---
kind: "section"
citation: "14 C.F.R. § 23.2320"
title: "14"
number: "23.2320"
heading: "Occupant physical environment."
url: "https://uscodex.org/cfr/14/23.2320"
---

# §23.2320. Occupant physical environment.

- (a) The applicant must design the airplane to—
  - (1) Allow clear communication between the flightcrew and passengers;
  - (2) Protect the pilot and flight controls from propellers; and
  - (3) **Protect the occupants from serious injury due to damage to windshields, windows, and canopies.**
- (b) For level 4 airplanes, each windshield and its supporting structure directly in front of the pilot must withstand, without penetration, the impact equivalent to a two-pound bird when the velocity of the airplane is equal to the airplane's maximum approach flap speed.
- (c) The airplane must provide each occupant with air at a breathable pressure, free of hazardous concentrations of gases, vapors, and smoke during normal operations and likely failures.
- (d) If a pressurization system is installed in the airplane, it must be designed to protect against—
  - (1) Decompression to an unsafe level; and
  - (2) **Excessive differential pressure.**
- (e) If an oxygen system is installed in the airplane, it must—
  - (1) Effectively provide oxygen to each user to prevent the effects of hypoxia; and
  - (2) **Be free from hazards in itself, in its method of operation, and its effect upon other components.**

## Notes

### Authority

Authority: 49 U.S.C. 106(f), 106(g), 40113, 44701-44702, 44704, Pub. L. 113-53, 127 Stat. 584 (49 U.S.C. 44704) note.

### Source

Source: Doc. No. FAA-2015-1621, Amdt. 23-64, 81 FR 96689, Dec. 30, 2016, unless otherwise noted.