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FA-66266 / Aviation weight and balance / Open access

ISA temperature computed at field elevation · case 01

Density altitude is off whenever the altimeter differs from standard.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The ISA lapse uses field elevation instead of pressure altitude.

VERIFIED REPAIR

Compute the ISA temperature at pressure altitude.

Unsuccessful approach: Using sea-level ISA at every field grossly overstates density altitude at high elevations.

Case contract

Input {'elev_ft','altimeter' inHg,'oat_c','mtow'}. Pressure altitude = elev + (29.92 - altimeter)*1000; ISA temp = 15 - 2 per 1000 ft of PA; DA = PA + 120*(OAT - ISA). Allowed weight = MTOW - 20 lb per 1000 ft (pro rata) of DA above 3000 ft, rounded DOWN to 10 lb. Return [DA rounded, allowed].

Why this case matters

A stipulated density-altitude weight derate: the reduction must use pressure altitude, the ISA temperature at that altitude, and conservative rounding.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    pa = x['elev_ft'] + (29.92 - x['altimeter']) * 1000
    isa = 15 - 2 * x['elev_ft'] / 1000
    da = pa + 120 * (x['oat_c'] - isa)
    excess = max(0.0, da - 3000)
    red = 20 * excess / 1000
    allowed = x['mtow'] - red
    return [round(da), int(allowed // 10) * 10]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['hot high field', {'elev_ft': 5100, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [7876, 2450]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.400000000000002, 'oat_c': 25, 'mtow': 2400}, [3705, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -9, 'mtow': 3100}, [5180, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 36, 'mtow': 2550}, [1925, 2550]], ['sampled case 1', {'elev_ft': 4630, 'altimeter': 30.0, 'oat_c': 25, 'mtow': 3600}, [6842, 3520]], ['sampled case 2', {'elev_ft': 8210, 'altimeter': 29.1, 'oat_c': 43, 'mtow': 2550}, [14557, 2310]], ['sampled case 3', {'elev_ft': 4490, 'altimeter': 29.18, 'oat_c': 29, 'mtow': 2550}, [8165, 2440]]], [['hot high field', {'elev_ft': 5200, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8000, 2450]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.380000000000003, 'oat_c': 25, 'mtow': 2400}, [3730, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -8, 'mtow': 3100}, [5300, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 37, 'mtow': 2550}, [2045, 2550]], ['sampled case 1', {'elev_ft': 2900, 'altimeter': 29.44, 'oat_c': 26, 'mtow': 2300}, [5511, 2240]], ['sampled case 2', {'elev_ft': 2480, 'altimeter': 29.04, 'oat_c': -9, 'mtow': 3100}, [1286, 3100]], ['sampled case 3', {'elev_ft': 1880, 'altimeter': 29.23, 'oat_c': 38, 'mtow': 2550}, [5947, 2490]]], [['hot high field', {'elev_ft': 5300, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8124, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.360000000000003, 'oat_c': 25, 'mtow': 2400}, [3754, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -7, 'mtow': 3100}, [5420, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 38, 'mtow': 2550}, [2165, 2550]], ['sampled case 1', {'elev_ft': 5530, 'altimeter': 30.57, 'oat_c': 16, 'mtow': 2550}, [6171, 2480]], ['sampled case 2', {'elev_ft': 8640, 'altimeter': 29.52, 'oat_c': -7, 'mtow': 2550}, [8570, 2430]], ['sampled case 3', {'elev_ft': 8250, 'altimeter': 29.93, 'oat_c': 35, 'mtow': 2300}, [12618, 2100]]], [['hot high field', {'elev_ft': 5400, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8248, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.340000000000003, 'oat_c': 25, 'mtow': 2400}, [3779, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -6, 'mtow': 3100}, [5540, 3040]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 39, 'mtow': 2550}, [2285, 2550]], ['sampled case 1', {'elev_ft': 8680, 'altimeter': 29.91, 'oat_c': -21, 'mtow': 2550}, [6456, 2480]], ['sampled case 2', {'elev_ft': 5840, 'altimeter': 29.35, 'oat_c': 15, 'mtow': 2300}, [7948, 2200]], ['sampled case 3', {'elev_ft': 200, 'altimeter': 30.56, 'oat_c': 11, 'mtow': 2550}, [-1026, 2550]]], [['hot high field', {'elev_ft': 5500, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8372, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.32, 'oat_c': 25, 'mtow': 2400}, [3804, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -5, 'mtow': 3100}, [5660, 3040]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 40, 'mtow': 2550}, [2405, 2550]], ['sampled case 1', {'elev_ft': 5350, 'altimeter': 29.18, 'oat_c': -19, 'mtow': 2550}, [3472, 2540]], ['sampled case 2', {'elev_ft': 1480, 'altimeter': 30.27, 'oat_c': -13, 'mtow': 3600}, [-1959, 3600]], ['sampled case 3', {'elev_ft': 5150, 'altimeter': 30.11, 'oat_c': 16, 'mtow': 3600}, [6270, 3530]]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
hot high field[7924, 2450][7876, 2450]Failed
standard sea level[0, 2550][0, 2550]Passed
low pressure[3580, 2380][3705, 2380]Failed
cold high field[5180, 3050][5180, 3050]Passed
just above threshold[3560, 2530][3560, 2530]Passed
below sea level[1992, 2550][1925, 2550]Failed
sampled case 1[6861, 3520][6842, 3520]Failed
sampled case 2[14360, 2320][14557, 2310]Failed
sampled case 3[7988, 2450][8165, 2440]Failed

