ReeferGuy wrote:

Long before the B1 and B2 there was the B52, B58, and B70.
That is why I asked.
Same deal as the fighters.

Up to 1962, the Air Force, Army and Navy each used their own aircraft
designation systems. In 1962, they had to adopt a common system (because
SecDef McNamara said so). This was essentially the same as the former USAF
system, but most of the numbering sequences were restarted at -1.

In most series, the initial numbers were used for redesignating existing
Navy and Army aircraft under the new system. In the F-series, all numbers
except one between F-1 and F-11 were former Navy planes. The first new
fighter designation after 1962 was F-12 (for the YF-12A prototypes). The
F-series numbers -13 (missing) and up have been listed elsewhere in this
thread. It's the same for bombers - the old series had reached B-70, but
was then restarted. However, there were no Navy bombers to redesignate, and
therefore B-1 remained open for allocation to the first new bomber design
after 1962.

And, BTW, please don't omit the dash ... it just doesn't look good ;-).

Hope this helps!

Andreas