In Moed Katan daf 5: the gemara mentions tumas ohel as one walking over a corpse (or a large % of one). How high does this tumas Ohel extend?? Does flying over a corpse or jumping over one make one tomei as well??
This Tum'ah extends upward indefinitely (unless there is a cover over the corpse and there is a Tefach or more of space between the corpse and the cover), as the Mishnah in Ohalos says.
Flying or jumping over a corpse would make one Tamei. The Halachah follows the opinion in the Gemara that maintains that "Ohel Zaruk Lav Shmei Ohel" -- a flying Ohel is not considered a partition (between the Tum'ah below it and the people inside of it).
Indeed, the CHAZON ISH (YD 211:9) rules that nowadays, a Kohen may not fly in an airplane which will definitely be flying over a Jewish cemetery. RAV MOSHE STERNBUCH (She'eilos u'Teshuvos III:347) rules that a Kohen may fly in an airplane when there is only a doubt if the airplane will fly over a cemetery (he proves that in such a situation, we follow the principle of "Rov," and the majority of land over which an airplane will fly does not contain any corpses).