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FA-65926 / Aviation weight and balance / Open access

Landing weight limit relaxed by the whole takeoff fuel · case 01

Short sectors with lots of reserve fuel report a higher allowed takeoff weight than the landing limit permits.

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

ROOT CAUSE

MLW is translated to a takeoff weight by adding all takeoff fuel, including reserves that are still on board at landing.

THE FAILURE

MLW is translated to a takeoff weight by adding all takeoff fuel, including reserves that are still on board at landing.

Unsuccessful approach: Subtracting taxi fuel from the trip term double-counts a burn that happens before takeoff weight is measured.

Case contract

Input weights in kg. Allowed takeoff weight = lowest of MTOW, MLW+trip fuel, MZFW+takeoff fuel, MRW-taxi fuel; ties go to the earlier entry in that order. Allowed payload = allowed TOW - OEW - takeoff fuel, floored at 0. Return [allowed TOW, payload, limiting name].

Why this case matters

The classic loadsheet payload limitation takes the lowest of four structural limits, each translated to a takeoff weight with the correct fuel quantity.

1 / The failure

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

N = 1
observations = []
def solve(x):
    cands = [('MTOW', x['mtow']), ('MLW', x['mlw'] + x['takeoff_fuel']), ('MZFW', x['mzfw'] + x['takeoff_fuel']), ('MRW', x['mrw'] - x['taxi_fuel'])]
    best = cands[0]
    for c in cands[1:]:
        if c[1] < best[1]:
            best = c
    payload = best[1] - x['oew'] - x['takeoff_fuel']
    if payload < 0:
        payload = 0
    return [best[1], payload, best[0]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16100, 'trip_fuel': 13000}, [70000, 11900, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5010, 'trip_fuel': 2000}, [63000, 15990, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5510}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 501, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69699, 7699, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15100, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 45200, 'mtow': 63600, 'mlw': 62300, 'mzfw': 57500, 'mrw': 64200, 'taxi_fuel': 500, 'takeoff_fuel': 9200, 'trip_fuel': 5700}, [63600, 9200, 'MTOW']], ['sampled case 2', {'oew': 35600, 'mtow': 48200, 'mlw': 46600, 'mzfw': 44800, 'mrw': 48400, 'taxi_fuel': 400, 'takeoff_fuel': 4100, 'trip_fuel': 500}, [47100, 7400, 'MLW']], ['sampled case 3', {'oew': 36100, 'mtow': 50400, 'mlw': 48100, 'mzfw': 42500, 'mrw': 50400, 'taxi_fuel': 800, 'takeoff_fuel': 20900, 'trip_fuel': 16300}, [49600, 0, 'MRW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16200, 'trip_fuel': 13000}, [70000, 11800, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5020, 'trip_fuel': 2000}, [63000, 15980, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5520}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 502, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69698, 7698, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15200, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 48000, 'mtow': 71700, 'mlw': 60600, 'mzfw': 59700, 'mrw': 72100, 'taxi_fuel': 300, 'takeoff_fuel': 17500, 'trip_fuel': 14300}, [71700, 6200, 'MTOW']], ['sampled case 2', {'oew': 45100, 'mtow': 57700, 'mlw': 55900, 'mzfw': 50100, 'mrw': 57900, 'taxi_fuel': 200, 'takeoff_fuel': 5800, 'trip_fuel': 3300}, [55900, 5000, 'MZFW']], ['sampled case 3', {'oew': 38900, 'mtow': 70900, 'mlw': 64200, 'mzfw': 58600, 'mrw': 71100, 'taxi_fuel': 800, 'takeoff_fuel': 19800, 'trip_fuel': 