Overspeed is the mechanism described in AD 0262 -
Analysis of the available elements from the incident
investigation shows that an oil fire in the High Pressure / Intermediate Pressure
(HP/IP) structure cavity may have initiated a sequence of events leading to
rupture of the drive arm of the IP Turbine (IPT) disc and subsequent overspeed
and burst of that same disc.
Other complications have no standing per rule of Occam's razor.
Last edited by firstfloor; 29th Dec 2010 at 14:43.