Lost of aircraft controls on 747-8

During a flight Paris-New York at 42000 feet, 270 knots, altitude and speed controlled by AP are lost. The plane loses its altitude and the speed decreases and I can nothing to do.

out of fuel?

I’ve had a similar situation. Turned out that my fuel level was high and the AP couldn’t sustain the altitude on nearly a full tank. I backed it up to a lower flight level, and stepped it up as the fuel dropped, my problem was solved. Right now, for example I’m on a 6,000 mile flight, I took off with 75% fuel load to FL310…have since stepped up to FL350…when my trim is down under 15% I will step up to 370 or 390 etc. Good luck

No, absolutely not.

I fly according to the most simple way of difficulty, with a 50% of fuel. With what grade of difficulty do you fly ? I continue to think, that this game is not being ready !

If we consider that the travel is of 5800 km and lasts 8 hours of pure flight, that means the plane flys at about 400 kias. Then in fact, at high altitude, the aircraft cannot fly more than 270 kias. There is a big problem, then at that speed, the 747 needs that its flaps be at least at 5%.

If you fly at 31000 feet, the air control has to call back you to increase your altitude for a travel of 6000 km ?

I just completed London to Jakarta. I started with 75% fuel. Not sure what you mean be grade of difficulty but if you are talking about assists, I don’t use them. Flaps should never be used at cruise altitude. If I set my initial altitude at FL310 in the nav log the ATC doesn’t have to call me back to increase the altitude. I wait until my fuel level drops and then contact ATC to request a higher altitude.

I think you need to read up on the difference between IAS (indicated air speed), TAS (true air speed), mach numbers, and GS (ground speed).

The higher up you are, the lower the IAS is, even if you’re going just as fast over the ground.

Have a google, there’s plenty of information out there.

what I want to say about grade of difficulty, figure in the chapter of “options” and" assistance", where it’s possible to choose the level of complexity of the flights.flys n
As to the flaps, when you fly at 260/270 knots on a 747, the plane doesn’t horizontally fly, but the nose slightly towards the top, one have to correct with a little bit flap, that is not normal in regular flight.

The nose on a jet is never level at normal cruising speeds. On most jets the pitch attitude is ~ +2°.
It can be noticeable higher at lower, long range or maximum range, cruising speeds.

So you had your flaps down? Even a bit, in high speed, ir can make the aircraft uncontrolable. You can test it starting a flight over the ocean and, then, apply some flaps and also throttle up…in a couple of minutes the aircraft will fall like a stone. Try it and check if the behavior of your aircraft at this test was the same as you faced during your flight

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