Before revision: Later designs attached a forward propeller underneath the protruding bow, as the typical rear propellers were incapable of effectively steering the ship through the ice Air travel Rime ice on the leading edge of an aircraft wing , partially released by the black pneumatic boot .
After revision: Later designs attached a forward propeller underneath the protruding bow, as the typical rear propellers were incapable of effectively steering the ship through the ice Air travel Rime ice on the leading edge of an aircraft wing .