FAILURE MAP
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FA-66001 / Aviation weight and balance / Open access

Aircraft exactly on a limit asked to carry ballast · case 01

A CG exactly on the forward or aft limit produces a nonzero ballast or an error.

Verified by executionVariant 1 · 12 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The envelope test excludes its end points, so limit-line CGs fall into the ballast computation.

VERIFIED REPAIR

Treat both limits as inside the envelope.

Unsuccessful approach: Including only the forward limit still misclassifies CGs exactly on the aft limit.

Case contract

Input [W lb, CG, fwd limit, aft limit, ballast arm, max weight]. Inside inclusive limits -> 0. Otherwise ballast B brings CG to the violated limit: B = W*(CG-limit)/(limit-arm), rounded up to whole lb; ballast arm not on the corrective side of that limit -> 'ERR_BALLAST_ARM'; W+B above max -> 'ERR_OVERWEIGHT'.

Why this case matters

Ballast adds weight at a fixed station; the required amount depends on the distance from the ballast arm to the violated limit, and adds to gross weight.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    W, cg, fwd, aft, ba, maxw = x
    if fwd < cg < aft: return 0
    lim = aft if cg > aft else fwd
    if (cg > aft and ba >= aft) or (cg < fwd and ba <= fwd): return 'ERR_BALLAST_ARM'
    b = math.ceil(round(W * (cg - lim) / (lim - ba), 6))
    if W + b > maxw: return 'ERR_OVERWEIGHT'
    return b
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['aft CG nose ballast', [1800, 48.0, 35.0, 47.3, 10.0, 2550], 34], ['forward CG tail ballast', [1700, 34.2, 35.05, 47.3, 150.0, 2550], 13], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 21.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2250, 36.0, 36.0, 46.0, 101.0, 2700], 0], ['sampled case 2', [2220, 44.7, 33.9, 44.7, 121.5, 2550], 0], ['sampled case 3', [2400, 39.05, 36.3, 46.8, 9.5, 2400], 0]], [['aft CG nose ballast', [1800, 48.1, 35.0, 47.3, 10.0, 2550], 39], ['forward CG tail ballast', [1700, 34.2, 35.1, 47.3, 150.0, 2550], 14], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 22.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2035, 44.73, 36.5, 45.1, 11.9, 3000], 0], ['sampled case 2', [1925, 46.69, 36.9, 45.7, 120.5, 2550], 'ERR_BALLAST_ARM'], ['sampled case 3', [2440, 47.5, 35.1, 47.5, 46.2, 2400], 0]], [['aft CG nose ballast', [1800, 48.199999999999996, 35.0, 47.3, 10.0, 2550], 44], ['forward CG tail ballast', [1700, 34.2, 35.15, 47.3, 150.0, 2550], 15], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 23.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2510, 41.12, 36.1, 47.4, 155.2, 2700], 0], ['sampled case 2', [1785, 32.94, 35.6, 44.4, 94.3, 2400], 81], ['sampled case 3', [2400, 37.65, 34.3, 45.9, 140.6, 2550], 0]], [['aft CG nose ballast', [1800, 48.3, 35.0, 47.3, 10.0, 2550], 49], ['forward CG tail ballast', [1700, 34.2, 35.2, 47.3, 150.0, 2550], 15], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 24.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [1590, 30.16, 33.1, 46.2, 118.7, 2550], 55], ['sampled case 2', [1710, 32.9, 34.8, 45.0, 129.9, 2550], 35], ['sampled case 3', [1755, 35.34, 36.3, 47.0, 127.7, 2700], 19]], [['aft CG nose ballast', [1800, 48.4, 35.0, 47.3, 10.0, 2550], 54], ['forward CG tail ballast', [1700, 34.2, 35.25, 47.3, 150.0, 2550], 16], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 25.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [1745, 31.68, 34.3, 46.9, 112.4, 2550], 59], ['sampled case 2', [1645, 34.52, 36.5, 47.5, 5.2, 2400], 'ERR_BALLAST_ARM'], ['sampled case 3', [1850, 32.93, 34.5, 46.9, 56.9, 2700], 130]]]
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
aft CG nose ballast3434Passed
forward CG tail ballast1313Passed
in envelope00Passed
exactly on aft limitERR_OVERWEIGHT0Failed
exactly on forward limit00Passed
ballast arm behind aft limitERR_BALLAST_ARMERR_BALLAST_ARMPassed
forward case ballast in noseERR_BALLAST_ARMERR_BALLAST_ARMPassed
ballast would overweightERR_OVERWEIGHTERR_OVERWEIGHTPassed
ballast reaches exactly max1010Passed
sampled case 100Passed
sampled case 2-2730Failed
sampled case 300Passed

