{
  "vercy": "1.0-draft",
  "publication": {
    "status": "research-draft",
    "adjudicationStatus": "unreviewed",
    "publishableCanonical": false,
    "generatedAt": "2026-09-12T10:39:21Z",
    "providers": [
      "Codex"
    ],
    "breadth": "recalled by Codex without web access - no source was read",
    "missingProviders": [],
    "pass": 2,
    "cost": {
      "grok": {
        "seconds": 22.8,
        "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.4\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a09532-0e1d-7b72-9bbf-c4b6c89b627d\n--------\nuser\nDescribe what is already known about one registered thing. Answer as JSON only, no prose around it.\n\nThing: J75\nSense to describe: (none recorded)\nDomain code: PHY.OBJ\nAlso known as: (none)\n\n\nContext for this batch of 1001 things:\n# Batch 043: 1001 registered ",
        "usd": 0.0,
        "recall": true
      },
      "codex": {
        "seconds": 81.2,
        "error": "Reading additional input from stdin...\nOpenAI Codex v0.153.4\n--------\nworkdir: R:\\02_PROJECTS\\02_Meta_Models_Platforms\\Ver.cy\\current\\thing-registry-backlog\nmodel: gpt-6-astra\nprovider: openai\napproval: never\nsandbox: read-only\nreasoning effort: none\nreasoning summaries: none\nsession id: 01a09532-0e1d-7561-9bcd-2e28b46cc80c\n--------\nuser\nYou are drafting a Vercy meta-model for one registered thing. Answer as JSON only, no prose around it.\n\nThing: J75\nRegistry id: vr.tr.j75\nPlane / domain: PHY / PHY.OBJ\nRegistry definition: (none recorded)\nNames folded into this entry: (none)\n\n\nContext for this"
      }
    },
    "enrichment": {
      "pass": 3,
      "engine": "claude",
      "producedAt": "2026-10-06T12:00:00Z",
      "ingestedAt": "2026-10-06T08:41:10+00:00",
      "fields": [
        "agent_conduct",
        "ethics",
        "owners"
      ]
    },
    "gate": {
      "passed": true,
      "version": "1.0",
      "at": "2026-10-07T10:10:32+00:00",
      "evidence": [
        "completeness 1.00",
        "sense: Wikidata description",
        "2 live sources",
        "review by codex: pass"
      ]
    }
  },
  "metaModel": {
    "id": "THING-Q688730",
    "registryId": "vr.tr.j75",
    "name": "J75",
    "version": "0.1.0-research.1",
    "entryKind": "thing",
    "family": "Thing Registry",
    "domain": [
      "PHY.OBJ"
    ],
    "status": "research-draft"
  },
  "canonicalUrl": "https://ver.cy/models/thing/q688730/",
  "model": {
    "registry_id": "vr.tr.j75",
    "name": "J75",
    "purpose": "Enable an agent to identify a J75 engine configuration, assess evidence of its condition and installation compatibility, and determine which handling, maintenance or operating actions require further authorization.",
    "definition": "The Pratt & Whitney J75 is a family of axial-flow, twin-spool turbojet aircraft engines, including afterburning variants, developed for military aircraft and related to the civilian JT4A.",
    "scope_statement": "Provisionally interpret vr.tr.j75 as the Pratt & Whitney J75 turbojet family, owning its distinguishing configuration, performance descriptors, interfaces and condition-assessment requirements rather than any particular engine specimen; Smithsonian records identify J75-P-13B and J75-P-19W examples, but the registry identity still needs confirmation. Sources: [Smithsonian J75-P-13B record](https://www.si.edu/object/pratt-whitney-j75-p-13b-turbojet-engine%3Anasm_A19820380014), [Smithsonian J75-P-19W record](https://www.si.edu/object/pratt-whitney-j75-p-19w-turbojet-engine-afterburner-water-injection%3Anasm_A19820064004).",
    "in_scope": [
      "J75 family identification, variant designations and documented configuration differences",
      "Compressor, combustion, turbine and exhaust configuration relevant to identifying and assessing a J75",
      "Variant-specific thrust ratings, operating limits and augmentation equipment",
      "Engine-side mounting, inlet, exhaust, fuel, lubrication, starting and control interfaces",
      "Evidence requirements for serviceability, preservation, maintenance and permissible actions"
    ],
    "out_of_scope": [
      "Individual engine asset records, ownership histories and serial-number inventories",
      "Complete aircraft flight characteristics and aircraft-level operating approval",
      "Standalone models of fuel, lubricants, bearings or other constituent materials and parts",
