Release Notes

These notes summarize release highlights. They are not a complete commit log.

For detailed asset-by-asset history, use the GitHub releases page:

• Euroscope-ALB_Releases Releases

0.4.6 - Streamlined Timeline Controls and Navigation

Added

• Added local TL* / TL- and STAT* / STAT- controls for showing or hiding the timeline and statistics areas. * means shown and - means hidden.
• Added a right-side vertical elevator for each visible timeline. Drag the thumb or click the track to navigate the displayed future time window.
• Added Page Up, Page Down, Home, and End navigation for the active timeline elevator.
• Added optional startupShowTimeline and startupShowStatistics config defaults for the first successful ALBCore startup.

Changed

• Reorganised the top button row into presentation, operational, and display groups, with clearer separators and stable button spacing.
• Added the visible FULL / LEAN compute-mode control as a reserved future surface. It remains disabled in 0.4.6, so ALB continues to run in FULL mode.
• With the timeline hidden, ALB uses compact statistics-only or header-only presentation. Manual resizing is disabled in those compact views and normal timeline size is restored when the timeline is shown again.
• Improved LT order retention and tactical placement so normal estimate movement does not unnecessarily reshuffle the shared landing plan.
• Improved handling of contradictory route-distance evidence so it does not drive normal timing or sequencing until the route picture becomes credible.

Operational notes

• TL, STAT, and the timeline elevator are local presentation controls only. They do not change aircraft state, sequencing, FMR authority, or peer data.
• Use Advance 1 or Resequence through the normal FMR workflow when the operational traffic situation genuinely requires a sequence change.

0.4.5

This release publishes the latest 0.4.x line through August 24, 2026.

Release position

• 0.4.5 is the current public documentation baseline for the mature 0.4.x line.
• No new normal operator workflow was introduced on top of the late 0.4.4 behavior summarized below.

0.4.4

This release follows 0.4.1A.

Changed

• Stabilized LT order retention and tactical landing placement so late entrants, startup sequencing, and protected traffic preserve a more coherent runway plan.
• Restored feeder-style AR demand and stream overview from valid via timing without requiring LT-only landing products.
• Runway EAT:LT Gain/Lose display now reads against the current live landing estimate branch instead of relying on a stale scheduler-only comparison basis.

Fixed

• Prevented catastrophic route-distance contradictions from poisoning ETA:ES, ETA:ALB, ELT-ES, or ELT-ALB.
• Corrected the stable 30' overview column so unavailable values show as aligned --% instead of temporary factual-count substitutions.
• Refined tactical LT admission and manual-slot precedence so unresolved tactical traffic no longer steals protected manual authority prematurely.

0.4.1A

This hotfix follows 0.4.0.

Fixed

• Prevented implausible near-via route timing from cascading into the ETA:ALB / ELT-ALB branch.

Changed

• When route-derived via-fix timing close to the via-fix is physically implausible, ALB now refuses to let that bad near-via estimate drive the ALB landing branch.
• In those situations, ALB can fall back to the live ES branch or retain a still-trusted prior ALB branch until the timing evidence becomes credible again.
• Exiting-hold traffic that is still operationally pre-via keeps its intended hold-planning context instead of being treated like a normal free near-via transition.

0.4.0

This release promotes the validated 0.3.1W line to the 0.4 series after the successful VtC run on August 3, 2026.

Release position

• 0.4.0 is the stable promotion of the matured 0.3.1W feature and recovery line.
• The user-facing behavioral highlights of that promoted line are already summarized below under 0.3.1W.

0.3.1W

This release follows the previous public 0.3.1T release and includes the user-facing work that landed through the internal 0.3.1U and 0.3.1V milestones.

Added

• Added first-entry sequencing gating so newly observed aircraft are not turned into canonical ALB sequence traffic before they have reached the normal admission conditions.
• Added the informational EST UNST pre-entry estimate indication for route-resolved aircraft that are still being held outside normal canonical sequencing.

Changed

• Reworked normal backend seqsync sender behavior so estimate-only SET2 updates can be bounded and coalesced while operationally important canonical transitions still go out immediately.
• Reload config now reapplies the configured legacy default AR or scenario baseline to restored timelines instead of letting retained AR state come back undefined.
• Suppressed false No Fix style warning behavior for traffic that is still intentionally pre-entry and not yet admitted to normal sequencing.
• Peer presence and route aging now distinguish backend freshness from scratchpad freshness more cleanly, so peer display and transport-specific authority stay aligned with the route that is actually still fresh.

Fixed

• Protected follower HOLD_EAT timeline lookup more safely.
• Hardened peer receive handling so a same-revision conflicting SET2 payload is rejected instead of being treated like a harmless duplicate.

Technical notes

• This step also advanced the staged recovery-programme transport contract and related runtime hardening in the development source tree.

