{"abstract":"Aft-loaded aircraft show heavy nose-wheel loads and forward-loaded aircraft show light ones.","category":"Aviation weight and balance","checks":10,"contract":"Input {'items':[[lb,arm]],'main_arm','nose_arm'}. CG at or aft of the main gear -> ['TIP', CG r2]. Otherwise nose reaction = W*(main-CG)/(main-nose), main = W - nose; status 'LIGHT_NOSE' if nose < 5% of total weight else 'OK'. Return [status, nose r1, main r1].","evaluation_group":"w2-aviation-weight-balance-gear-reaction-loads","failed_approach":"Dividing by the main-gear arm instead of the wheelbase measures from the datum, not the nose gear.","family":"w2-aviation-weight-balance-gear-reaction-loads-nose-lever","id":"FA-66216","implementations":{"attempt":{"sha256":"e51e61dfb67e3b039f5ea0628a73bce90ec24f2224cf7cdd7da9a02a25b14366","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    w = sum(a for a, _ in x['items'])\n    m = sum(a * b for a, b in x['items'])\n    cg = m / w\n    mg, ng = x['main_arm'], x['nose_arm']\n    if cg >= mg: return ['TIP', round(cg, 2)]\n    nose = w * (mg - cg) / mg\n    main = w - nose\n    status = 'LIGHT_NOSE' if nose < 0.05 * w else 'OK'\n    return [status, round(nose, 1), round(main, 1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['normal ground load', {'items': [[9000.0, 250.0], [1510.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1762.2, 8747.8]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 321.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 54.3, 11445.7]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 331.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 296.5]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 119.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2160.0, 7640.0]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[8891.0, 243.3], [4548.0, 151.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 4549.9, 8889.1]], ['sampled case 2', {'items': [[836.0, 112.7], [2149.0, 136.1], [3914.0, 149.9]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 4891.9, 2007.1]], ['sampled case 3', {'items': [[2341.0, 136.2], [1333.0, 147.9], [1880.0, 155.7]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 3207.8, 2346.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1520.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1763.5, 8756.5]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 322.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 43.5, 11456.5]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 332.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 296.75]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 118.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2163.5, 7636.5]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[966.0, 212.0], [6090.0, 178.6], [4538.0, 174.9], [1442.0, 103.6]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 7356.6, 5679.4]], ['sampled case 2', {'items': [[4506.0, 204.0], [8513.0, 219.6]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 3947.3, 9071.7]], ['sampled case 3', {'items': [[8984.0, 243.5], [6602.0, 268.8]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 2655.8, 12930.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1530.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1764.8, 8765.2]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 323.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 32.6, 11467.4]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 333.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.0]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 117.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2167.0, 7633.0]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[8812.0, 250.9]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 1640.7, 7171.3]], ['sampled case 2', {'items': [[4325.0, 295.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 295.0]], ['sampled case 3', {'items': [[7004.0, 198.3], [410.0, 239.6], [2416.0, 150.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 4350.8, 5479.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1540.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1766.1, 8773.9]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 324.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 21.7, 11478.3]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 334.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.25]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 116.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2170.4, 7629.6]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[1599.0, 205.2]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 645.7, 953.3]], ['sampled case 2', {'items': [[283.0, 287.5], [2116.0, 231.6], [600.0, 209.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 751.1, 2247.9]], ['sampled case 3', {'items': [[2210.0, 260.8]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 258.1, 1951.9]]], [['normal ground load', {'items': [[9000.0, 250.0], [1550.