Originally Posted by
Uneasy Rider
Following on from Colibri49's posts further up the page, I quizzed the guys in Norway about the REDL incident when I did my L2 type rating. I was told the root cause of the accident was the break up of the 'critical mast bearing'. The guy actually went and got one from the stores to show us what it looked like.
Just for clarity.
The REDL accident was due to the failure or a 2nd stage epicyclic planet gear, not a "critical mast bearing". The gear broke up and one piece was dragged between the epi case/ring gear and the remaining gears which burst the case. Case failure caused the rotor torque to be transmitted through the lift struts which then failed.
The 225 and the 332L2 have a large amount of MGB commonality. The 225 main module is the same configuration as the 332L2 with some material / coating changes to various gear wheels. The epicyclic module on the 225 is common to the 332L2. The 332L2s conical housing is replaced by the 225s flared housing with the emergency lube system.