MW-50 Bf 109s Vs Fw 190 A

[GregP]

One point, Gaston. You seem to think the top of the prop arc moves backwards when the aircraft pitches up.

In reality, the aircraft is moving through the air very fast and all that happens is the top of the prop arc moves infintessimally slower forward than the bottom of the prop arc does. The only time the top of the prop arc will move backward is when the aircraft is a model in a wind tunnel which is stationary and the the model pitches up. That action is not scalable since the real aircraft is moving forward WAY too fast for the top of the prop arc to actually move backward. Rate of pitch is nowhere NEAR fast enough, even in a Pitt's Special or an Edge 540.

Please don't reply with some other part of your theory; your theory is wrong. When you are the only one who thinks something is possible, then there are only two possibilities. Either everyone else is wrong and you are the genius ... or the everyone else is right and you are mistaken. In this cases, since the airplanes fly as designed by people using conventional aerodynamic principles, you are most probably the one who is wrong in all reasonableness. Think about it. If the planes fly as designed, where are the aerodynamic formulas used to design them wrong when they depart from your theories? Hey, the WWII fighters fly very well ... when the fan in front is turning. When the fan stops, they descend remarkably well and remarkably quickly.

Keep in mind ... One out of every four people is crazy. Think of your three best friends ... if they're OK ... it's you.

And it doesn't matter if the wing bends within the design envelope ... it is designed to do that. All that matters is if the wing is overstressed to the point of plastic deformation or failure. If that happens, the formulas are not important ... the aircraft is damaged or has failed and it's nylon letdown time or time for a CAREFUL landing at low speed.

 

[Jenisch]

Hey Gaston, if you come to Brazil someday, contact me, I can take you to my flight school to you discuss with the intructors your theories. Then we can take you to a flight in order to you prove then. LOL!

 

[Gaston]

I believe there was also a lot photography work done, both movies and stills, of wings both on aircraft in flight and in wind tunnels. Wind tunnels used both the wool tuft and smoke to study air patterns while in flight tests used the wool tuft.
Some aircraft were tested with different airfoil sections on parts of the wing. I would think that somebody might have noticed if the lift,drag and airflow in all these experiments didn't go along with the calculated values. Or if it didn't that th e calculations were sometimes modified.

I did consider the implications for the extra wing bending causing extra drag: That puzzled me.

But there are two ways this could have escaped detection: First, if the effect in a turn has the same extent accross the board on all similar types, where is your reference point to know that extra drag is extra drag?

Yes they can calculate thrust to drag in a straight line, but my theory isn't about straight lines...

Second, propeller aircrafts have better low speed acceleration than comparable power contemporary jets: That is why steam catapults are essential to jets on aircraft carriers. This means that at low speeds, propeller aircrafts have more useable excess power to counter the drag, and in my theory reducing the power also reduces the wing bending, so it reduces the drag. But if you increase the power, then the prop's acceleration has a lot reserve to take on the drag compared to a jet.

You can see the effect on a jet of similar power and near-identical wingloading to a late Griffon Spitfire: The Vampire.

Quote: "The maximum speed obtainable with a Goblin II engine giving 3,000 lb. sea-level static thrust is 528 m.p.h. at 20,000 ft."

So that is less thrust than a 1800 hp prop fighter, and the 1946 Griffon Mk XIV Spits had much more than that, maybe they could even do +25 lbs by then...

In theory, in low speed sustained turns, the Vampire has even less power available because of lower incoming air intake speed, yet wingloading is nearly the same as a Mk XIV Spitfire: This means a Mk XIV Spitfire should out-turn it at low speeds, since it can apply full power in sustained turns, something which is robbed from the jet's intake by the turn-reduced speed...

What do you know: The Vampire out-turned the Mk XIV Griffon Spitfire in sustained turns in 1946, despite inferior acceleration:

Quote: "Just been reading Alfred Price's book Spitfire in combat and I have to say it is a lovely little potted reference work.