0.3.1V (Source-only)

Added

• Added the first-entry sequencing gate for newly observed aircraft.

Changed

• Successful config reload now restores the configured legacy default AR or scenario baseline for retained timelines instead of leaving active AR state undefined.

Technical notes

• Internal recovery-programme and validation material also advanced in the source tree during this milestone.

0.3.1U (Source-only)

Fixed

• Protected follower HOLD_EAT timeline lookup more safely.

0.3.1T

This release follows the previous public 0.3.1R release and includes the user-facing work that landed after the internal 0.3.1S milestone.

Added

• Allowed EAT:LT to assign landing slots to aircraft that have a usable landing ELT even when fuller route-timing products are not yet available.

Changed

• Completely reworked the EAT and Combi tag callback path around prepared read-only display snapshots instead of callback-time mutable assembly.
• ALB can now seal the ELT-ALB branch earlier when a validated route via-fix bypass provides good enough timing evidence.
• Feeder gain/lose no longer shows a misleading G00 for traffic that is already operationally downstream of where that feeder indication is useful.
• The new callback model improves tag-rendering consistency, safety, and hot-path responsiveness.

Technical notes

• This step included the typed-display and immutable-snapshot preparation work needed to support that callback-path redesign.

0.3.1S (Source-only)

Added

• Enabled backend A2A participation for eligible VIA_PROXY ALB instances using normal canonical ALB identities.

Changed

• Tightened backend fallback convergence so mixed backend or scratchpad groups can agree on peer state more cleanly when some peers are on fallback.
• EAT:LT manual Resequence is now a more deterministic FMR-owned landing re-entry from the live ELT boundary instead of a generic best-fit style placement.
• AR gain/lose now follows the final authoritative EAT-versus-ETO basis more consistently and honors configured holdLeXState inside the hold threshold.
• HOLD_EAT write, restore, provenance, and per-aircraft dedup handling were hardened so repeated planned updates are preserved more safely.
• Timeline count publication and legend aggregate consistency were corrected.
• Sequencing integrity is preserved more safely across suppressed RDA states.

0.3.1R

This release follows 0.3.1Q.

Added

• Added optional glEatCombiDisplay.gainLooseEmptyText config support for a trimmed placeholder when Gain/Lose is the selected Combi state but the actual Gain/Lose value is empty.

Changed

• Reload config no longer re-opens the ALB window if it is currently closed.
• Combi radar-tag output is now gated by active timeline destination coverage, so only aircraft whose destination belongs to a currently active ALB timeline can show Combi output.
• Route-based directRouting fallback now shows the actual current next fix instead of the following waypoint.
• Corrected certain compact field labels, including the combined Combi and via-fix timing headings.

Fixed

• Prevented unrelated non-ALB traffic from showing configured empty Gain/Lose placeholders in Combi output.

Technical notes

• openAutomatically remains the startup auto-open behavior. It is no longer reapplied during later config reloads.
• gainLooseEmptyText is backward-compatible and optional. If omitted or blank, ALB keeps the older empty-string behavior for empty Gain/Lose cases.

0.3.1Q

This release is the next published step after 0.3.1N.

It includes the public-facing work developed through the internal 0.3.1O and 0.3.1P source milestones as well as the final 0.3.1Q transport and continuity hardening.

Added

• Added airport-configurable WTC-aware EAT:LT landing spacing for L, M, H, and J.
• Added the Expected LR landing-rate forecast row below PLR.
• Added startup-only baseline keys for preferred startup policy and hold-write state:
• eatModeOnStartup
• etaModeOnStartup
• holdEatWriteOnStartup
• Added a local runtime hold-display control for the compact glEatCombi field.

Changed

• EAT:LT now uses the larger of PLR spacing, minimum spacing behind the leader, and minimum space required in front of the follower while preserving the established canonical landing order.
• Runtime EAT, ETA, and HLW selections are preserved more cleanly across Reload config.
• Config reload is now transactional and also tries to preserve the current timeline zoom.
• Backend reconnects and mixed backend or scratchpad peer routing are hardened so collaboration continuity is safer through reconnect windows.

Fixed

• Hardened ALB close or teardown behavior around config reload and controller finalization.
• Improved AR debounce shutdown handling on ALB window close.
• Hardened cloud send timeout handling so failed setup, send, or receive paths fail safely.

Technical notes

• Mixed-peer reconnect continuity is automatic. Operators still use the normal FMR, seqsync, and config-reload controls.
• Expected LR remains informational. It does not automatically change PLR, LT order, EAT, or PLT.

0.3.1P (Source-only)

Changed

• Made config reload transactional instead of publishing partial live state.
• Preserved active UI and intercom state more cleanly across successful reload.

