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#3887951 - 01/02/14 03:36 PM flight manouvers: optimal zoom-climb  
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Laurwin Offline
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Does such a manouver exist, for any given Boom&Zoom plane? (I'm thinking mostly in the region of propeller aircraft WW2 era - the question may be relevant because these aircraft were designed with the propeller functionality as a definite design aspect)

I would think that the propeller controls (propeller settings) does become a factor at certain dive speeds, probebly dependant on the actual example plane though?

Definition of optimal in this case would be simply most energy retained possible (disregarding angular advantage for purpose of air combat advantage)

Presumably you would compare total energy state just before the dive attack, to the energy state at the end of the zoom-climb?

Presumably low G manouvers would be better for energy retention? (low G manover may not give you angles easily against opponent though, if it were only so easy I know!!!) Isn't this what the so-called "energy egg picture" tries to depict? (tactical egg, energy egg, showing flight paths of a plane, across horizontal and vertical)

Energy loss happens as you go faster (faster than you should?), drag increases? How much drag can be diminished, by properly manipulating the propeller? How much drag is inevitable, as a result of airframe drag?

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#3887956 - 01/02/14 03:45 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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Optimal zoom climb is something all aircraft have. It's just your best climb speed for a zoom climb, usually the peak power speed.


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#3887976 - 01/02/14 04:05 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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"Optimal" requires a definition.

Optimal may mean different things in different situations. Are we looking for max altitude gained...or max separation distance...are we 'zooming' to set up another attack or are we trying to leave the engagement?

"Best" climb speed comes in two forms...best rate and best angle. Best angle speed is typically a lower value than best rate and may be less than what is tactically desired.

#3887978 - 01/02/14 04:10 PM Re: flight manouvers: optimal zoom-climb [Re: GrayGhost]  
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Laurwin Offline
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Originally Posted By: GrayGhost
Optimal zoom climb is something all aircraft have. It's just your best climb speed for a zoom climb, usually the peak power speed.
I'm sorry I don't quite understand, what would this optimal speed characteristic be eg. for a bf-109 F4? Or P-47 D-27 (paddle prop)

#3887989 - 01/02/14 04:20 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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I don't know, it's different for every aircraft (though usually around M0.9 for jets). You have to look up the performance manuals for those aircraft, if they exist. Otherwise, you need to create your own smile

Last edited by GrayGhost; 01/02/14 04:21 PM.

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#3887993 - 01/02/14 04:22 PM Re: flight manouvers: optimal zoom-climb [Re: Andy Bush]  
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Laurwin Offline
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Originally Posted By: Andy Bush
"Optimal" requires a definition.

Optimal may mean different things in different situations. Are we looking for max altitude gained...or max separation distance...are we 'zooming' to set up another attack or are we trying to leave the engagement?

"Best" climb speed comes in two forms...best rate and best angle. Best angle speed is typically a lower value than best rate and may be less than what is tactically desired.



What I had in mind, was spending altitude, to gain speed, and spend speed to re-gain some of that altitude. (we are commited to the fight, we are not going to run away unless we must)

Let's imagine the situation as such: we are flying P-47 D27, protecting heavy bombers from German Me262. Protecting this valuable asset from enemy, we are engaging Me262 from above in diving attacks.

Now if the situation was strictly 1v1, I can understand you point Andy! If you gain enough separation, (let's remember we started with altitude advantage in beginning), then you may be able to lose visual tally of the enemy (and vice versa), and you could escape reasonably. And after that you would climb comfortably back to your altitude.

How would the situation play out for the P-47 D27, if we would go for the max altitude though?

What about strictly 1v1, P-47 D27 and if we went for separation instead?

#3887998 - 01/02/14 04:27 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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It is useful for minimising horizontal turn radius to use vertical manoeuvres ~ as few aircraft have had the ability to sustain or accelerate in a vertical climb these are almost always zoom climbs. In order to complete these it is desirable to start with at least vertical manoeuvring speed (sufficient to get the nose vertical before speed falls below minimum control speed (stall not being too meaningful when the wings don't actually need to provide gross lift).