In it he detailed a performance evaluation between a Spitfire Mk XIV and a de Haviland Vampire Mk1. The Spit was superior only in initial acceleration, climb rate and apparently roll. Unsuprisingly the Vampire was superior in everything else but what did suprise me was that the Vampire could turn inside a Spitfire!"

Spitfire MkXIV vs Vampire 1 1946 - Key Publishing Ltd Aviation Forums


I am pretty sure the same thing would have turned up had any pusher-prop figther been extensively tested against a similar power-wingloading nose-pulled fighter: The fact that no such high-power pusher fighter ever saw extensive service is a clue as to why the disparity in nose-driven wingloading in sustained turns was never discovered...

As to the wing-flexing camera work during testing, look at it this way: US test conclusions is that the P-51B will get behind the P-47D needle-tip prop Razorback in 3-3.5turns... Russian tests conclude the same needle-tip P-47D Razorback is at 27 seconds, while they say the Bf-109G is at 22 seconds...

German tests conclude an underpowered needle-tip prop P-47D out-turns the Bf-109G: All combat accounts agree with them on multiple low-speed 360°s, and no one here has presented here ONE counter-example of the contrary. (I do know the later P-47D Bubbletop is not as good, and also that right or diving turns are comparatively not as good as well.)

For the early Razorback, either the Germans testers are dolts, or the US/Soviets testers are dolts: Make your choice!

Combat accounts indicates Allied testing procedures, in those days, were rather poor or even extremely poor at finding the unexpected, despite better testing circumstances... The US Navy tests of the FW-190As are particularly stupid in their conclusions, and indicate to me these people usually found exactly what they expected to find, which is not conducive to finding out something weird and unexpected... This is could extend to the camera work you mention, which was probably focussed on some specialized narrow purpose, a specific wing airfoil etc, not putting into question the sum of available knowledge...

Gaston

 

[GregP]

Gaston,

One more time, wing bending doesn't matter unless you overstress the wing. if you don't overstress it, the bending is as designed and is taken into account in the performance predictions. You are living in a dream world of sharp-turning, needle-prop P-47's and slow-turning Me 109's, coupled with delusions of mathematical copmpetence. GO GET AN AERODYNAMICS TEXT. The dolt is not the Germans or the Soviets; it is ... well, you can fill in the blank.

You link above is not a link to a report; it is a link to a quote by Phil Foster ... who is Phil Foster? Nobody I recognize as a expert in anything.

 

[Jenisch]

Gaston,

You are living in a dream world of sharp-turning, needle-prop P-47's and slow-turning Me 109's, coupled with delusions of mathematical copmpetence. GO GET AN AERODYNAMICS TEXT. The dolt is not the Germans or the Soviets; it is ... well, you can fill in the blank.

Dear Greg, you are probably not aware, but Mr. Churchill made a radio pronuncement today, where he vitally stated the following:

We shall ignore trolls in France, we shall ignore trolls on the seas and oceans, we shall ignore trolls with growing confidence and growing strength in the air, we shall ignore trolls in our forums, whatever the cost may be.

 

[Jabberwocky]

Found an extract from the test - taken from a jet out turning a spitfire?

"Turning Circles: The Vampire I is superior to the Spitfire XIV at all heights. The two aircraft were flown in line astern formation. The Spitfire was positioned on the Vampire's tail. Both aircraft tightened up to the minimum turning circle with maximum power. It became apparent that the Vampire was able to keep inside the Spitfire's turning circles. After four or five turns the Vampire was able to position itself on the Spitfire's tail so that the deflection shot was possible. The wing loading of the Vampire is 33.1lbs per sq. ft. compared with Spitfire XIV's 35.1 lbs per sq. ft.
...The Vampire will outmanoeuvre the Spitfire type of aircraft at all heights, except for initial acceleration at low speeds and in rolling.
... The Spifire XIV used in the comparison trial was a fully operational aircraft fitted with a Griffon 65, giving 2,015 h.p. at 7,500 ft. Vampire I had an operational take-off weight of 8,800 pounds, powered by a de Havilland Goblin 2 turbojet, developing 3,000 pounds static thrust."