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1767.4, 8782.6]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 325.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 10.9, 11489.1]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 335.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.5]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 115.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2173.9, 7626.1]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[649.0, 272.6]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 49.1, 599.9]], ['sampled case 2', {'items': [[6458.0, 136.9], [8392.0, 168.7]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 8026.7, 6823.3]], ['sampled case 3', {'items': [[8932.0, 311.4]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['TIP', 311.4]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"99bdadacc784e8bac4a4676010d2d067307e69f98b41decf0b291cef30b4c6c6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    w = sum(a for a, _ in x['items'])\n    m = sum(a * b for a, b in x['items'])\n    cg = m / w\n    mg, ng = x['main_arm'], x['nose_arm']\n    if cg >= mg: return ['TIP', round(cg, 2)]\n    nose = w * (cg - ng) / (mg - ng)\n    main = w - nose\n    status = 'LIGHT_NOSE' if nose < 0.05 * w else 'OK'\n    return [status, round(nose, 1), round(main, 1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['normal ground load', {'items': [[9000.0, 250.0], [1510.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1762.2, 8747.8]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 321.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 54.3, 11445.7]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 331.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 296.5]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 119.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2160.0, 7640.0]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[8891.0, 243.3], [4548.0, 151.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 4549.9, 8889.1]], ['sampled case 2', {'items': [[836.0, 112.7], [2149.0, 136.1], [3914.0, 149.9]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 4891.9, 2007.1]], ['sampled case 3', {'items': [[2341.0, 136.2], [1333.0, 147.9], [1880.0, 155.7]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 3207.8, 2346.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1520.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1763.5, 8756.5]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 322.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 43.5, 11456.5]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 332.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 296.75]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 118.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2163.5, 7636.5]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[966.0, 212.0], [6090.0, 178.6], [4538.0, 174.9], [1442.0, 103.6]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 7356.6, 5679.4]], ['sampled case 2', {'items': [[4506.0, 204.0], [8513.0, 219.6]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 3947.3, 9071.7]], ['sampled case 3', {'items': [[8984.0, 243.5], [6602.0, 268.8]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 2655.8, 12930.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1530.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1764.8, 8765.2]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 323.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 32.6, 11467.4]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 333.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.0]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 117.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2167.0, 7633.0]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[8812.0, 250.9]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 1640.7, 7171.3]], ['sampled case 2', {'items': [[4325.0, 295.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 295.0]], ['sampled case 3', {'items': [[7004.0, 198.3], [410.0, 239.6], [2416.0, 150.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 4350.8, 5479.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1540.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1766.1, 8773.9]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 324.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 21.7, 11478.3]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 334.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.25]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 116.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2170.4, 7629.6]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[1599.0, 205.2]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 645.7, 953.3]], ['sampled case 2', {'items': [[283.0, 287.5], [2116.0, 231.6], [600.0, 209.