the basic physics are the same—B737-200 or C-5 and everything in between
Would love to hear anything further if you come across any detail ..
“Why?” “Well, let me explain.....”
Bit of a worry .. That's my main interest in Tech Log - we have an opportunity to discuss things which the minimalist training styles these days don't look at .. or, perhaps, don't have a clue.
Okay, in the sim, but why would I ever have used a V1 < VR?
Oftentimes, the numbers won't let you push V1 up to a comfortable value.
Consider the case of a min weight, min speed schedule with V1 down near Vmcg, decent crosswind .. and a critical failure. If the wind is from the wrong side, you're gone, no ifs, buts or maybes ... and it all happens super fast. In such a case, the pilot is faced with recognising that control has been lost and changing to an overspeed abort to salvage whatever might be salvageable.
The message we'd like to get across is this: if you are down near Vmcg with a strong crosswind, do have a think about pushing the V1 up (within the book range of figures) to give you a pad for the crosswind-driven increase in real world Vmcg. Alternatively, if you have the option, perhaps delay until the wind abates ?
The exception is when the terrain is challenging.
Even then, the gross/net fudge makes the continued takeoff preferable with typical terrain problems.
.. or the speed schedule is on minimum numbers and there is a stiff crosswind.
And yes, there's 2 seconds added for crew response time.
We need to keep in mind that the 2 second pad only applies to the more recent certifications. Older Types basically are raw data.