This is carrying 80 of the load blocks - with room to spare. It is a bit difficult to take off with such a heavy load, so this has VTOL nozzles to help. To take off, activate the VTOL engines with group 1. You can move the slider to the top to help gain speed if you like, but make sure it is back in the middle position by the time you reach the end of the runway. This gives a kick of upward thrust to get the nose off the ground, but you're going to want to kill it immediately after takeoff or it'll send you out of control. Once in the air and stable, you can go 100% throttle and hit supersonic speeds (especially if you switch the VTOL power on to give you extra thrust), or throttle back to about 30% for slower cruising. There's also a cargo door / ramp in the back of the plane, open it by activating group 2 and moving the VTOL slider down.