# What are the forces acting on the doors of the main landing gear?

When opening and closing the landing gear doors, what forces act upon them and how much power would the actuators need to exert upon the doors to open/close them mid-flight (assuming the landing gear cavity is not pressurised)? I haven't found anything on the actual doors in my research, only the landing gear itself, so I would appreciate some sources if you can provide them.

• Your question is probably too broad. It depends on the opening direction and the geometry of the doors itself. For the aerodynamic forces modeling them as flat plates is probably good enough, I wouldn't be surprised however if ground handling forces are the critical ones. – Gypaets Mar 5 '17 at 18:59
• I agree with Gypaets that this is going to be too broad for a definitive answer and will probably be closed as such if you can't boil it down to something more specific. There are many ways the doors can work. Some doors have separate actuators, some are mechanically attached to the gear extension mechanism. Some doors close or partially close after the gear is extended. It's going to be different for each aircraft type. – TomMcW Mar 5 '17 at 19:19

Aircraft have a maximum gear extension speed (V$_{LO}$, as in maximum landing gear operating speed), which is normally 1.6 times stall speed, so when the doors move, the dynamic pressure is rather low. Therefore, the forces during gear extension are not the only ones to check.