Section 107.4. Definitions

The following words and terms, when used in this chapter, have the following meanings, unless the context clearly indicates otherwise:

Basic plane—A plane through the centers of the right and left external ear openings and the lower edge of the eye sockets, as shown in Figure 1 of Appendix A, of a reference headform, as shown in Figure 2 of Appendix A or test headform.

Helmet positioning index—The distance in inches, as specified by the manufacturer, from the lowest point of the brow opening at the lateral midpoint of the helmet to the basic plane of a reference headform, when the helmet is firmly and properly positioned on the reference headform.

Midsagittal plane—A longitudinal plane through the apex of a reference headform or test headform that is perpendicular to the basic plane, as shown in Figure 3 of Appendix A.

Reference headform—A measuring device contoured to the dimensions of one of the four headforms described in Appendix A of this chapter with surface markings indicating the locations of the basic, midsagittal, and reference planes, and the centers of the external ear openings.

Reference plane—A plane above and parallel to the basic plane on a reference headform or test headform, as shown in Figure 2 of Appendix A, at the distance indicated in the Appendix A.

Retention system—The complete assembly by which the helmet is retained in position on the head during use.

Test headform—A test device contoured to the dimensions of one of the four reference headforms described in Appendix A for all surface areas that contact the helmet, with surface markings indicating the locations of the basic, midsagittal and reference planes.

Notation

Notes of Decisions

Helmet Coverage

A motorcycle helmet must cover at least to the center of the ear. Commonwealth v. Hull, 705 A.2d 911 (Pa. Super. 1998); appeal denied, 725 A.2d 179 (Pa. 1998).

Vagueness

Although the language of this regulation is complex, complicated and requires careful deliberation on the part of motorcyclists, the language is not vague. Commonwealth v. Hull, 705 A.2d 911 (Pa. Super. 1998).