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
0.21	1
0.35	2
0.48	3
0.59	4
0.72	5
0.82	6
0.92	7
1.03	8
1.12	9
1.21	10
1.30	11
1.38	12
1.46	13
1.55	14
1.63	15
1.72	16
1.80	17
1.89	18
1.96	19
2.04	20
2.13	21
2.20	22
2.28	23
2.36	24
2.44	25
2.52	26
2.59	27
2.67	28
2.75	29
2.83	30
2.92	31
3.01	32
3.08	33
3.16	34
3.25	35
3.32	36
3.41	37
3.50	38
3.56	39
3.64	40
3.73	41
3.81	42
3.90	43
4.00	44
4.07	45
4.16	46
4.25	47
4.34	48
4.43	49
4.52	50
4.60	51
4.69	52
4.77	53
4.88	54
4.97	55
5.06	56
5.17	57
5.27	58
5.35	59
5.46	60
5.58	61
5.68	62
5.79	63
5.89	64
6.01	65
6.10	66
6.23	67
6.35	68
6.48	69
6.62	70
6.75	71
6.90	72
7.03	73
7.17	74
7.32	75
7.47	76
7.64	77
7.83	78
8.00	79
8.17	80
8.37	81
8.55	82
8.75	83
8.97	84
9.21	85
9.45	86
9.69	87
10.01	88
10.30	89
10.60	90
11.00	91
11.39	92
11.86	93
12.40	94
12.94	95
13.63	96
14.55	97
15.81	98
17.90	99
28.08	100