Never heard of this done before! They shipped an engine to Johannesburg, South Africa, from Sydney, thusly:
"We're undertaking this rare task to get our customers and our aircraft on their way as soon as possible — rather than shipping this engine across by boat or chartering a freighter aircraft," Qantas said in a statement.""
http://mashable.com/2016/01/06/qantas-extra-engine/#RoJ38ShCXmqr

"We're undertaking this rare task to get our customers and our aircraft on their way as soon as possible — rather than shipping this engine across by boat or chartering a freighter aircraft," Qantas said in a statement.""
http://mashable.com/2016/01/06/qantas-extra-engine/#RoJ38ShCXmqr