[FIXED INTERNALLY] Wind not accounted for in flight model and display.

To evaluate the performance of an aircraft(speed, climb, turn rate, energy), we use True Airspeed.

No. Climb rate, turn rate, stall speed etc. is usually measured in CAS/IAS/EAS not TAS.

You still haven't understood aerodynamics, the related physics and you are still throwing navigation into the equation which doesn't belong there.

IMO you weren't more clear. Rather the opposite. To me it was confusing and wrong as usual. I really don't understand why you keep discussing without knowing the basics about aerodynamics and aviation terminology.

But if we are talking about navigation all the time! Sorry but navigation isn't moving somewhere for you? The talk was not born about the FM?

I'm still waiting to know your answer to the two questions i asked, nobody has yet answered but everyone continues to separate from my example (except Deano87) only the aerodynamic part, and thanks! so it is obvious that there is no difference between airspeed and wind.

The questions were:

2 different cases. No WCA.

First case, make a pass over the runway at maximum speed.(pointing the nose steadily towards the center of the runway)

Second case, do the same passage at minimum speed.(pointing the nose steadily towards the center of the runway)

How does it change in general or how does the FM change?

The questions were:

2 different cases. No WCA.

First case, make a pass over the runway at maximum speed.(pointing the nose steadily towards the center of the runway)

Second case, do the same passage at minimum speed.(pointing the nose steadily towards the center of the runway)

How does it change in general or how does the FM change?

If you want an answer, just read my previous post: https://forums.eagle.ru/showpost.php?p=4197183&postcount=100

To evaluate the performance of an aircraft(speed, climb, turn rate, energy), we use True Airspeed, not Ground Speed. Ground speed is mainly for navigation.

If you "hover" in a 200 kts head wind, cut your thrust and you will get negative ground speed. If you use ground speed for kinetic energy caculation, you will find it's increasing. That's not correct. You must use True Airspeed, which is decreasing.

Yes, it is not correct because a plane never flies backwards. Of course, in the example I have done, the thrust must not be cut. Negative groundspeed is energy, in this case cutting the trust has the same effect on True airpseed as doing it with a groundspeed of 200kts but without wind.

NO, and NO again.

According your flawed theory the energy is zero, hence and aircraft shouldn't be able to climb at 0kts groundspeed, which is obviously wrong.

An aircraft flying at 200kts indicated airspeed in a headwind of 200kts does NOT have zero energy despite a ground speed of 0kts!!!!!!!!!!!!!!!!!!!!!

Dude read better, we are talking about vertical climb 90 degrees up.

And yes 0 groundspeed is equal at 0 kinetic energy (if we take our earth as the center of the universe)

of course

Zero ground speed means 0 energy(material point=kinetic energy), regardless of the airspeed.

400 ground speed means energy much > 0, so in this case we have a vertical energy ..

Sorry but you didn't answer

2 different cases. No WCA.

First case, make a pass over the runway at maximum speed.(pointing the nose steadily towards the center of the runway)

Second case, do the same passage at minimum speed.(pointing the nose steadily towards the center of the runway)

How does it change in general or how does the FM change?

Yes, it is not correct because a plane never flies backwards

According to you explanation which always includes ground, aircraft can of course fly backwards!

50kts TAS/IAS (which is the same at low altitude), 100kts headwind = -50kts groundspeed.

No. Climb rate, turn rate, stall speed etc. is usually measured in CAS/IAS/EAS not TAS.

CAS/IAS/EAS is mostly for dynamic/structural strength/load caculation, not performance.

If you use IAS for turn performance, you will get a circumference of 360 degrees turn less than 2pi*radius.

...we are talking about vertical climb 90 degrees up.

And yes 0 groundspeed is equal at 0 kinetic energy

NO!!!! The climb angle is completely irrelevant. It doesn't matter if it's 9 or 90deg. In both cases you need excess energy to be able to climb.

CAS/IAS/EAS is mostly for dynamic/structural strength/load caculation, not performance.

So all flight manual performance tables like climb & turn performance & stall speed etc. are useless?

No. Climb rate, turn rate, stall speed etc. is usually measured in CAS/IAS/EAS not TAS.

And yes! becouse CAS tell you what type of air you are invested in but your groundspeed so your energy does not depend on the CAS therefore all the maneuvers at 90 degrees vertical to the wind take this energy into account.

NO!!!! The climb angle is completely irrelevant. It doesn't matter if it's 9 or 90deg. In both cases you need excess energy to be able to climb.

