§572.153. Neck-headform assembly and test procedure. — Inbound Citations

(ii) 921022-041, Neck Assembly, incorporated by reference in §§ 572.151, 572.153, 572.154, and 572.155;

(b) When the neck and headform assembly, as defined in § 572.153(a), is tested according to the test procedure in § 572.153(c), it shall have the following characteristics:

(i) Plane D referenced in Figure R3 of this subpart shall rotate in the direction of pre-impact flight with respect to the pendulum's longitudinal centerline not less than 75 degrees and not more than 86 degrees. Within this specified rotation corridor, the peak positive moment about the occipital condyles shall be not less than 36 N-m (26.6 ft-lbf) and not more than 45 N-m (33.2 ft-lbf).

(ii) The positive moment about the occipital condyles shall decay for the first time to 5 N-m (3.7 ft-lbf) between 60 ms and 80 ms after time zero.

(iii) The moment about the occipital condyles shall be calculated by the following formula: Moment (N-m) = My − (0.005842m) × (Fx), where My is the moment about the y-axis, Fx is the shear force measured by the neck transducer (drawing SA572 -S23) and 0.005842m is the distance from the point at which the load cell measures the force to the occipital condyle.

(i) Plane D referenced in Figure R4 of this subpart shall rotate in the direction of preimpact flight with respect to the pendulum's longitudinal centerline not less than 80 degrees and not more than 92 degrees. Within the specified rotation corridor, the peak negative moment about the occipital condyles shall be not more than −12 Nm (−8.9 ft-lbf) and not less than −23 N-m (−17.0 ft-lbf) within the minimum and maximum rotation interval.

(ii) The negative moment about the occipital condyles shall decay for the first time to −5 Nm (−3.7 lbf-ft) between 76 ms and 90 ms after time zero.

(iii) The moment about the occipital condyles shall be calculated by the following formula: Moment (N-m) = My − (0.005842m) × (Fx), where My is the moment about the y-axis, Fx is the shear force measured by the neck transducer (drawing SA572 -S23) and 0.005842m is the distance from the point at which the load cell measures the force to the occipital condyle.

(b) When the neck and headform assembly, as defined in § 572.153(a), is tested according to the test procedure in § 572.153(c), it shall have the following characteristics:

(i) Plane D referenced in Figure R3 of this subpart shall rotate in the direction of pre-impact flight with respect to the pendulum's longitudinal centerline not less than 75 degrees and not more than 86 degrees. Within this specified rotation corridor, the peak positive moment about the occipital condyles shall be not less than 36 N-m (26.6 ft-lbf) and not more than 45 N-m (33.2 ft-lbf).

(ii) The positive moment about the occipital condyles shall decay for the first time to 5 N-m (3.7 ft-lbf) between 60 ms and 80 ms after time zero.

(iii) The moment about the occipital condyles shall be calculated by the following formula: Moment (N-m) = My − (0.005842m) × (Fx), where My is the moment about the y-axis, Fx is the shear force measured by the neck transducer (drawing SA572 -S23) and 0.005842m is the distance from the point at which the load cell measures the force to the occipital condyle.

(i) Plane D referenced in Figure R4 of this subpart shall rotate in the direction of preimpact flight with respect to the pendulum's longitudinal centerline not less than 80 degrees and not more than 92 degrees. Within the specified rotation corridor, the peak negative moment about the occipital condyles shall be not more than −12 Nm (−8.9 ft-lbf) and not less than −23 N-m (−17.0 ft-lbf) within the minimum and maximum rotation interval.

(ii) The negative moment about the occipital condyles shall decay for the first time to −5 Nm (−3.7 lbf-ft) between 76 ms and 90 ms after time zero.

(iii) The moment about the occipital condyles shall be calculated by the following formula: Moment (N-m) = My − (0.005842m) × (Fx), where My is the moment about the y-axis, Fx is the shear force measured by the neck transducer (drawing SA572 -S23) and 0.005842m is the distance from the point at which the load cell measures the force to the occipital condyle.