Thanks John, very interesting info, I doff my cap..er I mean helmet at you! Yes quite right about the settling helmet lining leading to replacement on bike helmets. I remember many moons ago when I was on contract in RAFO (Sultanate of Oman), we complained about the new PC9M's ejection seat cushions, which for some reason felt not very confortable. Someone suggested sheep skins on the seat, Martin Baker came back swiftly with "that tiny bit of space, could mean the differewnce between just a bruised back, or a few crushed vertibrae...
