Will Korean Air board a passenger connecting via ICN to NRT with a standby ticket to the USA on United?
Don't know the passenger's citizenship, but without a valid visa for Japan I doubt so.
With the Covid restrictions still in place in Japan, the current rules (using a UK citizenship here, but it shouldn't change much for others) are:
Admission and Transit Restrictions:
Passengers transiting through Tokyo (NRT) must transit on the same calendar day.
TWOV (Transit Without Visa):
Passengers with a confirmed onward ticket for a flight to a third country on the same calendar day. They must stay in the international transit area of the airport and have documents required for the next destination.
Passengers transiting through Tokyo (HND) or Osaka (KIX) with a confirmed onward ticket for a flight to a third country within 72 hours. They must stay in the international transit area of the airport and have documents required for the next destination.
Additional Information: Valid visas in expired passports are accepted if accompanied by a new passport.
Here you have two issues:
- The ticket is not confirmed since it's standby
- The onward flight is on another ticket and a different carrier, and airlines have been known to ignore such tickets.
So passenger would need a visa for Japan to be allowed boarding, and such visas are quite difficult to obtain these days.