Proposal to amend para. 5.1.1.3. to adjust the lower vertical datum point from 5 degrees to 4 degrees below the horizontal and update the corresponding figure in Annex 4, Figure 1. This harmonizes the location of the lower datum point with the angle of obstruction requirement in para. 5.1.3., resolving an inconsistency between the allowed area of obstruction and the mandated transparent area of the windscreen.