Hello Folks I'd like to know if anyone of you guys know how to calculate the gforces in a glider (in this case helicopter) during maximum performance acceleration? Tonight I had a very serious discousion with a relative of mine who doubt that it's possible to accelerate from 0 to 140 kts within 3 seconds. His argument was that it's unplausible due to too much g-forces. I have to admit that I counldn't seat on the "jump seat" but I could glimpse at the MFD (artificial horizon) of the "captain" during this maneuver. I could see that we climbed to aproximatly 500 fts. agl (above ground level) within 5 seconds. There after the PIC (pilot in comand) dived 30° to 35° nose down for aproximatly 3 seconds to accelerate from 0 to 140 kts (~260 kmh). Right now I'd like to know tow things. First of all why I couldn't feel any sort of acceleration at all and secondly what would be the exact formular behind it (please with detailed eplanations). To be honest it was the same feeling which I had during the acceleration in a glider. By the way my body where afected with lateral g-forces while my head has been exposed to transvesre g-forces during the last second. I'd like to thank everyone of you in advance for your replies. Best Wishes Chris_L PS.: First of all I want to say that I'm not a native English speaker and secondly due to my school system I never could take serious physics lessons so please bear with me and thirdly I don't know if this question would be either an basic or advanced question.