---
kind: "unit"
title: "51"
title_heading: "National and Commercial Space Programs"
key: "stIV/ch407"
level: "chapter"
label: "Chapter 407"
heading: "Environmentally Friendly Aircraft"
release: "119-102"
date: "2026-07-12"
url: "https://uscodex.org/usc/51/stIV-ch407"
sections_count: 4
---

# Chapter 407 — Environmentally Friendly Aircraft

Title 51 — National and Commercial Space Programs › Subtitle IV — Aeronautics and Space Research and Education

## Sections

- [§40701. Research and development initiative](/usc/51/40701.md)
- [§40702. Additional research and development initiative](/usc/51/40702.md)
- [§40703. Research alignment](/usc/51/40703.md)
- [§40704. Research program on perceived impact of sonic booms](/usc/51/40704.md)