A DM/FM bug that lead me down a rabbit trail of more bugs.

[Volant_Eagle]

Wow, I'd like to apologize before hand but this post got WAY longer than I'd original intended. I probably could have just left a simple one paragraph bug report. I still think it turned out alright though so I'll just leave it as is.

 

 

I was working on my gunnery skills as well as testing out different armaments in single player. In the process I came across an unexpected bug (or bunch of bugs). I had a formation of Heinkels set up as targets. I set them to empty so I could just focus on my shooting without worrying about return fire. I did this for a while and flew several different planes to test out different weapons. I got a little bored eventually and while using the Tomahawk decided to finish off the last Heinkel by chewing its tail off with my prop. Since he couldn't shoot back I was able to approach very slowly and carefully. I just barely nudged him in the elevator and instantly my engine stopped and his whole empennage fell off. This isn't exactly a very realistic result but I didn't really expect much different from a sim. Most of the time in combat sims we're supposed to shoot each other not ram each other. Therefore I can understand why super realistic collisions aren't a very high priority. HOWEVER, I then went to an outside view and checked the damage to my nose.....

 

 

My engine wasn't just off, it was off the plane!

 

The fact the engine came off so incredibly easily is certainly something I disagree with, but that's not exactly a bug. It's more a DM realism issue that can hopefully be worked on sometime in the future.

 

What IS definitely a bug is the fact that the plane was still flying along perfectly fine. I wouldn't even have known the engine was gone if I hadn't looked outside! Just the Allison itself weighs about 1,400lbs not to mention the prop, accessories and everything else making up the entire nose section. There's simply no way an airplane can maintain controlled flight with that much of a shift in Center of Gravity. Most likely the plane would 'pancake' straight down like a falling leaf. Instead, I still had perfectly normal control of the airplane and was able to glide it in for a belly landing at the airfield below me.

 

 

. . . my judgement of the glide angle was obviously a bit off . . . 

 

This was the first time I'd ever "de-engined" a plane in CloD so I thought this was just the way CloD was. That was very disappointing as I expected better from a sim which in my opinion has one of the best flight models out there. If this wasn't a bug and was just the way the FM worked then that was going to be a huge problem for me. For me the FM is by far and above the most important part of any flight sim. That's the part that makes it a "simulator". Not the way it looks (though that is important), but how it behaves. If the planes in a game don't behave how a the real things behaved, both in performance and handling, then it isn't a sim. It's just an aviation themed game. However, not having personal access to the real life planes in question, I have to put a lot of trust in simulators that the developers really did their homework. Issues like this really put my faith in a particular sim in question. This is because I don't know what else in it I can't trust to be done correctly. And I don't usually have the resources to properly 'fact check' every way in which a sim behaves. 

 

However, I knew from experience that CloD is still pretty buggy and this particular issue WAS something I could test myself to see if it was just a bug or not. All I had to do was jump into another airplane, knock its engine off, and see if the same thing happens. So, I did the same thing in a Hurricane. . . 

 

 

To my great relief, once the engine came off, the plane started to pancake and even began sliding backwards. I could still cause some motion through the flight controls but no matter what I did I was unable to regain any form of controlled flight. This was exactly what I was hoping for and confirmed that my issue in the Tomahawk was only a bug in that particular plane, not a fundamental game engine issue. Out of curiosity I then tried the Kittyhawk . . .

 

 

Darn it, same bug again. If the contrail angle isn't enough proof, I was able to fly it back to England and set it down nicely in a field.

 

 

Well at least I now knew I was dealing with something that was only a bug. A bug that's probably really easy to fix. But before I reported this bug I thought I might as well do my research and see just how common this bug is. So, I spent a good portion of a day knocking the engines off of every single engine fighter in the game . . .

 

 

Well all the main variants at least. I didn't do every single sub variant. I'm not THAT mental.

 

I didn't find any other aircraft with the same issue of completely disregarding the CG change like the P-40s did. Luckily that bug seems to be isolated to just those 2 airframes. But then again I didn't test every single variant. I did also come across some other buggy behavior in the process though. First some minor visual bugs: I found the spinner base remaining in place on the Spitfires and the whole engine cowling remaining in place on the Bf 109F as can be seen above. That's really knit picking though.