SHA-256 / 97e882e86c684dec60ca88a3b187660eb839757487e7385e216baf9da0ecbe4e

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    pa = x['elev_ft'] + (29.92 - x['altimeter']) * 1000
    isa = 15
    da = pa + 120 * (x['oat_c'] - isa)
    excess = max(0.0, da - 3000)
    red = 20 * excess / 1000
    allowed = x['mtow'] - red
    return [round(da), int(allowed // 10) * 10]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['hot high field', {'elev_ft': 5100, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [7876, 2450]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.400000000000002, 'oat_c': 25, 'mtow': 2400}, [3705, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -9, 'mtow': 3100}, [5180, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 36, 'mtow': 2550}, [1925, 2550]], ['sampled case 1', {'elev_ft': 4630, 'altimeter': 30.0, 'oat_c': 25, 'mtow': 3600}, [6842, 3520]], ['sampled case 2', {'elev_ft': 8210, 'altimeter': 29.1, 'oat_c': 43, 'mtow': 2550}, [14557, 2310]], ['sampled case 3', {'elev_ft': 4490, 'altimeter': 29.18, 'oat_c': 29, 'mtow': 2550}, [8165, 2440]]], [['hot high field', {'elev_ft': 5200, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8000, 2450]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.380000000000003, 'oat_c': 25, 'mtow': 2400}, [3730, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -8, 'mtow': 3100}, [5300, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 37, 'mtow': 2550}, [2045, 2550]], ['sampled case 1', {'elev_ft': 2900, 'altimeter': 29.44, 'oat_c': 26, 'mtow': 2300}, [5511, 2240]], ['sampled case 2', {'elev_ft': 2480, 'altimeter': 29.04, 'oat_c': -9, 'mtow': 3100}, [1286, 3100]], ['sampled case 3', {'elev_ft': 1880, 'altimeter': 29.23, 'oat_c': 38, 'mtow': 2550}, [5947, 2490]]], [['hot high field', {'elev_ft': 5300, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8124, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.360000000000003, 'oat_c': 25, 'mtow': 2400}, [3754, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -7, 'mtow': 3100}, [5420, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 38, 'mtow': 2550}, [2165, 2550]], ['sampled case 1', {'elev_ft': 5530, 'altimeter': 30.57, 'oat_c': 16, 'mtow': 2550}, [6171, 2480]], ['sampled case 2', {'elev_ft': 8640, 'altimeter': 29.52, 'oat_c': -7, 'mtow': 2550}, [8570, 2430]], ['sampled case 3', {'elev_ft': 8250, 'altimeter': 29.93, 'oat_c': 35, 'mtow': 2300}, [12618, 2100]]], [['hot high field', {'elev_ft': 5400, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8248, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.340000000000003, 'oat_c': 25, 'mtow': 2400}, [3779, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -6, 'mtow': 3100}, [5540, 3040]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 39, 'mtow': 2550}, [2285, 2550]], ['sampled case 1', {'elev_ft': 8680, 'altimeter': 29.91, 'oat_c': -21, 'mtow': 2550}, [6456, 2480]], ['sampled case 2', {'elev_ft': 5840, 'altimeter': 29.35, 'oat_c': 15, 'mtow': 2300}, [7948, 2200]], ['sampled case 3', {'elev_ft': 200, 'altimeter': 30.56, 'oat_c': 11, 'mtow': 2550}, [-1026, 2550]]], [['hot high field', {'elev_ft': 5500, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8372, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.32, 'oat_c': 25, 'mtow': 2400}, [3804, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -5, 'mtow': 3100}, [5660, 3040]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 40, 'mtow': 2550}, [2405, 2550]], ['sampled case 1', {'elev_ft': 5350, 'altimeter': 29.18, 'oat_c': -19, 'mtow': 2550}, [3472, 2540]], ['sampled case 2', {'elev_ft': 1480, 'altimeter': 30.27, 'oat_c': -13, 'mtow': 3600}, [-1959, 3600]], ['sampled case 3', {'elev_ft': 5150, 'altimeter': 30.11, 'oat_c': 16, 'mtow': 3600}, [6270, 3530]]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
hot high field[6700, 2470][7876, 2450]Failed
standard sea level[0, 2550][0, 2550]Passed
low pressure[3220, 2390][3705, 2380]Failed
cold high field[3620, 3080][5180, 3050]Failed
just above threshold[3080, 2540][3560, 2530]Failed
below sea level[2040, 2550][1925, 2550]Failed
sampled case 1[5750, 3540][6842, 3520]Failed
sampled case 2[12390, 2360][14557, 2310]Failed
sampled case 3[6910, 2470][8165, 2440]Failed

