Hello everyone, just a quick question on the takeoff data analysis, I made a normal real southwest flight from KMCO to KDAL, all fine as normal but I noticed on the LIDO format in the runway data information I already get the takeoff speeds, however when I go to the takeoff calculation option after creating the flight, the takeoff speeds are very different, not sure why the flight plan will show some numbers and the calculation tool will differ, please if anyone can explain, I tried to add pictures but is not possible; here u go
Flight shows V1 142 VR 143 V2 149
Takeoff tool shows 145 146 152
one showing assumed temp of 48 and the other one 49
The winds in the 2 calculations were different. Because the METAR winds at the time were variable (VRB), the 2 tools returned slightly different wind values when auto-populating.
Not sure what the real tools would do, but I’ve heard it’s typical for pilots to plan the “worst case scenario” with variable winds, i.e. basically use the opposite of the runway track as the wind heading (so variable winds at N knots translate to an N-knot tailwind).
Perhaps it makes sense to apply the same logic here?
Although then the “populate weather” would need to read the runway selected in the corresponding drop-down and adjust the direction accordingly (in case of variable winds), which would make the implementation a touch more complex?
Yes exactly. Maybe down the road, but for now I’ve updated it to use the general TAF wind direction when variable winds are reported (in most cases this will be close to reality).