 

I did find a lot of variance in exactly how each plane fell though. Some fell flat (Bf 109E and G.50), some slid tail first (Hurricane and CR.42), and others fell nose first but weren't recoverable because the wings remained stalled or mostly stalled (Gladiator, Spitfires, D.520, Bf 109F). The nose down attitude really doesn't seem right to me but then again I'm a pilot not an engineer so I could be wrong. Whether I'm right or wrong it isn't that big a deal though. All these cases have the same end result: an uncontrollable plane. So whether that particular plane should actually be falling rearwards, forwards, or flat doesn't really have much effect on gameplay. However, some of these differences are stark enough that they do cause questions in the back of my mind about the flight model. The most obvious is the difference between the Gladiator and the CR.42. These planes both have a very similar layouts yet in the game they fall completely differently. The Gladiator falls sorta between flat and nose down, the CR.42 instantly flips up and falls tail straight down. I'm a bit puzzled as to why that could possibly be.

 

More on the bright side I was very happy to discover that the FM correctly models the effects of control surfaces even when going backwards:

 

Some much more serious bugs I found were a few planes that would completely ignore damage and knock the tail off the bomber without even taking a scratch. I had this happen sometimes with the D.520 and the Bf 109F but not always. The C.202 and the Martlet were by far the worst. I was actually never able to knock the engine off of either of these. The engine not departing isn't really the problem. I'm actually pretty certain that in real life giving a slight nudge to a bomber's tail would leave the engine on any of these planes firmly in place. The main issue I want to point out is that these planes weren't taking any damage AT ALL and yet they were knocking the whole tail section off of bombers. This can be seen in the C.202 and Martlet pictures above. 

 

Once while in the C.202 and ramming a BR.20M, I actually passed into the fuselage of the bomber and was flying inside of it for a couple seconds! Then my whole airplane vaporized in an instant except for its engine. The aftermath is picture below.

 

While using the Martlet I discovered that if I came in with a little too much speed I would vaporize into powder and the bomber might be fine. However, if I made contact at a low enough speed the Martlet was basically invulnerable and could plow right through the bomber and blow it to bits without so much as a scratch to the Martlet.

 

I'm not sure if these issues with collision damage can really be classified as bugs though. They're probably just products of a very flawed damage model for collisions. I think the damage model as far as it relates to weapon damage is quite excellent right now in CloD. However, when it comes to collisions, some improvements are sorely needed. I'm not saying collisions need to be perfect nor do I think that is possible. I'm just saying that the current collision mechanics are so bad that they can and are having detrimental effects on gameplay. Shortly after doing these tests I had multiple incidents while on the TWC server where I ended up ramming an enemy AI. (Not intentionally! I just really need to work on my judgment of closure. [Hmm, spending hours intentionally doing mid-airs probably didn't help me much with that?]). I barely clipped a Hurricane from behind as well as a Blenheim. Both of them vaporized and I was left undamaged. That's not exactly a way you want players to be able to score kills. I also had an incident where I clipped a Blenheim and instantly blew into tiny bits. The Blenheim just flew away unscathed. A very irritating way for a career to end.

 

Sorry again for the long rant but once my mind gets going on something I kinda need to either drop it or go all in. I know I might sound critical but I only critique things I care about. And right now there's both a lot of things to critique about this game as well as it still being my favorite game period . . . so you'll probably be hearing from me again. I understand if fixing these issues (even the very simple P-40 fix) has to take the back burner for a while. Getting the visual update out needs to be top priority right now given how long it's already been delayed.

 

Oh, and one last thing. If anyone now wants to repeat the same test I have some pointers. It is oddly entertaining and quite challenging to do it correctly. So you may want to have a go at it well the game still works this way.

 

1. Make the bombers friendly. Even if you empty the guns on any enemy bomber they're still "uneasy" around you. They tend to fidget around making them harder to hit correctly.

 

2. Approach very slowly and very stabilized from direct behind. You want to aim for making contact at about a walking pace for reliable results.

 

3. When making faster rams (likely with the Martlet), don't plan for making your escape right under the bomber you just de-tailed . . . that's kinda dumb . . .

[Buzzsaw]

Thanks for your experiments on the aircraft.

 

We will look at the aircraft which show anomalies in their aerodynamics after engine loss when we have time... likely this is a CoG bug.  The Physics Engine of CLIFFS is a very complex one, and it does reflect accurately object behaviour when factors like CoG are calculated correctly.

 

I would remind everyone these odd effects are not typically experienced in normal combat situations... as mentioned by the poster, in order to get close enough, you need to be closing with a friendly type... and there is not much logic to adopting such behavior in the game unless you are deliberately trying to game the simulation.

