Best Climb Speed Con't for Nashwan

[mw]

Hi Nashwan:

Documents I have on the Spit I show the following (below FTH its fairly linear):

Increasing climb speed from 160 mph EAS to 175 mph EAS costs about 28 ft/min in climb rate. Increasing climb speed from 160 mph EAS to 200 mph EAS costs about 315 ft/min in climb rate.  This would suggest that increasing the climb speed on a Spit IX from 170 IAS to 182 mph IAS would have a negligible effect on climb rate.

[Crumpp]

Increasing climb speed from 160 mph EAS to 175 mph EAS costs about 28 ft/min in climb rate. Increasing climb speed from 160 mph EAS to 200 mph EAS costs about 315 ft/min in climb rate. This would suggest that increasing the climb speed on a Spit IX from 170 IAS to 182 mph IAS would have a negligible effect on climb rate.

Yeah by dropping the climb angle and adjusting your location on the power curve.  The FW-190 can do the same thing.  Just look at the USAAF test's against an F4U and a F6F.

Crumpp

[Karnak]

Crump,

As I posted earlier, this is the only way that I can see what you're saying making sense:

Or are you saying the the Spitfire can match the climb rate, but cannot keep a gun solution as the Spitfire needs an angle of, say, 16 degrees to match the climb at 182mph whereas the 190 has an angle of 14.5 degrees? So if the Spitfire sets the angle to 14.5 degrees for a gunsolution, the Spitfire's climb rate is less than the 190's. Is this what you're driving at?


What I am trying to say here is that at 182mph the Spitfire can climb at a faster rate than the Fw190, but cannot keep a gun solution because to do so, or even match the Fw190's climb, the Spitfire needs a greater AoA than the Fw190 is using for it's best climb rate.  The Spitfire can lower it's AoA to the same as the Fw190, but then the Fw190 will climb away from the Spitfire.


You previously said this was wrong.  I was wondering if you could deconstruct it.  Where am I wrong?

[mw]

Come to think of it, it follows that a Spit IX matching a 190's best climb rate would have sufficient speed to run the the 190 down.

[Crumpp]

Come to think of it, it follows that a Spit IX matching a 190's best climb rate would have sufficient speed to run the the 190 down.

That is specifically what we are talking about.  And No it's not happening.  The Spitfire just cannot maintain the airspeed to catch the 190.


Karnack

The 190's best climb speed is 182 mph.

The Spitfires best climb speed is 170 Merlin 66 (+25)

http://www.fourthfightergroup.com/eagles/jl165.html

I am saying that the Spitfire cannot directly follow an FW-190A in a climb and hope to catch him.

They are traveling on the same vector but the 190 is moving along it at a faster speed.

Now this only works at the 190's best climb rate and below.

If the spitfire STOPS moving along the 190's direct vector and pulls the much sharper angle he is capable of climbing.  THEN he will end up above the 190.

If he keeps his nose pointed at the 190 then the 190 will soon be above him.

Again, I am not trying to sound arrogant, so please forgive me. I am also not wondering, speculating, or guessing.  I am correct on this.  I am just frustrated I cannot explain it well enough for you guys to understand what I am saying!

Or are you saying the the Spitfire can match the climb rate, but cannot keep a gun solution as the Spitfire needs an angle of, say, 16 degrees to match the climb at 182mph whereas the 190 has an angle of 14.5 degrees? So if the Spitfire sets the angle to 14.5 degrees for a gunsolution, the Spitfire's climb rate is less than the 190's. Is this what you're driving at?

He might be able to trim his angle of attack to match the 190's and still climb on the same vector.  He might be forced to climb at a completely different AoA.  I suspect he does simply because different planes and different numbers. That is much harder to prove than the climb speed vs angle.  However it is not like he will simply be able to lift the nose and shoot.  Maybe in the artificial world of AH.  In reality he would have things like Phugoid Oscillation (comes from changing conditions of flight) to deal with. Things that could make getting a shot an unlikely event.


http://www.av8n.com/how/htm/aoastab.html#sec-phugoid

Crumpp

[Karnak]

Originally posted by Crumpp
If the spitfire STOPS moving along the 190's direct vector and pulls the much sharper angle he is capable of climbing.  THEN he will end up above the 190.

If he keeps his nose pointed at the 190 then the 190 will soon be above him.

That is exactly what I said way up in my edit and you said I was wrong.  At least that is what I meant and it is what I meant in my repost when I tried to reword it as it remained the only way I could see what you were saying actually working..

Originally posted by Karnak:
What I am trying to say here is that at 182mph the Spitfire can climb at a faster rate than the Fw190, but cannot keep a gun solution because to do so, or even match the Fw190's climb, the Spitfire needs a greater AoA than the Fw190 is using for it's best climb rate. The Spitfire can lower it's AoA to the same as the Fw190, but then the Fw190 will climb away from the Spitfire.

