CS-E 850 Compressor, Fan and Turbine Shafts

• ED Decision 2007/015/R found in: CS-E Amdt 5 - Engines (Dec 2018)

CS-E 850 Compressor, Fan and Turbine Shafts ED Decision 2007/015/R (See [AMC E 850](#_DxCrossRefBm1371447831)) (a) *Objectives.* (1) It must be demonstrated that Failures of the shaft systems will not result in Hazardous Engine Effects, except as provided in CS-E 850(a)(3). (2) It must be established that the shaft systems are designed so that Failures are predicted to occur at a rate not in excess of that defined as Remote. (3) If compliance with the objective of CS-E 850(a)(1) is not achieved for certain elements of a shaft, it must be shown that Failures of these elements are predicted to occur at a rate not in excess of that defined as Extremely Remote. (b) *Compliance.* (1) Non-Hazardous Shaft Failures. When it is claimed that Failures of the shaft systems will not result in Hazardous Engine Effects, a test will normally be required to demonstrate the consequences of these shaft Failures unless it is agreed that the consequences are readily predictable. (2) Hazardous Shaft Failures. In complying with CS-E 850(a)(3), the Failure rate of certain elements of shaft systems will be accepted as Extremely Remote, if: - (i) The shaft is identified as an Engine Critical Part and compliance is shown with [CS-E 515](#_DxCrossRefBm1371447573). and (ii) Their material and design features are well understood and are conducive to well established and validated stressing techniques. and (iii) The surrounding environment of the elements considered is such that it is accepted that a shaft Failure owing to this environment can be judged as sufficiently unlikely that the Failure mode can be discounted. This consideration of the environment must include complexity of design, corrosion, wear, vibration, fire, contact with adjacent components or structure, overheating, and secondary effects from other Failures or combinations of Failures. and (iv) In making the assessment described in CS-E 850(b)(2)(iii), any assumptions regarding the Engine installation are identified and declared in accordance with [CS-E 30](#_DxCrossRefBm1371447577). and (v) Experience with parts of similar design is assessed and taken into account as appropriate. [Amdt No: E/1]