Drug smugglers are buying disused airliners to fly massive amounts of cocaine across the Atlantic, it has been claimed.
US government investigators said South American gangs have struck deals to fly drugs to West Africa and from there to Europe.
One trafficker claimed he already had six aircraft flying. Another said he was managing five planes.
Big jets can cross the Atlantic virtually undetected because there is no radar in the middle of the ocean.
Experts say the air route is remarkable because of the distances involved and the complexity of flying the jets.
"The sky's the limit," one Sierra Leone smuggler boasted to a US Drug Enforcement Administration informant, according to court documents.
The UN Office on Drugs and Crime began warning about trans-Atlantic drug planes a year ago when a burned-out Boeing 727 was found in the desert in Mali. Drug smugglers had flown it from Venezuela, unloaded it and then torched the aircraft.
In some cases, executive jets have been used, including a Gulfstream II that landed in Guinea-Bissau in 2008 and another Gulfstream seized in 2007 as it tried to depart Venezuela for Sierra Leone.
In the last year, a flurry of arrests has begun shedding light on how the air routes work.
The cases are being prosecuted in a New York federal court because some of the cocaine was supposed to have been sent to the United States.