I sometimes have to cut throttle to prevent myself from locking up and augering, but that means I usually end up 1000ft under my original altitude from when I began the dive.
Ah, so instead of diving straight down, I should get lower than my target at fullspeed?You are confusing energy with speed (just the kinetic energy part).
But doesn't that expose me to other planes for a longer time? Since I'm now lower than they are?
You are confusing energy with speed (just the kinetic energy part).
You have two kind of energy: kinetic and potential, but lets call them speed and alt.
You also have a single energy source - engine power
and two kinds of energy sinks: parasitic drag that simply scales with your speed and induced drag which depends on your maneuvering.
Speed bleeds energy to the parasitic drag. At low speeds this bleed is weak enough to be compensated by the engine power. You therefore gain energy over time. If you dive and pick up speed, the energy bleed increase significantly (like the square of the speed) and you are not gaining net energy. Therefore if you need mor eenergy you have to be slow.
Alt is banked energy - its is stored and does not bleed. This is why the most efficient way to build energy is to climb - what E you gain, you immediately store in alt so it does not bleed.
When you zoom climb you do not loose energy - you convert the speed into alt. Diving is the was to cash back the stored energy into something you can use, but remember that if your speed is high you are not gaining new energy due to the drag bleed. On the other hand you can actually use this energy to do something. Being low than you opponent is not a disadvantageous position! being lower ENERGY than you opponent is - this means that if you are lower but faster, such that your total energy is higher than his you have the upper hand! You can zoom up to him to his alt and still be as fast or faster than he is. He can dive down to you, but will not catch you because if he cashes his alt for speed it is still not enough to match you.
Speed means that ability to maneuver and the ability to position. So you cash alt for speed and then cash speed into maneuvering. There is absolutely no advantage in being higher when considering maneuvering. It is even disadvantageous. If both planes have the same total E, the higher one is slower (more stationary target that cannot move out of the way), cannot maneuver as well (G limited), and has gravity against him in maneuvers - yes, against!. The plane that attacks uphill (with lots of speed!) can pull more G, can change his actual position in the sky (because he is moving faster) and the next pull to point at the other guy will have the gravity vector inside his turn, meaning that gravity makes him turn faster.
The rules of thumb are:
* Energy is both speed and alt.
* Higher is just a vertical position, not an advantage.
* You want to go up to store and build more energy in times when you do not need to maneuver a lot.
* The alt is there just as an energy bank, waiting for you to cash it into speed and then into maneuvering at the right moment.
* If you die slow and high you are doing it wrong. It is like saving all your life to die a rich man - what is the point in that?
look up the "lag pursuit" turn and practice using the vertical and your awesome roll rate.
You are confusing energy with speed (just the kinetic energy part).
You have two kind of energy: kinetic and potential, but lets call them speed and alt.
You also have a single energy source - engine power
and two kinds of energy sinks: parasitic drag that simply scales with your speed and induced drag which depends on your maneuvering.
Speed bleeds enrgy to the parasitic drag. At low speeds this bleed is weak enough to be compensated by the engine power. You therefore gain energy over time. If you dive and pick up speed, the energy bleed increase significantly (like the square of the speed) and you are not gaining net energy. Therefore if you need mor eenergy you have to be slow.
Alt is banked energy - its is stored and does not bleed. This is why the most efficient way to build energy is to climb - what E you gain, you immediately store in alt so it does not bleed.
When you zoom climb you do not loose energy - you convert the speed into alt. Diving is the was to cash back the stored energy into something you can use, but remember that if your speed is high you are not gaining new energy due to the drag bleed. On the other hand you can actually use this energy to do something. Being low than you opponent is not a disadvantageous position! being lower ENERGY than you opponent is - this means that if you are lower but faster, such that your total energy is higher than his you have the upper hand! You can zoom up to him to his alt and still be as fast or faster than he is. He can dive down to you, but will not catch you because if he cashes his alt for speed it is still not enough to match you.
Speed means that ability to maneuver and the ability to position. So you cash alt for speed and then cash speed into maneuvering. There is absolutely no advantage in being higher when considering maneuvering. It is even disadvantageous. If both planes have the same total E, the higher one is slower (more stationary target that cannot move out of the way), cannot maneuver as well (G limited), and has gravity against him in maneuvers - yes, against!. The plane that attacks uphill (with lots of speed!) can pull more G, can change his actual position in the sky (because he is moving faster) and the next pull to point at the other guy will have the gravity vector inside his turn, meaning that gravity makes him turn faster.
The rules of thumb are:
* Energy is both speed and alt.
* Higher is just a vertical position, not an advantage.
* You want to go up to store and build more energy in times when you do not need to maneuver a lot.
* The alt is there just as an energy bank, waiting for you to cash it into speed and then into maneuvering at the right moment.
* If you die slow and high you are doing it wrong. It is like saving all your life to die a rich man - what is the point in that?
to say having ALT on a nme con is not an advantage is very wrong.
I pretty much agree with most every thing here..except what I high lighted in red.....
having a superior ALT is an advantage...I am really surprised by your statement that its not....in the MA it is the best advantage there is....a crappy plane with a good stick in it will kill the lower con in any plane most of the time.....if its not an advantage then why try to Climb above to dictate the fight.......the HIGHER con dictates the fight.
one higher con can destroy(if he is a good shot and knows his plane) any number of nme cons lower then him......
to say having ALT on a nme con is not an advantage is very wrong.
I pretty much agree with most every thing here..except what I high lighted in red.....
having a superior ALT is an advantage...I am really surprised by your statement that its not....in the MA it is the best advantage there is....a crappy plane with a good stick in it will kill the lower con in any plane most of the time.....if its not an advantage then why try to Climb above to dictate the fight.......the HIGHER con dictates the fight.
one higher con can destroy(if he is a good shot and knows his plane) any number of nme cons lower then him......
to say having ALT on a nme con is not an advantage is very wrong.
Now all I have to work on is learning to stall fight and trying to initiate a rolling scissor.
I pretty much agree with most every thing here..except what I high lighted in red.....
having a superior ALT is an advantage...I am really surprised by your statement that its not....in the MA it is the best advantage there is....a crappy plane with a good stick in it will kill the lower con in any plane most of the time.....if its not an advantage then why try to Climb above to dictate the fight.......the HIGHER con dictates the fight.
one higher con can destroy(if he is a good shot and knows his plane) any number of nme cons lower then him......
to say having ALT on a nme con is not an advantage is very wrong.
Perhaps instead of saying "Higher is just a vertical position, not an advantage" it would be better to phrase it as "Higher is just a vertical position, not necessarily an advantage". I think the purpose of the discussion was to get newer players to understand and contemplate both speed and alt (kinetic and potential) energy. I see a lot of frustration from some of the new players because they can't understand what happened and how the lost, and a lot of that frustration comes from statements like "we were co-e" when they meant to say co-alt.
Having altitude can definitely be an advantage, but I think it's a common mistake to think have more altitude than our opponent automatically equates to having more E.
having a superior ALT is an advantage...I am really surprised by your statement that its not....in the MA it is the best advantage there is....a crappy plane with a good stick in it will kill the lower con in any plane most of the time.....if its not an advantage then why try to Climb above to dictate the fight.......the HIGHER con dictates the fight.If the two planes have equal total E, then the low-fast one is generally in a better position than the high-slow one. You go across shops and suddenly spot a good "today only" deal - you can take the opportunity if you have your money in your pocket. You cannot take advantage of the deal if you have lots of money which is locked away in savings accounts in the bank.
one higher con can destroy(if he is a good shot and knows his plane) any number of nme cons lower then him......
If the two planes have equal total E, then the low-fast one is generally in a better position than the high-slow one.
...damn Hurri no way can you climb up to me...they didn't realize I was doing like 400....
The plane with the lower weight has a higher specific energy, which is a better metric than total energy. From a tactical perspective, "co-e", I'll take the altitude.
The Corsair isn't the hardest plane to fly in this game, but It's one the busiest....
I've never heard the term 'specific energy' and Google has failed me at least as far as how it applies to aircraft. What does it mean and how do you apply it to ACM?In science and engineering "specific" usually means "per mass" (or per other equivalent quantity that describes total amount ), like specific heat.
Thanks for the help and info guys. :aok I'm understanding a lot more about E management now.
I went into the TA yesterday and asked Stogey for some help. I had the task of sticking on his 6 for as long as I could and I'm glad to say I sat there like glue. He was in a P38 and I was in a -1D.
One more question, for convergence, do you guys do point convergence or zone convergence? I currently set all the guns to 450 and I start firing at the moment 400 appears on the con. It works fine as long as I'm on their 6, but when they fly past me or I have to do a deflection shot, my bullets either shred them to bits or miss completely because they're all coming in 1 spot. With the latter happening more often than I'd like it to.
I'd be willing to bet this scenario is the single biggest cause of new guy 'cheater' whines in the game.
I've never heard the term 'specific energy' and Google has failed me at least as far as how it applies to aircraft. What does it mean and how do you apply it to ACM?
Wiley.
I learned this a couple of years ago, and it really started some things clicking for me personally with respect to energy overall, and how it applies practically.
(Glossed over some things here in the interest of simplicity).
If you merely think about energy as speed and altitude, it ignores the impact of weight. If we consider the impact of weight on the maneuvering energy of the aircraft, then we get a better comparison of how much energy each aircraft has for maneuvering.
With this in mind, its easy to see how a Spit 16 (that weighs 9,000 lbs) flying at 15,000 feet and 380 mph TAS could have more "energy" than say a P-47N (at 16,000 lbs) flying at 20,000 feet and 380 mph. I didn't do the math to check that result, but you get my point hopefully. This is why higher is not always better, as Bozon and others stated earlier.
I probably shouldn't have used the term "specific energy" as it has a different actual meaning, but basically, you want to account for weight when you compare aircraft. 400 mph isn't as useful when you weigh 40,000 lbs as it is when you weigh 12,000.
If you merely think about energy as speed and altitude, it ignores the impact of weight. If we consider the impact of weight on the maneuvering energy of the aircraft, then we get a better comparison of how much energy each aircraft has for maneuvering.
I probably shouldn't have used the term "specific energy" as it has a different actual meaning, but basically, you want to account for weight when you compare aircraft.
400 mph isn't as useful when you weigh 40,000 lbs as it is when you weigh 12,000.
Actually it is, that's why heavier aircraft zoom better.
So the C-5 should zoom better than a F-15 then right? ;)
I meant if all else is equal.
I probably shouldn't have used the term "specific energy" as it has a different actual meaning, but basically, you want to account for weight when you compare aircraft. 400 mph isn't as useful when you weigh 40,000 lbs as it is when you weigh 12,000.
this is something I never considered, but then again I don't "think" when I fight I just react.
Unless I am looking at something incorrectly, 400 mph= 400 mph regardless of the mass of the aircraft. The kinetic energy would be exactly the same in this case but the potential energy of the 40,000 lb aircraft would be much higher, so if altitude is the same and speed is the same than the 40,000 airplane would have more total energy than the 12,000 airplane (absolute). I understand that in some situations the 12,000 lb plane would have some advantages in this state, but wouldn't the 40,000 lb airplane also have some advantages in the same circumstance? I realize that specific "E" would be higher in the 12,000 airplane, but I cant see where this would always be an advantage (such as in a dive) (maybe I'm not looking at this correctly).
Can you please clarify this because I am not seeing correctly here if this is the case.
ps. Im not being argumentative or disrespectful here, I am just trying to visualize this and learn.
