How to regain lost E? (F4U)

[Soulyss]

Thanks for the help and info guys.  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.

Can't speak as much to the 38J and L because it's been a while since I flew either one with much regularity but in the 38G I have my hands full against the F4U.  I have to either more E going into the fight so that I can get above and work downhill or I have to press for a shot early in the fight, once E bleeds off and the fight slows down the F4U pretty much holds all the cards.  The J or L may have a little more margin for error because of the increased power and WEP but I imagine the options are pretty much the same, go pure E fight and try and get superior position or press for the shot early and hope.

[Saxman]

Convergence is very much a personal preference thing. However I prefer a short range (200yds) and point convergence. The .50cal is an absolute buzzsaw at that range.

[Stoney]

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.

[ink]

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.

this is something I never considered, but then again I don't "think" when I fight I just react.

[dtango]

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.

Shoulda, woulda, coulda - but you have it right .  That's exactly what specific energy means, energy per unit weight.

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To further add to the insightful posts in this thread thus far here are some fundamental concepts that will hopefully help the OP continue to grasp energy management.



This is a nifty diagram that shows an aircraft's energy relationships and how they can be exchanged.  Of course the key is for a given aircraft the rate of energy exchange is determined by specific constraints governed by aircraft specific excess power (Stoney's favorite topic).

For more details on work, energy, power, and energy retention feel free to look at this old post: How is N-R-G retention determined?

Hope thats helpful!

[2bighorn]

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.

[dtango]

Actually it is, that's why heavier aircraft zoom better.

So the C-5 should zoom better than a F-15 then right?

(EDIT: given the same thrust) The heavier aircraft zooms worse.  Trust me.

[2bighorn]

So the C-5 should zoom better than a F-15 then right?

I meant if all else is equal.

[dtango]

I meant if all else is equal.

Yes, if all else is equal the heavier aircraft will zoom worse.    Otherwise it would be aeroballistics and not aerodynamics.

Mace sums up why nicely here: Dispelling myth of increased weight improving zoom

If that's not enough buried in that thread are calcs to drive the point home here: Dispelling myth of increased weight improving zoom Part Deux

[Edgar]

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.

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.

[Stoney]

this is something I never considered, but then again I don't "think" when I fight I just react.

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... 

[Stoney]

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.

[Edgar]

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.

Thanks Stoney,

I appreciate it. I will read thru those posts and see if I can get a grasp of it.

<S>
Edgar

[2bighorn]

Yes, if all else is equal the heavier aircraft will zoom worse.   

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.






 

[ink]

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