Which V speeds to use?
Here's the scenario.
B737-400
Take-off weight 55T
The max we can lift out with bleeds on is 54.8T
Decision made to go bleeds off.
On this chart we can get 57T at full power and the associated speeds are
144 149 and 154 (just guessing those).
There is also a slight reduction available at 55.2 T with speeds 142 147 152.
Question; if the take-off is made at full thrust, at the take-off weight stated, bleeds off, which speeds do you use?
I had this scenario in Ausi just a few days ago and I wanted to use the speeds 142 147 152 because they were closest to our weight, my side kick wanted to use the higher speeds because that was the thrust setting we were using. Have I gone mad or do you use the speeds closest to but not lower than your weight?
The way I see it the aircraft weighs x amount and there will only be one set of correct speeds for that weight regardless of what thrust setting you use to get there....(acually V1 will change but not the other two). If you take it to the extreme and go full power in an empty aircraft your V speeds are def not going to be high like the full thrust limiting weight speeds......I'm not crazy am I?