol tower. Rotterdam tower and approach are also worked by AUTO controllers.

The choice isn't fixed for the session. From COSYS you can take a position over from an AUTO controller or hand it back while the game runs. You can also monitor a position before you take it over: its labels turn blue, so you can see what you're about to get yourself into.

COSYS

Talking to aircraft is half the job. The other half is agreeing things with the sectors next to you, and in multisector you do that in COSYS (Coordination System). The standard agreements between sectors decide where an aircraft is handed over and at what level. COSYS lets you change those for specific traffic, and the AUTO controller on the other side then handles that traffic the way you agreed. Agreeing it in advance saves you last-minute fixes and repeated work. If you already know the next arrival has to come in lower or earlier, you arrange it while it is still with area control, before it reaches your airspace. Once you've selected an aircraft, setting up a coordination takes a few clicks and a few seconds. COSYS is small and docks to the edge of the screen, so the traffic stays in view while you coordinate.

These are some of the coordinations you can send:

• Request aircraft on frequency: get an aircraft from area control or a feeder earlier, optionally already on a heading, to a direct, level or speed you choose.
• Transfer Level (XFL): have an aircraft transferred to your sector, or to the next one, at a non-standard level, either for one aircraft or as a general coordination.
• Area Delegation: borrow part of a neighbouring area, so you get more flexibility in altitude bands.
• Inbound Clearance: tell area control to clear inbounds onto a different route or heading after their STAR.
• Runway Change: open or close a departure or arrival runway.
• Request a Holding: ask area control to open a hold at one of the IAFs, with expected approach times (EAT), either as a general delay or for specific aircraft.

The AUTO controller checks your request against its own traffic and airspace before it answers. It approves, denies with a reason, or sends a COUNTER with values it can accept. Some messages come to you. When an aircraft goes around, the tower sends you a Missed Approach message. Acknowledge it and the aircraft flies the published missed approach, or COUNTER with a heading or level of your own. Rotterdam tower asks you for a departure release before a Rotterdam departure leaves into your airspace. The supervisors send their flow warnings through COSYS as well.

AUTO CONTROLLERS

The AUTO controllers take care of the sectors you don't take. Each AUTO controller works to the separation minima of its own unit. Area control keeps aircraft 5 NM or 1000 ft apart and plans four minutes ahead. It sequences the arrivals to each IAF 7 NM apart, and spaces departures 10 NM apart towards their exit points. The AUTO approach controller sequences arrivals to the runway. It climbs departures to their XFL FL130 where that is clear of other traffic, then hands them to area control. It works to 3 NM and 1000 ft along each aircraft's predicted path. You can ask the AUTO controller via COSYS to create a little more spacing, hand an aircraft over early or make the spacing as tight as is still safe. In multisector you can't pick more traffic than the runways can take, but arrivals can still bunch up. When delay builds, the supervisor lets you know, and the AUTO controllers deal with it the way a real unit does: with delay vectors, speed control and holding, so you still get the flow you asked for. An arrival manager (AMAN) gives every arrival a slot that fits the runway's capacity.

NEXT WEEK

Devlog 03 is about the Academy Box, our own ATCO student programme. Follow and wishlist MultiScope ATC on Steam and the next devlog shows up in your activity feed. We're also on Discord: discord.gg/BDvP6ZuY5m See you on frequency. - The MultiScope Team