Uplinker
The Boeing way is to add a fixed amount to Vapp as gust factor based on tower reported wind to ensure at least Vapp close to flare height and that is below the bug. It has nothing to do with winds higher up on the approach. However you carry this baggage during entire approach even when there is no gust. Also during approach when experiencing higher or lower gust factor the speed can drop below the bug or overshoot the target before recovering. This leads to excessive ATHR activity. GS mini concept doesn't target a Vapp but targets the ground speed based on tower reported wind. To achieve this it varies the Vapp when required to keep the GS constant which tends to vary due to instantaneous experienced gust throughout the approach. This reduces the thrust variations. In Boeing method if there's no gust during flare you carry extra speed, in GS mini you will only carry Vapp. Boeing method is gross correction, GS mini is real time correction. Landing distance depends only on the GS.
Last edited by vilas; 10th Jun 2019 at 11:30.