# Tower strike with latest versions of OpenFAST and IEA 15MW

**URL:** <https://forums.nlr.gov/t/tower-strike-with-latest-versions-of-openfast-and-iea-15mw/3024>\
**Category:** Computer-Aided Engineering Software Tools\
**Created:** [March 30, 2022, 8:20pm UTC](https://forums.nlr.gov/t/tower-strike-with-latest-versions-of-openfast-and-iea-15mw/3024 "2022-03-30T20:20:53Z")\
**Posts on this page:** 1\
**Showing post:** 35

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**Author:** ![Jason.Jonkman](https://dub1.discourse-cdn.com/nrel/user_avatar/forums.nlr.gov/jason.jonkman/32/3086_2.png) [@Jason.Jonkman](https://forums.nlr.gov/u/Jason.Jonkman)\
**Post date:** [May 6, 2022, 12:46pm UTC](https://forums.nlr.gov/t/tower-strike-with-latest-versions-of-openfast-and-iea-15mw/3024/35 "2022-05-06T12:46:57Z")

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Dear @Andre.White,

At certain yaw errors in the idling condition, a known blade-edgewise instability exists, e.g., as discussed in the following forum topic: [Designing for yaw errors using FAST - #7 by Jason.Jonkman](http://forums.nlr.gov/t/designing-for-yaw-errors-using-fast/1051/7).

Note that in the parked/idling condition, I would expect that you’d set the initial rotor speed in ElastoDyn to zero (`RotSpeed` = 0).

Best regards,

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