Author Topic: Optimal reversals in a dueling environment (Read 330 times)

LoneStarBuckeye · « **on:** September 18, 2002, 12:23:22 PM »

In a dueling situation, where two planes are merging co-alt, co-speed, and with a slight lateral separation, what is the optimal reversal, assuming that both planes have sufficient speed to pull maximum g throughout the reversals and that both planes will, in fact, pull maximum g throughout the reversals? In my very limited dueling experience, it seems that most pilots pull Immelmans, either pure or oblique. The variable seems to be the proper oblique angle. When I first started, I would use non-oblique Immelmans (i.e., half loops) but found myself getting losing angles to pilots that used oblique (e.g., 45-degree) Immelmans. Perhaps the answer depends on the types of planes used for the duel, and on how AH's g-limit works (see my earlier post).

Originally, I assumed that AH's g-limit was such that planes (and their virtual pilots) could experience no more than 6 g. In that case, it seems to me that a pure Immelman reversal should be the fastest reversal when a plane has enough energy to pull maximum g throughout the reversal. Thinking in terms of a "doghouse" EM (energy maneuverability) plot (one source of examples and explanations of EM plots is Badboy's article at http://www.simhq.com/simhq3/sims/air_combat/energymgmt/), planes performing oblique and non-oblique Immelman reversals will be to the right of the "peak" throughout the maneuvers (i.e., they will be pulling maximum g throughout the reversals), but the plane performing the pure Immelman will lose more speed than a plane performing any oblique Immelman, because it is converting more of its speed into altitude. Thus, it seems to me that the plane performing the pure Immelman should turn tighter and get its nose around faster (i.e., it should, throughout the maneuver, be closer to the "doghouse" peak and therefore be turning with a smaller radius and at a greater rate) than one performing an oblique Immelman. My experience has not borne this out, however.

My observations may be explained by the way that AH's g-limit works (or by the fact that I suck

). Namely, if AH's g-limit limits the g that planes can generate, rather than the total g (i.e., g generated by plane plus or minus that contributed by gravity) by which they can be affected, a plane pulling a maximum-g oblique Immelman may, on average, experience higher g than a plane pulling a maximum-g non-oblique Immelman. Thus, a maximum-g oblique Immelman may reverse a plane faster than a maximum-g pure Immelman.

If anyone has any insight or corrections, I would really appreciate reading them! Thanks in advance.

- JNOV

humble · « **Reply #1 on:** September 18, 2002, 12:51:48 PM »

No easy answer to your question...the best suggestion I can give you is look for rocketmans link on the merge.

Briefly, There is no set "winner" in a merge situation. A couple of factors come into play. Same plane or different plane...angles opener or E opener. Also what "rules" if any. As a general fact the lower plane at the merge has an edge. Without a hard deck many duels start with both sides screaming low. The second issue is deciding on a "long" or "short" opener. A long opener is the start to an E fight and is a safer opener...you basically are zooming the merge and extending up...the key is minimal energy loss. A short opener is the start of an angles fight, your trading energy for a favorable tactical position early and banking on winning by keeping the pressure on. Both can work well...or kill you. The worst thing is the "tweener" a merge that doesn't really give you one extreme or the other...that being said there are some outstanding 1 on 1 sticks who reguarly open with a tweener and rely on there skills to out fly the opponent.

E fighting is to complex...at least for me...to explain in a post but angles fights are decided quickly. The key is generating a lead turn...usually starting the merge at 1.2 out or so...one sign you've been smoked is seeing your opponent flash right up thru your front quarter view as you "merge"....a sure sign he'll be screaming back down on your prettythang 2 sec later. The second key is deciding which option at the "top" or remerge. 1 choice is getting your nose over 1st for a front quarter shot...often you need to shed a lot of e...it's really a vertical scissors merge. The 2nd is to "top out" the other guy. The guy who falls of first loses the initiative.

The best angles opener is the dreaded "rudder slap" ala DMF (leviathen) or nash. Hard to describe and harder to do...but fun when and if you get a feel.

Nath Lev nash are among those I always felt were great one on one...I'm sure there are a lot of others who can add to this.

dtango · « **Reply #2 on:** September 18, 2002, 06:00:45 PM »

Good points by humble.

LoneStar - regarding EM charts...

Remember that with EM plots - the "doghouse" portion of the plot is instantaneous turn performance. E.g. at the peak of the doghouse (corner velocity) is where you get your best turn performance. This only lasts as long as this velocity can be maintained which is usually short-lived since pulling max-g's typically means you're bleeding E.

Assuming co-e, co-alt, similar planes the aircraft and given the merge you've described the aircraft that is ending up with better angles is probably the aircraft that was able to fly in a envelope closer to the optimum turn performance vs. the other.