 

We have had others raise the issue of collisions previously... and all I can say is the game tries to show minor damage effects as a result of mid air collisions... as an variation to total destruction... to allow pilots to survive collisions in some instances.  However, unlike gunfire which can show almost infinite variation in how the forces of the bullets/shrapnel/explosions work to apply damage, collisions do not model all the variables of impact force and angle.  In real life invariably mid air collisions result in the loss of both aircraft, either instantly or after a short period, and the game generally delivers this result in Single player when both aircraft are hostile.  But of course if the player deliberately adopts these practiced 'slo-motion' ramming techniques versus friendly aircraft you may see anomalies. 

 

We still think our system is better than most other games... when contact usually instantly results in total destruction.

 

If the OP can post this to the Bugtracker I would appreciate it.

[Volant_Eagle]

By posting this to the bugtracker you mean posting a thread under "Bug tracking and Error Reporting" in the ATAG forums correct? Sorry, I'm pretty new to this whole forum thing in general.

 

The whole reason I was using that specific slow ramming technique and using friendly aircraft was just to facilitate a way to knock the engine and only the engine off an aircraft. What I was testing was the CG bug not the collision mechanics. That doesn't mean a player needs to use that exact technique to run into these other strange collision behaviors. I first ran into them while ramming enemy bombers. I only adopted the ramming friendlies technique later because it was easier and testing how collision mechanics could affect gameplay wasn't my primary focus at the time. 

 

I actually spend the majority of my time on CloD in MP. As I described above, I've actually run into these strange effects quite often. Of the 7 times my career has ended so far in the current TWC campaign, 4 of them were from mid-airs. Each time it was at relatively high speed and approaching from more or less behind the enemy. Each time my aircraft was completely obliterated. During none of these collisions was the enemy aircraft also obliterated. Sometimes they would be heavily damaged and crash, other times they would be negligibly damaged and get back to base (Supposedly. I don't remember getting any credit even though I also shot them. I was dead though so maybe that's why). Also as I stated above, I've had instances where these same collisions from the rear result in the enemy vaporizing and me not even getting a scratch.

 

I'm not saying the game needs to have a whole new collision mechanic that's on par with the weapon damage mechanics. That would be far too much work, far too much time spent, far too much extra CPU load (I think), and although it would be epic it would absolutely not be necessary. What I am saying is the way things work right now can't be classified as 'good enough' in my book. I think the game needs at least some tweaking in this regard at some point in the future.

 

I don't know exactly what those tweaks would be yet but I plan to do some testing and hopefully come up with some suggestions. I'm no programmer though so I'm not sure how much help I'll be. I'm just a dingus with a PC and too much free time.

[9./JG52_J-HAT]

11 minutes ago, Volant_Eagle said:

By posting this to the bugtracker you mean posting a thread under "Bug tracking and Error Reporting" in the ATAG forums correct? 

 

No, it's "the"CloD Bugtracker, a dedicated site. You need to register under the following link. 

 

https://www.tfbt.nuvturais.de/

 

This is an old post about it in case you want to check the semi-debious link before clicking?. 

 

[Volant_Eagle]

Awesome, thanks! I'll get right on it.

[Buzzsaw]

On 4/10/2023 at 11:08 AM, Volant_Eagle said:

Of the 7 times my career has ended so far in the current TWC campaign, 4 of them were from mid-airs. Each time it was at relatively high speed and approaching from more or less behind the enemy. Each time my aircraft was completely obliterated. During none of these collisions was the enemy aircraft also obliterated. Sometimes they would be heavily damaged and crash, other times they would be negligibly damaged and get back to base (Supposedly. I don't remember getting any credit even though I also shot them. I was dead though so maybe that's why). Also as I stated above, I've had instances where these same collisions from the rear result in the enemy vaporizing and me not even getting a scratch.

I understand you might be frustrated with the effects of collisions in Multiplayer.

 

However, much of the results are a function of online lag.

 

Your computer is continually sending and receiving updates on the positioning of your aircraft vis a vis other aircraft... this requires your PC sending data packets to the server showing where your aircraft is in the game world, and then the server sending the data to other players PC's.  And vice versa.

 

The time it takes to send these packets of data back and forth are typically around 1/4 of a second, but if one of the player's connection is particularly poor, the 'lag time' to update position can be multiple seconds.

 

This means one player sees an aircraft in one position in the game world... but another player sees it in another position.  When the aircraft are travelling at very high speeds, as they do in our simulation, then this can mean quite large differences in the position one player's PC 'sees' compared to what another player's PC 'sees'.