      "Detailed repair instructions and executable engine-start procedures",
      "Independent models of related engine families or civilian designations without registry boundary research"
    ],
    "distinguishing_features": [
      "Require a manufacturer designation or authoritative record linking the object to J75; a similar-looking jet engine is insufficient.",
      "Distinguish the J75 family from a named variant such as J75-P-13B and from a serial-numbered example of that variant.",
      "Check the documented compressor, turbine and exhaust arrangement against the identified J75 variant before accepting identification from external appearance.",
      "Treat augmentation equipment as variant-specific: Smithsonian explicitly identifies a J75-P-19W example with afterburner and water injection, which does not establish those features for every J75. Source: [Smithsonian J75-P-19W record](https://www.si.edu/object/pratt-whitney-j75-p-19w-turbojet-engine-afterburner-water-injection%3Anasm_A19820064004).",
      "Resolve related designations through documented lineage and configuration evidence rather than treating shared ancestry or an aircraft installation as proof of equivalence."
    ],
    "characteristics": [
      {
        "name": "Variant and configuration identity",
        "kind": "category",
        "unit_or_values": "Full J75 designation, documented modification standard, or unresolved",
        "why_it_matters": "Selects applicable ratings, parts, interfaces and maintenance evidence."
      },
      {
        "name": "Gas-path architecture",
        "kind": "category",
        "unit_or_values": "Documented spool arrangement, compressor and turbine stage counts, combustor form and exhaust configuration",
        "why_it_matters": "Supports identification and prevents borrowing architecture claims from another engine."
      },
      {
        "name": "Augmentation configuration",
        "kind": "category",
        "unit_or_values": "Afterburner and water-injection applicability, each recorded as installed, absent, removed or unknown",
        "why_it_matters": "Changes applicable thrust ratings, consumables and operating constraints."
      },
      {
        "name": "Rated thrust",
        "kind": "measurement",
        "unit_or_values": "kN, with variant, augmentation mode, atmospheric reference, installation basis and permitted duration",
        "why_it_matters": "Makes ratings comparable without treating an augmented or test-stand value as universal."
      },
      {
        "name": "Rotor speed",
        "kind": "measurement",
        "unit_or_values": "rpm or percent of a documented reference speed, identifying the measured rotor",
        "why_it_matters": "Allows comparison with the correct rotor-specific operating limits."
      },
      {
        "name": "Gas temperature",
        "kind": "measurement",
        "unit_or_values": "Degrees Celsius, with measurement station, operating phase and applicable limit",
        "why_it_matters": "A temperature reading is meaningful only against its sensor location and permitted exposure."
      },
      {
        "name": "Fuel and lubricant requirements",
        "kind": "category",
        "unit_or_values": "Approved specification and revision for the identified variant and installation; unknown where unsupported",
        "why_it_matters": "Prevents substituting generic aviation-fluid assumptions for documented compatibility."
      },
      {
        "name": "Installation envelope",
        "kind": "measurement",
        "unit_or_values": "Length and diameter in mm, mass in kg, with included accessories and augmentation equipment stated",
        "why_it_matters": "Supports handling and fit assessment without conflating bare-engine and installed dimensions."
      },
      {
        "name": "Installation compatibility",
        "kind": "relation",
        "unit_or_values": "Links to supported aircraft or test-stand configurations and their approval evidence",
        "why_it_matters": "Historical use does not by itself establish compatibility with a proposed installation."
      },
      {
        "name": "Serviceability evidence state",
        "kind": "state",
        "unit_or_values": "Unassessed, preserved, under inspection, restricted, released under documented authority, or withdrawn",
        "why_it_matters": "Separates physical completeness and apparent condition from permission to operate."
