Author: Chieu Nguyen
The puzzle consists of 16 flights, each between two airports indicated by their 3-letter IATA codes, along with a distance in kilometers. If sorted by the first airport code (as is given), then the first letter of the second airport in each pair forms part of a message: these spell out ANSWER IS YOUKILIS.
In four of the flights, the distance given is exactly the great circle distance between the two airports, but in the others, the distance given is much shorter than the real distance ... it is actually half the circumference of the Earth minus the real distance. In the pairs where there is a discrepancy, the two distances add up to about 20,000 km; there is some variation here because the Earth is not exactly a sphere and is slightly wider than it is tall.
|IATA code||Location||Latitude||Longitude||Actual distance (km)||Given distance (km)|
|BLT||Blackwater, Australia||23.60° S||148.81° E||16069||3942|
|ASI||Georgetown, St Helena, Ascension and Tristan da Cunha||7.97° S||14.39° W|
|CFG||Cienfuegos, Cuba||22.15° N||80.41° W||1459||1459|
|NOB||Nosara, Costa Rica||9.98° N||85.65° W|
|DJB||Jambi, Indonesia||1.64° S||103.64° E||17665||2340|
|SNU||Santa Clara, Cuba||22.49° N||79.94° W|
|DOH||Doha, Qatar||25.26° N||51.57° E||4776||4776|
|WAM||Ambatondrazaka, Madagascar||17.80° S||48.43° E|
|DOP||Dolpa, Nepal||28.99° N||82.82° E||16337||3689|
|EZE||Ezeiza, Argentina||34.82° S||58.54° W|
|GVR||Governador Valadares, Brazil||18.90° S||41.98° W||15138||4869|
|ROK||Rockhampton, Australia||23.38° S||150.48° E|
|KDM||Kaadedhdhoo, Maldives||0.49° N||73.00° E||17041||2963|
|IPC||Hanga Roa, Chile||27.16° S||109.42° W|
|KHW||Khwai River Lodge, Botswana||19.15° S||23.79° E||3185||3185|
|SRH||Sarh, Chad||9.14° N||18.37° E|
|MAO||Manaus, Brazil||3.04° S||60.05° W||16162||3846|
|YGJ||Yonago, Japan||35.49° N||133.24° E|
|NAW||Narathiwat, Thailand||6.52° N||101.74° E||5478||5478|
|OHE||Mohe, China||52.91° N||122.43° E|
|PIU||Piura, Peru||5.21° S||80.62° W||15562||4444|
|URC||Ürümqi, China||43.91° N||87.47° E|
|PMR||Palmerston North, New Zealand||40.32° S||175.62° E||16628||3379|
|KAN||Kano, Nigeria||12.05° N||8.52° E|
|SHC||Shire, Ethiopia||14.08° N||38.27° E||15995||4013|
|ITO||Hilo, United States||19.72° N||155.05° W|
|TND||Trinidad, Cuba||21.79° N||80.00° W||18578||1455|
|LEA||Exmouth, Australia||22.24° S||114.09° E|
|TWU||Tawau, Malaysia||4.31° N||118.12° E||17271||2760|
|IOS||Ilhéus, Brazil||14.82° S||39.03° W|
|XMH||Manihi, French Polynesia||14.44° S||146.07° W||16111||3900|
|SMS||Sainte Marie, Madagascar||17.09° S||49.82° E|
This suggests that the flights are not connecting points on the surface of the real spherical Earth but rather on the surface of an alternate Earth that is topologically a projective plane (also hinted in the flavortext), specifically the one where every point on the surface of the real Earth is equated with its antipode, the point on the opposite side.
Plotting these paths on a map of the alternate Earth yields a message, seen here in an azimuthal-equidistant projection:
It is also possible to plot the paths on the surface of the real Earth, but replacing points with antipodes so that all the paths end up on the same hemisphere, or to plot two paths for every path, one on each hemisphere.
Since there is no inherent orientation to the projective-plane Earth, there is an additional arrow to confirm the message, due to the possibility of reading it upside-down, flipped, and/or out of order. The intended message (and the title of the puzzle) is MIAMI, and the arrow points roughly to the city of Miami, Florida, United States.