This is where I glossed over some terms...
In order to climb, accelerate, turn, or otherwise maneuver, that 40,000 lb aircraft is going to obliterate its theoretical advantage because of its extra weight. Tango mentioned the term "specific excess power" and that's the true metric that should be used for comparison. I was suggesting that a cursory comparison could be made merely by considering the theoretical amount of energy possessed by one aircraft with respect to its weight. I highly recommend that you read through both of the posts Tango added. Mace's discussion and Tango's considerable effort on explaining zoom climbs, IMO, are probably 2 of the top 10 threads on aerodynamics in the game. Badboy has a few as well, and I encourage you to read about Energy Maneuverability Diagrams as well. Anyway, I can't think of a quick way to fully answer your question, and I need to go grab some dinner. I'll see if I can't post something more substantive later.
Yes, if all else is equal the heavier aircraft will zoom worse. :)
I'm not saying you need to keep a calculator next to the stick and do these computations in the cockpit. All I'm saying is that if you're flying a heavy fighter like a U.S. ride, and you see a lighter fighter below you, and you know it has speed, watch out, because the energy advantage you think you have may not be there. We've all seen the guy on 200 or on Country channel screaming about how some La-7 or Spit-16 climbed 5,000 feet and shot him down at altitude in a matter of seconds. Don't be that guy... :)lol never been that guy...I am one of the guys, that gets said about.....I have been called a cheater no less then 15 times since I have been here, especially when I flew the hurri2 :devil
this is something I never considered, but then again I don't "think" when I fight I just react.
Isn't that the truth. My eyes glaze over when folks start talking about the ins and outs of ACM. I react. After all these years, I think I react the right way for the most part, but I couldn't tell you what I did or why, just whether it worked or not :)
Isn't that the truth. My eyes glaze over when folks start talking about the ins and outs of ACM. I react. After all these years, I think I react the right way for the most part, but I couldn't tell you what I did or why, just whether it worked or not :)
That's the trick to teaching BFM/ACM. You have to look back at what you did and then explain why or why it didn't work. When I first started training, I had to think about all the things I did automatically and never thought about, and figure out why it worked.
:salute
BigRat
Isn't that the truth. My eyes glaze over when folks start talking about the ins and outs of ACM. I react. After all these years, I think I react the right way for the most part, but I couldn't tell you what I did or why, just whether it worked or not :)
zoom climb test p47d vs p47n
http://www.spitfireperformance.com/p-47/p-47n-zoom.pdf
It is also true that, if all else is equal the heavier aircraft will zoom better. :)
All I have to do is adjust zoom length and climb angle to get desirable sin value.
That's the trick to teaching BFM/ACM. You have to look back at what you did and then explain why or why it didn't work. When I first started training, I had to think about all the things I did automatically and never thought about, and figure out why it worked.
:salute
BigRat
thanks all for the posts and info :aok trying to learn the corsairs a bit atm and this is really useful
would be great to see some film of an f4u demonstrating this :pray
Its amazing what extra horsepower and 10% more wing area will do... This is one of those comparisons where you'd have to compute excess power in order to illustrate the difference.
Its amazing what extra horsepower and 10% more wing area will do... This is one of those comparisons where you'd have to compute excess power in order to illustrate the difference.
P-47C v. Spitfire IX.............
Climb – The rate of climb if the Spitfire is much higher at these heights than that of the P-47C. .............. The difference, however, is not nearly so marked in zoom climbs, and if the P-47 dives slightly and then pulls up in the climb, its performance is similar to that of the Spitfire over limited intervals.
Dive – The P-47 is able to out-dive the Spitfire quite easily.
What excess power? HP/lb? Wing area? How about wing loading?
What excess power? HP/lb? Wing area? How about wing loading?