      }
    ],
    "affordances": [
      "Classify a candidate engine within the J75 family and flag unresolved variant identity.",
      "Compare documented J75 configurations and their thrust ratings under equivalent conditions.",
      "Assess engine-side compatibility with a proposed aircraft installation or test stand.",
      "Identify missing maintenance, inspection or preservation evidence before proposing an action.",
      "Route suspected operating-limit exceedances to the applicable technical instructions and qualified authority.",
      "Prepare an evidence-based handling or maintenance request without representing the model as operating approval."
    ],
    "agent_conduct": {
      "may": [
        "Describe the J75 engine family and the aircraft it powered, citing sources.",
        "Distinguish it from the civil JT4A in documents and images."
      ],
      "must_not": [
        "Run, repair or restore an engine without proper qualification and approval.",
        "Misattribute parts to sell them as airworthy or historic.",
        "Share export-controlled technical data.",
        "Downplay fire and fuel hazards around stored engines."
      ],
      "requires_human": [
        "Running a historic engine on a test stand."
      ]
    },
    "ethics": {
      "considerations": [
        "Jet engines are dangerous to run and handle.",
        "Historic hardware is heritage that deserves preservation."
      ],
      "affected_parties": [
        "Restorers and mechanics",
        "Museum visitors"
      ]
    },
    "owners": {
      "steward": "Museums, collectors or operators who hold engines; the manufacturer holds design records.",
      "master_systems": []
    },
    "what_it_is_for": [
      "J75 engines are encountered in historical military aircraft, preserved collections and specialist maintenance documentation.",
      "Identifying the engine variant supports interpretation of aircraft installations, component compatibility and maintenance records."
    ],
    "standards_and_regulation": [
      "MIL-STD-130, issued by the United States Department of Defense, governs identification marking when required for engines or components supplied as military property.",
      "MIL-STD-129, issued by the United States Department of Defense, governs military shipment and storage marking when required for an engine shipment."
    ],
    "visual_identification": [
      "An engine identification plate bearing the J75 designation and variant suffix provides stronger identification than its overall silhouette.",
      "The engine has an elongated cylindrical body with an axial intake and external accessory equipment, without the broad front fan of a high-bypass turbofan.",
      "Afterburning variants have an extended exhaust section and variable exhaust nozzle, although these features alone do not establish the engine model."
    ],
    "failure_modes_and_hazards": [
      "Operating engines expose people and nearby property to intake suction, hot exhaust and high noise levels.",
      "Rotating component failure can release fragments and cause severe injury or aircraft damage.",
      "Fuel or lubricant leaks can cause fire and damage surrounding equipment.",
      "Incorrect lifting or unsupported storage can allow the heavy engine to fall or overturn."
    ]
  },
  "sources": [
    {
      "id": "wikidata",
      "title": "Wikidata item Q688730: J75",
      "url": "https://www.wikidata.org/wiki/Q688730",
      "url_status": "live",
      "what_it_supports": "identity and sense of the item",
      "checked_by": "wikidata-api"
    },
    {
      "id": "wikipedia-en",
      "title": "Wikipedia: Pratt & Whitney J75",
      "url": "https://en.wikipedia.org/wiki/Pratt_%26_Whitney_J75",
      "url_status": "live",
      "what_it_supports": "general description of the item",
      "checked_by": "wikidata-api sitelink"
    }
  ],
  "structure": {
    "bundles": [
      {
        "id": "j75-identity-and-boundaries",
        "name": "J75 identity and boundaries",
        "description": "Establish what the registry name denotes and how family, variant and specimen identities relate.",
        "rationale": "The bare designation J75 has no registry definition, so every subsequent assessment depends on resolving its referent.",
        "layers": [
          {
            "id": "registry-referent",
            "name": "Registry referent",
            "description": "Connect the registry entry to an evidenced engine-family identity.",
            "findings": [
              {
                "id": "designation-evidence",
                "name": "Designation evidence",
                "description": "Record the evidence supporting the provisional Pratt & Whitney interpretation and its confidence.",
                "questions": [
                  {
                    "text": "Which original registry source identifies vr.tr.j75 as the Pratt & Whitney engine family?",
                    "kind": "provenance",
                    "id": "designation-evidence-q01"
                  },
                  {
                    "text": "Does the entry denote the family, one variant or a particular physical engine?",
                    "kind": "boundary",
                    "id": "designation-evidence-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "variant-and-lineage",
            "name": "Variant and lineage",
            "description": "Distinguish configuration identities from related names and individual examples.",
            "findings": [
              {
                "id": "variant-applicability",
                "name": "Variant applicability",
                "description": "Attach technical statements to the exact designation and modification standard they describe.",
                "questions": [
                  {
                    "text": "Which evidence establishes the full variant designation and modification standard?",