Not really that surprising. Lower wing loading and more thrust, just like the flight text books would have it.

 

[GregP]

Thanks Jenisch, I have tried reasonableness to no avail and give up on Gaston. He has a very good imagination and could probably write very good fiction without the science part.

Like I said earlier, his theories are interesting even if wrong, but enough is enough, and I have had enough of them.

 

[Gaston]

One point, Gaston. You seem to think the top of the prop arc moves backwards when the aircraft pitches up.

In reality, the aircraft is moving through the air very fast and all that happens is the top of the prop arc moves infintessimally slower forward than the bottom of the prop arc does. The only time the top of the prop arc will move backward is when the aircraft is a model in a wind tunnel which is stationary and the the model pitches up. That action is not scalable since the real aircraft is moving forward WAY too fast for the top of the prop arc to actually move backward. Rate of pitch is nowhere NEAR fast enough, even in a Pitt's Special or an Edge 540..

The outer turn prop disc "half" (I put hyphens as it is just an illustrative term) is not accelerating during the initiation of the turn, so it is the inside turn prop disc half that is decelerating. It is thus pulled "back" compared to the trajectory, and where it would be along its path if the trajectory was straightened out, as it is difficult to compare a curved path to a straight line...

But the AoA has increased, which also means the prop is more off-center, if the curve was again averaged out to a straight line: Again, try lifting the one-side barbell straight up, or with that AoA slant: Big difference in effort to lift and maintain the equivalent to AoA "slant"... The longer the barbell handle the bigger the effort...

But on top of that, you must add that slower air is hitting one half of the prop vs the faster air on the other half, which means that, as you lift the barbell with a sideways AoA from the vertical, someone is slightly pushing sideways to reduce the AoA slant you try to maintain while lifting... And yet your hold is firm enough to nullify completely that sideway effort: That is a large achievement, with a correspondingly large counter-acting force implied.

Please don't reply with some other part of your theory; your theory is wrong. When you are the only one who thinks something is possible, then there are only two possibilities. Either everyone else is wrong and you are the genius ... or the everyone else is right and you are mistaken. In this cases, since the airplanes fly as designed by people using conventional aerodynamic principles, you are most probably the one who is wrong in all reasonableness. Think about it. If the planes fly as designed, where are the aerodynamic formulas used to design them wrong when they depart from your theories?

This is a classic authority argument.

Second, if WWII fighter airframes are typically designed for a safety factor of two (12-14 Gs before deformation, vs 6-7 Gs of safe use), there is plenty of room for my theory to be correct if the safety factor was unknowingly narrower than assumed.

Third, I am not the one ignoring significant test evidence (but truly overwhelming amounts of pilot accounts) that clearly shows the flight physics is completely wrong for these particular types of nose-pulled aircrafts...

For instance, no one has explained to me how an experienced 28 kill Me-109G ace could claim (not an exact quote, but accurate in substance): "Optimum sustained turning speed for the Me-109G-6 is around 250 km/h with the throttle reduced." In other words, barely 50-55 mph above stall...

Fourth, all the valid arguments that could have, at a stroke, destroyed my theory, turn out to be precisely what is missing from the evidence record:

1- Wing bending data while in turning flight, compared at various throttle settings, is not available for these type of old fighters (so far).

2- Pusher-prop aircrafts with similar characteristics were never available for extended combats or comparisons.

And then of course, probably the closest thing to a pusher prop WWII fighter that WAS used for a comparison, the Vampire Mk I, turns out unexpectedly to out-turn a Spitfire in sustained turns despite having less power, inferior acceleration and an inferior climb rate...

