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
0.11	1
0.33	2
0.47	3
0.63	4
0.74	5
0.83	6
0.92	7
0.99	8
1.07	9
1.15	10
1.22	11
1.29	12
1.35	13
1.39	14
1.46	15
1.53	16
1.57	17
1.63	18
1.70	19
1.75	20
1.81	21
1.86	22
1.91	23
1.96	24
2.03	25
2.07	26
2.11	27
2.16	28
2.23	29
2.28	30
2.32	31
2.38	32
2.42	33
2.48	34
2.53	35
2.58	36
2.64	37
2.68	38
2.71	39
2.77	40
2.82	41
2.87	42
2.93	43
2.98	44
3.01	45
3.06	46
3.12	47
3.18	48
3.23	49
3.30	50
3.36	51
3.40	52
3.46	53
3.51	54
3.57	55
3.62	56
3.69	57
3.75	58
3.81	59
3.85	60
3.91	61
3.98	62
4.06	63
4.11	64
4.17	65
4.24	66
4.32	67
4.40	68
4.46	69
4.53	70
4.60	71
4.66	72
4.72	73
4.80	74
4.90	75
5.00	76
5.07	77
5.17	78
5.28	79
5.38	80
5.47	81
5.60	82
5.75	83
5.89	84
6.05	85
6.18	86
6.33	87
6.46	88
6.61	89
6.79	90
6.99	91
7.24	92
7.56	93
7.84	94
8.19	95
8.69	96
9.28	97
9.88	98
11.26	99
17.96	100