If in the example we were at 0kts groundspeed with a headwind of 200kts this means that the engines are pushing, it seems obvious to me. If the engines push more than the weight then yes that goes vertical up otherwise no, but this was not part of the example.

... your groundspeed therefore your energy does not depend on the CAS

Wrong again. It's exactly the other way round. GS depends on IAS/CAS/TAS but IAS/CAS/TAS does NOT depend on GS.

Flying at e.g. 400kts IAS will always result in the same energy, regardless of GS.

If you pull up into a 90deg climb at 400kts IAS, the climb rate will be always the same, regardless if the GS is 200, 400 or 600kts.

According to you explanation which always includes ground, aircraft can of course fly backwards!

50kts TAS/IAS (which is the same at low altitude), 100kts headwind = -50kts groundspeed.

Please don't cut the rest of the part. Sure it can but if we are talking about an f-16 with 200kts headwind he can easily push and go beyond the 0 groundspeed.

Which pilot in reality would be carried backwards by the wind?

So all flight manual performance tables like climb & turn performance & stall speed etc. are useless?

IAS is very useful for pilot to handle the aircraft. But it's useless for performance ralated like energy analysis, BFM tactics etc. You'll never care about your enmey's IAS in combat, but only his TAS.

Please don't cut the rest of the part. Sure it can but if we are talking about an f-16 with 200kts headwind he can easily push and go beyond the 0 groundspeed.

 

Which pilot in reality would be carried backwards by the wind?

Try the AV-8.

Please don't cut the rest of the part. Sure it can but if we are talking about an f-16 with 200kts wind he can easily push and go beyond the 0 groundspeed.

You are disregarding my example only because it doesn't fit into your wrong picture?

Ok, I give up. Luckily it occurs rather seldom that someone is so stubborn. This is costing me way too much time and it's apparent that you are not even willing to consider changing your flawed view of the world/aerodynamics and their relationship.

I've promised myself to leave this thread many pages ago....I should have stuck to my decision.

You'll never care about your enmey's IAS in combat, but only his TAS.

Corner speed is in TAS?

Wrong again. It's exactly the other way round. GS depends on IAS/CAS/TAS but IAS/CAS/TAS does NOT depend on GS.

Flying at e.g. 400kts IAS will always result in the same energy, regardless of GS.

Ok let me understand what you mean. Are you saying that, maintaining the same engine power, an aircraft with headwind 200kts and GS 0kts, vertically climbing is the same as another plane with tailwind 200kts and GS 400kts?

Corner speed is in TAS?

Corner speed is for pilot to maneuver. To evaluate how good the aircraft turn, you must use TAS.

Ok let me understand what you mean. Are you saying that, maintaining the same engine power, an aircraft with headwind 200kts and GS 0kts, vertically climbing is the same as another plane with tailwind 200kts and GS 400kts?

Yes, finally, he got it!

IAS is very useful for pilot to handle the aircraft. But it's useless for performance ralated like energy analysis, BFM tactics etc. You'll never care about your enmey's IAS in combat, but only his TAS.

Exactly. CAS is a "calibrated" airspeed, eg when flying at 30000ft at 250kts CAS, the CAS is much lower than the TAS and if you go vertically you can go up a lot comparing it with a 1000ft TAS, for that it is used as a parameter of energy.

Corner speed is in TAS?

Yes, because it affects the centrifugal force, if i understand what you mean by corner speed, that affects the FM. I'm sorry we don't understand each other.

Corner speed is for pilot to maneuver. To evaluate how good the aircraft turn, you must use TAS.

This doesn't make much sense IMO in your mentioned combat scenario. Furthermore if both aircraft are at roughly the same altitude, TAS will be the same for both at the same IAS. So what would be the point to know TAS?

Especially when maneuvering close to, or at the edge of the envelope, I'm much more interested in IAS than in TAS.

if i understand what you mean by corner speed

Corner speed is defined as the minimum airspeed at which the maximum allowable g can be generated.

Corner speed is defined as the minimum airspeed at which the maximum allowable g can be generated.

And that's IAS/CAS. From an aerodynamic POV the aircraft doesn't care about TAS at all.

This doesn't make much sense IMO in your mentioned combat scenario. Furthermore if both aircraft are at roughly the same altitude, TAS will be the same for both at the same IAS. So what would be the point to know TAS?

Especially when maneuvering close or at the edge of the envelope I'm much more intereste in IAS and TAS.

For e.g. CAS is useful for the pilot to know when he will stall, how much lift his wings will generate ect.. but does not tell him what energy his aircraft has, it does not tell him how much space he will be able to travel in a certain time ect..