Fixed

• Replaced the detached ALB window finalizer with a joinable controller worker.
• Fixed finalizer publication and closed-ordering races.
• Destroyed the ALB controller before plugin singleton and log teardown.
• Fixed ALB window AR debounce worker lifetime on close.

0.3.1O (Source-only) - WTC-aware EAT:LT spacing and Expected LR

WTC-aware EAT:LT spacing

• Added airport-configurable WTC-dependent landing spacing for L, M, H, and J.
• Landing spacing now uses the largest of:
• PLR-derived spacing
• minimum spacing behind the leader
• minimum space required in front of the follower
• Added complete built-in default matrices, making config overrides optional.
• Missing or unknown WTC uses the configured airport fallback category, defaulting to M.
• Applied pair spacing consistently through normal sequencing, forced placement, deferred placement, FIFO gap-fill, protected-FZ2 endpoint checks, and comparison chains.
• Preserved natural traffic gaps and the established canonical landing order.

Expected landing rate

• Added a demand-limited Expected LR forecast based on final canonical LT PLTs.
• The default forecast window is 30 minutes and may be configured per airport.
• Added an Expected LR row directly below PLR.
• The row shows:
• expected hourly landing rate
• eligible aircraft count
• forecast window
• difference from PLR
• A result below PLR is informational and is not automatically shown as a warning.
• No smoothing, trend, or automatic PLR adjustment is applied.

Hardening

• Improved duplicate-callsign handling in the Expected LR calculation.
• Preserved candidate-specific spacing during LT gap-fill.
• Strengthened protected-FZ2 adjacent-pair checks.
• Extended WTC-spacing and Expected LR diagnostics.
• Corrected gap-fill preview diagnostics to use the final assigned PLT.

Compatibility

• Existing configurations remain valid.
• WTC matrix overrides are optional.
• No SET2, POL, PREF, scratchpad, backend, or cloud-schema change was required.
• FMR remains authoritative for canonical sequence, EAT, and PLT.
• LT slot tolerance remains PLR-based.

Validation status

• Implementation, static review, and direct ALBCore.dll build verification are complete.
• Operational live or playback validation remains pending.

0.3.1N (Source-only)

This section summarizes the 0.3.1N change set from the development source tree.

Added

• Added a local runtime control for the combined hold-display threshold and pre-threshold display mode used by glEatCombi.
• Added grouped display buttons for the compact EAT or PLT combi selection and the hold-display selection.
• Added holdEatWriteOnStartup so HLW can start in a chosen local state on the initial config load.

Changed

• eatModeOnStartup and etaModeOnStartup are now applied only during the initial config load instead of being reapplied on every config reload.
• Startup EAT and ETA mode strings now accept valid values case-insensitively and fall back independently to AR and ES if missing or invalid.
• Runtime EAT, ETA, and HLW selections are now preserved across Reload config.
• Hold-display runtime settings are seeded from config and reset on a successful config reload.
• The new hold-display button keeps hold-inside-threshold display fixed to countdown while making the pre-threshold display easier to adjust locally.
• Control-bar display buttons now use grouped styling, fixed-width labels, and more stable spacing so neighboring buttons do not shift.

Fixed

• Unsupported holdGtXState values are now normalized more safely to Blank.
• Tooltip and window cleanup around the new hold-display controls is handled more safely during shutdown.

Technical notes

• This change set is mainly startup-config and local display/runtime cleanup.
• Shared sequencing logic, peer synchronization, and the normal ALB planning models are not intentionally changed by the new hold-display controls.

0.3.1M (Source-only)

Added

• Added a cleaner normal operator surface by hiding more legacy-visible control-bar items.

Changed

• Hid the visible FPC control-bar button while preserving underlying FPC state, protocol behavior, peer sync, and logging behavior.
• Hid the visible Scenarios menu while preserving internal scenario config and apply logic for compatibility.
• Moved Peers(...) to appear immediately after Layout in the visible menu order.

Technical notes

• This step is mainly public UI cleanup rather than a change to ALB planning logic.

0.3.1L (Source-only)

Added

• Expanded cloud operational logging across ALB authority and policy flows.

Technical notes

• This step is mainly operational logging and internal traceability work.

0.3.1J (Source-only)

Added

• Added backend-authority timeout and timeout-now release handling for reduced-sync and horizon coverage-loss cases.
• Added throttled backend-health and auto-fallback diagnostics.
• Added clearer FMR recovery and backend owner-shadow diagnostics.
• Added alias telemetry for the MODEL_HANDOFF performance cause.

Changed

• Runway Advance 1 peer requests can now proceed without requiring local predecessor context.
• Advance 1 direct local apply and runway peer-request routing are now handled more explicitly.
• Natural resequence reset now clears committed-slot and LT gap latches more cleanly.
• Repeated same-fix HOLD scratchpad assignments now preserve HOLD_EAT state more safely.
• HOLD and XHOLD scratchpad ingestion is now treated more like event handling instead of implicit state clear on scratchpad restore.
• Near-origin RDA visual-clear diagnostics were clarified.