Maybe the wing bending data will prove me wrong in the end, but I have to say, from my point of view, I can't be impressed with points of view that won't even address the fact that the contradictions, from believable sources, are TOTAL.

IE: Tsagi: P-47D (Razorback needle prop): 27 seconds, Me-109G: 21-22 seconds VS "The P-47D (Razorback needle prop) out-turns our Bf-109G" (KG 200)

Or: US Navy test (paraphrasing): "This is mainly an interceptor best used in vertical combat" VS "Red Fleet" 1943 article on a concensus of observed combat behaviour: "The FW-190A will inevitably offer turning combat at a minimum speed"

Like I said, either one or the other is a complete dolt: The fact that these contradictions were not even really noticed, and never before even discussed in those particular counter-intuitive terms, says more about the usual consensus than about me...

Gaston

P.S: And for that minor 33 vs 35 wingloading value difference, do you know how large a turn difference is the Vampire reversing a tail position in FOUR 360° turns?: It means a gain of + 90° for every 360°.... That is pretty large for an aircraft with much less power... G.

 

[Shortround6]

Gaston,

the very idea that the Vampire had less power than the Spitfire just shows how far from reality you really are.

try figuring out how thrust and power work in a straight line and in a straight climb before trying to figure out turns.

 

[tyrodtom]

You keep saying the Vampire had less power, absolutely incorrect. A pound of thrust is equal to more than 1 horsepower at 400 knots or what ever speed this contest took place. The Vampire Mk I had 3300 lb of thrust, the Griffon powered Spitfire 1800 hp? The Vampire had more than twice as much power.

There's a formulae for converting pounds of thrust to horsepower, look it up Gas Ton.

 

[FLYBOYJ]

 

[DerAdlerIstGelandet]

I think we need one of those "...for Dummies" books.

 

[Siegfried]

There are some formulae here that will help. For a Jet engine the equivalent power can be calculated as:
P = F x v (power = Force x velocity). The usnits are SI metric
P = Power in watts
F = Force in Newtons (approximetly 98 grams of thrust)
v = velocity in meters/sec

Loss in propellor efficiency needs to be considered.

The equivalent thrust of a prop aircraft can be calculated by rearranging

F = P/v.

The basic understanding that comes from this is that jet thrust remains constant irrespective of speed while the equivalent thrust a propellor aircraft can provide falls of inversely proportional to speed.

Another result is that because drag increases with the square of velocity then cube root law applies to speed increase with prop aircraft.

To double speed in a prop aircraft would require a 8 fold increase in power.
To double speed in a jet aircraft would required a 4 fold increase in thrust.

Note that piston engined aircraft can have a lot of jet thrust, about 300lbs for a two stage Merlin 66. A Jumo 213E maybe 448lbs (about 200kg).

Technically thrust in engines is now declared in kP (kilopond) as KG is a unit of weight caused by gravity not a unit of force. On the earths surface 1KG produces 1KP of force.

 

[FLYBOYJ]

The outer turn prop disc "half" (I put hyphens as it is just an illustrative term) is not accelerating during the initiation of the turn, so it is the inside turn prop disc half that is decelerating. It is thus pulled "back" compared to the trajectory, and where it would be along its path if the trajectory was straightened out, as it is difficult to compare a curved path to a straight line...

And have you considered the prop is bending AND producing lift (thrust) while this is going on in your mind???

But the AoA has increased, which also means the prop is more off-center, if the curve was again averaged out to a straight line: Again, try lifting the one-side barbell straight up, or with that AoA slant: Big difference in effort to lift and maintain the equivalent to AoA "slant"... The longer the barbell handle the bigger the effort...

But on top of that, you must add that slower air is hitting one half of the prop vs the faster air on the other half, which means that, as you lift the barbell with a sideways AoA from the vertical, someone is slightly pushing sideways to reduce the AoA slant you try to maintain while lifting... And yet your hold is firm enough to nullify completely that sideway effort: That is a large achievement, with a correspondingly large counter-acting force implied.

