Indeed it was common. Quoting from the article: > Qantas has used the Boeing 747’s ability to ferry an extra engine in the past, most recently in 2011. Qantas

Indeed it was common. Quoting from the article: > Qantas has used the Boeing 747’s ability to ferry an extra engine in the past, most recently in 2011. Qantas used the method often with their Boeing 707s when engines were less reliable, but the procedure has become quite rare.