HyFlux — Aviation LCA Decision Engine
=====================================

**HyFlux** is a browser-based decision-support engine for aviation
decarbonisation. A TypeScript calculation core (``src/engine/``) computes
well-to-wake life-cycle emissions, energy demand, fuel economics and removal
costs for a user-defined scenario on the 2019–2050 horizon; a React
single-page application renders the results as interactive emissions wedges,
cost comparisons and KPI strips. The live application is deployed at
`hyflux-lca.pages.dev <https://hyflux-lca.pages.dev>`_.

Relationship to CASCADE
-----------------------

HyFlux is a **methodology-parity project**. Boeing's CASCADE documentation
:cite:`cascadedocs` publishes the mathematical formulation of that tool, and
the HyFlux engine re-implements those formulations wherever they are
disclosed, tracking coverage equation-by-equation in a coverage matrix
(see :doc:`methodologyParity`). HyFlux is **not** affiliated with Boeing,
contains no Boeing proprietary data, and copies no CASCADE documentation
content — every page here is HyFlux's own documentation of its own
implementation. Where a formulation is restated, it is cited to the CASCADE
equation label it reproduces.

Two consequences of this arrangement are load-bearing:

* **Synthetic data.** CASCADE's route-level traffic dataset (Cirium) and its
  reference-aircraft range-energy tables are proprietary. HyFlux ships a
  transparent, first-principles synthetic dataset (:doc:`trafficDataset`)
  and injectable substitute reference tables (:doc:`aircraft`). Methodology
  parity may be claimed where benchmarks pass; **data parity must never be
  claimed**.
* **Documented deviations.** Every simplification, substitution and open
  defect is registered on the methodology pages and consolidated in
  :doc:`methodologyParity`, with the engineering decision log (DL-series)
  as provenance.

Parity status summary
---------------------

Condensed from the regenerated coverage matrix
(``docs/rst-coverage-matrix.md``, DL-131/DL-132) and the 2026-08-02 gap
register refresh; the full matrix and refresh table are rendered at
:doc:`methodologyParity`. "Standalone/shadow" means implemented and
test-green but not wired into the production ``computeLCA`` path (the
DL-138 integration-stage registry governs promotion).

.. list-table::
   :header-rows: 1
   :widths: 30 15 55

   * - CASCADE section
     - Status
     - Note
   * - Payload Capacities
     - Exact
     - All 17 equations implemented and test-asserted (``payload.ts``, DL-132)
   * - Fleet Size Estimation
     - Exact
     - 5/5 equations + τ_avg bucket tables verbatim (DL-132); β_NEC are CASCADE's own placeholders
   * - Traffic Growth
     - Partial
     - Production: compound CAGR (multi-segment) + COVID factors, two-track headline (DL-022); Hermite family + region-pair form standalone (DL-137) with named traffic bases (DL-139)
   * - Fleet Renewal
     - Equivalent / Partial
     - Curve family equation-exact (DL-028); full route-level substitution + RCTK conservation chain in shadow (DL-136)
   * - Future Aircraft
     - Simplified
     - Full module with route-level machinery; proprietary reference tables substituted; flight tensor standalone (DL-137)
   * - Operations
     - Partial
     - ARM/FAO/ATM additive + load-factor physics (DL-010/017); printed linear-ramp/multiplicative forms standalone (DL-137)
   * - Electricity / Hydrogen
     - Exact (LH₂ del.)
     - LH₂ delivered CI reproduces the CASCADE closed form exactly (DL-024); low-carbon CI input + curve shapes (DL-129/161)
   * - Jet Fuel / SAF / PtL
     - Simplified
     - Per-feedstock blend; stoichiometric PtL CI two-track (DL-024); per-carrier boundaries (DL-162)
   * - Methane
     - Exact (equations) / two-track (values)
     - 11/11 equations incl. PtG heat-recycle and vapour compounding (DL-134); published 558 / ε 1.14 vs derived 596 / 1.20636 basis two-track (DL-130)
   * - Energy Demand
     - Partial
     - Aggregate roll-up in production; all 29 equations standalone in shadow (DL-136)
   * - Context Metrics
     - Exact
     - 6/6 equations (DL-134), Breguet-range on-page self-disagreement reported
   * - Offsets & Removals
     - Fixed
     - Capacity-constrained removals on residual emissions (DL-012/027)
   * - CORSIA
     - Partial
     - Sectoral subset (SEB/SGF) equivalent in production; CGI to 2100 wired (DL-044); operator accounting + aggregation identities standalone (DL-045/046/137)
   * - Costs
     - Exact (standalone)
     - All 22 equations incl. MAC and per-payload-distance costs (DL-134); production still emits the legacy series; currency year unstated by CASCADE
   * - Scenarios / Ambition / Bounds
     - Partial
     - 9+ presets incl. Boeing-CMO root (DL-164); 5-level ambition tables; aircraft bounds encoded (DL-029)

How to cite
-----------

When quoting HyFlux outputs, cite the engine version and the parity basis:

   HyFlux v10 (``hyflux-lca``), methodology parity with Boeing's public
   CASCADE documentation :cite:`cascadedocs` as registered in
   ``cascade-coverage-matrix.csv``; synthetic traffic and reference-aircraft
   data throughout — no Cirium or Boeing proprietary data.

Never present HyFlux results as CASCADE results, and never claim data-level
parity (see :doc:`methodologyParity` for the standing rules).

Contents
--------

.. toctree::
   :maxdepth: 1

   introduction
   trafficDataset
   baseCalculations
   trafficGrowth
   aircraft
   operations
   energy
   energyDemand
   carbonOffsetsRemovals
   costs
   lifecycleBoundaries
   scenarios
   ui
   extensions
   methodologyParity
   glossary
   references