V2 and V2 min ???

[john_tullamarine]

At the risk of being labelled a pedant ... a few qualifications to Old Smokey's post, above.

1. the current FAR 25 rule is a bit more involved - Old Smokey is referring to earlier two-motor rules (737 etc)
   
2. for earlier certifications, 3/4-motor rules permitted a stall-limited V2 of 1.15Vs. Note that the V2min term isn't used in the earlier reg, but the end result is much the same.
   
3. if one looks up the current rule for anything (as I did in (a)), please remember that it doesn't necessarily apply to Aircraft X. If you need to research rules applying to a particular aircraft, the first place to go is the TCDS library to find out the certification rule basis for the aircraft, and then to the superseded rule section of the FAA website to get a handle on what rules applied. However, be aware that all certifications involve a bit of horse-trading between the applicant and the regulator so there may well be a few further differences which are not easily unearthed .. however, by reviewing the relevant FARs, you will be close to the mark.
   
4. the climb performance curve (against speed) is a bit like an upturned teacup with V2min well down on the slow side of best climb at the top. As the speed for V2 is increased above V2min, initially there is a comparatively significant improvement in climb gradient which then rapidly tapers off as the speed approaches the maximum performance level. The penalty is a BIG bunch of extra runway distance required so the end result generally is a modest speed range above V2min scheduled in the AFM. The distance penalty sometimes is made more extreme by the need to use low flap settings to get any significant benefit.