CFR > Title 14 - Aeronautics and Space > CHAPTER I—FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION > SUBCHAPTER C—AIRCRAFT (parts 21 to 50) > PART 31—AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS > SUBPART D—Design Construction (§31.31 to §31.65) > 31.51—Ballast.

31.51—Ballast.

Each captive gas balloon must have a means for the safe storage and controlled release of ballast. The ballast must consist of material that, if released during flight, is not hazardous to persons on the ground.