I set up a flight plan from Narita to Heathrow in the 787-8, but the plane has to do a dangerous pitch to climb and maintain altitude. Right now, it is holding altitude but losing speed, even with throttle 100%.

 

 

Bump

I fixed it. For future reference, the problem was the vertical speed. I held the vertical speed instead of the altitude, though the vertical speed hold kept me at 40000 ft