Author Topic: P-38 Flaps  (Read 5416 times)

Offline FLS

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P-38 Flaps
« on: December 15, 2020, 08:04:23 PM »
With the new models I'd like to revisit this discussion.  I don't recall the source, possibly Hanger Flying, but I've read that the P-38 had it's best turn rate and radius at the maneuvering setting which was the flaps extended half way.  The P-38 only had up, down, and maneuvering positions on the flap control. Any other intermediate position was possible but wasn't marked on the control. The gauge shows more positions but the control does not.

In Aces High the half extended maneuvering position appears to be the 3rd or 4th flap position. Badboy's flap test shows the best performance at the 4th.

The flap speed limit for the maneuvering position is 250 but in AH this is applied to the first flap extension where the performance increase is less.

I don't expect the flap system to set any flap intermediate angle like the real P-38 but it would be nice if the speed limit was applied to the half extended flap position rather than the first notch.

Offline Mongoose

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Re: P-38 Flaps
« Reply #1 on: December 15, 2020, 08:54:12 PM »
I regularly extend two or three notches of flaps at 250 mph.  Someone many years ago told me that two notches of flaps is equivalent to maneuver flaps, but recent discussion disputes that. 
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Offline Badboy

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Re: P-38 Flaps
« Reply #2 on: December 15, 2020, 09:55:52 PM »

I've read that the P-38 had it's best turn rate and radius at the maneuvering setting which was the flaps extended half way.

In Aces High the half extended maneuvering position appears to be the 3rd or 4th flap position. Badboy's flap test shows the best performance at the 4th.

There is more than one best performance. There is best sustained turn rate and radius, and best instantaneous turn rate and radius. The question is which one was being referred to in the source you read?

I generally refer to best sustained values because that is where aircraft in AH usually end up in a protracted turning engagement, but historically I believe that instantaneous values are more likely to have been referred to because that was more important to real pilots for the following reasons.
  • That point on the envelope was closer to what could be achieved in high speed attacks
  • The turn rate at corner is significantly higher than sustained values
  • Staying at speeds at or above corner velocity improved survivability
  • Typical pilot G tolerance meant sustained turning engagements were less desirable
  • Typical relative aircraft performance in the pacific theater made sustained turning less desirable
  • High speed attacks with brief (high G) tracking shots were therefore more common
With that in mind, I would be more than a little surprised if any real design was based on sustained performance values.

If you look at the positions of those two performance points on the EM diagram below you can see that while the best sustained turn occurs at 4 notches of flaps, the best instantaneous turn occurs at 3 notches of flaps at a corner velocity of 236mph and just inside the flap limit of 250mph at that setting, which seems to correspond to what you have read.



When I did this back in the day I recall thinking that this was yet another fine example of the excellent AH flight model and the high standard of indepth research done by HTC :salute

Hope that helps

Badboy
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Offline FLS

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Re: P-38 Flaps
« Reply #3 on: December 15, 2020, 10:14:07 PM »
I took another look at the flap lever in the new cockpit and the marked maneuver position coincides with the 4th notch of flaps. I realize this is just a graphic but it fits the turn tests and the claim that the maneuvering position gave the best performance.

Now we just need the flap deployment speed adjusted to match the placard in the cockpit.  :aok


Offline atlau

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Re: P-38 Flaps
« Reply #4 on: December 16, 2020, 09:33:50 AM »
Badboy- did you do em diagrams on other aircraft too? I think these would be great for HTCs aircraft performance comparison pages.

Offline Badboy

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Re: P-38 Flaps
« Reply #5 on: December 17, 2020, 01:46:56 PM »
Badboy- did you do em diagrams on other aircraft too? I think these would be great for HTCs aircraft performance comparison pages.

Hi Atlau,

Yes, I've done quite a few others over the years but far from all.

I agree, it would be great to see doghouse plots on the aircraft performance comparison pages, and of course I would be delighted to help, but I suspect that player interest would not be sufficient to drive such a project forward. Naturally I'd be equally delighted to learn otherwise.

Over the years I've posted everything on these boards including analysis tools so that players can do their own comparisons of turning performance. Unfortunately, links have expired with age and posts have become buried over the decades, so this may not have been the best medium.   

Despite that, I've always been willing to share information openly with fellow players and will continue to do so unless a better alternative presents itself.

Kind regards

Badboy
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Offline DaddyAce

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Re: P-38 Flaps
« Reply #6 on: December 17, 2020, 04:42:52 PM »
Badboy,

I have always enjoyed and appreciated your posts, having an interest in the technical aspects of WW2 aircraft technology, and am very glad to see you back and active on this forum.   :salute

Offline Oldman731

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Re: P-38 Flaps
« Reply #7 on: December 17, 2020, 05:41:12 PM »
I have always enjoyed and appreciated your posts, having an interest in the technical aspects of WW2 aircraft technology, and am very glad to see you back and active on this forum. 