SHA-256 / a583f5d32b7bd32c6c2718aa3b2a49267e293390f8f32813a211ef48f8baa459

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(x):
    pa = x['elev_ft'] + (29.92 - x['altimeter']) * 1000
    isa = 15 - 2 * pa / 1000
    da = pa + 120 * (x['oat_c'] - isa)
    excess = max(0.0, da - 3000)
    red = 20 * excess / 1000
    allowed = x['mtow'] - red
    return [round(da), int(allowed // 10) * 10]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['hot high field', {'elev_ft': 5100, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [7876, 2450]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.400000000000002, 'oat_c': 25, 'mtow': 2400}, [3705, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -9, 'mtow': 3100}, [5180, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 36, 'mtow': 2550}, [1925, 2550]], ['sampled case 1', {'elev_ft': 4630, 'altimeter': 30.0, 'oat_c': 25, 'mtow': 3600}, [6842, 3520]], ['sampled case 2', {'elev_ft': 8210, 'altimeter': 29.1, 'oat_c': 43, 'mtow': 2550}, [14557, 2310]], ['sampled case 3', {'elev_ft': 4490, 'altimeter': 29.18, 'oat_c': 29, 'mtow': 2550}, [8165, 2440]]], [['hot high field', {'elev_ft': 5200, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8000, 2450]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.380000000000003, 'oat_c': 25, 'mtow': 2400}, [3730, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -8, 'mtow': 3100}, [5300, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 37, 'mtow': 2550}, [2045, 2550]], ['sampled case 1', {'elev_ft': 2900, 'altimeter': 29.44, 'oat_c': 26, 'mtow': 2300}, [5511, 2240]], ['sampled case 2', {'elev_ft': 2480, 'altimeter': 29.04, 'oat_c': -9, 'mtow': 3100}, [1286, 3100]], ['sampled case 3', {'elev_ft': 1880, 'altimeter': 29.23, 'oat_c': 38, 'mtow': 2550}, [5947, 2490]]], [['hot high field', {'elev_ft': 5300, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8124, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.360000000000003, 'oat_c': 25, 'mtow': 2400}, [3754, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -7, 'mtow': 3100}, [5420, 3050]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 38, 'mtow': 2550}, [2165, 2550]], ['sampled case 1', {'elev_ft': 5530, 'altimeter': 30.57, 'oat_c': 16, 'mtow': 2550}, [6171, 2480]], ['sampled case 2', {'elev_ft': 8640, 'altimeter': 29.52, 'oat_c': -7, 'mtow': 2550}, [8570, 2430]], ['sampled case 3', {'elev_ft': 8250, 'altimeter': 29.93, 'oat_c': 35, 'mtow': 2300}, [12618, 2100]]], [['hot high field', {'elev_ft': 