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
0.26	2
0.42	3
0.55	4
0.70	5
0.78	6
0.84	7
0.91	8
0.98	9
1.04	10
1.11	11
1.17	12
1.22	13
1.27	14
1.32	15
1.38	16
1.42	17
1.46	18
1.51	19
1.55	20
1.60	21
1.66	22
1.70	23
1.74	24
1.80	25
1.84	26
1.90	27
1.94	28
2.00	29
2.03	30
2.07	31
2.12	32
2.18	33
2.24	34
2.28	35
2.32	36
2.37	37
2.41	38
2.45	39
2.49	40
2.54	41
2.58	42
2.61	43
2.67	44
2.74	45
2.80	46
2.85	47
2.89	48
2.94	49
2.97	50
3.01	51
3.05	52
3.11	53
3.17	54
3.21	55
3.27	56
3.32	57
3.40	58
3.45	59
3.49	60
3.54	61
3.59	62
3.67	63
3.73	64
3.78	65
3.84	66
3.90	67
3.96	68
4.03	69
4.09	70
4.16	71
4.23	72
4.30	73
4.37	74
4.42	75
4.50	76
4.58	77
4.66	78
4.75	79
4.84	80
4.94	81
5.02	82
5.11	83
5.27	84
5.41	85
5.52	86
5.67	87
5.82	88
6.00	89
6.17	90
6.44	91
6.70	92
6.94	93
7.28	94
7.55	95
7.95	96
8.55	97
9.34	98
12.21	99
20.81	100