AC 120-41

Historical

Advisory circular · Criteria for Operational Approval of Airborne Wind Shear Alerting and Flight Guidance Systems

Approved
November 7, 1983
Last reviewed
October 25, 2024
This change
Canceled by Memo signed by Robert M. Ruiz for Lawrence Fields; dated 08/26/2024.
Family
AC 120-41 · 1 version
14 CFR parts
121, 125, 135

Guidance, not mandatory unless a rule or AD requires it. DRS record last changed November 22, 2025.

Show pages 25–36

1148.29 -6.41 27.21 4.10 1312.33 -6.34 27.21 4.66 1476.37 -6.41 27.40 5.05 1640.42 -5.83 27.21 5.19 11,488.3 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

0.00 -5.34 14.87 0.00

164.04 -5.44 18.46 0.78

328.08 -5.25 23.42 1.55

492.12 -5.93 26.63 2.14

656.17 -5.64 27.41 2.04

820.21 -6.26 27.41 2.18

984.25 -7.19 27.41 2.37 1148.29 -6.71 27.40 2.33 1312.33 -6.55 27.40 2.20 1476.37 -6.71 27.40 2.57 1640.42 -6.84 27.40 2.53 40,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

0.00 -5.34 14.87 0.00

164.04 -5.44 18.46 0.78

328.08 -5.25 23.42 1.55

492.12 -5.93 26.63 2.14

656.17 -5.64 27.41 2.04

820.21 -6.26 27.41 2.18

984.25 -7.19 27.41 2.37 1148.29 -6.71 27.40 2.33 1312.33 -6.55 27.40 2.20 1476.37 -6.71 27.40 2.57 1640.42 -6.84 27.40 2.53 Wind Field 9 Dryden Turbulence Data Altitude Rms Intensities Scale Lengths (feet) (Kts) (feet) Long Lat Vert Long Lat Vert

20.00 3.40 2.70 2.34 105.70 49.70 10.40

100.00 4.05 3.46 3.53 216.70 134.20 53.00

200.00 4.43 3.95 4.35 306.50 213.50 106.00

400.00 4.85 4.50 5.36 433.50 339.60 212.00

600.00 5.11 4.86 6.05 530.90 445.60 318.00

1500.00 5.74 5.78 7.94 840.90 824.50 795.30 Wind Field 10 40,000.0 feet beyond the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 -9.70 3.00 0.00

150.00 -12.20 7.50 -0.20

250.00 -12.90 8.00 -0.70

350.00 -16.40 9.00 2.20

450.00 -13.60 10.00 14.70

550.00 -19.50 11.00 -9.70

650.00 -6.30 12.00 -9.70

800.00 2.60 12.80 -6.50 1200.00 3.20 11.20 -3.30 1500.00 2.40 10.00 -3.40 At the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 -9.70 3.00 0.00

150.00 -12.20 7.50 -0.20

250.00 -12.90 8.00 -0.70

350.00 -16.40 9.00 2.20

450.00 -13.60 10.00 14.70

550.00 -19.50 11.00 -9.70

650.00 -6.30 12.00 -9.70

800.00 2.60 12.80 -6.50 1200.00 3.20 11.20 -3.30 1500.00 2.40 10.00 -3.40 2,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 -8.30 3.00 0.00

150.00 -13.10 7.50 -0.40

250.00 -14.20 8.00 -2.50

350.00 -16.60 9.00 -1.10

450.00 -19.50 10.00 -2.50

550.00 -18.80 11.00 -8.00

650.00 -16.30 12.00 -12.90

800.00 1.60 12.80 -7.70 1200.00 4.10 11.20 -7.40 1500.00 4.90 10.00 -6.10

4,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 -6.00 3.00 0.00

150.00 -12.70 7.50 0.00

250.00 -15.00 8.00 -3.60

350.00 -13.60 9.00 -6.00

450.00 -18.40 10.00 0.00

550.00 -21.20 11.00 0.00

650.00 -15.90 12.00 -11.40

800.00 -1.90 12.80 -10.90 1200.00 4.50 11.20 -8.40 1500.00 4.80 10.00 -9.00 6,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 1.70 3.00 0.00

150.00 -2.70 7.50 -0.90

250.00 -3.20 8.00 -6.10

350.00 -3.20 9.00 -17.90

450.00 -3.90 10.00 -27.70

550.00 0.20 11.00 -30.60

650.00 3.10 12.00 -27.00

800.00 7.20 12.80 -16.60 1200.00 7.20 11.20 -14.80 1500.00 7.20 10.00 -14.80 8,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 12.70 3.00 0.00