 

So that means one player's PC may see a collision, but another player's PC may not.  So the player whose PC sees a collision will have the damage applied to his aircraft, but the other player, whose PC does not see a collision will not have any damage.

 

Frustrating, but this is a fact of life for all online games... and for Flight Simulations, it is a particularly annoying factor.  I can remember playing RED BARON 3D in 1998, and the continual complaint on the forums at that time was lag effects and lag collisions/non-collisions and how much of this was hacking and how much lag.

 

The only solution is for all players to have very good high speed connections so the lag time is reduced... or for servers to ban players whose connections are slow.

[Volant_Eagle]

33 minutes ago, Buzzsaw said:

I understand you might be frustrated with the effects of collisions in Multiplayer.

 

However, much of the results are a function of online lag.

 

Your computer is continually sending and receiving updates on the positioning of your aircraft vis a vis other aircraft... this requires your PC sending data packets to the server showing where your aircraft is in the game world, and then the server sending the data to other players PC's.  And vice versa.

 

The time it takes to send these packets of data back and forth are typically around 1/4 of a second, but if one of the player's connection is particularly poor, the 'lag time' to update position can be multiple seconds.

 

This means one player sees an aircraft in one position in the game world... but another player sees it in another position.  When the aircraft are travelling at very high speeds, as they do in our simulation, then this can mean quite large differences in the position one player's PC 'sees' compared to what another player's PC 'sees'.

 

So that means one player's PC may see a collision, but another player's PC may not.  So the player whose PC sees a collision will have the damage applied to his aircraft, but the other player, whose PC does not see a collision will not have any damage.

 

Frustrating, but this is a fact of life for all online games... and for Flight Simulations, it is a particularly annoying factor.  I can remember playing RED BARON 3D in 1998, and the continual complaint on the forums at that time was lag effects and lag collisions/non-collisions and how much of this was hacking and how much lag.

 

The only solution is for all players to have very good high speed connections so the lag time is reduced... or for servers to ban players whose connections are slow.

Thanks. Yeah, that’s a hard issue to get around. Is it more or less the same with AI aircraft on a server? I suppose it would be but less. It’s only player-server lag, not player-server-player. I think I’ve only ever collided with AI aircraft in MP. I don’t ever notice any visible lag in these instances but I guess that doesn’t mean it isn’t there. Luckily I haven’t had any instances where from my point of view a collision should not have happened but did. Every time it was certainly a result of my misjudgment. 
 

That doesn’t mean better collisions wouldn’t be helpful in SP though. But I guess it does mean that even with better collision mechanics MP would still remain buggy in this regard.

 

If collisions can register differently from one player to another in MP, then that must also be true for weapon hits correct? I’ve had several instances where I don’t hear or see myself being hit or sometimes even being fired at. But all of the sudden out of the blue my cockpit renders as all shot up. So are hits to my aircraft dependent on what the person/AI shooting me sees and not what I see?

 

You mentioned in your first reply that collisions do not model all the effects of impact force and angle. If it’s not too much trouble, what does it take into account? Is it just the general section of the aircraft which made contact with something and the speed at which it did so? That’s what it seems like from my limited experimenting. It seems like there’s only a couple speed thresholds. For example; if a component hits something below a certain speed, that component will simply fall off, but if above that threshold the whole plane blows up.

[Lorena_Scout]

very good bug investigation @Volant_Eagle o/

[Dagwoodyt]

4 hours ago, Buzzsaw said:

...Frustrating, but this is a fact of life for all online games... and for Flight Simulations, it is a particularly annoying factor.  I can remember playing RED BARON 3D in 1998, and the continual complaint on the forums at that time was lag effects and lag collisions/non-collisions and how much of this was hacking and how much lag.

 

The only solution is for all players to have very good high speed connections so the lag time is reduced... or for servers to ban players whose connections are slow.

These multiplayer limitations are not news and are why some view multiplayer as a time wasting rabbit hole.

[BladeMeister]

"However, if I made contact at a low enough speed the Martlet was basically invulnerable and could plow right through the bomber and blow it to bits without so much as a scratch to the Martlet. "

 

And thus, the moral of the story is kids

THAT THE MARTLET IS THE ONE FIGHTER CREATED  BY THE ELVIN KINGS TO RULE OVER ALL PLANES! 

 

S!Blade<><

Edited April 13, 2023 by BladeMeister

[LLv34_Flanker]

S! 

 

So do these bugs have an impact on the general FM? Have found the P-40 to be extremely forgiving in even the most hamfisted turns at low power/speed, for example. 