It is useful for a continuing offensive position to have at least sufficient control authority to roll during the vertical portion and then to recover to horizontal flight before loss of control, so entry speed should be higher than minimum vertical manoeuvring speed by some margin.

This is the core of several offensive methods, most notably the rolling scissors, which are a sequence of zoom climbs and rolling lead turns in the vertical, before recovering to the target's altitude in an attempted attack/lag pursuit.

Zooms are dangerous if you zoom higher, but he retains control at a lower speed, as you will often find yourself slow and close ahead of the bogey... in order to be safe you must reduce the bogey energy to below *his* vertical manoeuvring speed, force him to lose sight, or terminate your zoom before you pass ahead of the bogey... in no circumstances attempt to zoom against a bogey with a large angular advantage (in your rear hemisphere) unless you know he is too low on energy to even attempt to place his nose on you.


Other uses of zoom climbs include many of the turning climbs (chandelle et al.) These are often safer if you have an energy advantage and climb rate advantage, as the steepening sight angle caused by your turn forces a steeper zoom from the lower bogey *and* a tighter turn, which is usually not available in combination. Note this only prevents him following you with a guns solution, and not shadowing in lag pursuit, which may permit higher energy state and a better angle off nose/position than you might expect... if you lose sight of a bogey during a climbing turn, be prepared for a neutral pass at best.

#3888008 - 01/02/14 04:40 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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In general terms, an 'optimal' zoom is a steep pitch up to convert excess airspeed to altitude, before settling to the max rate (or max angle if you have a notable advantage) of sustained climb. It is seldom advantageous to eke every bit of speed out of the zoom to below optimal sustained climbing speeds.

In a combat zone, you may even opt to zoom less, and climb at a slightly less than optimal speed significantly above the best rate value, to add defensive capability against an unseen bogey.

In practice almost all combat is many v many (even if it is actually 1v1 there is always the possibility of additional unseen bogies entering the fight... and it is prudent to operate around the edge of a possible bogey cloud, with minimal continuous turning, high speeds, limited straight line flight without belly checks etc. Take a quick shot, and then exit the fight, re-entering once cleared, but only on the periphery. Provide cover by proximity, rather than attempting formation flight, and enter/exit with a wingman if possible.

Planned out well, you might get 2-3 snapshots against different bogies per entry into the fight, with immediate exit with less than 90 degrees total turning. Any more advanced than a simple turn will seem exotic, and will 'fix' you in a limited portion of sky, which may attract unwanted attention from unseen/multiple threats. In the worst case you may find yourself the focus of the dogfight, with threats all around you... at best all on your own, with the fight moving off elsewhere...

#3888013 - 01/02/14 04:44 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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I remember once, I was flying mosquite fighter (in IL2 game), and a fw190 dove on me, he missed and presumably thought he would retain his energy, if he just zoom climbed. So what he did, he shot at me, then he went under my plane, and zoomed up in front of me.

fw190 started zooming up in a straight line basically, at 50deg angle upwards, in front of me.

At first, for one second I was a little bit dumbstruck from the fw190's attack on me, but then I just pressed the trigger and devastated the enemy fw190 with 4x20mm and .303 british MGs.

It certainly helped that I had heavy concentrated fire cone to use against him. He would have been beyond my usualy wing convergence, if I had had wing mounted guns. Luckily now all guns were in nose.

Last edited by Laurwin; 01/02/14 04:44 PM.
#3888024 - 01/02/14 04:53 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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Lieste is of course right, best climb can leave you quite vulnerable to attack. Is this what you meant? (most altitude gained per time)

Effectively you become very slow in this kind of climbing with e.g. a bf-109. It's good for fuel efficiency(?), and for sustained climbing but that caveat is that you are quite slow speed for the duration of the climb.
Effectively, a low speed target in the sky.