17300}, [70300, 11600, 'MRW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16300, 'trip_fuel': 13000}, [70000, 11700, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5030, 'trip_fuel': 2000}, [63000, 15970, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5530}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 503, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69697, 7697, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15300, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 41500, 'mtow': 65300, 'mlw': 54900, 'mzfw': 51800, 'mrw': 65500, 'taxi_fuel': 800, 'takeoff_fuel': 15200, 'trip_fuel': 11100}, [64700, 8000, 'MRW']], ['sampled case 2', {'oew': 48100, 'mtow': 69500, 'mlw': 66400, 'mzfw': 60800, 'mrw': 70100, 'taxi_fuel': 400, 'takeoff_fuel': 8000, 'trip_fuel': 3500}, [68800, 12700, 'MZFW']], ['sampled case 3', {'oew': 48200, 'mtow': 70500, 'mlw': 63100, 'mzfw': 61400, 'mrw': 70700, 'taxi_fuel': 500, 'takeoff_fuel': 10300, 'trip_fuel': 8800}, [70200, 11700, 'MRW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16400, 'trip_fuel': 13000}, [70000, 11600, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5040, 'trip_fuel': 2000}, [63000, 15960, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5540}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 504, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69696, 7696, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15400, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 44100, 'mtow': 69600, 'mlw': 65500, 'mzfw': 61100, 'mrw': 70200, 'taxi_fuel': 200, 'takeoff_fuel': 3000, 'trip_fuel': 500}, [64100, 17000, 'MZFW']], ['sampled case 2', {'oew': 37600, 'mtow': 51800, 'mlw': 48800, 'mzfw': 47700, 'mrw': 52400, 'taxi_fuel': 800, 'takeoff_fuel': 6100, 'trip_fuel': 2300}, [51100, 7400, 'MLW']], ['sampled case 3', {'oew': 48900, 'mtow': 68600, 'mlw': 60100, 'mzfw': 56600, 'mrw': 69000, 'taxi_fuel': 300, 'takeoff_fuel': 23600, 'trip_fuel': 19400}, [68600, 0, 'MTOW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16500, 'trip_fuel': 13000}, [70000, 11500, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5050, 'trip_fuel': 2000}, [63000, 15950, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5550}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 505, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69695, 7695, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15500, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 40700, 'mtow': 68300, 'mlw': 61100, 'mzfw': 59900, 'mrw': 68300, 'taxi_fuel': 300, 'takeoff_fuel': 7200, 'trip_fuel': 4000}, [65100, 17200, 'MLW']], ['sampled case 2', {'oew': 41600, 'mtow': 69800, 'mlw': 66700, 'mzfw': 61300, 'mrw': 69800, 'taxi_fuel': 400, 'takeoff_fuel': 18100, 'trip_fuel': 14300}, [69400, 9700, 'MRW']], ['sampled case 3', {'oew': 46200, 'mtow': 65500, 'mlw': 55600, 'mzfw': 54600, 'mrw': 65700, 'taxi_fuel': 800, 'takeoff_fuel': 8400, 'trip_fuel': 4900}, [60500, 5900, 'MLW']]]]
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
long sector MTOW limited[70000, 11900, 'MTOW'][70000, 11900, 'MTOW']Passed
short sector MLW limited[65010, 18000, 'MZFW'][63000, 15990, 'MLW']Failed
tankering MZFW limited[67000, 18000, 'MZFW'][67000, 18000, 'MZFW']Passed
ramp limited heavy taxi[69699, 7699, 'MRW'][69699, 7699, 'MRW']Passed
MTOW and MLW tie[68000, 14000, 'MTOW'][68000, 14000, 'MTOW']Passed
no payload possible[70000, 0, 'MTOW'][70000, 0, 'MTOW']Passed
sampled case 1[63600, 9200, 'MTOW'][63600, 9200, 'MTOW']Passed
sampled case 2[48000, 8300, 'MRW'][47100, 7400, 'MLW']Failed
sampled case 3[49600, 0, 'MRW'][49600, 0, 'MRW']Passed