                    "kind": "provenance",
                    "id": "variant-applicability-q01"
                  },
                  {
                    "text": "How should JT4A and other related designations link to this entry without creating duplicate models?",
                    "kind": "boundary",
                    "id": "variant-applicability-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "j75-gas-path-and-augmentation",
        "name": "J75 gas path and augmentation",
        "description": "Describe the architecture and augmentation distinctions needed to recognize a configuration.",
        "rationale": "Family resemblance does not establish internal configuration or the presence of thrust-augmentation equipment.",
        "layers": [
          {
            "id": "core-architecture",
            "name": "Core architecture",
            "description": "Record the variant's compressor, combustion and turbine arrangement.",
            "findings": [
              {
                "id": "gas-path-identification",
                "name": "Gas-path identification",
                "description": "Use authoritative architecture evidence to check candidate identification and component consistency.",
                "questions": [
                  {
                    "text": "What spool arrangement, stage counts and combustor form does the applicable J75 technical description specify?",
                    "kind": "definition",
                    "id": "gas-path-identification-q01"
                  },
                  {
                    "text": "Which observed markings or component features support or contradict that configuration?",
                    "kind": "provenance",
                    "id": "gas-path-identification-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "augmentation-equipment",
            "name": "Augmentation equipment",
            "description": "Separate core-engine capability from fitted afterburner and water-injection configurations.",
            "findings": [
              {
                "id": "augmentation-applicability",
                "name": "Augmentation applicability",
                "description": "Record installed equipment and documented applicability separately from family-level assumptions.",
                "questions": [
                  {
                    "text": "Does this variant support afterburning, water injection, both or neither, and which equipment is actually fitted?",
                    "kind": "definition",
                    "id": "augmentation-applicability-q01"
                  },
                  {
                    "text": "Which technical source establishes the associated nozzle, supply and control requirements?",
                    "kind": "provenance",
                    "id": "augmentation-applicability-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "j75-ratings-and-operating-evidence",
        "name": "J75 ratings and operating evidence",
        "description": "Make performance claims and operating observations interpretable for a specific configuration.",
        "rationale": "Thrust and limit values can mislead when variant, augmentation mode, sensor station or test conditions are missing.",
        "layers": [
          {
            "id": "rated-performance",
            "name": "Rated performance",
            "description": "Qualify thrust and consumption data by configuration and reference conditions.",
            "findings": [
              {
                "id": "qualified-thrust-rating",
                "name": "Qualified thrust rating",
                "description": "Represent a rating as a conditional claim supported by an applicable source.",
                "questions": [
                  {
                    "text": "What thrust is specified for each supported mode, at what atmospheric and installation conditions?",
                    "kind": "measurement",
                    "id": "qualified-thrust-rating-q01"
                  },
                  {
                    "text": "What duration and fuel or augmentation-consumable conditions accompany each rating?",
                    "kind": "measurement",
                    "id": "qualified-thrust-rating-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "operating-state-and-limits",
            "name": "Operating state and limits",
            "description": "Relate observations to the relevant phase and documented limits.",
            "findings": [
              {
                "id": "limit-applicability",
                "name": "Limit applicability",
                "description": "Require the correct speed reference, temperature station and operating phase before interpreting readings.",
                "questions": [
                  {
                    "text": "Which rotor speeds, temperatures and pressures are monitored, and what references and sensor locations define them?",
                    "kind": "measurement",
                    "id": "limit-applicability-q01"
                  },
                  {
                    "text": "Which applicable instructions govern response to a recorded start anomaly, surge, flameout or limit exceedance?",
                    "kind": "action",
                    "id": "limit-applicability-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "j75-installation-and-control",
        "name": "J75 installation and control",
        "description": "Describe the engine-side conditions required for supported installation and control.",
        "rationale": "A J75 designation alone cannot establish fit, supply compatibility or the division of responsibility between engine and host.",
        "layers": [
          {
            "id": "physical-and-fluid-interfaces",
            "name": "Physical and fluid interfaces",