Wait until you meet him in the arena, one dark night...

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Offline atlau

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Re: P-38 Flaps
« Reply #8 on: December 17, 2020, 07:57:44 PM »
Hi Atlau,

Yes, I've done quite a few others over the years but far from all.

I agree, it would be great to see doghouse plots on the aircraft performance comparison pages, and of course I would be delighted to help, but I suspect that player interest would not be sufficient to drive such a project forward. Naturally I'd be equally delighted to learn otherwise.

Over the years I've posted everything on these boards including analysis tools so that players can do their own comparisons of turning performance. Unfortunately, links have expired with age and posts have become buried over the decades, so this may not have been the best medium.   

Despite that, I've always been willing to share information openly with fellow players and will continue to do so unless a better alternative presents itself.

Kind regards

Badboy

Gotta be a smart web programmer ln these boards who could create a drop down comparison view of those diagrams just like the speed and climb ones. Would be cool especially for new guys to learn the planes.

Offline Puma44

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Re: P-38 Flaps
« Reply #9 on: December 18, 2020, 07:49:22 AM »
A very familiar EM chart similar to what’s in modern day fighter manuals.  Excellent work, Badboy!  :salute



All gave some, Some gave all

Offline DaddyAce

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Re: P-38 Flaps
« Reply #10 on: December 18, 2020, 08:34:02 AM »
Wait until you meet him in the arena, one dark night...

Oh, I know he's good as well as a great tech resource.  We had a session together where Badboy flew a variety of luftwaffe birds against me to help prep for a scenario, 'twas great fun as well as a great learning experience.

Offline Drano

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Re: P-38 Flaps
« Reply #11 on: December 18, 2020, 08:36:25 AM »
I've been on a "purge the house" kick lately. I've found lots of things I thought I'd lost only to find that once again that thing was in perfect condition packed in a box! I found a box of Air Warrior stuff. The game, all the Kraits' stuff, etc. A bunch of Badboy's pdfs that I'd printed out and put into report holders. Was great reading in my formative years of this trying to figure out how not to die so dang much! I always looked forward to Badz kicking out another one.

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Offline Cluzig

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Re: P-38 Flaps
« Reply #12 on: December 18, 2020, 08:40:55 AM »
I would honestly love to see all those diagrams and charts I think it's very helpful to form a picture of what aircraft can and can't do.
I remember in aces high 2 there were some turn radius charts but not so detailed.

Offline FLS

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Re: P-38 Flaps
« Reply #13 on: December 18, 2020, 09:22:58 AM »
When you look at the aircraft list in the hanger you can right click and select charts for speed or climb rate. You can use climb rate to indicate acceleration.

The EM diagrams are very informative but you get a good start with the speed and climb charts.

The EM diagrams show your corner speed, which you can't maintain unless you're diving but it's a good number to know, and it shows your best sustained level turn, but dogfights tend to the vertical. 

You're also less likely to monitor your speed and G while keeping your eye on the bandit in a busy airspace. So while EM charts are useful they are not necessary, but they do quantify performance differences. This is more critical when you only have one life but in game we can learn from our fatal mistakes.

Offline Badboy

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Re: P-38 Flaps
« Reply #14 on: December 19, 2020, 11:45:02 AM »

The key thing to remember about the kind of information we are discussing is that to the military it is vital intelligence, to game players it might seem less important, perhaps just nice to have. However, for a business hoping to grow a player base, it is a little more than that. So this comment surprised me:

Quote from: FLS
This is more critical when you only have one life but in game we can learn from our fatal mistakes.

This game has always had a steep learning curve. It takes time before new players figure out how to kill more and die less and thus take pleasure in success and enjoy the game more fully. That is a major factor in the high player attrition rate. Learning by trial and error is time consuming and while it is essential to be able to learn from our mistakes, because they are impossible to avoid, a key idea in education and training is to control how much of that is really necessary.

Unfortunately learning from mistakes isn’t always possible. I’ve encountered AH vets with many years’ experience consistently being out turned in their favorite aircraft because they didn’t know the best configuration as revealed after consulting an EM diagram. The problem with trial and error is that the outcome of a 1v1 engagement is the combination of pilot ability, initial conditions and aircraft performance. That means you may think you have learned something about an aircraft after lengthy trial and error, only to discover that it had more to do with the other factors after all. That may be why we see so much frustration and unwarranted accusations in the MA, even among seasoned players.
 
