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
0.24	2
0.37	3
0.53	4
0.67	5
0.76	6
0.83	7
0.90	8
0.95	9
0.99	10
1.05	11
1.13	12
1.17	13
1.23	14
1.28	15
1.32	16
1.38	17
1.43	18
1.48	19
1.54	20
1.58	21
1.62	22
1.66	23
1.72	24
1.76	25
1.80	26
1.85	27
1.89	28
1.92	29
1.96	30
2.00	31
2.05	32
2.08	33
2.13	34
2.18	35
2.22	36
2.27	37
2.32	38
2.36	39
2.40	40
2.45	41
2.49	42
2.52	43
2.56	44
2.60	45
2.64	46
2.68	47
2.72	48
2.76	49
2.81	50
2.85	51
2.89	52
2.93	53
2.98	54
3.03	55
3.07	56
3.13	57
3.19	58
3.24	59
3.30	60
3.34	61
3.41	62
3.49	63
3.54	64
3.58	65
3.63	66
3.68	67
3.73	68
3.79	69
3.85	70
3.93	71
4.01	72
4.10	73
4.16	74
4.24	75
4.32	76
4.37	77
4.48	78
4.56	79
4.65	80
4.74	81
4.85	82
4.97	83
5.08	84
5.21	85
5.31	86
5.47	87
5.60	88
5.75	89
5.93	90
6.08	91
6.39	92
6.61	93
6.88	94
7.23	95
7.65	96
8.10	97
8.66	98
10.86	99
21.19	100