[dazako]

I love flying the Kittyhawk but often wonder if something is slightly off in the physical model of the P40 types. When landing it always tends to oscillate, dipping each wing repeatedly. This can happen in any aircraft on landing, but the P40 types do it consistently. I've discovered raising the flaps on touchdown all but negates this issue. But even then, while running straight and true, vortices are visible at both wingtips indicating a stall ? I don't see this with any other type - though I only fly red a/c so I may be unaware.

Definitely not complaining, just something I've noted. 

 

Daz

[Volant_Eagle]

I don’t have as much experience with the P-40s as I do with other types in CloD. I’m usually flying either a Bf 109 or a Hurricane. However, given what I do know about actual P-40s, the odd behavior you described Daz does actually make a lot of sense to me.

 

Most of the planes in CloD right now are German and British. Most planes from a particular nation either intentionally or accidentally follow similar design philosophies in certain areas. Almost all planes at the time had tailwheel (conventional) landing gear and there are two very different methods of landing tailwheel aircraft. These are called the “3-point” and the “wheels” landing methods. Most British and German aircraft were designed with the “3-point” method in mind whereas most US Army aircraft were designed with the “wheels” method in mind. Therefore the handling of the P-40 on landings should be different than any of the other fighters that happen to be in the game right now. This was actually a training issue the British had to address when transitioning pilots to the P-40. All British pilots were trained on “3-point” landings and that’s what they found natural because that’s all they ever did. However, in the case of the P-40, “3-pointing” isn’t just not preferred, it’s actually a rather bad idea. Sometimes units who would soon be getting P-40s were first given outdated American fighters (P-36s) or other American aircraft to accustom them to “wheels” landings. That way it wouldn’t be so foreign to them when they got their P-40s.

 

Here are some overly wordy descriptions of the two methods:

 

Generic 3 point landing technique: (as far as I know this is the proper technique for every other fighter in the game)

Approach at a relatively slow speed and with full flaps. (flaps not necessary but recommended). Right before touchdown cut the throttle and just before the wheels touch; pitch back to hold the airplane off the ground. (This is called “the flare” or “flaring”) As the airspeed bleeds off the airplane will get into a nose high attitude. Eventually you’ll loose enough speed and the plane will just settle into the ground. If done properly, all 3 wheels will gently contact the ground at exactly the same time and this will happen at the minimum possible speed (basically stall speed for given flap setting). Ideally you want only enough extra speed on approach to arrest your decent right before you touch down. If you come in with too much speed, you can still make a perfect 3 point, but you’ll float much further and may run out of runway. If you come in already at stall speed, you won’t have any authority to stop the decent and you’ll just slam into the runway at whatever decent rate you approached with (or worse because you may stall and then fall into the runway). This technique is also how tricycle gear airplanes should be landed. Except with tricycle gear the nose high attitude obviously results in only the main wheels touching down first.

 

Generic “Wheels” technique:
Approaches are generally made at higher speeds than for 3-points. Instead of “flaring” just before contact and “holding” the plane off the runway, you need to “fly” the plane onto the runway. You want to touch only the main wheels first. And I don’t mean slightly first, I mean still in a perfectly level attitude. The plane is essentially still 100% flying when the mains touch, it just so happens that the wheels are in contact with the ground while it’s flying. This takes a very steady hand and a very good sense of height to do properly. In order to still be level, you’ll have enough speed the plane won’t “sink” into the runway, you’ll have to make it touch the runway. But you have to make it touch as gently as possible. If you nose forward too much you may hit the prop. If you “drop” the wheels into the runway the nose will pitch up because the center of gravity is behind the wheels, then because you still have airspeed you’ll climb and “bounce” off the runway. The idea is to “paint” or “kiss” the runway with your main wheels on touchdown. You want to make the mains touch with basically no vertical speed. Only after both the mains are on the runway can you let the plane decelerate and then the tail will come down. This technique sounds harder and I think most people would agree. However, it does offer the benefits of better forward visibility on touchdown (a plus for WW2 fighters which commonly have long noses), and the ability to use a fast approach without floating all the way down the runway. There is no equivalent to this type of landing for tricycle gear planes. Using this technique with tricycle gear would result in a 3 point which is a big no no in tricycle gear planes.

 

If my explanations aren’t clear enough you’ll easily notice the difference in videos. Look up a video of a British fighter landing and then look up a video of a P-40 landing. The difference is obvious.

