that really did need the curvature of the earth to climb and a clearway of about 20 miles
Performance was always better with a westerly wind as the 'curvature' came towards you quicker than with an easterly direction takeoff.
Ah them's were the days. No perf A. Yank it off the ground and flattened it out to get above VMCA ASAP. Then breath a sigh of relief, again.