Some UPS and FedEx planes are grounded. What does that mean for holiday shipping?

The tails of three UPS aircraft are shown parked at Miami International Airport in Miami in 2020. Some UPS and FedEx planes are grounded after a UPS plane crashed.

UPS and FedEx's fleets of MD-11 planes are grounded, which can each carry thousands of packages. Logistics experts say some cargo could shift to passenger planes, trains and trucks.

(Image credit: Wilfredo Lee)