Will a helicopter sink upright?
My reason for the above question is that as a HUET instructor our organisation is constantly being bombarded by companies demanding that we practice this competency as part of the course.
My thoughts on the matter are that a helo will, in a well controlled autorotation situation with correctly functioning floatation and a relatively calm sea, remain upright. However if one of the favourable circumstances above are removed then in all probability the airframe will roll over.
The only scenario I can imagine of a helicopter sinking upright would be a controlled autorotation and failure of the floatation to inflate. My question though is whether or not it is feasable to sink in this attitude given the high centre of gravity? Also is it feasable that a main rotor blade striking the water would transfer torque forces through the airframe and twist it at least onto its side?
It appears that the design of the METS HUET system is driving the training competencies rather than what is statistically shown to be the oucome of a ditching.
Would appreciate views from anyone with HUET training or crews with ditching experience. Also where I can find any authoritative statistics on the subject.