What you may be observing between oblique or non-oblique immels is this relationship. E.g. - non-oblique immel, you're loosing more airspeed in the vertical vs. the oblique immel which is putting you further away from the "peak" than the aircraft using the oblique.

Key for the instantaneous portion of the EM chart is that inst. turn performance is velocity dependent and that velocity is changing as you maneuver.

Tango, XO
412th FS Braunco Mustangs

LoneStarBuckeye · « **Reply #3 on:** September 18, 2002, 06:25:25 PM »

Tango and Humble:

Thanks for the replies.

Humble:

Sounds like a lot of good advice. I did go (http://www.netaces.org) to find Rocketman's articles on the merge. Really good stuff there.

Tango:

I recognize the instantaneous nature of the EM charts and that when pulling maximum gs, you quickly move from right to left on the chart. But sometimes (e.g., in a co-alt, co-speed merge between two Spit Vs at ~280 MPH) both planes have enough speed to pull maximum gs throughout the entire reversal. What I was wondering was whether, in that case, the plane pulling the pure Immelman should always be closer to the doghouse peak (although still in the g-limited range of the chart) and peak turn performance than the plane pulling an oblique Immelman?

Something I didn't consider earlier is that my opponent may have been chopping throttle or getting on his rudder to bleed speed. There is also the possibility that he was continually able to lead turn me, although that wasn't the impression I got during the fights.

Thanks again for your help.

- JNOV

dtango · « **Reply #4 on:** September 18, 2002, 11:41:26 PM »

LoneStar:

I just did a couple of offline tests. Spit V, 50% fuel, ~ 1.5K alt, 280 MPH, WEP on...

Pure loop (wings-level), max performance turn throughout- at the peak of the loop (roughy 180 degree reversal) airspeed was around ~160 MPH's. Range of airspeeds was between 280mph-150mph throughout the maneuver.

Oblique loop, max performance turn throughout - at the peak of the loop (roughly 180 degree reversal) airspeed was around ~180 MPH's. Range of airspeeds was between 280mph-170 MPH's throughout the maneuver.

This indicates to me the oblique vertical move allows you to maximize turn performance over the wings-level vertical since the oblique maneuver (a) results in a smaller difference in velocity change and (b) keeps you closer to corner velocity.

I'll have to think on why this is aerodynamically so. I think it has to do with the relationship between potential and kinetic energy transfer but need to think on the math a little.

Tango, XO
412th FS Braunco Mustangs

Lephturn · « **Reply #5 on:** September 19, 2002, 06:57:22 AM »

Basically it's because in the pure loop you gain more altitude than in the oblique. The result is that you trade more kinetic energy (speed) for potential energy (altitude) than you do in the oblique loop. However, being that max turn performance occurs at a certain speed, your overall performance will be a bit better if you don't trade too much speed for altitude during the maneuver. As you said, staying closer to corner speed works better overall. This is all dependent on what speed you are flying when you start the maneuver of course. If you start at a higher speed, you may need to trade more speed during the maneuver to keep from being too far above corner speed overall.

There is a second reason for using an oblique immelman as well. (You don't really want to loop, just immelman if you have the speed.) If you go straight up all the time, you are very predictable, and your opponent will quickly adjust his tactics to kill you when he knows what you will do next. Best to use an oblique maneuver, and vary which direction you go to keep it mixed up.

Also, I'd like to point out that you don't want to merge level with the other guy if you can help it. The sharp merge tactician wants to merge slightly lower than his opponent and be already turning upward as they pass. You also need to take lag into account online, in that you can start your break before you actually merge, and you know the other fellow can't actually see the maneuver for a second or so. That means you need to start your break earlier than it "looks like" to take maximum advantage of the situation. The best way to get this down is to practice breaking earlier and earlier. Eventually you'll simply turn in front of him and get killed a few times, and that will let you find the sweet spot. Just keep in mind the "sweet spot" on when to start your merge turn depends on the latency of the Internet between you, the host, and your opponent at that particular point in time, so it's quite variable.

LoneStarBuckeye · « **Reply #6 on:** September 19, 2002, 08:44:13 AM »

Tango:

Thanks for taking the time to run some tests. It sounds like your tests negate my hypothesis: namely, that a Spit V at 280 MPH IAS can pull a maximum-g, non-oblique Immelman and stay to the right of the "peak of the doghouse." That, in and of itself, is useful. Thanks also for the other useful information and insight.

Lephturn:

Thanks for your thoughtful response. After reading Rocketman's articles on the merge, I take your point that it is best to avoid the co-alt merge to heart. Also, I know from my own experience that, in general, enemies that use non-oblique or in-plane reversals are much easier to kill (or at least ping) than those that use out-of-plane reversals.

Thanks again - JNOV