QRH speeds

[supergimp]

I am a little confused as to when you can use the QRH V speeds. My understanding is that you can only use the QRH speeds when you have a balanced field situation with no obsticles, Is this correct?

[sudden Winds]

qrh speeds are a function of weight, temperature, press alt, and flaps. The qrh provides for wind component and runway slope corrections, this is of BFL. Other more complicated adjustments are provided, such wet and contaminated rwys, but now at this point you´re unbalancing the field.

If you refer to your dispatch manual, performance book, or airport analysis manual you´ll find performance limited MTOWs for temperature and wind, and you´ll also find the V speeds for every weight. Except for improved climb ops and wet rwy, you´ll see that the V speeds for every wt agree with the ones in the QRH.
Now, if there are any obstacles present, or if the runway is short, the performance limited wt will be lower, and consequently the V speeds will be lower.
Put it this way. You use the QRH to obtain the V speeds for your actual wt and you use the performance book to obtain your performance limited MTOW and to compare it against your actual, to see if you´re safe and legal to go.
Regards.

[supergimp]

Thanks sudden wind, that is a very helpful explination.