[elwesties]

There is also the question of relative airspeed. Planes need to create enough lift to stay in the air. With a large tailwind they need to go faster to keep enough air flowing over the wings thus higher ground speed to keep the same relative air speed.

[histriosum]

This is a common misconception, but very much incorrect. I am a private pilot.

When an airplane is in a body of air which is moving across the ground, the airplane moves within that body of air with no knowledge that it is in a strong wind. Airspeed is unaffected, except for gusts or shear events. The airplane maintains it's normal airspeed within that body of air, even though that body of air is moving very quickly in relation to the ground.

This is evident in all phases of flight. For example, landing into a strong headwind does not change the approach speed required or the thrust required to obtain that approach speed. The only allowance is for gusty conditions, during which a gust will momentarily affect airspeed due to the inertia of the airplane. The heavier the airplane, the more time it takes a gust or shift to defeat the airplanes inertia.

[Filligree]

I'm confused. Are you saying that it'll maintain its normal ground speed despite flying through fast-moving air? Or that it maintains the same air-speed?

The former doesn't make any sense, but the latter is what the GP was saying.

[maweki]

The original comment seems to mean, that the plane has to (actively) keep a larger ground speed in high winds while the reply meant that this just naturally happens as the plane is only "aware" of its relative air speed.

[histriosum]

The ground speed will vary, but the airspeed will not be affected by wind (except momentarily for gusts or shears).

The poster I replied to was implying that due to the strong tailwind, they had to maintain an increased airspeed. That is incorrect. The airplane has no idea it is in a tailwind, and airspeed will be unchanged.

[dTal]

I think the root of disagreement here is that to you, as a pilot, "speed" means airspeed. But to a layperson, "speed" means groundspeed. So saying that an airplane with a tailwind "must go faster to keep enough air going over the wings" reads very strangely to you, as (although it is technically correct) it belies a groundspeed-first type of thinking that is a poor intuition for staying alive in a plane.

[pdonis]

> The poster I replied to was implying that due to the strong tailwind, they had to maintain an increased airspeed.

No, he wasn't. He explicitly said the opposite:

"higher ground speed to keep the same relative air speed."

[danaliv]

I think the confusion here is stemming in part from the fact that "relative airspeed" isn't a well-defined term. In aviation airspeed means the speed of the airplane through the air (modulo specifiers for true vs. indicated vs. calibrated airspeed).

[pdonis]

> "relative airspeed" isn't a well-defined term

The original was "relative air speed", which I would simply take as the way a person not familiar with aviation terminology would say "airspeed"--speed relative to the air.

[JshWright]

I don't think anyone other than you interpreted the comment that way.

[mritun]

I did. Saying “everyone” when it’s just probably one person is not usually ok. It’s fine to say if you interpreted the comment in a certain way, and ok to be the outlier. But assuming your interpretation applies to others more broadly than it does, is counterproductive.

[JshWright]

Both comments were significantly downvoted at the time of my comment, which was what I was referring to. The original comment explicitly mentioned "relative airspeed", which I thought was pretty clear (it's the speed of the plane relative to the air that matters).

I think calling it a "common misconception" is also assuming a lot.

[sibartlett]

The first answer is correct, but I think the misunderstanding is because it can be read as the higher ground speed being the cause for the same relative air speed. Whereas it’s technically the opposite.

This is further compounded when they say “they need to go faster”, as though the pilot needs to push the throttle harder. In actuality, the pilot doesn’t do anything differently to maintain their normal cruising speed.

The correct phrasing would have been the relative air speed and high wind speed combined, to result in a higher ground speed.

[CMCDragonkai]

Glider pilots will add half of windspeed to their landings.