Why are we not talking about this...

[jpe828 624]

The decrease in airspeed when entering clouds. Go ahead. Try it. Take a Bonanza, or Caravan... and go into an overcast layer. The speed will fall. Sometimes up to 10 knots. The rate of climb will fall. Then, when you break out the speed and rate of climb shoots up. No, it is not icing. Set the temperature at 20 celsius if you like. Does not seem like it is on anyones radar, but it is really annoying. 

[bobcat999 8,444]

I thought that was realistic behavior.  The temperature and density inside clouds is different, that is why, if you are in an airliner, you can feel the aircraft 'surge' as it enters the cloud, as the air is denser.

 

 

[MorrisMinor 47]

I have noticed this, and assumed it was due to density, although the difference would not be great compared to clear air. Maybe a real life pilot can clarify this? 

[bobcat999 8,444]

6 minutes ago, MorrisMinor said:

I have noticed this, and assumed it was due to density, although the difference would not be great compared to clear air. Maybe a real life pilot can clarify this? 

I think it is quite significant.  The water vapour density is what holds the energy, and causes the turbulence in the clouds, updraft/downdraft etc.  Thunderstorms are just a movement of that trapped kinetic and electrical energy, and it is stored in the water vapour, not so much the air in itself.

Edited December 20, 2020 by bobcat999

[RichieFly 728]

I've seen this and, yeah, it's bogus. There may be a micro change in TAS in actual flight, but it would be undetectable to the pilot. The atmospheric differences between a cloud and not cloud is infinitesimal.

I just chocked it up to yet another weird aspect of MSFS. What I don't recall is if it happens every time, in every cloud.

[Johnny19 344]

So by this logic, a car would decelerate on the road when you enter low clouds or fog while driving. Clouds are not that dense to cause a slowdown of a moving object. 

[dilore 126]

Since clouds are made of cotton one would expect a decrease in velocity.

[bobcat999 8,444]

I just checked the science, and most sites say that wet air is LIGHTER than dry air, which seems counter-intuitive, but apparently is due to the molecular size of the water molecule compared to Oxygen and Nitrogen molecules (which combined make up about 99% of the air of course).

So the surging feeling you get when an airliner (real life) enters and leaves clouds can be due to this density change, but it seems it is the other way around to what I suspected.

I have definitely been in strong updrafts and downdrafts inside large clouds in MSFS, so my feeling was that this is programmed in. 

Interesting subject raised by the OP!  I suppose Asobo would be interested in answering this in one of the twitch sessions, especially if it is something they have built in (such as the turbulence by mountains etc.)

Edited December 20, 2020 by bobcat999

[bobcat999 8,444]

6 minutes ago, Johnny19 said:

So by this logic, a car would decelerate on the road when you enter low clouds or fog while driving. Clouds are not that dense to cause a slowdown of a moving object. 

No.  That is not a reasonable extrapolation of the logic.  The speed difference between an aircraft and a car, and moving in air rather than on a road, would make the difference. 

Air acts like a fluid at greater speed, and the higher the speed, the greater the resistance, and it isn't proportional.

Put your arm out of a car at 80 mph and you will feel the resistance.  Try that at 160 mph and prepare to lose your arm! 😁

However, like I said above.  It seems wet air is less dense, because 'Science'.

Edited December 20, 2020 by bobcat999

[StoreyedTrain 13]

Mach goes down at same throttle when you get higher and therefore in thinner air.

 

Ergo denser air makes you able to put more pressure with your prop or jetengine, so denser should be faster ??? (i would think)

Ofcourse until the density resistance on the wings + fuselage starts overruling the "grip" of the propulsion.

[bobcat999 8,444]

Well now going back to the OP's point.  It seems clouds are slightly less dense than dry air (the opposite to what I originally thought).

If this is the case, then with less dense air there will be less power, and less lift (such as at a higher altitude, or a high altitude airfield), so what we are seeing is possibly realistic physics programmed in to the sim, and it would correct as the OP sees it.

There is no other reason for it otherwise, as the sim must detect the aircraft in the cloud, and it responds with realistic changing of conditions.  Maybe a bit overdone like the icing effect though.

Like I say, it would be a good question for MS/Asobo at the next twitch feed.  

 

Edited December 20, 2020 by bobcat999

[WestAir 2,522]

Could be climbing through layers. Climb through clear air into a cloud layer with 10kts crossind, then climb out back into clear air with a returning crosswind.

As for actual density and pressure change, that's not a factor in real life, unless the cloud is part of a front or line or mountain wave or whatever.

[mtr75 653]

Because nobody cares about clickbait thread titles. 

[G550flyer 1,011]

Not accurate. As others have said, you will feel some bumps as you enter but shouldn't notice speed changes unless you are hitting a temperature inversion or a shear. You will be able to see some inversions as the clouds will be flat near it as if the cloud can't rise above it. You can notice the shear too as part of the cloud will appear blown out or stretched out. They can also appear like waves. Clouds do have an effect on aircraft performance, but not to that extent. When climbing in FLCH type modes, you will notice the aircraft will pitch when hitting those temperature inversions. That's when I hit the vert speed mode and return to FLCH after the speed recovers.

[Stona 39]

Perhaps a real pilot can share there lived experience flying into a cloud and resolve this discussion!