re CAA Icarus air accident report:

Note that, despite the historical explanations for this accident and the CAA
conclusions, independent 'Brtish investigations at an earlier date have
suggested that a more plausible failure mode may have been wax embrittlement
dur to low temperatures at altitude. See end of report below for more
details on this.


      R



2010/1/1 Vitaliy <piclist@maksimov.org>

> http://www.messybeast.com/dragonqueen/icarus-accident.htm
>
> Excerpt from the report:
>
> "The novel composite structure of the aircraft was known to be the subject
> of physical restrictions on operating temperature. These restrictions had
> been carefully explained to the pilot before the flight. When the pilot
> climbed to a higher altitude the levels of ambient solar radiation probably
> led to these temperature restrictions being exceeded, resulting in a
> thermal
> degradation of the basic structure.
> A progressive failure would have occurred, initial delamination of the
> upper
> skin material would have been be followed by a compressive failure of the
> upper mainspar. Brazier forces would then have extruded the internal wax
> core material leading to a catastrophic failure of the entire primary
> structure. This theory would help to explain why the second aircraft (at a
> lower altitude) experienced no such failure."
>
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist