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I was really scratching my head with that one! If I read that correct if equal to or below that line, you could hold a level turn?
Also, regarding true airspeed and corrected airspeed, which is accurate? I assume corrected...
When you say propeller advance ratio, you mean pitch right? Regardless, normally I would be inclined to say "engine power only affects sustained agility", but with propellers, the slipstream does augment lift itself, so that is actually important.
Mach effects don't just affect the wing and tail surfaces, but the propeller too, the same for exhaust thrust (ram compression).
Roll rate is highly important actually...
From what I read, with the top Bf 109 pilots the "fun" didn't start until the slats extended. It was then just a question of skill and nerve.However, FWIW: the 109 pilots I knew said that an Emil/etc could stay with a Spit at typical altitudes/airspeeds if the 109 driver was willing to fight in buffet with the lats extended..
Unfortunately if you do that you will have lost all your energy and speed and would be a sitting duck if there are other enemy aircraft nearbyFrom what I read, with the top Bf 109 pilots the "fun" didn't start until the slats extended. It was then just a question of skill and nerve.
It is way above my pay grade on aerodynamics but I was under the impression that the deployment was dependent on the wings angle of attack, in a combat situation no more or less dangerous than for an opposing Spitfire for example as the speeds were about the same.Unfortunately if you do that you will have lost all your energy and speed and would be a sitting duck if there are other enemy aircraft nearby
This is my favorite graph on this subject.
http://www.spitfireperformance.com/spit109turn.gif
Please note the variations in turning times, speeds, diameters. also note the line marked "angle of straight climb" as it pretty well defines the ability to turn without losing altitude. It pretty much explains why turning fights rapidly descended in altitude.
To me the imaginary absurdity, held by many, is that in WW2 there were huge numbers of pilots who engaged in a turning radius combat. and the loser watched the victor closing in over a series of turns and then got shot down. Malans rules of air fighting stated, do not fly straight and level for more than thirty seconds, circling around for a period of minutes is even worse.I don't particularly care if the chart isn't 100% accurate. I knew that it was a mathematical construct.
However it points out the absurdity of trying to pick one "test" such as the time to turn a 360 degree circle (especially with both speed and radius/diameter unspecified) and use it to decide which plane turned better. Or to try to come up with a "simple" equation/formula based on wing loading or some other basic parameter.
I would also note that the chart is figured for 12,000ft and that the ability to sustain a turn is tied to the surplus/excess power available.
Different wings are going to have different "lift" at different altitudes affecting the turning circles and since the surplus/excess also varies (by a greater amount) with altitude sustained turns are going vary considerably with altitude.
They are also going to vary considerably between different models of the same aircraft if the engines vary in power by much.
Personally I regard the whole report as....well... I`ll give you another quote and leave it for you to decide.
"The tests have shown that as a fighter the Me109 is in general inferior to the Hurricane or Spitfire"
I'll take a look if I get the chance (I'm starting another criminal justice course -- I should major in this).Advance ratio is airspeed (ft or meters per second) divided by (diameter (ft pr meters) times rate of rotation(rev/sec); pitch is chosen from advance ratio. For more about prop parameters, see 11.7 Performance of Propellers
Actually at the corner velocity, the plane could sustain around 7g, which would put it above the sustained turn rate of the MiG-21. The problem was the corner velocity was like 420 knots, and the MiG-21's was in the 300-knot range. The F-102's were about the same, the F-106 was probably somewhat higher (10-15 knots) because it had a heavier air-frame on a similar wing (the early F-102's has a wing of 661 square feet, later on 695; the F-106A's first had a 695 square foot wing, enlarged to 697) but with a cleaner frame, better inlets it'd probably have better sustained performance.I'm writing a detailed Topgun book with the school's founder, and he describes how (in specific circumstances) the F-4 could turn with other "fighterjets" if the Phantom pilot had trained to fight in deep buffet.
Well, technically it was a function of dynamic pressure and g-loadIt is way above my pay grade on aerodynamics but I was under the impression that the deployment was dependent on the wings angle of attack, in a combat situation no more or less dangerous than for an opposing Spitfire for example as the speeds were about the same.
And where are you getting your reference for this? I've flown in an F-4, did some aerobatics and found you needed very little rudder at lower speeds. At high speeds you didn't touch the rudderThe F-4 required some skill to fly it, due to a combination of heavy adverse yaw and a highly swept wing, you'd be using fairly firm rudder inputs with aileron under some case, and at higher alpha, you'd just be using the rudder and centering the stick, pulling back as needed to hold the g-load.
There was a book entitled "Clashes", but also thisAnd where are you getting your reference for this?
I've wondered why that happened: There were some guesses about that, as well as some personal speculation.
