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
0.08	1
0.10	2
0.11	3
0.13	4
0.15	5
0.16	6
0.17	7
0.19	8
0.20	9
0.22	10
0.25	11
0.26	12
0.26	13
0.29	14
0.31	15
0.34	16
0.34	17
0.38	18
0.40	19
0.42	20
0.45	21
0.50	22
0.51	23
0.55	24
0.58	25
0.61	26
0.64	27
0.68	28
0.71	29
0.76	30
0.78	31
0.83	32
0.88	33
0.89	34
0.94	35
1.01	36
1.02	37
1.04	38
1.11	39
1.15	40
1.17	41
1.21	42
1.26	43
1.29	44
1.34	45
1.40	46
1.41	47
1.46	48
1.52	49
1.56	50
1.61	51
1.67	52
1.72	53
1.75	54
1.76	55
1.80	56
1.88	57
1.92	58
2.01	59
2.03	60
2.09	61
2.15	62
2.24	63
2.30	64
2.34	65
2.34	66
2.40	67
2.50	68
2.57	69
2.63	70
2.68	71
2.80	72
2.84	73
3.00	74
3.02	75
3.08	76
3.20	77
3.33	78
3.43	79
3.51	80
3.58	81
3.75	82
3.86	83
4.02	84
4.18	85
4.33	86
4.51	87
4.67	88
4.84	89
5.07	90
5.30	91
5.57	92
5.84	93
6.18	94
6.66	95
7.03	96
7.69	97
8.72	98
10.30	99
24.70	100