CS 31HB.25 Factors of safety

• ED Decision 2011/013/R found in: CS-31HB Amdt 1 - Hot Air Balloons (Dec 2011)

CS 31HB.25 Factors of safety ED Decision 2011/013/R (a) A factor of safety must be used in the balloon design as provided in the table. <table border="1" cellpadding="0" cellspacing="0" width="94%"><tr><td valign="top" width="52%"><p></p></td><td valign="top" width="47%"><p><b>Safety factor</b></p></td></tr><tr><td valign="top" width="52%"><p><b>Envelope</b></p></td><td valign="top" width="47%"><p>5.00</p></td></tr><tr><td valign="top" width="52%"><p><b>Suspension components (fibrous or non-metallic)</b></p></td><td valign="top" width="47%"><p>2.25</p></td></tr><tr><td valign="top" width="52%"><p><b>Suspension components (metallic)</b></p></td><td valign="top" width="47%"><p>1.50</p></td></tr><tr><td valign="top" width="52%"><p><b>Other</b></p></td><td valign="top" width="47%"><p>1.50</p></td></tr></table> (b) A reduced factor of 2 or more may be used in the envelope design if it is shown that the selected factor will preclude failure due to creep or instantaneous rupture from lack of rip stoppers. The selected factor must be applied to the more critical of the maximum operating pressure or envelope stress. (c) The primary attachments of the envelope to the basket must be designed so that any single failure will not jeopardise safety of flight. (d) For design purposes, an occupant mass of at least 77 kg must be assumed. [Amdt No.: 31HB/1]