When did V1, VR, and speed bugs come into use?
I'm researching how flying methods changed over time. One development I'm interested in is the use of V1 speeds: 1) that a must go/ok to stop speed exists, 2) it should be calculated before each flight and depends on conditions, 3) the terminology of V1, V2, VR, etc.
WW2 bombers: Decision on whether to keep going was pure judgment, according to all the first-person accounts I have read.
V1 is mentioned in some DC-3 manuals from the 1950s, as a fixed /specified speed. As far as I can figure out, this is "incorrect," i.e. the correct V1 should always depend on weight and runway length, among other things.
What was the origin of formal calculations for V1 before each takeoff? Was it FAA/CAB mandated, or up to each airline?
Same questions for landing speeds VR.
And, when did speed bugs come into use? I've found several photos and an NTSB crash report that the DC-9 had a single speed bug, set by hand of course. The report was 1976. But for all I know, speed bugs could have been common 10 or 20 years earlier - I just have not found any references yet.
I've also seen mention of pilots carrying their own bugs with them, so they could add on additional ones.
Any anecdotes or other information would be appreciated, even six months from now. Thanks much.
Web site, with some discussion of this research among other things: Art2science.org