The nose cone if fully extended would close the nose inlet during take off. During flight, the nose cone would withdraw inwards, opening the inlet to allow the air in. That's how I suspect it might work.
We read & hear nothing but preparation for War and hostilities by the major powers with new weapons, missiles etc. Introduced. It is real unfortunate as the people will suffer, in fact if there is a WAR nuclear weapons will be used which means total destruction of countries. Important to talk TRADE & DIPLOMACY & not being belligerent or lying or inconsistent. NO country can win in a nuclear war. May 2020 & beyond be a Peaceful Year for all people & countries. “PEACE & GOODWILL TO ALL” (hopefully if possible).