 

You can usually wheel land a plane that was intended to be 3-pointed. Most people don’t though because 3-pointing is usually considered to be easier. However, since wheel landings are done at higher speeds, it is possible that a plane designed to be wheel landed may be dangerous to try and land 3-pointed. This is because when 3-pointing you could be slower than the designers had intended for the plane to be without ground contact. This is the case with the P-40. The ailerons weren’t designed to still be effective at speeds that slow. Thus you tend to loose roll control before touchdown if you try to 3-point this plane. This can result in a hard and uncoordinated touchdown which can damage or break the airplane (usually the gear). The C-47 is another plane that shouldn’t be 3-pointed but for a different reason. With the C-47 it’s because the airflow to the horizontal stabilizer can get blocked in nose high attitudes.
 

It therefore makes sense why landing with less flaps partiality fixed the problem for you. Without flaps the plane will stop flying at a higher airspeed and thus when 3-pointing, you won’t get as slow before making ground contact. Not sure how well this would work in a real P-40, but the theory checks out and it’s probably easier to do than a true wheels landing.

 

The vortices don’t necessarily mean the aircraft is stalling or near a stall. Although it does mean the plane is closer to stalling than it was before the vortices appeared. The vortices just mean the pressure change from top to bottom of the wing at the tip has gotten very sharp. Sharp enough that the corresponding drop in temperature is causing the moisture in the air to condense. Thus you can see the vertices that were already there. Stalling is only based on angle of attack but vortices will appear at different angles of attack depending on airspeed, air density, humidity, etc. With the flaps down the plane tends to fly in a more nose down attitude. This is because the flaps have essentially caused the inboard section of the wing to be angled upwards more (Chord line is draw from leading edge to trailing edge). The wing then seeks to be more head-on with the wind and drops the nose. This results in the outboard section of the wing having a vary low angle of attack. Thus it’s a lot harder to get wing tip vortices with the flaps down. That doesn’t exactly mean the wing as a whole is harder to stall though, it just means it’s harder to get the tips to stall. With the flaps up the tips are more in line with the rest of the wing and thus reach high angles of attack (causing sharp pressure differences) when you get slow.

I don’t know enough about the P-40’s handling in the sim or in real life to make a good judgment on its forgiveness at low speeds or when “ham fisted”. However, I don’t recall any bad reports on the plane’s handling (other than needing to wheels land it). Overall the Hawks were usually praised for their handling qualities. Many foreign countries’ first impressions with the Hawk (often the P-36) were mixed. But one thing they commonly made note of was how impressed they were with its handling (not the same as maneuverability) in comparison to their own fighters. However, if I remember correctly, a lot of the praise was for its handling at high speeds.

 

The fact that people can actually notice some odd quirks with a plane in this sim, and those quirks check out with reality, make me far more confident in the accuracy of this sim. Overall I think the flight model in this sim is absolutely superb. I do get some doubts when parts start falling off though, and some of the AI behavior seems super simplified and gamey. But as far as the basic flight model goes, no other combat sim I’ve tried feels as “flightlike” to me as CloD.

[dazako]

Fab response on the P-40, and very likely the right answer. Much more informative for everyone who enjoys the P40 types then my initial thoughts that I'm just crap at landing it. 

 

Daz

[Buzzsaw]

Volant Eagles post is generally correct in his explanation of the differences between 3 point landing technique and his 'Wheels' technique.

 

However, his suggestion the P-40 was particularly designed for the 'Wheels' technique is not really correct.  Any aircraft can be landed with either technique, although those with longer propellor blades, or those which have limited clearance between blades and runway are at more risk when using 'Wheels' as the risk of the blades contacting the runway is greater due to the aircraft fuselage being in a level attitude, with the nose lower and the prop blades closer to the ground... the interval between when the front wheels contact the runway and when the tail drops and the rear wheel touches is the dangerous moment.

 

Most of the time rookie pilots do better with the 3 point technique for the above reason... all three wheels touching simultaneously... with the tail low and the nose and prop higher... less chance of prop contact and nosing over.

 

However, while the RAF generally taught 3 point landing technique, more experienced pilots in the RAF would often graduate to using the Wheels technique.

 

I had several discussions with James 'Stocky' Edwards before he passed, he was one of the most successful P-40 pilots during WWII... he also flew Spitfires, Tempests, P-51's, etc.

 

He used Wheel landings for all these types.