SHA-256 / e0a60af78d51bf1caac473608d2867f1a60668a3941c6e08eac771e97536cb2e

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    W, cg, fwd, aft, ba, maxw = x
    if fwd <= cg < aft: return 0
    lim = aft if cg > aft else fwd
    if (cg > aft and ba >= aft) or (cg < fwd and ba <= fwd): return 'ERR_BALLAST_ARM'
    b = math.ceil(round(W * (cg - lim) / (lim - ba), 6))
    if W + b > maxw: return 'ERR_OVERWEIGHT'
    return b
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['aft CG nose ballast', [1800, 48.0, 35.0, 47.3, 10.0, 2550], 34], ['forward CG tail ballast', [1700, 34.2, 35.05, 47.3, 150.0, 2550], 13], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 21.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2250, 36.0, 36.0, 46.0, 101.0, 2700], 0], ['sampled case 2', [2220, 44.7, 33.9, 44.7, 121.5, 2550], 0], ['sampled case 3', [2400, 39.05, 36.3, 46.8, 9.5, 2400], 0]], [['aft CG nose ballast', [1800, 48.1, 35.0, 47.3, 10.0, 2550], 39], ['forward CG tail ballast', [1700, 34.2, 35.1, 47.3, 150.0, 2550], 14], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 22.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2035, 44.73, 36.5, 45.1, 11.9, 3000], 0], ['sampled case 2', [1925, 46.69, 36.9, 45.7, 120.5, 2550], 'ERR_BALLAST_ARM'], ['sampled case 3', [2440, 47.5, 35.1, 47.5, 46.2, 2400], 0]], [['aft CG nose ballast', [1800, 48.199999999999996, 35.0, 47.3, 10.0, 2550], 44], ['forward CG tail ballast', [1700, 34.2, 35.15, 47.3, 150.0, 2550], 15], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 23.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2510, 41.12, 36.1, 47.4, 155.2, 2700], 0], ['sampled case 2', [1785, 32.94, 35.6, 44.4, 94.3, 2400], 81], ['sampled case 3', [2400, 37.65, 34.3, 45.9, 140.6, 2550], 0]], [['aft CG nose ballast', [1800, 48.3, 35.0, 47.3, 10.0, 2550], 49], ['forward CG tail ballast', [1700, 34.2, 35.2, 47.3, 150.0, 2550], 15], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 24.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [1590, 30.16, 33.1, 46.2, 118.7, 2550], 55], ['sampled case 2', [1710, 32.9, 34.8, 45.0, 129.9, 2550], 35], ['sampled case 3', [1755, 35.34, 36.3, 47.0, 127.7, 2700], 19]], [['aft CG nose ballast', [1800, 48.4, 35.0, 47.3, 10.0, 2550], 54], ['forward CG tail ballast', [1700, 34.2, 35.25, 47.3, 150.0, 2550], 16], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 25.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [1745, 31.68, 34.3, 46.9, 112.4, 2550], 59], ['sampled case 2', [1645, 34.52, 36.5, 47.5, 5.2, 2400], 'ERR_BALLAST_ARM'], ['sampled case 3', [1850, 32.93, 34.5, 46.9, 56.9, 2700], 130]]]
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
aft CG nose ballast3434Passed
forward CG tail ballast1313Passed
in envelope00Passed
exactly on aft limitERR_OVERWEIGHT0Failed
exactly on forward limit00Passed
ballast arm behind aft limitERR_BALLAST_ARMERR_BALLAST_ARMPassed
forward case ballast in noseERR_BALLAST_ARMERR_BALLAST_ARMPassed
ballast would overweightERR_OVERWEIGHTERR_OVERWEIGHTPassed
ballast reaches exactly max1010Passed
sampled case 100Passed
sampled case 2-2730Failed
sampled case 300Passed