            "description": "Identify configuration-dependent mounting, airflow and service connections.",
            "findings": [
              {
                "id": "installation-fit",
                "name": "Installation fit",
                "description": "Tie envelope and connection requirements to an evidenced installation configuration.",
                "questions": [
                  {
                    "text": "What engine envelope, mass and mounting arrangement apply with the specified accessories and exhaust equipment?",
                    "kind": "measurement",
                    "id": "installation-fit-q01"
                  },
                  {
                    "text": "Which inlet, exhaust, fuel, lubrication and starting-supply requirements must the host satisfy?",
                    "kind": "boundary",
                    "id": "installation-fit-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "controls-and-protection",
            "name": "Controls and protection",
            "description": "Locate command, indication and protective functions at the engine-host boundary.",
            "findings": [
              {
                "id": "control-authority",
                "name": "Control authority",
                "description": "Document actual control and protection provisions without assuming modern electronic safeguards.",
                "questions": [
                  {
                    "text": "Which functions govern fuel delivery, ignition and any fitted augmentation equipment in this configuration?",
                    "kind": "definition",
                    "id": "control-authority-q01"
                  },
                  {
                    "text": "Which shutdown or protective functions reside on the engine, in the aircraft or on the test stand, and how is their availability evidenced?",
                    "kind": "boundary",
                    "id": "control-authority-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "j75-condition-and-permitted-actions",
        "name": "J75 condition and permitted actions",
        "description": "Connect configuration, maintenance evidence and preservation state to defensible action decisions.",
        "rationale": "An intact historic J75, a preserved engine and an engine released for operation require different evidence and treatment.",
        "layers": [
          {
            "id": "maintenance-and-life-evidence",
            "name": "Maintenance and life evidence",
            "description": "Specify the records needed to assess applicable inspections, component life and unresolved defects.",
            "findings": [
              {
                "id": "serviceability-basis",
                "name": "Serviceability basis",
                "description": "Keep missing records and suspected damage visible rather than inferring readiness from appearance.",
                "questions": [
                  {
                    "text": "Which applicable manuals and records establish inspection requirements, component life limits and maintenance status?",
                    "kind": "provenance",
                    "id": "serviceability-basis-q01"
                  },
                  {
                    "text": "What evidence records foreign-object damage, corrosion, hot-section distress or abnormal operation, and which findings remain unresolved?",
                    "kind": "provenance",
                    "id": "serviceability-basis-q02"
                  }
                ]
              }
            ]
          },
          {
            "id": "preservation-and-release",
            "name": "Preservation and release",
            "description": "Distinguish storage and display condition from authorized handling, testing or operation.",
            "findings": [
              {
                "id": "action-prerequisites",
                "name": "Action prerequisites",
                "description": "Require action-specific technical instructions and authority, including identification of disabled or removed equipment.",
                "questions": [
                  {
                    "text": "What preservation, deactivation, fluid-removal or component-removal records constrain handling and assessment?",
                    "kind": "provenance",
                    "id": "action-prerequisites-q01"
                  },
                  {
                    "text": "What applicable instructions, inspection evidence and responsible authority are required before lifting, installation, ground testing or operation?",
                    "kind": "action",
                    "id": "action-prerequisites-q02"
                  }
                ]
              }
            ]
          }
        ]
      },
      {
        "id": "evidence-and-external-alignment",
        "name": "Evidence and external alignment",
        "description": "What the world already says about this thing, gathered so the model can be checked against it.",
        "rationale": "A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.",
        "layers": [
          {
            "id": "reported-evidence",
            "name": "Reported evidence",
            "description": "Findings from the breadth pass, kept separate from the structural claims.",
            "findings": [
              {
                "id": "evidence-confidence-notes",
                "name": "Check these first",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "The bare label J75 is ambiguous; this description assumes the registered thing is the Pratt & Whitney aircraft engine family.",
                  "Variant designations, aircraft installation details and thrust ratings should be checked against engine or aircraft manuals.",
                  "Hazards listed are general turbojet hazards, not claims about documented J75-specific failure rates."
