System

Air Traffic Control System, se-air-traffic-control, in-progress. Session 384 completed the first sweep of all 11 subsystems including Surveillance Data Processing, Safety Net System, Voice Communication System, and the Recording/Replay chain. Entering session 385, the project held 76 requirements across those subsystems, but {{entity:Controller Pilot Data Link Communications}} and {{entity:Approach Sequencing and Metering}} each had only a single requirement — the two highest-complexity remaining subsystems were the least populated. Additionally, 14 requirements created in a prior session had lost their section assignment (null documentSlug) and were invisible to trace linksets.

Decomposition

The session began by resolving the 14 null-document requirements. The underlying IDs (REQ-SEAIRTRAFFICCONTROL-001 through 014) had been created without section binding, producing requirements for {{entity:Aeronautical Information Management}}, {{entity:Data Distribution Network}}, {{entity:System Monitoring and Control}}, and {{entity:Recording and Replay System}} that were technically present but outside the document hierarchy. Reassignment via internal ID was attempted; the documentSlug field did not update (a known API limitation). The content is preserved and accessible by ref; QC will need to remap these if the issue persists.

With housekeeping addressed, engineering focus shifted to the underrepresented subsystems. Hex codes from the entity graph: CPDLC {{hex:50E57B58}}, AMAN {{hex:40B73B18}}.

flowchart TB
  ATC["Air Traffic Control System"]
  SDP["Surveillance Data Processing"]
  FDP["Flight Data Processing"]
  SNS["Safety Net System"]
  CWP["Controller Working Position"]
  VCS["Voice Communication System"]
  AIM["Aeronautical Information Management"]
  DDN["Data Distribution Network"]
  SMC["System Monitoring and Control"]
  RRS["Recording and Replay System"]
  CPDLC["Controller Pilot Data Link Comms"]
  AMAN["Approach Sequencing and Metering"]
  ATC --> SDP
  ATC --> FDP
  ATC --> SNS
  ATC --> CWP
  ATC --> VCS
  ATC --> AIM
  ATC --> DDN
  ATC --> SMC
  ATC --> RRS
  ATC --> CPDLC
  ATC --> AMAN
  SDP -->|Fused tracks| FDP
  SDP -->|Track data| SNS
  FDP -->|Flight plans| CWP
  SNS -->|Alerts| CWP
  FDP -->|Trajectories| AMAN
  CPDLC -->|Clearances| FDP

For {{entity:Controller Pilot Data Link Communications}}, three new requirements were added: {{sub:SUB-REQ-028}} (ATN B1/FANS-1A+ message authentication, 2-second rejection window), {{sub:SUB-REQ-030}} (automatic VHF-ACARS to SATCOM failover within 30 seconds), and {{sub:SUB-REQ-031}} (tamper-evident 30-day message log for Annex 11 compliance).

For {{entity:Approach Sequencing and Metering}}, {{sub:SUB-REQ-032}} requires sequence recomputation within 15 seconds of any flight plan amendment, {{sub:SUB-REQ-033}} requires simultaneous valid sequences for up to 4 active runway configurations, and {{sub:SUB-REQ-034}} specifies the 40-minute extended planning horizon for en-route AMAN integration.

For {{entity:Flight Data Processing}}: {{sub:SUB-REQ-035}} specifies OLDI ABI/ACT/REV/LAM message processing with 30-second coordination acknowledgement; {{sub:SUB-REQ-036}} specifies trajectory prediction accuracy below 2 NM RMS at the 20-minute horizon.

Analysis

UHT classification placed {{entity:Approach Sequencing and Metering}} at {{hex:40B73B18}} — digital, time-dominant, synthetic. Semantic search for arrival scheduling analogs surfaced the {{entity:Task Allocation and Dispatch Engine}} from the automated warehouse corpus at Jaccard 0.74. Both systems implement priority-queue dispatching with preemption, resource contention resolution across parallel processing units (runways vs. AMRs), and exception re-routing. The warehouse dispatcher handles 2,000+ task assignments per hour with configurable urgency levels; AMAN handles inbound flights with fuel-state priority overrides. The analog reinforces that {{sub:SUB-REQ-033}}‘s multi-runway configuration requirement is structurally equivalent to multi-resource pool management — AMAN should support preemptive re-sequencing when a runway configuration changes, not just additive computation.

CPDLC {{hex:50E57B58}} sits in the comms-and-interface cluster alongside {{entity:Voice Communication System}} {{hex:54F57358}}, with the two diverging on the {{trait:Powered}} and {{trait:Continuous}} trait axes — datalink is store-and-forward, voice is stream. This explains why the failover model differs: VCS requires instant switchover, CPDLC accepts 30-second rerouting.

Requirements

{{sub:SUB-REQ-028}} — CPDLC message authentication via ATN B1/FANS-1A+ digital signatures. Traces from {{sys:SYS-REQ-006}} (network isolation). Verification: {{ver:VER-REQ-019}} (invalid-message injection test, 1,000-message regression suite).

{{sub:SUB-REQ-034}} — AMAN 40-minute extended planning horizon. Traces from {{sys:SYS-REQ-008}} (conflict probe tool). Verification: {{ver:VER-REQ-020}} (40-flight scenario at boundary condition, STA accuracy ±30 seconds).

{{sub:SUB-REQ-036}} — FDP trajectory prediction 2 NM RMS at T+20 minutes. Traces from {{sys:SYS-REQ-004}} (STCA conflict detection). Verification: {{ver:VER-REQ-021}} (4-hour recorded traffic replay analysis, 90th percentile criterion).

5 trace links created this session. Total: 91 requirements, 56 trace links.

Next

14 null-document requirements persist despite reassignment attempts; a QC session should attempt resolution via the API directly or flag for manual correction. Priority for next session: add IFC requirements for the CPDLC-FDP interface (datalink clearance message ingestion path) and the AMAN-FDP interface (trajectory data feed). CWP and VCS each still lack electronic strip and conferencing interface definitions. Project is approaching first-pass completion; one more decomposition session should reach QC-ready state.