And you base this comment of yours on ????

This is a classic authority argument.

Second, if WWII fighter airframes are typically designed for a safety factor of two (12-14 Gs before deformation, vs 6-7 Gs of safe use), there is plenty of room for my theory to be correct if the safety factor was unknowingly narrower than assumed.

Third, I am not the one ignoring significant test evidence (but truly overwhelming amounts of pilot accounts) that clearly shows the flight physics is completely wrong for these particular types of nose-pulled aircrafts...

For instance, no one has explained to me how an experienced 28 kill Me-109G ace could claim (not an exact quote, but accurate in substance): "Optimum sustained turning speed for the Me-109G-6 is around 250 km/h with the throttle reduced." In other words, barely 50-55 mph above stall...

Is it because you fail to relize that stall speed INCREASES with bank angle???? At what bank angle??????

Fourth, all the valid arguments that could have, at a stroke, destroyed my theory, turn out to be precisely what is missing from the evidence record:

1- Wing bending data while in turning flight, compared at various throttle settings, is not available for these type of old fighters (so far).

2- Pusher-prop aircrafts with similar characteristics were never available for extended combats or comparisons.

And then of course, probably the closest thing to a pusher prop WWII fighter that WAS used for a comparison, the Vampire Mk I, turns out unexpectedly to out-turn a Spitfire in sustained turns despite having less power, inferior acceleration and an inferior climb rate...

Maybe the wing bending data will prove me wrong in the end, but I have to say, from my point of view, I can't be impressed with points of view that won't even address the fact that the contradictions, from believable sources, are TOTAL.

IE: Tsagi: P-47D (Razorback needle prop): 27 seconds, Me-109G: 21-22 seconds VS "The P-47D (Razorback needle prop) out-turns our Bf-109G" (KG 200)

Or: US Navy test (paraphrasing): "This is mainly an interceptor best used in vertical combat" VS "Red Fleet" 1943 article on a concensus of observed combat behaviour: "The FW-190A will inevitably offer turning combat at a minimum speed"

Like I said, either one or the other is a complete dolt: The fact that these contradictions were not even really noticed, and never before even discussed in those particular counter-intuitive terms, says more about the usual consensus than about me...

Gaston

P.S: And for that minor 33 vs 35 wingloading value difference, do you know how large a turn difference is the Vampire reversing a tail position in FOUR 360° turns?: It means a gain of + 90° for every 360°.... That is pretty large for an aircraft with much less power... G.

My god, there is so much jibberish there I don't know where to start!

 

[Jenisch]

Gaston,

the very idea that the Vampire had less power than the Spitfire just shows how far from reality you really are.

]

 

[drgondog]

quit feeding the troll - it's bad for (your) digestion.

You really have to give him a hand. How many guys have drawn so many knowledgable members of this forum down ratholes with his talented but unmitigated bovine fecal matter?

Each of us has been introduced to more mangled terminology than even the late great jimmy Durante, Casey Stengle or Yogi Berra were able to collect over 50 years.

 

[GregP]

Spot on Drgondog, and at just the right prop-to-tail ratio! Can't help it, that one just cracks me up!

 

[FLYBOYJ]

Prop to Tail Ratio - the ratio between the diameter of a propeller when compared to the size of the tail. This measurement includes the tail wheel as it sits in on a dirt strip that has just had a smooth layer of cow manure spread over the measuring area.

 

[GregP]

You can only spread the manure if the rear end moves backwards momentarily and the if the center of crap drops for a microsecond to become craptacular.

 

[wuzak]

Surely the CoC (centre of crap) has to collapse for a micorsecond, with the loading on the wings by multipled by a factor of 3 due to the prop to tail ratio, the wing deflections cauing microgaps in the panels so that as the turn tightens the crap gets squeezed out?