                ],
                "questions": [
                  {
                    "id": "evidence-confidence-notes-q01",
                    "text": "Which of these check these first hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-kinds",
                "name": "Kinds and varieties",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "J75-P-17",
                  "J75-P-19"
                ],
                "questions": [
                  {
                    "id": "evidence-kinds-q01",
                    "text": "Which of these kinds and varieties hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-identifiers",
                "name": "Identifiers and schemes",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  {
                    "scheme": "United States military aircraft engine designation",
                    "value_or_pattern": "J75-P- followed by a variant number",
                    "note": "J75 identifies the engine family; P identifies Pratt & Whitney; the suffix distinguishes variants."
                  }
                ],
                "questions": [
                  {
                    "id": "evidence-identifiers-q01",
                    "text": "Which of these identifiers and schemes hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-real-world-use",
                "name": "Real-world use",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "Propulsion for the Republic F-105 Thunderchief.",
                  "Propulsion for the Convair F-106 Delta Dart.",
                  "Propulsion for certain early Lockheed U-2 variants."
                ],
                "questions": [
                  {
                    "id": "evidence-real-world-use-q01",
                    "text": "Which of these real-world use hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-measurements",
                "name": "Typical measurements",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  {
                    "quantity": "Rated thrust without afterburning",
                    "typical_range": "Approximately 70-80, depending on variant and rating conditions",
                    "unit": "kN"
                  },
                  {
                    "quantity": "Rated thrust with afterburning",
                    "typical_range": "Approximately 100-120, depending on variant and rating conditions",
                    "unit": "kN"
                  }
                ],
                "questions": [
                  {
                    "id": "evidence-measurements-q01",
                    "text": "Which of these typical measurements hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-failure-modes-and-hazards",
                "name": "Failure modes and hazards",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  "Compressor stall or surge can interrupt thrust and damage the engine.",
                  "Foreign-object ingestion can damage compressor blades.",
                  "Flameout can cause loss of thrust.",
                  "Lubrication failure or excessive turbine temperature can damage rotating components.",
                  "Intake suction, hot exhaust and jet blast endanger nearby personnel."
                ],
                "questions": [
                  {
                    "id": "evidence-failure-modes-and-hazards-q01",
                    "text": "Which of these failure modes and hazards hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              },
              {
                "id": "evidence-neighbours",
                "name": "Neighbouring kinds and how to tell them apart",
                "description": "Recalled without web access and unsourced; every item is a lead to verify.",
                "evidence": [
                  {
                    "name": "Pratt & Whitney JT4A",
                    "difference": "The related civilian turbojet family has its own commercial designation and application history."
                  },
                  {
                    "name": "Pratt & Whitney J57",
                    "difference": "A separate, smaller twin-spool turbojet family from which the J75 design developed."
                  },
                  {
                    "name": "Turbofan engine",
                    "difference": "A turbofan produces thrust partly through a bypass airflow; the J75 is a turbojet."
                  }
                ],
                "questions": [
                  {
                    "id": "evidence-neighbours-q01",
                    "text": "Which of these neighbouring kinds and how to tell them apart hold for the sense of J75 this model covers, and on what evidence?",
                    "kind": "provenance"
                  }
                ]
              }
            ]
          }
        ]
      }
    ]
  },
  "openQuestions": [
    "Does the original registry evidence confirm that vr.tr.j75 denotes the Pratt & Whitney J75 family, and does an existing world model already cover that concept?",
    "Which J75 variants belong under this entry, and how does authoritative registry granularity treat JT4A and other related designations?",
    "Which primary technical documents establish architecture, augmentation differences, ratings, dimensions and consumable specifications for each included variant?",
    "Which installation-specific manuals, military technical orders or other governing approvals establish controls, protective functions and operating limits?",
    "Which documented failure patterns, life limits and preservation requirements can be established without extrapolating from another engine family or a single museum specimen?"
  ],
  "statistics": {
    "bundles": 6,
    "layers": 11,
    "findings": 17,
    "questions": 27
  }
}