I could tell you that's very generic and probably the same on about dozen combat aircraft of the period. You could actually roll an F-4 with the rudder only (the aircraft shakes and buffets while this is going on). I would disagree that the F-4 "required some skill to fly it." Like any combat aircraft of the day, "training enables capability." Don't buy into many of those 1960's training clips, they could be a little over-dramatic.There was a book entitled "Clashes", but also thisView: https://www.youtube.com/watch?v=Y6RcTtGfG3E
which seem to have similarities in descriptions.
I've wondered why that happened: There were some guesses about that, as well as some personal speculation.
- The Me-109's slats acted as a stall-warning device, which the Spitfire did not have: This allowed them to better gauge when they were getting close to stalling
- The Spitfire seemed to indicate a tendency for being potential twitchy on the controls (neutral stability), so some pilots might have feared snapping the wings off
All I read from this is that experienced pilots do better than inexperienced ones, which is well known.5.1 Dog fights with Spitfire and Hurricane .
...
When the Me.109 was following the Hurricane or Spitfire, it was found that our aircraft turned inside the Me.109 without difficulty when flown by determined pilots who were not afraid to pull their aeroplanes round hard in a tight turn. In a surprisingly large number of cases, however, the Me.109 succeeded in keeping on the tail of the Spitfire or Hurricane during these turning tests, merely because our pilots would not tighten up the turn sufficiently from fear of stalling and spinning.
...
5.4 Discussion .
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As mentioned in 5.1., the Me.109 pilot succeeded in keeping on the tail of the Spitfire in many cases, despite the latter aeroplane's superior turning performance, because a number of the Spitfire pilots failed to tighten up the turn sufficiently. If the stick is pulled back too far on the Spitfire in a tight turn, the aeroplane may stall rather violently, flick over on to its back, and spin. Knowledge of this undoubtedly deters the pilot, particularly if he is not very experienced, from tightening his turn when being chased.
Please explain how the g load deployed the leading edge slats? I believe it is the angle of attack of the wing because I read it here. (My bold) Leading-edge slat - WikipediaWell, technically it was airspeed and g-load...
I've wondered why that happened: There were some guesses about that, as well as some personal speculation.
- The Me-109's slats acted as a stall-warning device, which the Spitfire did not have: This allowed them to better gauge when they were getting close to stalling
- The Spitfire seemed to indicate a tendency for being potential twitchy on the controls (neutral stability), so some pilots might have feared snapping the wings off
The slats did not act as a stall warning device with expert pilots because they continued to push in a turning combat after they deployed. The Spitfire had the same stall warning as most aircraft of the period, that is buffeting on the wings caused by the washout. In this respect the Spitfire was better than most. As previously, many pilots were in combat during the BoB with just 50 hours on type whereas 200 hrs is actually needed. With the extra 150 hrs pilots become familiar with stall performance and stall recovery. Did any Spitfire actually snap its wings off, ever, while turning?
- The Me-109's slats acted as a stall-warning device, which the Spitfire did not have: This allowed them to better gauge when they were getting close to stalling
- The Spitfire seemed to indicate a tendency for being potential twitchy on the controls (neutral stability), so some pilots might have feared snapping the wings off
So the issue was the fear over being able to properly gauge when they'd stall?When the Me.109 was following the Hurricane or Spitfire, it was found that our aircraft turned inside the Me.109 without difficulty when flown by determined pilots who were not afraid to pull their aeroplanes round hard in a tight turn. In a surprisingly large number of cases, however, the Me.109 succeeded in keeping on the tail of the Spitfire or Hurricane during these turning tests, merely because our pilots would not tighten up the turn sufficiently from fear of stalling and spinning. . .If the stick is pulled back too far on the Spitfire in a tight turn, the aeroplane may stall rather violently, flick over on to its back, and spin.
That makes sense, different amount of stick forces are needed to pull a given g-load at a given speed.Please remember that there were no anti-suits, and no "G" meters in the cockpit. Pulling 5-6 "G"s means you are near blacking out (or at least greying out) and your arms are 5-6 times heavier than normal while trying to control the stick. Nobody pulled a perfect 5 "G" turn. There was constant adjustment of the elevators to control the turn and the actual "G"s could fluctuate considerably from one second to the next even in a 10 second 180 degree turn.
Would that flood the engine?What they worried about was stalling the plane while turning at over a 70 degree bank and snapping into an inverted spin.
Makes enough sense: They don't know what they can and cannot get away with... there's natural skill in that, but also practice is often a helpful cure.Low time pilots in just about all WW II fighters rarely pushed the aircraft to the aircraft's limits
Automatic slats were extended through usually two means: Dynamic pressure and G-loadPlease explain how the g load deployed the leading edge slats?
It would provide a guide as to how close you were getting...The slats did not act as a stall warning device with expert pilots because they continued to push in a turning combat after they deployed.