150.00 17.10 7.50 -0.90

250.00 17.60 8.00 -6.10

350.00 17.60 9.00 -17.90

450.00 18.30 10.00 -27.70

550.00 14.20 11.00 -30.60

650.00 11.30 12.00 -27.70

800.00 7.20 12.80 -16.60 1200.00 7.20 11.20 -14.80 1500.00 7.20 10.00 -14.80 9,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 19.10 3.00 0.00

150.00 24.70 7.50 -0.70

250.00 26.00 8.00 -6.10

350.00 28.00 9.00 -10.30

450.00 26.00 10.00 -12.30

550.00 24.60 11.00 -24.00

650.00 13.40 12.00 -24.60

800.00 12.80 12.80 -13.40 1200.00 9.60 11.20 -14.00 1500.00 8.70 10.00 -12.30 10,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 20.40 3.00 0.00

150.00 27.10 7.50 0.00

250.00 29.40 8.00 -3.60

350.00 28.00 9.00 -6.00

450.00 32.80 10.00 0.00

550.00 35.60 11.00 0.00

650.00 30.30 12.00 -11.40

800.00 16.30 12.80 -10.90 1200.00 9.90 11.20 -8.40 1500.00 9.60 10.00 -9.00 11,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 21.70 3.00 0.00

150.00 28.00 7.50 -0.40

250.00 28.70 8.00 -2.60

350.00 30.30 9.00 -4.10

450.00 36.20 10.00 2.30

550.00 35.60 11.00 0.00

650.00 32.60 12.00 11.90

800.00 15.00 12.80 9.70 1200.00 10.40 11.20 8.90 1500.00 9.60 10.00 7.00 12,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 22.70 3.00 0.00

150.00 27.50 7.50 -0.40

250.00 28.60 8.00 -2.50

350.00 31.00 9.00 -1.10

450.00 33.80 10.00 2.50

550.00 33.20 11.00 -8.00

650.00 30.70 12.00 -12.90

800.00 12.80 12.80 -7.70 1200.00 10.30 11.20 -7.40 1500.00 9.50 10.00 -6.10 13,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 24.00 3.00 0.00

150.00 27.30 7.50 -0.20

250.00 28.00 8.00 -0.90

350.00 31.00 9.00 0.00

450.00 32.70 10.00 6.00

550.00 32.50 11.00 -12.90

650.00 28.00 12.00 -12.90

800.00 12.10 12.80 -8.10 1200.00 10.50 11.20 -5.60 1500.00 13.30 10.00 -4.40 14,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 24.10 3.00 0.00

150.00 26.60 7.50 -0.20

250.00 27.30 8.00 -0.70

350.00 30.80 9.00 2.20

450.00 28.00 10.00 14.70

550.00 33.90 11.00 -9.70

650.00 20.70 12.00 -9.70

800.00 11.80 12.80 -6.50 1200.00 11.20 11.20 -3.30 1500.00 12.00 10.00 -3.40 16,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 24.30 3.00 0.00

150.00 26.50 7.50 0.00

250.00 27.20 8.00 -0.20

350.00 30.40 9.00 2.20

450.00 33.80 10.00 -2.50

550.00 25.00 11.00 -4.40

650.00 22.80 12.00 -3.00

800.00 13.80 12.80 -1.90 1200.00 13.30 11.20 -1.50 1500.00 13.00 10.00 -0.90

40,000.0 feet in front of the GPIP Mean Winds (Knots) Altitude (feet) Longitudinal Lateral Vertical

20.00 16.80 3.00 0.00

150.00 26.30 7.50 0.00

250.00 27.30 8.00 0.00

350.00 30.10 9.00 0.00

450.00 33.90 10.00 0.00

550.00 26.20 11.00 0.00

650.00 23.00 12.00 0.00

800.00 14.20 12.80 0.00 1200.00 13.70 11.20 0.00 1500.00 13.20 10.00 0.00 Wind Field 10 Dryden Turbulence Data Altitude Rms Intensities Scale Lengths (feet) (Kts) (feet) Long Lat Vert Long Lat Vert

20.00 3.40 2.70 2.34 105.70 49.70 10.40

100.00 4.05 3.46 3.53 216.70 134.20 53.00

200.00 4.43 3.95 4.35 306.50 213.50 106.00

400.00 4.85 4.50 5.36 433.50 339.60 212.00

600.00 5.11 4.86 6.05 530.90 445.60 318.00 1500.00 5.74 5.78 7.94 840.90 824.50 795.30