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
0.31	1
0.41	2
0.47	3
0.55	4
0.63	5
0.72	6
0.78	7
0.85	8
0.88	9
0.92	10
0.97	11
1.04	12
1.07	13
1.13	14
1.17	15
1.21	16
1.29	17
1.33	18
1.35	19
1.39	20
1.42	21
1.46	22
1.49	23
1.51	24
1.60	25
1.66	26
1.67	27
1.70	28
1.77	29
1.80	30
1.82	31
1.84	32
1.87	33
1.92	34
1.94	35
1.95	36
1.97	37
2.00	38
2.05	39
2.09	40
2.13	41
2.14	42
2.17	43
2.20	44
2.24	45
2.26	46
2.29	47
2.31	48
2.35	49
2.38	50
2.40	51
2.42	52
2.45	53
2.47	54
2.52	55
2.56	56
2.58	57
2.62	58
2.67	59
2.75	60
2.77	61
2.78	62
2.86	63
2.88	64
2.94	65
3.02	66
3.06	67
3.10	68
3.13	69
3.14	70
3.17	71
3.19	72
3.23	73
3.27	74
3.32	75
3.35	76
3.37	77
3.43	78
3.56	79
3.65	80
3.78	81
3.82	82
3.87	83
3.95	84
4.07	85
4.21	86
4.44	87
4.52	88
4.73	89
4.86	90
5.03	91
5.24	92
5.83	93
5.87	94
5.98	95
6.96	96
7.43	97
8.08	98
8.45	99
9.11	100