Last edited by Laurwin; 01/02/14 04:57 PM.
#3888870 - 01/03/14 08:04 PM Re: flight manouvers: optimal zoom-climb [Re: Lieste]  
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Laurwin Offline
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Originally Posted By: Lieste
It is useful for minimising horizontal turn radius to use vertical manoeuvres ~ as few aircraft have had the ability to sustain or accelerate in a vertical climb these are almost always zoom climbs. In order to complete these it is desirable to start with at least vertical manoeuvring speed (sufficient to get the nose vertical before speed falls below minimum control speed (stall not being too meaningful when the wings don't actually need to provide gross lift).

It is useful for a continuing offensive position to have at least sufficient control authority to roll during the vertical portion and then to recover to horizontal flight before loss of control, so entry speed should be higher than minimum vertical manoeuvring speed by some margin.

This is the core of several offensive methods, most notably the rolling scissors, which are a sequence of zoom climbs and rolling lead turns in the vertical, before recovering to the target's altitude in an attempted attack/lag pursuit.

Zooms are dangerous if you zoom higher, but he retains control at a lower speed, as you will often find yourself slow and close ahead of the bogey... in order to be safe you must reduce the bogey energy to below *his* vertical manoeuvring speed, force him to lose sight, or terminate your zoom before you pass ahead of the bogey... in no circumstances attempt to zoom against a bogey with a large angular advantage (in your rear hemisphere) unless you know he is too low on energy to even attempt to place his nose on you.


Other uses of zoom climbs include many of the turning climbs (chandelle et al.) These are often safer if you have an energy advantage and climb rate advantage, as the steepening sight angle caused by your turn forces a steeper zoom from the lower bogey *and* a tighter turn, which is usually not available in combination. Note this only prevents him following you with a guns solution, and not shadowing in lag pursuit, which may permit higher energy state and a better angle off nose/position than you might expect... if you lose sight of a bogey during a climbing turn, be prepared for a neutral pass at best.


Well, you don't have to keep chandelling in a circle, if the enemy is lag pursuint you? Turn it back into a drag and bag?

I thought it was enough to simply try to gain the angular advantage. (behind enemy's 3-9 line).

I saw this tactic of simply turninig into the enemy, above him, and climbing. It was in apeoftheyear's CLOD video on youtube. He did that with bf109 vs spit, first, instead of chandelling from the get-go, as I recall.

The idea would be, the enemy below you, cannot pull unlimited amount of elevator for very accurate snapshot, he will have to exceed AoA of his wing and stall at some point, robbing him of energy.

Last edited by Laurwin; 01/03/14 08:06 PM.
#3888995 - 01/03/14 10:42 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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What you do depends on your opponents energy state and available weapons. If the energy of the bandit and your own is not known, then there's not much context for answering such questions and the answer always becomes 'it depends'.


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#3893480 - 01/11/14 08:40 AM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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I just discovered this topic today. Am I right in assuming that, for maximum energy retention, the zoom climb profile should look something like this?



Initially you should try to convert all your speed into altitude before it is reduced by drag. However, once your speed has dropped to the optimal climb speed, you should leave vertical flight and assume an optimal climb profile.

#3893743 - 01/11/14 11:08 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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The FW190s and P51Ds do that all the time on DCS.



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#3912093 - 02/14/14 10:59 PM Re: flight manouvers: optimal zoom-climb [Re: B25Mitch]  
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Originally Posted By: B25Mitch
I just discovered this topic today. Am I right in assuming that, for maximum energy retention, the zoom climb profile should look something like this?



Initially you should try to convert all your speed into altitude before it is reduced by drag. However, once your speed has dropped to the optimal climb speed, you should leave vertical flight and assume an optimal climb profile.


I suppose, that would be right...?

Although, intuitively you would think, that in the start of the exit climb, you ought to avoid "over-Ging" the airframe. Whether this is correct thinking is... left to somebody more knowledgeable on this forum, to correct me upon this line of thinking. xwing

But then again, on the flipside of the coin, does the stored kinetic energy (from diving in beginning) "carry the airframe on", even regardless of little bit high-G forces in the early turn, (climb towards the sky). This seems to be the case, at least to an extent.

Steep turns high-G, can have the crippling effect of increasing drag, - skidding with the airframe really. Maximum use of ailerons and rudder. This is the "infamous speedbreak" manouver.