SHA-256 / 7e27444822d19a333efe9ddb36c7c9318d6f3428dc11fa8a0e937c4f366463b6

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(x):
    cands = [('MTOW', x['mtow']), ('MLW', x['mlw'] + x['trip_fuel'] - x['taxi_fuel']), ('MZFW', x['mzfw'] + x['takeoff_fuel']), ('MRW', x['mrw'] - x['taxi_fuel'])]
    best = cands[0]
    for c in cands[1:]:
        if c[1] < best[1]:
            best = c
    payload = best[1] - x['oew'] - x['takeoff_fuel']
    if payload < 0:
        payload = 0
    return [best[1], payload, best[0]]
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16100, 'trip_fuel': 13000}, [70000, 11900, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5010, 'trip_fuel': 2000}, [63000, 15990, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5510}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 501, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69699, 7699, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15100, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 45200, 'mtow': 63600, 'mlw': 62300, 'mzfw': 57500, 'mrw': 64200, 'taxi_fuel': 500, 'takeoff_fuel': 9200, 'trip_fuel': 5700}, [63600, 9200, 'MTOW']], ['sampled case 2', {'oew': 35600, 'mtow': 48200, 'mlw': 46600, 'mzfw': 44800, 'mrw': 48400, 'taxi_fuel': 400, 'takeoff_fuel': 4100, 'trip_fuel': 500}, [47100, 7400, 'MLW']], ['sampled case 3', {'oew': 36100, 'mtow': 50400, 'mlw': 48100, 'mzfw': 42500, 'mrw': 50400, 'taxi_fuel': 800, 'takeoff_fuel': 20900, 'trip_fuel': 16300}, [49600, 0, 'MRW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16200, 'trip_fuel': 13000}, [70000, 11800, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5020, 'trip_fuel': 2000}, [63000, 15980, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5520}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 502, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69698, 7698, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15200, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 48000, 'mtow': 71700, 'mlw': 60600, 'mzfw': 59700, 'mrw': 72100, 'taxi_fuel': 300, 'takeoff_fuel': 17500, 'trip_fuel': 14300}, [71700, 6200, 'MTOW']], ['sampled case 2', {'oew': 45100, 'mtow': 57700, 'mlw': 55900, 'mzfw': 50100, 'mrw': 57900, 'taxi_fuel': 200, 'takeoff_fuel': 5800, 'trip_fuel': 3300}, [55900, 5000, 'MZFW']], ['sampled case 3', {'oew': 38900, 'mtow': 70900, 'mlw': 64200, 'mzfw': 58600, 'mrw': 71100, 'taxi_fuel': 800, 'takeoff_fuel': 19800, 'trip_fuel': 17300}, [70300, 11600, 'MRW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16300, 'trip_fuel': 13000}, [70000, 11700, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5030, 'trip_fuel': 2000}, [63000, 15970, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5530}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 503, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69697, 7697, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15300, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 41500, 'mtow': 65300, 'mlw': 54900, 'mzfw': 51800, 'mrw': 65500, 'taxi_fuel': 800, 'takeoff_fuel': 15200, 'trip_fuel': 11100}, [64700, 8000, 'MRW']], ['sampled case 2', {'oew': 48100, 'mtow': 69500, 'mlw': 66400, 'mzfw': 60800, 'mrw': 70100, 'taxi_fuel': 400, 'takeoff_fuel': 8000, 'trip_fuel': 3500}, [68800, 12700, 'MZFW']], ['sampled case 3', {'oew': 48200, 'mtow': 70500, 'mlw': 63100, 'mzfw': 61400, 'mrw': 70700, 'taxi_fuel': 500, 'takeoff_fuel': 10300, 'trip_fuel': 8800}, [70200, 11700, 'MRW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16400, 'trip_fuel': 