Pressure Altitude / Density Altitude implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t4-300

Effect

Computation or source lookup only

Input and validation requirements

The extreme-magnitude vector produces Infinity for both outputs in plain JavaScript arithmetic. The instrument should reject or flag such inputs rather than expose non-finite altitudes. The supplied specification has no actual denominator-based undefined-result trap and no explicitly defined multi-regime formula branch.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "field_elevation_ft": 0,
    "altimeter_setting_inHg": 29.92,
    "OAT_C": 15
  },
  "expected_outputs": {
    "pressure_altitude_ft": 0,
    "density_altitude_ft": 0
  },
  "working": "PA = 0 + (29.92 - 29.92)*1000 = 0 + 0 = 0 ft.\nISA_temp = 15 - 1.98*(0/1000) = 15.0 C.\nDA = 0 + 120*(15.0 - 15.0) = 0 + 120*0 = 0 ft."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche4/tranche4-results.json