...It always reduces Ps (in absolute value...), but not always the height of the zoom. Ps only tell you the rate of energy gain (per mass). It is not a direct measurement of the zoom. The benefit of the mass is implicit in this equation - it is in the time and the sign of Ps. Note that if Ps is negative, weight actually INCREASE Ps!
Ps = (thrust - drag) * velocity / weight
...
If you look at that relationship you can see that all else being equal (thrust, drag, velocity) increasing weight ALWAYS reduces Ps.
It's well known aerodynamically that the airplane with the greatest time average Ps in a zoom climb will out zoom one with a lower Ps.
What Stoney and you don't take into account
This advantage in zoom can be mainly attributed to the higher power available of the P-47N."[/i][/size]
If i get it right, the airplane with the highest thrust/weight ratio will out zoom the other if starting at the same speed? That's why a f-15 will outzoom a brewster :devil
Theres nothing more unsexy than fighter planes and equations :old:
:)
"Beware the lessons of a fighter pilot who would rather fly a slide rule than kick your ass!" Commander Ron "Mugs" McKeown, USN, Commander of the USN FWS "Top Gun" School.
If i get it right, the airplane with the highest thrust/weight ratio will out zoom the other if starting at the same speed? That's why a f-15 will outzoom a brewster :devil
What Stoney and you don't take into account (also well known) is state of energy (at zoom climb entry) and conservation of momentum.
Add that to your equation and it becomes halluva lot more complicated but also much closer to real life zoom climb tests.
Tango, I told ya we forgot something!!! I guess I need to get back in my books... :noid
bozon - I agree with most of what you said. Two points I would make:
1) Ps = (T-D)*V/W = rate_of_climb + rate_of_flight_path_velocity_ change. Yes, Ps is not a direct measure of zoom height. However it includes a direct measure of rate of change of climb, thus the time average of Ps over the course of a zoom climb tells you which airplane is going to zoom higher.
2) Mass absolutely is a factor which is why this topic totally throws people. The question is how much and when. Typically the portion of a zoom climb where T<D is very short in duration thus extra mass quickly becomes a detriment. In the links I've posted above I've done some examples to demonstrate this (numerical integration over the time domain). The fact that (for our prop aircraft) T increases with decreasing velocity while D decreases with decreasing velocity further ensures that T<D is only over a short duration.
:headscratch: :rolleyes:
:old: :airplane: :joystick:
Ah, my good sir but Ps absolutely takes momentum into account. The derivation of Ps comes directly from F=ma. The right-side m*a is the rate of change of momentum. Momentum is completely factored in.
Specific excess power is everything in comparing performance.
includes the mojo that defines turn performance.
It can tell you what your best climb speed is, what your best rate of climb is
If you understand Ps, you understand 80-90% of what makes airplanes do what they do.
:rofl You wish
Whatever bro. You crack a copy of a flight mechanics and performance text, and it will be plastered all over the place. But, humor me and tell me what you think we should be comparing here? If we're wrong, what's right?
2bighorn...
Because it's been repeated so much I too believed that heavier a/c builds up more speed in a dive and then retains that energy better into a zoom climb vs. lighter aircraft. Running through loads of dive/climb modeling has shown me this is completely misleading.
The question is not if increased mass makes a difference. The question is when and how much. I know of no other way to fully answer the question but quantitatively thru simulations via numerical integration. Over the years, running many simulations for myself has shown me increased weight is a relatively minor factor.
Yes, using a procrustean definition of zoom, narrowing it only to a particular moment of a zoom then at some point more mass helps. I just think it's non-helpful to repeat the heavier a/c zooms better mantra when this only applies to a narrow band & of minimal relative significance.
Gravity is proportional to mass.