Even when mistakes aren’t fatal, they can often be costly. That’s why it’s called learning the hard way. Fortunately in a gaming environment the costs are mostly trivial such as a loss of perks, mission objectives, and enjoyment. More importantly, in a gaming environment I would argue that the most important loss is the time required before players can enjoy the game enough to continue playing long term.

Dale has referred to this attrition of new players coming into the game as being like baby turtles trying to make it to the sea, very few new players survive to return. That’s why every form of assistance that reduces the learning curve, including speed charts, climb charts and doghouse plots are all absolutely necessary.

Quote from: FLS
while EM charts are useful they are not necessary

I would be confident in saying that every fighter pilot who has used doghouse plots since they were first used to compare the Spitfire and 109 engagement back in 1940, would consider them necessary and disagree with your sentiment. Indeed, when the method was first shared with the USA it was quickly used to provide intelligence from as early as 1943 and continues to have a profound influence on fighter tactics to this day.
 
Of course some lessons can be learned by trial and error eventually, but really… who would deliberately choose to die repeatedly to discover something they could have learned more quickly and easily before taking off. Trial and error is a slow and difficult process so in a game where reducing the learning curve is vital for player retention, I would suggest an idea like this is exactly what is necessary.

Quote from: FLS
but dogfights tend to the vertical.

They can do but the real tendency in a dogfight over time, as each pilot exchanges energy for position, is to get lower and more horizontal. As speed and altitude are depleted fights tend to the horizontal. Everyone ends a fight in flat turns on the deck at some point. The more evenly matched the pilots and aircraft are, the more often it happens. The more often it happens, the more important a good understanding of EM theory becomes.
 
Of course, an aircraft with a Ps advantage, can climb during a hard turn relative to an opponent but where in the envelope that capability exists, and against which aircraft can most readily be seen on an EM diagram. Knowing when you can do that and when you can’t, without having to die over and over to figure it out is why EM charts are necessary.

Quote from: FLS
You're also less likely to monitor your speed and G while keeping your eye on the bandit in a busy airspace.

All good pilots monitor their speed and G constantly during a dogfight. Not by looking at gauges, but in relative terms in comparison to whichever aircraft they are engaged with. For example, in terms of speed, having a sense of being too fast or too slow using external visual cues is key to success. Similarly with g loading, most pilots know that pulling too hard can be as bad as not pulling hard enough and they use external visual cues to monitor that constantly. The EM diagram is vital in that regard because an overlay shows at a glance if you have a turning advantage at lower speeds or higher so thinking in relative terms is key. For example, an overlay of the Ps curves for the P-51D and Me 109G6 reveals that while the 109G6 can easily out turn the P-51D at low speed, the P-51D can out turn the Me 109G6 at all speeds above 190mph. That can be seen from the point where the two Ps = 0 curve cross. The P-51D pilot doesn’t need to look at his gauge to know when he reaches that point because as they are fighting his visual cue for speed will be whether or not he appears to be gaining angles. While he is gaining, he knows his turn rate is higher and speed is therefore above that critical point, once the 109 begins to gain angles he knows he’s too slow.

The EM diagram also showed him that because he has a Ps advantage at higher speed, along with a higher top speed he has the choice to either zoom climb converting that excess power to an altitude advantage or extending and converting that excess power to acceleration and speed, depending on what else is happening around him. Many pilots learn to do this in a less precise manner without EM diagram overlays. But knowing what speeds are involved, what turn rates and if they are decisive or not and how steeply you can climb while turning and still match your opponent’s turn rate all add a degree of certainty and confidence that can lead players to enjoy the game more fully in a far shorter time.

Those things can all be learned quickly and with confidence from EM diagram overlays. Of course they can also be learned from trial and error, in some cases it can be painfully slow with much less certainty, if at all. The cost, is that the learning curve remains steep and new player attrition and levels of frustration remains high.

The scientific method used in WWII and elevated to new heights by John Boyd in the early 60's can reduce the learning curve and lead to a higher level of success and thus enjoyment in a shorter period of time. I've been sharing this information for a long time, and for many it has made the learning process enjoyable in its own right and in every case has helped improve their flying and made it more successful and enjoyable.

Sorry, but I've typed (and rambled) a little more than I intended, so in closing I would just like to add this:

I believe that AH already has an incredibly knowledgeable, well informed, talented and skillful player base. But sadly that player base seems to have stopped growing. The potential benefit for everyone in extending information and help to both new and old players alike would seem to be anything but unnecessary.

Kind regards

Badboy


The Damned (est. 1988)
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