5400, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8248, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.340000000000003, 'oat_c': 25, 'mtow': 2400}, [3779, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -6, 'mtow': 3100}, [5540, 3040]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 39, 'mtow': 2550}, [2285, 2550]], ['sampled case 1', {'elev_ft': 8680, 'altimeter': 29.91, 'oat_c': -21, 'mtow': 2550}, [6456, 2480]], ['sampled case 2', {'elev_ft': 5840, 'altimeter': 29.35, 'oat_c': 15, 'mtow': 2300}, [7948, 2200]], ['sampled case 3', {'elev_ft': 200, 'altimeter': 30.56, 'oat_c': 11, 'mtow': 2550}, [-1026, 2550]]], [['hot high field', {'elev_ft': 5500, 'altimeter': 30.12, 'oat_c': 30, 'mtow': 2550}, [8372, 2440]], ['standard sea level', {'elev_ft': 0, 'altimeter': 29.92, 'oat_c': 15, 'mtow': 2550}, [0, 2550]], ['low pressure', {'elev_ft': 1500, 'altimeter': 29.32, 'oat_c': 25, 'mtow': 2400}, [3804, 2380]], ['cold high field', {'elev_ft': 6500, 'altimeter': 29.92, 'oat_c': -5, 'mtow': 3100}, [5660, 3040]], ['just above threshold', {'elev_ft': 2000, 'altimeter': 29.92, 'oat_c': 24, 'mtow': 2550}, [3560, 2530]], ['below sea level', {'elev_ft': -200, 'altimeter': 30.2, 'oat_c': 40, 'mtow': 2550}, [2405, 2550]], ['sampled case 1', {'elev_ft': 5350, 'altimeter': 29.18, 'oat_c': -19, 'mtow': 2550}, [3472, 2540]], ['sampled case 2', {'elev_ft': 1480, 'altimeter': 30.27, 'oat_c': -13, 'mtow': 3600}, [-1959, 3600]], ['sampled case 3', {'elev_ft': 5150, 'altimeter': 30.11, 'oat_c': 16, 'mtow': 3600}, [6270, 3530]]]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(args), expected)
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
hot high field[7876, 2450][7876, 2450]Passed
standard sea level[0, 2550][0, 2550]Passed
low pressure[3705, 2380][3705, 2380]Passed
cold high field[5180, 3050][5180, 3050]Passed
just above threshold[3560, 2530][3560, 2530]Passed
below sea level[1925, 2550][1925, 2550]Passed
sampled case 1[6842, 3520][6842, 3520]Passed
sampled case 2[14557, 2310][14557, 2310]Passed
sampled case 3[8165, 2440][8165, 2440]Passed

SHA-256 / e4a92c10a5218a52e2f0f427327d7ad0ab59af2bc2f99f735ab4cb8c3a33ef35

Verification & scope

A deterministic toy loading model with stipulated constants; it is not an approved aircraft flight manual procedure and makes no claim of regulatory conformance. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.

Observations recorded using Python 3.12.14 at 2026-09-29T14:47:41.750955+00:00.

Case digest / 99f29bb6cc85035778a03a8f05d5da144cd9536b0d8921ab537c28cee2e9b31c