Ever heard of gliders? No excess power whatsoever, therefore no Ps to speak of. By your account, we wouldn't know of 80-90% of what makes them fly
Because it's been repeated so much I too believed that heavier a/c builds up more speed in a dive and then retains that energy better into a zoom climb vs. lighter aircraft. Running through loads of dive/climb modeling has shown me this is completely misleading.dtango, I fully agree with your theory, but I am not completely confident in its application to reality. There is a reason why pilots believed the P47 zoomed better than other AC that had better Ps ( though if one goes high enough, the P47 wins in Ps when the other's engine dies of hypoxia...). At the same time they ALL preferred less weight given the option, but this is not strictly with zoom ability in mind. Equal planes were never considered - it was not a P47 vs. a P47 with a ballast stone in it, but a P47 against a P51, or a 109. If the planes have only a small difference in power loading, the kinematic part (weight and drag) play a larger role.
so is inertia. they counter-balance through a direct relation. A heavier object does not fall faster nor does it accelerate faster. At least not because of gravity. The terminal velocity might be higher or lower when you factor in drag.
A heavier aircraft falls the same speed as a lighter one in a vacuum. In atmosphere a heavier aircraft gains more thrust from gravity than a similar lighter aircraft.
When thrust/weight ratio exceed 1:1, we have a craft that will accelerate pointing straight up, like a rocket on the launch pad or the space shuttle. Weight is not an advantage nor is it a disadvantage as long as you got a big enough engine to get you moving. A lot of factor come into play but it boils down to the aformentionned 4 forces. 3 of them are dynamic, 1 is not. You cannot change the laws of physics.
But with our aircraft in this game, none of them have a thrust to weight ratio that gets even close to 1:1 even in full WEP. Thrust to weight ratio isn't a good metric to use with prop aircraft anyway--that's more of a jet thing. Power to weight ratio is the metric used to characterize propeller aircraft, and to compute power, you have to account for the BHP at whatever altitude and propeller efficiency.
Anyway, weight will always be a limiting performance factor with the planes we have in-game. Every plane in this game will suffer a performance penalty when their weight is increased, and this applies to zoom climbs, turns, whatever...
I get the point. What I wrote was an effort in generalisation to illustrate the principle behind it, not taking into account the specific of ww2 planes and propeller and engine and such that complicate the thing to a point it's hard to grasp.
I'd like to point out though that if you factor propeller efficiency with engine power and other factor I dont even remotly know of, you get a measure of the thrust available at any point in time.
So why does a sailplane fly faster when it's heavier? :DMy guess would be, given the same craft, wing area and such only heavier, to generate enough lift you'd have to either have a larger AOA or fly faster. Since an increase in AOA will slow you down, you obviously don't want that. That leave you with nosing slightly more down to fly faster. You would drop faster but at an increased ground speed, thus not affecting too much you glide ratio. Up to the point where you reach maximum airspeed for the particular airframe and have to increase AOA instead shortening your flight time noticably because of increased induced drag.
The biggest difference is that jet thrust is constant. Thrust on propeller aircraft is dynamic, and only remains constant in level, unaccelerated flight. And, I understood your generalization--the problem is that many people on this board do not and will either (a) not understand or (b) take the generalization and run with it as fact.
I'm gonna start an Energy thread since this one got so goofy. I'll start at the very beginning and work through most of this stuff, within the next day or so.
