Airspeed Indicator Me262 -no TAS, it is Groundspeed!

[Otto_SH]

Hello,

 

i noticed there is a mistake with the airspeed indicator in the ME262.

It should display the True AirSpeed (TAS) of the aircraft when flying in the upper speed ranges.

 

I noticed while flying at high altitude in very strong wind condition, the speedindication changes with the direction of flight.

If you fly into the wind, you get a lower indication than flying with a tailwind, while the indicated airspeed in the HUD stays the same.

So i assume, the displayed value is not TAS, it is groundspeed.

There are three types of Airspeeds relevant for flight.

IAS - indicated airspeed: Just the air pressure measured with a probe converted to a matching speed, it is indicated by a conventional airspeed indicator

TAS - true airspeed: the real speed of the air moving around the aircraft. It is calculated from IAS with a correction for less dense air at higher altitude.

                                     The aispeedindicator in the ME262 did this correction.

Groundspeed: the speed the aircraft moves over the ground. Only in this speedindication the wind speed is included.

 

Historically there was no method to show the groundspeed on an instrument in an aircraft in the second world war ... today we measure it with GPS.

 

I would really appreciate if this mistake will be corrected in an upcoming update .. it is an annoying mistake, if you fly in the real world and notice, that this is

posed incorrectly in this otherwise great simulation.

Greetings, Otto_SH

 

Edited December 29, 2019 by Otto_SH

[=EXPEND=13SchwarzeHand]

Actually Il2 got it right

Basically IAS measures your speed relative to the air around you. As a result your IAS doesn’t change whether you go with or against the wind. This may sound counterintuitive first, but thin of it that way:

 

Assume some theoretic speed produced by your engine which is 100kph.
The wind is going at 30kph

Against the wind: The wind blows you back by 30 kph so you are traveling 70kph. The pressure in the pitot tube will show 100kph sind you move at 70 and wind blows in the Tube at 30.

With the wind: imagine you are going with the wind. Your speed will be 130kph, however the air around you is also going 30kph leaving you with the above 100kph.

 

So I think the sims got it simulated correctly.

 

You can google it, I’m sure someone can explain it better than me.

 

 

finally if you think about it, it cannot show speed over ground, since this is the figure that should vary when flying with or against the wind

Edited December 30, 2019 by =EXPEND=13SchwarzeHand

[SCG_OpticFlow]

12 minutes ago, =EXPEND=13SchwarzeHand said:

Actually Il2 got it right

Basically IAS measures your speed relative to the air around you. As a result your IAS doesn’t change whether you go with or against the wind. This may sound counterintuitive first, but thin of it that way:

 

Assume some theoretic speed produced by your engine which is 100kph. The wind is going at 30kph

The wind blows you back by 30 kph so you are traveling 70kph. The pressure in the pitot tube will show 100kph sind you Movie at 70 and wind blows in the Tube at 30.

Now imagine you are going with the wind. Your speed will be 130kph, however the air around you is also going 30kph leaving you with the above 100kph.

 

So I think the sims got it simulated correctly.

 

You can google it, I’m sure someone can explain it better than me.

 

This doesn't contradict what OP said. His point is that in your example the instrument in the 262 would show 70 or 130 kph depending on wind and he wants it to to show 100.

[=EXPEND=13SchwarzeHand]

Sorry, I think I misread OP the sorry and thanks!

Edited December 30, 2019 by =EXPEND=13SchwarzeHand

[=EXPEND=13SchwarzeHand]

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Edited December 30, 2019 by SYN_Haashashin