A kohain “may not fly with El Al if there is a [dead body being carried] on the plane, as there is no way of knowing for sure if it is being wrapped the correct way for shipping. Therefore, a Kohen must check before flying to make sure that there is no Niftar on the plane.”
Kohains Asked To Not Fly El Al From Israel To The US Due To Fears Of Improperly Packaged Dead Bodies In Cargo Holds
Shmarya Rosenberg • FailedMessiah.com
Kohains – people descended (in theory but rarely in fact) from the priests who served in the biblical temples in Jerusalem – are prohibited from flying El Al planes from Israel to the US unless they first determine that no dead bodies are in the plane’s cargo hold being shipped back to America for burial.
That decision was made by Rabbi Yecheskel Roth, who works with the haredi Misaskim organization in Brooklyn, better known for preventing autopsies in suspicious deaths that could have been murders or manslaughters than it is for their actual mission of providing burial and shiva assistance to grieving families.
Roth’s decision was made after a body arrived from Eretz Israel before Shabbat packaged in a way “that would make it non-permissible for a Kohen to fly according to Halacha,” Yeshiva World reported.
Roth decided that a kohain “may not fly with El Al if there is a [dead body being carried] on the plane, as there is no way of knowing for sure if it is being wrapped the correct way for shipping. Therefore, a Kohen must check before flying to make sure that there is no Niftar on the plane,” Misaskim said in a statement.
This problem only exists on El Al flights from Israel to the US and not the other way around, Misaskim continued, “as we are constantly checking [here in the New York metropolitan area] to see that it is done correctly [when bodies are flown to Israel for burial].”
Kohains are prohibited from having contact with dead bodies of Jews or from being in the same enclosed space with such dead bodies due to the "spiritual impurity" those dead bodies are thought under halakha (Orthodox Jewish law) to possess. That "spiritual impurity" is believed to be able to transfer through the air of enclosed spaces and also by direct physical contact like touching.
El Al has its own haredi rabbis who oversee its kosher food and other related religious issues – including the transportation of dead bodies.