 

He preferred wheel landings because he was in control for the entire landing... as previously mentioned in Volant's post, he would 'fly' the plane onto the runway.. whereas with the 3 point, there is always the moment when you no longer are in control... as the plane stalls and drops into the three point contact.  As long as the distance the plane drops onto the runway is small, there is no issue, but if a careless or less experienced pilot has the aircraft too high off the runway, the force of gravity can bite as the plane slams down with its full weight... then you can see blown tires, broken undercarriages etc.

 

Of course, mishandled wheel landings can also be damaging... coming in at too high a speed can do just as much damage as the force of the aircraft's weight multiplied by the speed exerts too much force on the tires and undercarriage.

 

Flaps are critical in most cases, especially for highly wing loaded types.

[Buzzsaw]

On 4/18/2023 at 11:01 PM, LLv34_Flanker said:

S! 

 

So do these bugs have an impact on the general FM? Have found the P-40 to be extremely forgiving in even the most hamfisted turns at low power/speed, for example. 

These are not bugs, they are the way the game's physics engine is designed to handle collisions.  Almost all Flight Sims have similar programming... the difference is that CLIFFS has a more complex damage system... so you get occasional odd results.

 

Basically most games have a system whereby whenever there is any aerial contact between aircraft, both aircraft are immediately destroyed.  (this discussion is assuming the collision is in single player... remember online lag effects in multiplayer can mean one aircraft can be seen as not being contacted, therefore it is unharmed, whereas the other can be totally destroyed)

 

In CLIFFS the modeling is slightly different because our damage modeling is much more complex... whenever two aircraft contact during flight, the parts of each which contact are destroyed/detached if the structural value is exceeded by the damage inflicted.  So for example if two aircraft go wing on wing... each will typically lose a portion of their wing from the point of contact.

 

If it is a two plane headon collision, then there will be multiple parts destroyed.... starting with the first point of contact and continuing through the various parts of each of the aircraft, (prop, nose, engine, pilot compartment, etc.) each being destroyed in turn.  When the destruction reaches the critical 'core' element of the colliding aircraft, which is usually defined as either the pilot compartment and/or fuel tanks, the aircraft will be totally destroyed.

 

In an asymetrical collision, i.e. when the the aircraft contact with the flight paths at an angle, with less of one aircraft being exposed to less contact than the other, then you can see asymetrical damage... for example, one aircraft might lose a wing, the other might be totally destroyed.

 

The structural sturdiness of the particular aircraft is taken into account... so a large heavy aircraft might survive a collision with a small fragile aircraft with relatively a relatively small amount of damage... but again, it depends on the point of contact.

 

In regards to your question Flanker:

 

If an aircraft is damaged in a collision, but survives... then it will be affected by the damage on its airframe in the same way an aircraft is affected by combat damage caused by bullets/fragments and/or explosions.

 

This has nothing to do with the way an undamaged P-40 behaves during flight.

 

The reason the P-40 is very forgiving is that it had a relatively thick aerofoil profile... which typically gives good lift and control at high angles of attack.  The P-40 actually uses the same basic aerofoil as a Spitfire, the difference is the Spitfire's aerofoil is thinner at the root compared to the P-40s.

 

P-40 aerofoil

Root:  NACA 2215
197 inchs from center of fuselage:  NACA 2209

 

Spitfire

Root:  NACA 2213

Tip:  NACA 2209.4

 

So the P-40's stall is almost at the same speed as the Spitfires, even though it has higher wing loading.

 

The negative of a thicker wing is more drag... hence the P-40 is generally slower than the Spitfire.  (exception... laminar flow aerofoils are relatively thick but have lower drag than conventional types... but also lower lift at higher AoA's than conventional aerofoils of the same thickness)

[dazako]

Regarding the original topic I've just had a head to head collision in my Kittyhawk with a 109 on the TWC server. My engine and prop flew off, but I still had full engine control and flew back for a landing.  Everything continued to function from pitch to rpm and relative temperature. Odd but fortunate or I'd likely have drowned off Dover.

 

Daz

[Buzzsaw]

On 5/3/2023 at 1:37 PM, dazako said:

Regarding the original topic I've just had a head to head collision in my Kittyhawk with a 109 on the TWC server. My engine and prop flew off, but I still had full engine control and flew back for a landing.  Everything continued to function from pitch to rpm and relative temperature. Odd but fortunate or I'd likely have drowned off Dover.

 

Daz

Please post in the Bugtracker.

 

Thanks  ?