SHA-256 / fa06a88fe7f1cdb43d8fdbe5a9001d15be844e20172207dc68e9945214f091d7

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(x):
    W, cg, fwd, aft, ba, maxw = x
    if fwd <= cg <= aft: return 0
    lim = aft if cg > aft else fwd
    if (cg > aft and ba >= aft) or (cg < fwd and ba <= fwd): return 'ERR_BALLAST_ARM'
    b = math.ceil(round(W * (cg - lim) / (lim - ba), 6))
    if W + b > maxw: return 'ERR_OVERWEIGHT'
    return b
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[['aft CG nose ballast', [1800, 48.0, 35.0, 47.3, 10.0, 2550], 34], ['forward CG tail ballast', [1700, 34.2, 35.05, 47.3, 150.0, 2550], 13], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 21.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2250, 36.0, 36.0, 46.0, 101.0, 2700], 0], ['sampled case 2', [2220, 44.7, 33.9, 44.7, 121.5, 2550], 0], ['sampled case 3', [2400, 39.05, 36.3, 46.8, 9.5, 2400], 0]], [['aft CG nose ballast', [1800, 48.1, 35.0, 47.3, 10.0, 2550], 39], ['forward CG tail ballast', [1700, 34.2, 35.1, 47.3, 150.0, 2550], 14], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 22.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2035, 44.73, 36.5, 45.1, 11.9, 3000], 0], ['sampled case 2', [1925, 46.69, 36.9, 45.7, 120.5, 2550], 'ERR_BALLAST_ARM'], ['sampled case 3', [2440, 47.5, 35.1, 47.5, 46.2, 2400], 0]], [['aft CG nose ballast', [1800, 48.199999999999996, 35.0, 47.3, 10.0, 2550], 44], ['forward CG tail ballast', [1700, 34.2, 35.15, 47.3, 150.0, 2550], 15], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 23.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [2510, 41.12, 36.1, 47.4, 155.2, 2700], 0], ['sampled case 2', [1785, 32.94, 35.6, 44.4, 94.3, 2400], 81], ['sampled case 3', [2400, 37.65, 34.3, 45.9, 140.6, 2550], 0]], [['aft CG nose ballast', [1800, 48.3, 35.0, 47.3, 10.0, 2550], 49], ['forward CG tail ballast', [1700, 34.2, 35.2, 47.3, 150.0, 2550], 15], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 24.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [1590, 30.16, 33.1, 46.2, 118.7, 2550], 55], ['sampled case 2', [1710, 32.9, 34.8, 45.0, 129.9, 2550], 35], ['sampled case 3', [1755, 35.34, 36.3, 47.0, 127.7, 2700], 19]], [['aft CG nose ballast', [1800, 48.4, 35.0, 47.3, 10.0, 2550], 54], ['forward CG tail ballast', [1700, 34.2, 35.25, 47.3, 150.0, 2550], 16], ['in envelope', [2000, 40.0, 35.0, 47.3, 10.0, 2550], 0], ['exactly on aft limit', [2000, 47.3, 35.0, 47.3, 10.0, 2550], 0], ['exactly on forward limit', [2000, 35.0, 35.0, 47.3, 150.0, 2550], 0], ['ballast arm behind aft limit', [1900, 48.0, 35.0, 47.3, 60.0, 2550], 'ERR_BALLAST_ARM'], ['forward case ballast in nose', [1900, 34.0, 35.0, 47.3, 25.0, 2550], 'ERR_BALLAST_ARM'], ['ballast would overweight', [2500, 48.5, 35.0, 47.3, 10.0, 2550], 'ERR_OVERWEIGHT'], ['ballast reaches exactly max', [2000, 47.5, 35.0, 47.3, 7.3, 2010], 10], ['sampled case 1', [1745, 31.68, 34.3, 46.9, 112.4, 2550], 59], ['sampled case 2', [1645, 34.52, 36.5, 47.5, 5.2, 2400], 'ERR_BALLAST_ARM'], ['sampled case 3', [1850, 32.93, 34.5, 46.9, 56.9, 2700], 130]]]
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
aft CG nose ballast3434Passed
forward CG tail ballast1313Passed
in envelope00Passed
exactly on aft limit00Passed
exactly on forward limit00Passed
ballast arm behind aft limitERR_BALLAST_ARMERR_BALLAST_ARMPassed
forward case ballast in noseERR_BALLAST_ARMERR_BALLAST_ARMPassed
ballast would overweightERR_OVERWEIGHTERR_OVERWEIGHTPassed
ballast reaches exactly max1010Passed
sampled case 100Passed
sampled case 200Passed
sampled case 300Passed

SHA-256 / 0c56172482e7f73b04eefe0b9dc455f717a913852fbca2f64676928558b1268f

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 2026-09-29T14:47:39.161757+00:00.

Case digest / 4cfb85afe030e8d15366c8632273d2dcbc21a7297eea26421b1e4dda4ac34ba1