This thesis was conducted in the design office of “Blackwing SwedenAB”, a Swedish aircraft manufacturer. The mission is to study air loadson a mechanical retractable landing gear. This study is realised to verifyif the structure is resistant enough for a landing and find the retractionspeed of the system. To accomplish those goals, the thesis was realisedon site with a state of-the-art, research on technical solutions, handcalculations, ANSYS analysis and tests with validation by a companyexpert. Testing is part of the certification and results show the structureis strong enough to resist air loads but present also an unexpected result.All this work assures the stability of the structure for a safe landing butalso a need to redesign the leg for a stronger support at impact.