Gravity's acceleration is constant regardless of the mass of the object. On earth it's 9.2m/s. Up to terminal velocity which is affected by the drag imposed by the shape of the specific object. As planes have roughly the same shape, they accelerate at about the same rate at first until they reach a point where drag dictate the final velocity of the fall. If what you said were true, heavier object would fall faster on earth(which has already been proved wrong by experiment). Similarly shaped object will acheive a very close terminal velocity, determined solely by the amount of drag they generate. A steel ball does not fall faster than a wooden one of the same size, even with a big mass differential. Now planes are not inert object, and they usually fly powered so their straight down acceleration rate will be (9.2m/s(gravity constant) + whatever the engine add minus drag). That makes a big difference. And it comes down again to thrust/weight ratio. Why? To answer that, we have to define what is acceleration. Acceleration is a change of velocity along a vector. To change the velocity, you have to apply enough force to overcome inertia. To apply it to powered flight, acceleration is proportionnal to the ability of the engine to overcome the inertia of the mass of the plane(and drag, that's why the faster you go the slower you accelerate. think about the time between 0-100 vs 200-300). Now to understand how this act, we must go back to the basic 4 forces that act on a plane : gravity, lift, thrust, and drag. When flying level, gravity is balanced by lift. When in a climb, some of the engine power is used to fight gravity and the extra lift is used to climb. Now if a plane point straight up, gravity sole opposite force is thrust as the lift vector now point parallel to the horizon. Deceleration rate is a function of (gravity constant - engine thrust - drag). A higher thrust/weight ratio will let you acheive a higher altitude. When thrust/weight ratio exceed 1:1, we have a craft that will accelerate pointing straight up, like a rocket on the launch pad or the space shuttle. Weight is not an advantage nor is it a disadvantage as long as you got a big enough engine to get you moving. A lot of factor come into play but it boils down to the aformentionned 4 forces. 3 of them are dynamic, 1 is not. You cannot change the laws of physics.
Now the question about how this is all modeled in the game is a completely different beast. But with what i've already seen iof the game, I'm sure HTC are already aware of all this.
My guess would be, given the same craft, wing area and such only heavier, to generate enough lift you'd have to either have a larger AOA or fly faster. Since an increase in AOA will slow you down, you obviously don't want that. That leave you with nosing slightly more down to fly faster. You would drop faster but at an increased ground speed, thus not affecting too much you glide ratio. Up to the point where you reach maximum airspeed for the particular airframe and have to increase AOA instead shortening your flight time noticably because of increased induced drag.
You're saying the heavier aircraft would go faster for a given glide slope. :D
Granted that might change in a zero lift dive and the weight effects are minimized by the engines but you seem to agree with me that increased mass increases the thrust from gravity so the aircraft goes faster over the same distance from the same height.
Weight is a force, F=mg ie mass x gravity acceleration (expressed in simplest way)
When plane dives straight down (points to Earth's center) forces which are accelerating plane are weight and thrust. Opposing force is drag.
Now do the math.
Weight is relative to the acceleration of gravity. Mass is not. It's an absolute measure, function of an object density and volume. Weight and mass are not the same thing, though they are often confounded as such. For proof, take the weightlessness astronaut experience in orbit. They do not feel their weight. Their mass is not canceled.
When plane dives straight down (points to Earth's center) forces which are accelerating plane are gravity and thrust. Opposing force is drag and inertia(not really a force, rather a tendency to not change state IE : resisting acceleration/deceleration/change in direction). The acceleration granted by gravity is constant. If it's not true then sir Isaac Newton and Albert Einstein (and might I add all physicist in between them and up to now) were wrong. I trust they were right. That's science. I know it's against common sense but it's true. Again, and I want it to be very clear, a given plane might dive better than another but it's not because gravity grants it more "thrust". Other factor are the cause. Airframe drag along with total thrust available at any given time determine how fast the plane accelerate through the dive. Gravity is a constant factor regardless of the mass of the plane.
Also I'd like you to define what make a good diver. A nimble zeke which control locks up at 400mph is not regarded as a great diver. A corsair which you can control at past 550 is a good diver. Even then both could accelerate quit well in a dive, one could maintain it longer before it begin shedding parts. I bet the zeke could even get faster. That is once it lost it's wings on the way down. Much less drag without those.
:salute
It need to. the heavier you are the shorter your run get. For a light glider the effect is not large. The heavier you get, the faster you need to be to maintain an optimal AOA. In a glider, the only energy available is alt. You will not end up in the exact same spot.
Since the thrust increase in this case is proportional to the mass increase you should end up in the same spot excepting a minor difference in induced drag.True, as long as the AOA one needs to maintain does not change the "efficiency" (i.e. lift/drag ratio) by much, you will end up in the same place, only faster.