14 CFR § 437.3 - Definitions.

---
identifier: "/us/cfr/t14/s437.3"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "14 CFR § 437.3 - Definitions."
title_number: 14
title_name: "Aeronautics and Space"
section_number: "437.3"
section_name: "Definitions."
chapter_name: "COMMERCIAL SPACE TRANSPORTATION, FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION"
subchapter_number: "C"
subchapter_name: "LICENSING"
part_number: "437"
part_name: "EXPERIMENTAL PERMITS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "51 U.S.C. 50901-50923."
regulatory_source: "Docket No. FAA-2006-24197, 72 FR 17019, Apr. 6, 2007, unless otherwise noted."
cfr_part: "437"
---


# 437.3 Definitions.

*Envelope expansion* means any portion of a flight where planned operations will subject a reusable suborbital vehicle to the effects of altitude, velocity, acceleration, or burn duration that exceed a level or duration successfully verified during an earlier flight.

*Exclusion area* means an area, within an operating area, that a reusable suborbital vehicle's instantaneous impact point may not traverse.

*Operating area* means a three-dimensional region where permitted flights may take place.

*Permitted vehicle* means a reusable suborbital rocket or a reusable launch vehicle that will be launched into a suborbital trajectory or reentered that is operated by a launch or reentry operator under an experimental permit.

*Reentry impact point* means the location of a reusable suborbital vehicle's instantaneous impact point during its unpowered exoatmospheric suborbital flight.

[Doc. No. FAA-2023-1656, Amdt. No. 437-

4, 89 FR 76726, Sept. 19, 2024]