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 751.1, 2247.9]], ['sampled case 3', {'items': [[2210.0, 260.8]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 258.1, 1951.9]]], [['normal ground load', {'items': [[9000.0, 250.0], [1550.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1767.4, 8782.6]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 325.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 10.9, 11489.1]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 335.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.5]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 115.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2173.9, 7626.1]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[649.0, 272.6]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 49.1, 599.9]], ['sampled case 2', {'items': [[6458.0, 136.9], [8392.0, 168.7]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 8026.7, 6823.3]], ['sampled case 3', {'items': [[8932.0, 311.4]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['TIP', 311.4]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"b806b1a487a374606ede77cb6427dfcfc0369016f31034f9fbc1c0a546e779a8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(x):\n    w = sum(a for a, _ in x['items'])\n    m = sum(a * b for a, b in x['items'])\n    cg = m / w\n    mg, ng = x['main_arm'], x['nose_arm']\n    if cg >= mg: return ['TIP', round(cg, 2)]\n    nose = w * (mg - cg) / (mg - ng)\n    main = w - nose\n    status = 'LIGHT_NOSE' if nose < 0.05 * w else 'OK'\n    return [status, round(nose, 1), round(main, 1)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[['normal ground load', {'items': [[9000.0, 250.0], [1510.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1762.2, 8747.8]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 321.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 54.3, 11445.7]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 331.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 296.5]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 119.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2160.0, 7640.0]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[8891.0, 243.3], [4548.0, 151.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 4549.9, 8889.1]], ['sampled case 2', {'items': [[836.0, 112.7], [2149.0, 136.1], [3914.0, 149.9]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 4891.9, 2007.1]], ['sampled case 3', {'items': [[2341.0, 136.2], [1333.0, 147.9], [1880.0, 155.7]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 3207.8, 2346.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1520.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1763.5, 8756.5]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 322.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 43.5, 11456.5]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 332.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 296.75]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 118.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2163.5, 7636.5]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[966.0, 212.0], [6090.0, 178.6], [4538.0, 174.9], [1442.0, 103.6]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 7356.6, 5679.4]], ['sampled case 2', {'items': [[4506.0, 204.0], [8513.0, 219.6]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 3947.3, 9071.7]], ['sampled case 3', {'items': [[8984.0, 243.5], [6602.0, 268.8]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 2655.8, 12930.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1530.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1764.8, 8765.2]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 323.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 32.6, 11467.4]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 333.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.0]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 117.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2167.0, 7633.0]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[8812.0, 250.9]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 1640.7, 7171.3]], ['sampled case 2', {'items': [[4325.0, 295.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 295.0]], ['sampled case 3', {'items': [[7004.0, 198.3], [410.0, 239.6], [2416.0, 150.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 4350.8, 5479.2]]], [['normal ground load', {'items': [[9000.0, 250.0], [1540.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1766.1, 8773.9]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 324.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 21.7, 11478.3]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 334.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.25]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 116.