Does the question make any sense?
No. You have a most baffling and bizarre way of thinking... I believe this one will travel 'great circle' to Spotter's Balcony or Jet Blast at aproximately the speed of light.
However, in an effort to answer the question which I believe you were trying to ask, your 'height loss' or 'vertical distance' is given by this cunning formula, which I have devised especially for you on your journey to the centre of the Earth:
'height loss' = 3438NM x (1 - COSINE ('distance travelled' / 60)), which works for any distance travelled, whether part way round the Earth, completely round it, and even going around it as many times as you care to go round in circles.
The above formula assumed Degrees in the COSINE function. If you need to use Radians on your unbelieveably bizarre journey, then the following formula may be used:
'height loss' = 3438NM x (1 - COSINE ('distance travelled' / 3438))
Now, by return, would you kindly answer for me, what relevance this is to anyone, for any purpose whatsoever, please??!!!