[TXnMA]

The RB-57F was a "whole 'nuther animal". The B-57 Canberra's wings were cut off at the nacelles, TF-33 turbofans were installed, and then "U2-like" extended wings were added outboard of the nacelles to increase the wingspan to 122 feet -- nearly 2X the length of the fuselage.

AFAIK, the true, classified "operational altitude" of the RB-57F (with the supplemental Pratt & Whitney J60-P-9 turbojets mounted) has never been declassified and published...

[chaosagent]

Yeah, these were mostly RB-57B’s with a couple of C’s. Spent almost a year in the early 70’s at Otis AFB, MA doing a IRAN on them. Never got to work on the D’s (106ft wings, J-57’s) or the F’s (122 ft wings, TF33’s)

The group of B’s we were working on had a bad habit of flying along and the entire tail assembly would just fall off. Ruins your whole day. So we were magafluxing and reinforcing everything.