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2170.4, 7629.6]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[1599.0, 205.2]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['OK', 645.7, 953.3]], ['sampled case 2', {'items': [[283.0, 287.5], [2116.0, 231.6], [600.0, 209.2]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 751.1, 2247.9]], ['sampled case 3', {'items': [[2210.0, 260.8]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 258.1, 1951.9]]], [['normal ground load', {'items': [[9000.0, 250.0], [1550.0, 260.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 1767.4, 8782.6]], ['aft cargo light nose', {'items': [[9000.0, 280.0], [2500.0, 325.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 10.9, 11489.1]], ['CG exactly over mains', {'items': [[9000.0, 290.0], [1000.0, 290.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 290.0]], ['tail tipping', {'items': [[9000.0, 285.0], [3000.0, 335.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['TIP', 297.5]], ['nose exactly five percent', {'items': [[10000.0, 278.5]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 500.0, 9500.0]], ['forward loading', {'items': [[9000.0, 250.0], [800.0, 115.0]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 2173.9, 7626.1]], ['CG a hair forward of mains', {'items': [[10000.0, 289.995]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['LIGHT_NOSE', 0.2, 9999.8]], ['sampled case 1', {'items': [[649.0, 272.6]], 'main_arm': 290.0, 'nose_arm': 60.0}, ['OK', 49.1, 599.9]], ['sampled case 2', {'items': [[6458.0, 136.9], [8392.0, 168.7]], 'main_arm': 290.0, 'nose_arm': 40.0}, ['OK', 8026.7, 6823.3]], ['sampled case 3', {'items': [[8932.0, 311.4]], 'main_arm': 290.0, 'nose_arm': 80.0}, ['TIP', 311.4]]]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"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.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-aviation-weight-balance-gear-reaction-loads-nose-lever","generated_at":"2026-09-29T14:47:41.119732+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Ground stability depends on the split of weight between nose and main gear; a CG over or behind the mains tips the aircraft onto its tail.","repair":"Nose reaction is W times (main arm - CG) divided by the wheelbase.","root_cause":"The nose reaction uses distance from the nose gear to the CG, which is the main-gear share.","sha256":"8bd10af1acdeda673de7fa83181cfd6f944375212530806126ddf2cbc2bd1e53","title":"Nose reaction computed with the main-gear lever · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.734,"exit_code":1,"observations":[{"actual":["OK",1397.6,9112.4],"check":"normal ground load","expected":["OK",1762.2,8747.8],"passed":false},{"actual":["LIGHT_NOSE",43.1,11456.9],"check":"aft cargo light nose","expected":["LIGHT_NOSE",54.3,11445.7],"passed":false},{"actual":["TIP",290.0],"check":"CG exactly over mains","expected":["TIP",290.0],"passed":true},{"actual":["TIP",296.5],"check":"tail tipping","expected":["TIP",296.5],"passed":true},{"actual":["LIGHT_NOSE",396.6,9603.4],"check":"nose exactly five percent","expected":["OK",500.0,9500.0],"passed":false},{"actual":["OK",1713.1,8086.9],"check":"forward loading","expected":["OK",2160.0,7640.0],"passed":false},{"actual":["LIGHT_NOSE",0.2,9999.8],"check":"CG a hair forward of mains","expected":["LIGHT_NOSE",0.2,9999.8],"passed":true},{"actual":["OK",3608.5,9830.5],"check":"sampled case 1","expected":["OK",4549.9,8889.1],"passed":false},{"actual":["OK",3542.4,3356.6],"check":"sampled case 2","expected":["OK",4891.9,2007.1],"passed":false},{"actual":["OK",2765.3,2788.7],"check":"sampled case 3","expected":["OK",3207.8,2346.2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal ground load\", \"actual\": [\"OK\", 1397.6, 9112.4], \"expected\": [\"OK\", 1762.2, 8747.8], \"passed\": false}, {\"check\": \"aft cargo light nose\", \"actual\": [\"LIGHT_NOSE\", 43.1, 11456.9], \"expected\": [\"LIGHT_NOSE\", 54.3, 11445.7], \"passed\": false}, {\"check\": \"CG exactly over mains\", \"actual\": [\"TIP\", 290.0], \"expected\": [\"TIP\", 290.0], \"passed\": true}, {\"check\": \"tail tipping\", \"actual\": [\"TIP\", 296.5], \"expected\": [\"TIP\", 296.5], \"passed\": true}, {\"check\": \"nose exactly five percent\", \"actual\": [\"LIGHT_NOSE\", 396.6, 9603.4], \"expected\": [\"OK\", 500.0, 9500.0], \"passed\": false}, {\"check\": \"forward loading\", \"actual\": [\"OK\", 1713.1, 8086.9], \"expected\": [\"OK\", 2160.0, 7640.0], \"passed\": false}, {\"check\": \"CG a hair forward of mains\", \"actual\": [\"LIGHT_NOSE\", 0.2, 9999.8], \"expected\": [\"LIGHT_NOSE\", 0.2, 9999.8], \"passed\": true}, {\"check\": \"sampled case 1\", \"actual\": [\"OK\", 3608.5, 9830.5], \"expected\": [\"OK\", 4549.9, 8889.1], \"passed\": false}, {\"check\": \"sampled case 2\", \"actual\": [\"OK\", 3542.4, 3356.6], \"expected\": [\"OK\", 4891.9, 2007.1], \"passed\": false}, {\"check\": \"sampled case 3\", \"actual\": [\"OK\", 2765.3, 2788.7], \"expected\": [\"OK\", 3207.8, 