Safety Measurement System

Measure vs. Percentile

Carrier violations or crashes are weighted by time and severity to produce a measure for that carrier in each BASIC. The measure is then used to assign that carrier to a percentile rank containing carriers’ information in similar safety event groups. Expand for more information.

Carrier violations or crashes are weighted by time and severity to produce a measure for that carrier in each BASIC. The measure only considers individual performance based on 24 months of data, with a measure of 0 indicating best performance. The measure is then used to assign that carrier to a percentile rank containing carriers’ information in similar safety event groups. The graph below shows how the carrier’s measure correlates with its percentile rank over a selected period of time.

Measure

Percentile

Measure	Percentile
0	0
0.02	1
0.02	2
0.02	3
0.03	4
0.03	5
0.04	6
0.05	7
0.05	8
0.06	9
0.07	10
0.07	11
0.08	12
0.09	13
0.10	14
0.10	15
0.11	16
0.12	17
0.13	18
0.14	19
0.15	20
0.16	21
0.17	22
0.17	23
0.18	24
0.19	25
0.20	26
0.21	27
0.22	28
0.23	29
0.24	30
0.25	31
0.26	32
0.27	33
0.28	34
0.30	35
0.31	36
0.32	37
0.33	38
0.34	39
0.35	40
0.36	41
0.38	42
0.39	43
0.40	44
0.42	45
0.43	46
0.45	47
0.46	48
0.48	49
0.49	50
0.50	51
0.52	52
0.54	53
0.55	54
0.57	55
0.59	56
0.61	57
0.63	58
0.65	59
0.67	60
0.69	61
0.72	62
0.74	63
0.77	64
0.79	65
0.82	66
0.85	67
0.88	68
0.91	69
0.94	70
0.97	71
1.01	72
1.04	73
1.07	74
1.11	75
1.15	76
1.20	77
1.24	78
1.29	79
1.34	80
1.39	81
1.44	82
1.49	83
1.56	84
1.62	85
1.69	86
1.76	87
1.85	88
1.95	89
2.06	90
2.17	91
2.31	92
2.46	93
2.62	94
2.85	95
3.10	96
3.44	97
3.92	98
4.73	99
8.88	100