Drag increases as more of the control surfaces and flight surface has been exposed to the airflow, in a different way than simply as though flying straight ahead (geez sounded painful). Then again, the aircraft could simply stall due to exceeding critical angle-of-attack of the wing. (in the pull-up phase I mean). Although, with certain planes the result would rather be, critical airframe failure, due to wings ripped off.

At the end of the curve, stored kinetic energy has been fully spent, and aircraft is flying on it's own energy, therefore necessitating more normal flight procedures to avoid stalling (such as optimal climb angle as depicted in diagram) OR simply going straight and level accelerate to better speed.

A different diagram would be, if you allowed for the attacker to "fly through the attack", also extending distance horizontally between the target and him, and climbing along the same way. (in the end, this attacker also, must revert to either optimal climbing, or normal straight flying in the end of the climb)

Would you lose less kinetic Energy into drag, with "gentler low G" extending and climbing, such as abovementioned? (less energy lost into drag, as compared to dive and zoomclimb steeply)

This "flying through attack" and extending long way seems to be just about the only practical way of fighting with some aircraft, such as P-47s (infamouosly heavy aircraft, - in stark contrast with an "energy fighter" such as bf109)

#3912785 - 02/16/14 07:27 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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I think, generally speaking, you are:

A. Rarely going to get a vertical climb out of this maneuver as, by the time you get your nose vertical you will be concerning yourself with getting it back down.

B. Seldom going to climb at "optimum climb speed" whatever that speed is. Best climb rate speed and best climb angle speed are both almost certainly entirely too slow. I would think "Peak Power Speed" (assuming that is higher) would be a far more realistic speed to assume.

Honestly, I don't know what that speed would be as a very general rule in the jets that I flew was to maintain at least corner speed whenever there wasn't a reason to maintain another speed. But that was predicated on, one, the possibility that I would need to be ever ready to defend against a missile shot and, two, because I could. In a prop, at least one of these things...and possibly both may not be true.

Still, I think Grey Ghost brings up a good point in that much of this is always going to depend.

Consider two possibilities. These are high aspect attacks. Tail chase would require other considerations:

1. I'm in a Wildcat fighting a Zero. As the energy fighter, I need to keep my speed and altitude advantage up...well up. If I'm going to bounce a Zero and climb away, I need to get back up to altitude, but also get some distance before he can turn around on me. If I'm cranking my nose into the vertical, then shoving it over to climb away, I stand a real risk of the Zero turning around on me and bringing guns to bear to find me hanging on the prop and still in guns range. In this case, your zoom maneuver is based at least as much on your opponent's capability as it is on your most "efficient" profile.

2. I'm in a Thunderbolt trying to keep 109s off the bomber stream. Historical tactics aside for a moment here, the 109s are going to be fast and preoccupied with running down the bombers while trying not to end up as sitting ducks in the process. In this case, you need to get your nose around as fast as possible as the fight is running away from you. So, you still won't want to park your nose, but rather convert only any excess airspeed to altitude and using the rest to get your nose around and back into the fight.

Just something to consider if we are trying to isolate the "ideal" energy fighter attack.

Deacon

#3912832 - 02/16/14 09:17 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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When the AI does this in DCS in their P51Ds it is quite annoying and man they can climb it is a real mission to nail them. BTW this reminds me of the story of "The last Gunfighter" 1 F8 crusader vs 8 Migs where he kept doing a zoom climb to build up more energy. My own view in DCS in F-15C vs SU27/Mig29 I use a climb and roll if I'm about to overhoot which has the same effect only the angle is not as steep. immelman



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#3939660 - 04/15/14 02:34 PM Re: flight manouvers: optimal zoom-climb [Re: Laurwin]  
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yes this kind of scenario reminded me also, of the history channel dogfights episode, with an American aircraft, out of missiles, with a jammed gun.

He had to fly REALLY WELL in order to survive and evade all those migs.

Initially, he used quite good energy fighting tactics and the vertical plane to convert the altitude into speed and vice versa.

At the end though, he managed to evade all enemies, and escape the fight and rtb

Last edited by Laurwin; 04/15/14 02:34 PM.

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