[Code of Federal Regulations] [Title 14, Volume 1] [Revised as of January 1, 2007] From the U.S. Government Printing Office via GPO Access [CITE: 14CFR31.21] [Page 764] TITLE 14--AERONAUTICS AND SPACE CHAPTER I--FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PART 31_AIRWORTHINESS STANDARDS: MANNED FREE BALLOONS--Table of Contents Subpart C_Strength Requirements Sec. 31.21 Loads. Strength requirements are specified in terms of limit loads, that are the maximum load to be expected in service, and ultimate loads, that are limit loads multiplied by prescribed factors of safety. Unless otherwise specified, all prescribed loads are limit loads.