Technical notes

• This step is a mixed backend-recovery, peer-sequencing, and hold-ingestion cleanup pass.

0.3.1I (Source-only)

Added

• Added a non-reentrant snapshot guard for structured backend recording.
• Added pending-retry tracking for temporary structured-recording snapshot collisions.

Changed

• Temporary device-busy or resource-busy snapshot collisions are now treated as recoverable instead of disabling structured recording for the session.

Fixed

• Fixed carrier-list self-lock and recording-lock callouts.

0.3.1H (Source-only)

Fixed

• Corrected a thrown exception.

0.3.1F (Source-only)

Added

• Added peer performance telemetry and FMR warning or report logging.
• Added lower-noise backend sequence authority-transition and blocked-write diagnostics.
• Added more focused apply-path and HOLD_EAT performance diagnostics while reducing SET2 receive churn.

Changed

• Separated active backend sequence authority from stale receive-revision memory so DEL clears peer write-blocking authority without losing stale-message protection.
• Aligned source comments with the backend sequence DEL authority teardown behavior.

0.3.1E (Released)

Changed

• Replaced the peer-list HLS display column with an EAT-policy column while keeping ETA as the ES or ALB branch indicator.
• Cleared HIG and RT-issue state more cleanly on /XHOLD/ and related non-hold scratchpad updates.
• Preserved exiting-hold HOLD_EAT protection more safely.
• Kept OBS-list removal retryable when flight-plan removal is temporarily unavailable.
• Kept peer PRA display informational only while improving PR-count resolution by ICAO and callsign in the active-timeline context.

0.3.1D (Released)

Changed

• Fixed FMR EAT-mode policy synchronization on peers.
• Clarified HOLD_EAT authority so HLW is the active local write gate.
• Retired the HLS control-bar button from normal operator use while keeping legacy compatibility state.
• Kept SEAT as legacy or fallback-only hold-EAT handling rather than part of the normal backend-primary path.
• Refreshed timeline notes more reliably on peer clear, expiry, and count changes.

0.3.1C

Added

• Added backend sequence synchronization load-management work through Stage 4.1.
• Added diagnostics-only instrumentation for backend SEQ/SET2 synchronization.
• Added HORIZON seqsync mode.
• Added seqsync status and diagnostic visibility for reduced-sync operation.
• Added passive peer update-cycle health monitoring.
• Added backend-only peer health warnings for the FMR when a peer appears slow to apply shared backend updates.

Changed

• Backend sequence synchronization can now reduce traffic under load while preserving backend canonical sequence authority.
• Added bounded overlay-clear DEL handling.
• Added bounded return-to-normal recovery behavior after reduced-sync modes.
• When a manual FMR is active, non-FMR peers are now blocked from mutating shared LT, PLR, AR, and scenario policy locally.
• In runway-sequence collaboration, Advance 1 and Resequence now use a request-reply path and wait for canonical backend sync instead of silently applying a competing local result.
• Tightened peer LT fallback gating so backend-primary runway-sequence handling stays aligned with canonical backend sync.
• Added timeout handling for pending runway peer Advance 1 and Resequence requests.

Technical notes

• Canonical per-aircraft sequence state remains backend-only.
• FLOAT remains parked and is not part of this release.
• This work does not intentionally alter the EAT:LT or EAT:AR sequencing algorithms.

0.3.1B

Added

• Added backend poll sub-phase performance breakdown.
• Added backend poll timing and backlog visibility to performance reporting.

Changed

• Improved diagnosis of backend-dominated timer spikes and performance pauses.

0.3.1A

Changed

• Adjusted perftest reporting.
• Refined live ALB policy button authority so active non-observer peers may control shared live policy when no manual FMR is present, while manual FMR ownership remains exclusive when active.

0.3.0

Added

• Established the 0.3.x release line.
• Introduced the loader/core packaging model:
• ALB.dll as the EuroScope loader
• ALBCore.dll as the runtime core
• Updated public install and release documentation around the new packaging model.

Changed

• Set the source version and minimum protocol floor to 0.3.0.

Notes for users

If you are updating from an older ALB installation:

• make sure EuroScope loads ALB.dll, not ALBCore.dll
• keep alb-config.json as your live config
• treat alb-config.default.json as a template or default file

For installation details, see Download & Install.

Maintainer note

The 0.3.x release tags may not line up cleanly with the release-version pointer history. For future release-note maintenance, prefer:

1. alb-plugin-release-version.txt history in Euroscope-ALB_Releases
2. MY_PLUGIN_VERSION history in ES-ArrivalLoadBallance
3. commit ranges between those anchors
4. release tags only after checking what content they actually point to