572.33—Neck.

(a) The neck consists of the assembly shown in drawing 78051-90, revision A and conforms to each of the drawings subtended therein.

(b) When the head and neck assembly (consisting of the parts 78051-61X, revision C; -90, revision A; -84; -94; -98; -104, revision F; -303, revision E; -305; -306; -307, revision X) which has a six axis neck transducer (Drawing number C-1709, Revision D, titled “Neck transducer,” dated February 1, 1993.) installed in conformance with § 572.36(d), is tested in accordance with paragraph (c) of this section, it shall have the following characteristics:

(1) Flexion. (i) Plane D, referenced in Figure 20, shall rotate between 64 degrees and 78 degrees, which shall occur between 57 milliseconds (ms) and 64 ms from time zero. In first rebound, the rotation of Plane D shall cross 0 degrees between 113 ms and 128 ms.

(ii) The moment measured by the six axis neck transducer (drawing C-1709, revision D) about the occipital condyles, referenced in Figure 20, shall be calculated by the following formula: Moment (lbs-ft) = My−0.058 × Fx, where My is the moment measured in lbs-ft by the “Y” axis moment sensor of the six axis neck transducer and Fx is the force measured in lbs by the “X” axis force sensor (Channel Class 600) of the six axis neck transducer. The moment shall have a maximum value between 65 lbs-ft and 80 lbs-ft occurring between 47ms and 58 ms, and the positive moment shall decay for the first time to 0 lb-ft between 97 ms and 107 ms.

(2) Extension. (i) Plane D, referenced in Figure 21, shall rotate between 81 degrees and 106 degrees, which shall occur between 72 ms and 82 ms from time zero. In first rebound, rotation of Plane D shall cross 0 degrees between 147 ms and 174 ms.

(ii) The moment measured by the six axis neck transducer (drawing C-1709, revision D) about the occipital condyles, referenced in Figure 21, shall be calculated by the following formula: Moment (lbs-ft) = My−0.058 × Fx, where My is the moment measured in lbs-ft by the “Y” axis moment sensor of the six axis neck transducer and Fx is the force measured in lbs by the “X” axis force sensor (Channel Class 600) of the six axis neck transducer. The moment shall have a maximum value between—39 lbs-ft and -59 lbs-ft, occurring between 65 ms and 79 ms, and the negative moment shall decay for the first time to 0 lb-ft between 120 ms and 148 ms.