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
0.09	1
0.25	2
0.40	3
0.57	4
0.69	5
0.79	6
0.85	7
0.92	8
0.98	9
1.04	10
1.09	11
1.15	12
1.20	13
1.26	14
1.31	15
1.36	16
1.40	17
1.46	18
1.52	19
1.56	20
1.60	21
1.65	22
1.68	23
1.74	24
1.78	25
1.83	26
1.89	27
1.95	28
1.99	29
2.04	30
2.09	31
2.13	32
2.17	33
2.21	34
2.26	35
2.29	36
2.34	37
2.37	38
2.41	39
2.45	40
2.49	41
2.55	42
2.59	43
2.64	44
2.71	45
2.75	46
2.81	47
2.84	48
2.89	49
2.93	50
2.99	51
3.05	52
3.11	53
3.15	54
3.19	55
3.24	56
3.29	57
3.35	58
3.40	59
3.46	60
3.50	61
3.57	62
3.66	63
3.72	64
3.76	65
3.81	66
3.87	67
3.95	68
4.01	69
4.07	70
4.13	71
4.18	72
4.24	73
4.29	74
4.36	75
4.46	76
4.54	77
4.66	78
4.73	79
4.81	80
4.88	81
4.94	82
5.05	83
5.16	84
5.30	85
5.41	86
5.57	87
5.69	88
5.86	89
6.11	90
6.38	91
6.68	92
6.92	93
7.24	94
7.61	95
7.90	96
8.63	97
9.32	98
11.95	99
21.18	100