Jiří Čečrdle
DOI Number: N/A
Conference number: IFASD-2019-049
Submitted paper describes the methodologies of compliance with whirl flutter-related requirements of FAR / CS 23 and 25 regulation standards. Methodologies are demonstrated on the example of a twin wing-mounted engine aircraft. For the compliance with FAR / CS 23 standard, two approaches are used: 1) standard approach to comply with the main requirement (§629(e)(1)) and 2) optimisation-based approach to comply with the requirement of parameter variations (§629(e)(2)). Standard approach, in which analyses are performed sequentially (state-by-state), is good for the nominal state. Optimisation-based analysis is used to calculate stability margins, which are then used for evaluation of stability reserve in terms of specific parameters. For compliance with FAR / CS 25 standard, the additional requirements to analyse specific failure states and adverse condition states are described.