Aircraft suddenly losing power

I just had the same issue again and this time I noticed the events: At least this time my aircraft suddenly went from 60% to 100% throttle when the winds started to change. The thing this time was that only the direction started to change and the velocity of the winds stayed the same. The throttle also only went up to 100% for a few seconds this time, so I am not sure if this was the same issue as the one I described in the topic initially, but this time the sudden throttle increase was the result of a starting (because the wind direction only starts to slowly change) wind change by a few degrees.

Direction of the wind changes is equal to wind speed change.

I also sometimes have this, throttle goes up for 1 sec to 100% for no reason at all

I have a very clear memory of this happening on ascent after take off. I watched as the wind direction changed steadily around from almost a direct headwind at take off to a direct tailwind. Autothrottle had to go to 100% because as the wind direction changed my IAS couldn’t keep up with the speed setting.

But this doesn’t make sense

when a wind direction slowly changes (yk how slow it changes in IF) and the wind speed stays the same, it makes 0 sense that the aircraft applies 40% more throttle for maybe 2kts difference at that exact moment, especially because it goes back to 60% before the end of the change, hence windspeed change is over.

Whenever the wind changes, the airspeed/AOA changes, hence the need for more or less power. Wind direction change means HW speed change.

40% for 2kts wind difference ?!?!?!

I am not saying this. My point is only to explain that wind speed or wind direction changes are equivalent as far as flying is concerned.
Other than that, flying at a safe altitude avoids most stalls, but yes, there can be weird moments wind wise in IF.

Can be, if and when way below the power curve, yes.

This time I was at 10k feet though (in a B787 with 65% weight)

If climbing, the VS matters. I set power and adjust VS manually during climb. This helps a lot, particularly since when a risk of stall arise, VS is where to act, not power…

Had the same thing happened to me yesterday from LA to New York on the 777. While cruising the autothrottle went to 100% from 70% and stayed there for a couple of seconds. I shrugged it off assuming it had to do something with the wind or turbulence.

I can vouch this strange phenomenon earlier today when on ascent shortly after take off at HAAB.
Departure speed was within normal limit (KIAS 190) due to relative high attitude at airport but then the wind direction started to change 180°and so the KIAS began to drop quite dramatically and was on point of stalling even on a relative low V/S 1500 climb rate. I applied throttle over 100% N1 with little effect and had to lower down to V/S 500 before the KIAS speed began to increase.
I have departed many times from this airport - primarily fly for ETVA and its the first time i’ve encountered this issue.
It was A350 and total weight was in region of 55%
I then proceeded to climb to FL400, within the weight specification without any issues.

It depends on different factors such as the aircraft, the actual wind speed and how fast the direction changes.

When I watched as my climb headwind became a tailwind I was in something like an a330 without much safety margin. The change in direction wasn’t so slow (if I remember correctly). 100% throttle to keep up.

I was trying your scenario in solo at 10k in a 787 at a mid range weight with 30kt vs 50kts head wind changing direction to more of a tailwind. You can see the 100% throttle up right away by playing off different wind heading changes vs wind speed.

A higher wind speed means even a slower change in wind direction can trigger a big throttle move.

It was 8kts though, so what I definitely know: not enough to justify this reaction. I myself have quite a lot of IF experience and I never experienced this in my 2,700 flight hours before until recently.

It’s certainly possible I could be talking apples and oranges about the cause. I assume by 8kts you’re referring to total wind speed. Clearly that is quite low. Of course the only way to nail down the scenario is to find a way to reproduce it or capture it on video.

I tried once more: 787, 10k feet, keeping headwind at 8kt. My heading was 0 degrees and headwind was directly out of that direction.

When I changed the wind direction slider to 45 degrees I didn’t see the auto throttle jump. But around 65 degrees or so or more, and it throttles up quite noticeably.

So if you say you know it was 8kts and wind direction was changing very slow or not at all, then it must have been something else.

On the A330 its kinda normal tho A330 in game is awfully weak

Yeah, it was at the speed the wind changes after a wind update in IF. Maybe 2 degrees per second