13000}, [70000, 11600, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5040, 'trip_fuel': 2000}, [63000, 15960, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5540}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 504, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69696, 7696, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15400, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 44100, 'mtow': 69600, 'mlw': 65500, 'mzfw': 61100, 'mrw': 70200, 'taxi_fuel': 200, 'takeoff_fuel': 3000, 'trip_fuel': 500}, [64100, 17000, 'MZFW']], ['sampled case 2', {'oew': 37600, 'mtow': 51800, 'mlw': 48800, 'mzfw': 47700, 'mrw': 52400, 'taxi_fuel': 800, 'takeoff_fuel': 6100, 'trip_fuel': 2300}, [51100, 7400, 'MLW']], ['sampled case 3', {'oew': 48900, 'mtow': 68600, 'mlw': 60100, 'mzfw': 56600, 'mrw': 69000, 'taxi_fuel': 300, 'takeoff_fuel': 23600, 'trip_fuel': 19400}, [68600, 0, 'MTOW']]], [['long sector MTOW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 16500, 'trip_fuel': 13000}, [70000, 11500, 'MTOW']], ['short sector MLW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 61000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 5050, 'trip_fuel': 2000}, [63000, 15950, 'MLW']], ['tankering MZFW limited', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 7000, 'trip_fuel': 5550}, [67000, 18000, 'MZFW']], ['ramp limited heavy taxi', {'oew': 42000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70200, 'taxi_fuel': 505, 'takeoff_fuel': 20000, 'trip_fuel': 16000}, [69695, 7695, 'MRW']], ['MTOW and MLW tie', {'oew': 42000, 'mtow': 68000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 12000, 'trip_fuel': 4000}, [68000, 14000, 'MTOW']], ['no payload possible', {'oew': 58000, 'mtow': 70000, 'mlw': 64000, 'mzfw': 60000, 'mrw': 70400, 'taxi_fuel': 300, 'takeoff_fuel': 15500, 'trip_fuel': 12000}, [70000, 0, 'MTOW']], ['sampled case 1', {'oew': 40700, 'mtow': 68300, 'mlw': 61100, 'mzfw': 59900, 'mrw': 68300, 'taxi_fuel': 300, 'takeoff_fuel': 7200, 'trip_fuel': 4000}, [65100, 17200, 'MLW']], ['sampled case 2', {'oew': 41600, 'mtow': 69800, 'mlw': 66700, 'mzfw': 61300, 'mrw': 69800, 'taxi_fuel': 400, 'takeoff_fuel': 18100, 'trip_fuel': 14300}, [69400, 9700, 'MRW']], ['sampled case 3', {'oew': 46200, 'mtow': 65500, 'mlw': 55600, 'mzfw': 54600, 'mrw': 65700, 'taxi_fuel': 800, 'takeoff_fuel': 8400, 'trip_fuel': 4900}, [60500, 5900, 'MLW']]]]
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
long sector MTOW limited[70000, 11900, 'MTOW'][70000, 11900, 'MTOW']Passed
short sector MLW limited[62700, 15690, 'MLW'][63000, 15990, 'MLW']Failed
tankering MZFW limited[67000, 18000, 'MZFW'][67000, 18000, 'MZFW']Passed
ramp limited heavy taxi[69699, 7699, 'MRW'][69699, 7699, 'MRW']Passed
MTOW and MLW tie[67700, 13700, 'MLW'][68000, 14000, 'MTOW']Failed
no payload possible[70000, 0, 'MTOW'][70000, 0, 'MTOW']Passed
sampled case 1[63600, 9200, 'MTOW'][63600, 9200, 'MTOW']Passed
sampled case 2[46700, 7000, 'MLW'][47100, 7400, 'MLW']Failed
sampled case 3[49600, 0, 'MRW'][49600, 0, 'MRW']Passed

SHA-256 / 5febf40497381a2e36defe34463879fcc6cb89b8cbcc3dd528b972e0ab517a9e

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The verified repair and its recorded checks are member-only.

This mechanism has 9 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

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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 2026-09-29T14:47:38.650880+00:00.

Case digest / a44d6d75cb16a4ef03e5b1a40681c954ad89767ee6a4ca4abb3ec3f39c698896