I believe there were two B747-200s that UA
purchased from another company that had better range..perhaps equipped with PW
JT9D-7R4G2 engines specifically assigned to do JFK
. I may be wrong on this but they were pretty much B747-300 engines mounted on a B747-200.
The other B747-100/200s that UA
owned were early models that lacked in range/performance to make such trip. NRT
were pretty much the best they could do..JAL and NW
had a few of these late model B747-200s also with improved engines specifically to do East Cost-NRT
before B747-400s were available.
[Edited 2004-09-14 19:42:30]