Create a flight plan, use weight and balance and correct CG. The aircraft climbs great until about FL250. When trying to reach anything above FL280 and above, rate of climb starts to decrease as well as Airspeed. The higher it climbs the slower the airspeed gets and is unable to maintain any altitude. At that point, the aircraft begins to stall. When I first brought the program, it had no issues with getting to altitude. I have reinstalled the program 3 times with no sucess.
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Do you have any 787 mods installed?
Yes, the boeing 787 heavy division mod. However, it had the problem before I installed the mod.
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Fuel has weight to it. In fact it adds a LOT of weight. Pilots on long haul flights often will sit at a lower altitude for several hours to burn off fuel before they climb a couple more thousand feet to sit there for several hours to burn off more Fuel before they reach their final altitude where they just kinda coast for the rest of the flight. This, in a nutshell, is step climbing.
This is something real world pilots have to do when flying heavy aircraft. No the Heavy Division mod does not manage your step climbs for you, you will need to monitor your vnav page on the FMC and wait for the recommended FL to go up before resetting your MCP to the new, higher altitude.
What you are experiencing is known as the “coffin corner”. You noticed how the airspeed was dropping. The autopilot was continuing to increase the altitude by increasing the pitch. The AutoThrottle was on but there was insufficient power to keep climbing. As the autopilot continued to climb, the airspeed had to decrease. If you looked at the airspeed tape, you would see the airspeed dropping dangerously low to the stall speed. You should have noticed the “AIRSPEED TOO LOW” warnings in yellow. Most modern aircraft have stall prevention in their computers. This is why the aircraft started descending, to prevent a stall by pushing the nose down.
The maximum altitude or service ceiling was determined by test pilots flying the aircraft into the coffin corner. This isn’t a Boeing guaranteed altitude, it isn’t the safest altitude, and it definitely isn’t the optimal or most efficient altitude.
I’m sure you found the 787 to fly much better at a lower altitude.
Mine is not the same situation, when setting final altitude let’s say of FL300 with a light load the AC used to climb at 1800 ftpm to FL300. However, the Ac now willl climb to about FL200 and will level off and not continue to climb even if I reduce the climb rate 1000 ftpm. I understand the “coffin Corner” as it relates to stalls. If I try and increase the climb rate, then I start to get into a stall situation . The ac should be able to climb and reach alitiude given a light load and the engines with its thrust to weight power.
I’m not sure exactly what procedures you are using to only reach FL200. It is a known fact that with any autopilot using V/S mode to climb at a fixed rate of climb may cause a stall as the airspeed decreases. The autopilot trades airspeed for a fixed rate of climb. LVL CHG mode is preferable and safer because it avoids stalling by keeping the airspeed constant while decreasing the rate of climb. Eventually the rate of climb becomes zero but the airspeed keeps the aircraft flying. In other words an aircraft cannot climb at a fixed rate of climb at a fixed airspeed. This isn’t particular to the 787.
In addition manufactures program their flight computers with stall avoidance and other things to protect passengers, the aircraft, and the engines against human error. This software can change aircraft performance significantly, that is the aircraft isn’t flying according to the pilots expectations.
I’m not sure why you are having problems with the 787 as I fly it regularly at FL300 and above. I do have other issues with the 787. It is not problem-free.