CS 31HB.27 Strength and proof of strength

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

CS 31HB.27 Strength and proof of strength ED Decision 2011/013/R (a) The structure must be able to support limit loads without permanent deformations or other detrimental effects. (b) The structure must be able to withstand ultimate loads for at least 3 seconds without failure. (c) For the balloon envelope, proof of strength must also make allowance for tear growth after damage of the envelope in order to prevent propagation of a tear to a hazardous size. (See [AMC 31HB.27(c)](#_DxCrossRefBm388745761)) (d) The basket must be of a generally robust design and afford the occupants adequate protection during a hard or fast landing. There must be no design feature that by reasonably envisaged distortion or failure would be likely to cause serious injury to the occupants. (See [AMC 31HB.27(d)](#_DxCrossRefBm388745760)) (e) The design and strength of components (particularly the burner frame/load frame) must also consider the effects of recurrent and other loads experienced during ground handling and transportation. (See [AMC 31HB.27(e)](#_DxCrossRefBm388745759)) (f) The effect of temperature and other operating characteristics that may affect strength of the balloon must be accounted for. (g) Each item of mass that could cause an unsafe condition if it broke loose must be restrained under all loads up to the ultimate loads specified in this paragraph. The local attachments in the load path between the restrains and the structure should be designed to withstand 1.33 times the specified ultimate loads (See [AMC 31HB.27(g)](#_DxCrossRefBm388745758)): — Horizontal 6.0g, — Downward 6.0g, — Upward 2.0g. [Amdt No.: 31HB/1]