2346.2], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.106,"exit_code":1,"observations":[{"actual":["OK",8747.8,1762.2],"check":"normal ground load","expected":["OK",1762.2,8747.8],"passed":false},{"actual":["OK",11445.7,54.3],"check":"aft cargo light nose","expected":["LIGHT_NOSE",54.3,11445.7],"passed":false},{"actual":["TIP",290.0],"check":"CG exactly over mains","expected":["TIP",290.0],"passed":true},{"actual":["TIP",296.5],"check":"tail tipping","expected":["TIP",296.5],"passed":true},{"actual":["OK",9500.0,500.0],"check":"nose exactly five percent","expected":["OK",500.0,9500.0],"passed":false},{"actual":["OK",7640.0,2160.0],"check":"forward loading","expected":["OK",2160.0,7640.0],"passed":false},{"actual":["OK",9999.8,0.2],"check":"CG a hair forward of mains","expected":["LIGHT_NOSE",0.2,9999.8],"passed":false},{"actual":["OK",8889.1,4549.9],"check":"sampled case 1","expected":["OK",4549.9,8889.1],"passed":false},{"actual":["OK",2007.1,4891.9],"check":"sampled case 2","expected":["OK",4891.9,2007.1],"passed":false},{"actual":["OK",2346.2,3207.8],"check":"sampled case 3","expected":["OK",3207.8,2346.2],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal ground load\", \"actual\": [\"OK\", 8747.8, 1762.2], \"expected\": [\"OK\", 1762.2, 8747.8], \"passed\": false}, {\"check\": \"aft cargo light nose\", \"actual\": [\"OK\", 11445.7, 54.3], \"expected\": [\"LIGHT_NOSE\", 54.3, 11445.7], \"passed\": false}, {\"check\": \"CG exactly over mains\", \"actual\": [\"TIP\", 290.0], \"expected\": [\"TIP\", 290.0], \"passed\": true}, {\"check\": \"tail tipping\", \"actual\": [\"TIP\", 296.5], \"expected\": [\"TIP\", 296.5], \"passed\": true}, {\"check\": \"nose exactly five percent\", \"actual\": [\"OK\", 9500.0, 500.0], \"expected\": [\"OK\", 500.0, 9500.0], \"passed\": false}, {\"check\": \"forward loading\", \"actual\": [\"OK\", 7640.0, 2160.0], \"expected\": [\"OK\", 2160.0, 7640.0], \"passed\": false}, {\"check\": \"CG a hair forward of mains\", \"actual\": [\"OK\", 9999.8, 0.2], \"expected\": [\"LIGHT_NOSE\", 0.2, 9999.8], \"passed\": false}, {\"check\": \"sampled case 1\", \"actual\": [\"OK\", 8889.1, 4549.9], \"expected\": [\"OK\", 4549.9, 8889.1], \"passed\": false}, {\"check\": \"sampled case 2\", \"actual\": [\"OK\", 2007.1, 4891.9], \"expected\": [\"OK\", 4891.9, 2007.1], \"passed\": false}, {\"check\": \"sampled case 3\", \"actual\": [\"OK\", 2346.2, 3207.8], \"expected\": [\"OK\", 3207.8, 2346.2], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.103,"exit_code":0,"observations":[{"actual":["OK",1762.2,8747.8],"check":"normal ground load","expected":["OK",1762.2,8747.8],"passed":true},{"actual":["LIGHT_NOSE",54.3,11445.7],"check":"aft cargo light nose","expected":["LIGHT_NOSE",54.3,11445.7],"passed":true},{"actual":["TIP",290.0],"check":"CG exactly over mains","expected":["TIP",290.0],"passed":true},{"actual":["TIP",296.5],"check":"tail tipping","expected":["TIP",296.5],"passed":true},{"actual":["OK",500.0,9500.0],"check":"nose exactly five percent","expected":["OK",500.0,9500.0],"passed":true},{"actual":["OK",2160.0,7640.0],"check":"forward loading","expected":["OK",2160.0,7640.0],"passed":true},{"actual":["LIGHT_NOSE",0.2,9999.8],"check":"CG a hair forward of mains","expected":["LIGHT_NOSE",0.2,9999.8],"passed":true},{"actual":["OK",4549.9,8889.1],"check":"sampled case 1","expected":["OK",4549.9,8889.1],"passed":true},{"actual":["OK",4891.9,2007.1],"check":"sampled case 2","expected":["OK",4891.9,2007.1],"passed":true},{"actual":["OK",3207.8,2346.2],"check":"sampled case 3","expected":["OK",3207.8,2346.2],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"normal ground load\", \"actual\": [\"OK\", 1762.2, 8747.8], \"expected\": [\"OK\", 1762.2, 8747.8], \"passed\": true}, {\"check\": \"aft cargo light nose\", \"actual\": [\"LIGHT_NOSE\", 54.3, 11445.7], \"expected\": [\"LIGHT_NOSE\", 54.3, 11445.7], \"passed\": true}, {\"check\": \"CG exactly over mains\", \"actual\": [\"TIP\", 290.0], \"expected\": [\"TIP\", 290.0], \"passed\": true}, {\"check\": \"tail tipping\", \"actual\": [\"TIP\", 296.5], \"expected\": [\"TIP\", 296.5], \"passed\": true}, {\"check\": \"nose exactly five percent\", \"actual\": [\"OK\", 500.0, 9500.0], \"expected\": [\"OK\", 500.0, 9500.0], \"passed\": true}, {\"check\": \"forward loading\", \"actual\": [\"OK\", 2160.0, 7640.0], \"expected\": [\"OK\", 2160.0, 7640.0], \"passed\": true}, {\"check\": \"CG a hair forward of mains\", \"actual\": [\"LIGHT_NOSE\", 0.2, 9999.8], \"expected\": [\"LIGHT_NOSE\", 0.2, 9999.8], \"passed\": true}, {\"check\": \"sampled case 1\", \"actual\": [\"OK\", 4549.9, 8889.1], \"expected\": [\"OK\", 4549.9, 8889.1], \"passed\": true}, {\"check\": \"sampled case 2\", \"actual\": [\"OK\", 4891.9, 2007.1], \"expected\": [\"OK\", 4891.9, 2007.1], \"passed\": true}, {\"check\": \"sampled case 3\", \"actual\": [\"OK\", 3207.8, 2346.2], \"expected\": [\"OK\", 3207.8, 2346.2], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}