Some points:
1. Press the engine button until all five engines are on;
2. The plane is heavy and underpowered, so take a time before it accelerate.
3. I modified the contact points. Please use this values:
[contact_points]
point.0=1,-15.68, 0.00, -4.60, 6153.30, 0, 0.62, 48.54, 0.30, 2.50, 0.72, 5, 5, 0, 0, 0
point.1=1, 8.14,-31.40, -8.60, 6153.30, 1, 0.62, 0.00, 0.40, 2.50, 0.72, 5, 5, 2, 0, 0
point.2=1, 8.14, 31.40, -8.60, 6153.30, 2, 0.62, 0.00, 0.40, 2.50, 0.72, 5, 5, 3, 0, 0
point.3=2, -1.66,-51.66, 1.33, 1574.80, 0, 0.00, 0.00, 0.00, 0.00, 0.00, 0, 0, 5, 0, 0.00
point.4=2, -1.66, 51.66, 1.33, 1574.80, 0, 0.00, 0.00, 0.00, 0.00, 0.00, 0, 0, 6, 0, 0.00
point.5=2,-50.00, 0.00, -0.66, 1574.80, 0, 0.00, 0.00, 0.00, 0.00, 0.00, 0, 0, 9, 0, 0.00
point.6=2, 18.00, 0.00, -3.33, 784.32, 0, 0.00, 0.00, 0.00, 0.00, 0.00, 0, 0, 4, 0, 0.00
static_pitch=8.19
static_cg_height=9.00//10.83
gear_system_type=0