Nearly 450 horses are crossing the Atlantic from Europe in a 14-day window from September 16.
Another 19 are flying from Australasia, taking a circuitous route around the Pacific rim, and 35 are flying from South America.
All will spend a minimum of 42 hours in quarantine before being released to compete in the Games, which get under way tomorrow.
The European horses face a nine-hour journey, with grooms aplenty to take care of their every equine whim.
The flying grooms have been supplied by Peden Bloodstock, the firm responsible for arranging the air charters.
Head groom Tim Rolfe has overseen six Olympic and five World Equestrian Games airlifts.
He said the grooms must spend many months in training for such journeys, in many ways similar to the training of commercial airline cabin crews.
The horses' in-flight diets include hay and an excellent selection of equine nibbles, including nuts, oats and bran.
"Business class" for horses means more room in each airborne stable. "Economy" class means three horses in each purpose-built container, while business class allows for two horses per container. "First class" means the horse gets a container all to itself.
Word is that one horse is going first-class all the way, but its identity is unknown.
Equine ticket prices range from €8500 to €13,000.
Pilots take extra care on the flights, aiming for smoother takeoffs and landings. Braking is much slower on landing and the angle of climb on takeoff is deliberately kept lower.