Originally Posted by
WHBM
I believe the aircraft had not yet been delivered to the UK. I visited Everett at the time and the new BOAC 747 fleet were lined up with concrete blocks hanging from the engine pylons, to maintain the structural loading.
The JT9D were in short supply because the early engines had a significant failure rate, and P&W could not keep up with overhauls.
NA, NB and NC were all delivered by mid year 1970.