This says exactly the same thing.

Am I correct in understanding what you are saying?


EDIT:
As a clarification, if the Spit points his nose directly at the 190 and wants to maintain 182mph the Spit will have to throttle back and the 190 will climb away even faster than if the Spitfire simply matched the 190's AoA.  In any case, matching the 190's AoA at 182mph means that the 190 will have a greater rate of climb.

The Spitfire still has the option of leveling off and attempting to use a zoom climb to get a brief gun solution on the 190, it simply cannot maintain an indefinate gun solution on the 190.

[justin_g]

And what my graph is trying to show is that if the Fw 190 is climbing at its best climb speed of 182mph, the Spitfire has enough excess climbrate at that point that it can sacrifice climbrate for greater speed, so that it moves down the back of the power curve until it reaches a point that matches the angle of the Fw 190 but with a GREATER VSI and IAS = Spitfire outclimbs Fw 190 while flying on THE EXACT SAME ANGLE.

The Spitfire will be able to do this until its power curve intersects and falls below the Fw 190 power curve, which on my graph is at about 280mph - probably too high, it should be more like 250mph as GODO pointed out, or 260mph as in Nashwans graph(which is showing the same thing but with straight lines).

If the Spitfire COULD NOT climb with the Fw 190 at speeds over 182mph(ie: intersected its power curve at this point), it would have a top speed of about 250mph which is obviously wrong. This was pointed out before IIRC.

[bozon]

Originally posted by GODO
The real point is that changing the current best climb for 190A5 from 159 to 182 mph will give it a much larger range of speeds where it can outclimb and outrun (BOTH) spits or any other slower plane. The effect would be much more noticeable with D9. Current 190A5 is outran and outclimbed (BOTH) by the "old" spitV at most useful speeds and climb rates.

actually I belive this would be of a benifit to the A5. Even a P47 will outclimb a spit V  - if they fly at 300 mph.

For an energy fighter like the 190A5, if he's trying to extend from the spit, the quickest way to gain both seperation and E advantage is a high speed shallow climb. If the spit tries to follow he'll eventually loose the E game. The spit's only option is to break the chase and climb.

Bozon

[bozon]

Karnak,
you were correct from the beginning. the only thing that matter is what is the spit's sustained climb rate is at 182mph.

for a gun solution, AoA or where the nose or the mounted guns, or the pitot tube are actually pointing is irrelevant. This is a 2D problem - velocity vectors don't have to be alligned, they can be parallel. If the spit needs to fly at a higher AoA (actually he'll be flying at a lower AoA at 182 than at 160mph, but I don't want to start a new argument here) he just need to be parallel and lower to the 190.

position is the only thing that matters, not allignment - you can consider the planes to be perfect round flying balls with an arbitrary power curve)

Bozon

[Crumpp]

LMAO

The spitfire does not climb at 182mph.  The spitfire's best climb speed is 170 mph!!!


The 190 has the faster best clmob speed at 182mph.


Now both A/C can move along the power curve and increase their speed.

However, as long as the 190 stays below his best angle of climb he will be faster than the spit.  The spit cannot directly follow him.  If he does the 190 will soon be above him.

Crumpp

[bozon]

Originally posted by Crumpp
LMAO

The spitfire does not climb at 182mph.  The spitfire's best climb speed is 170 mph!!!
 

let me get this straight - you are trying to claim the spit cannot maintain a 182mph climb ?!

look at the plots justin_g and nashwan posted. if they are true, they clearly indicate that the spit can follow and gain on a 190 in a sustained climb up untill 260 mph or so. just look at the graphs, no need for aerodynamics or weblinks or calculations - it's speed vs. speed plots clear and simple.

Bozon

[Crumpp]

let me get this straight - you are trying to claim the spit cannot maintain a 182mph climb ?!

No bozon, I am not.

Please read the whole thread.

Crumpp

[Crumpp]

look at the plots justin_g and nashwan posted. if they are true, they clearly indicate that the spit can follow and gain on a 190 in a sustained climb up untill 260 mph or so. just look at the graphs, no need for aerodynamics or weblinks or calculations - it's speed vs. speed plots clear and simple.

Pyro thought the FW-190A had the exact same Best Climb speed as the Spitfire.  It is not and he is going to change it.   So until he does our 190 does not climb correctly.  

Plane modeling is not HTC's priority right now.  

Crumpp

[Angus]

So at 182 mph, the 190 will pull out.
At a snails pace though

[MiloMorai]

How much does the climb rate of a Spit LF IX (@ +18lb, @ +25lb) decrease when increased to the Fw190A-8's best climb speed?

Are the speeds in IAS or TAS?