[Volant_Eagle]

Because of this discussion I’ve been researching the P-40 a little and comparing it with other planes. My last post was more or less from the top of my head using memory of things I believed because I read/heard them at some point. I now agree with Buzzsaw that saying the P-40 was “designed” for wheels landings isn’t necessarily correct. I overused that word which could be misleading. I only meant that the P-40’s ‘quirks’ were inherent to the airframe. I didn’t mean I thought they were built in on purpose but rather by accident.
 

It’s true that almost any tailwheel airplane can be taken off and landed either in a 3-point attitude or a wheels attitude. But it’s going a bit far to say that absolutely all of them can. And just because a plane can be landed or taken off both ways doesn’t necessarily mean they are both wise to try in a particular aircraft. Any airplane you’re not familiar with can have all sorts of quirks you never would have even thought of before flying it. It’s best to strictly follow the procedures and techniques established by the manufacturer until you get more experienced with a type. The recommended procedures have usually been established for a reason. Some aircraft are very forgiving and can be flown more or less anyway you want. Others can be flown in multiple ways but safety margins are significantly reduced when flown other than as recommended (i.e. prop clearance like Buzzsaw mentioned above). Yet others can be very unforgiving and you could consider yourself lucky to even be on your feet if you get away with deviating from proscribed procedures.

 

As far as take-offs and landings go, It seems that the P-40 is in the middle of these extremes. It can be taken off or landed with either method but the 3-point method seems to be discouraged for either. From my research so far it seems fairly common for fighters to have either the 3-point or the wheels attitude recommended for takeoff. However, it doesn’t seem very common for a fighter to have the wheels method recommended for landing. It seems that for the most part, fighters of the period could usually be landed just fine either way. Therefore it seems most of the time the 3-point was taught at first because it’s usually considered easier for new pilots. The wheels landing was usually considered a perfectly valid technique for any plane but it was something a pilot would ‘graduate’ to once they had more experience. Strangely, from what I can tell so far the P-40 seems to have this backwards. The technique taught to novice pilots in P-40 is the wheels landing and the 3-point landing is considered something you could do later once more experienced with the airplane. This is very out of the norm and must therefore have a reason. I’m not sure exactly what that reason is but it must have to do with something aerodynamic. I know I gave the “weak aileron authority” argument for this already but I’m not as sure about that anymore. There are several other possible reasons and I’m not finding much to support the ‘ailerons’ argument in particular.

 

There is a great 1944 training video called “Ways of the Warhawk” which can be found on YouTube. I’m sure anyone interested in flying the P-40 will find it very interesting. After the instructor explains the takeoff procedure, at about 22:10 the student asks “So you don’t take off in a 3-point attitude?” The instructor then says no and gives the reasoning that an engine failure or a gust of wind at that moment could easily result in a stall or loss of control. There isn’t enough information given to determine if this advice was specific to the P-40 or if it was just a general USAAF policy at the time. My guess is that the P-40 is closer to a stall in a 3-point attitude for one reason or another than was typical. The P-47 would have been very common in 1944 and I believe that is taken off in a 3-point attitude which suggests that wheels take-offs were not a general policy (prop clearance may be a factor there). I’m also now less confident in my claim that USAAF fighters of the period favored wheels landings. However, that just makes the P-40 stand put out even more. The video does show a wheels landing technique but unfortunately they don’t give a reason for it nor did they touch on whether a 3-point was considered ok.

 

After viewing the film I played around with both the Tomahawk and the Kittyhawk in CloD. I had no trouble doing both wheels or 3-point landings with either plane. Both flaps up and flaps down. I was using the the recommended approach speed from the training video of 115 mph. I didn’t run into any oscillations or control issues while airborne, but with the Kittyhawk there where considerable oscillations while taxiing. Was this what you were talking about in your post here Daz?

On 4/19/2023 at 11:21 AM, dazako said:

I love flying the Kittyhawk but often wonder if something is slightly off in the physical model of the P40 types. When landing it always tends to oscillate, dipping each wing repeatedly. This can happen in any aircraft on landing, but the P40 types do it consistently.

I was assuming you were meaning while airborne just prior to touchdown because that correlated with the “weak aileron authority” claim I’d heard. The lateral dipping I experienced while taxiing was very pronounced and at times the wingtips were striking the ground. This is definitely something I have not experienced with other aircraft in the game. I also did not experience this with the Tomahawk even though I was using the same airfield and taxiing in the same manner. I also tried an airfield on the Tobruk map using the trop variants and got the same results. Tomahawk taxied normally, Kittyhawk was flailing all over the place like I was driving over foot wide boulders. In my opinion there must be a bug with the gear/ground interface specifically on the Kittyhawk.

[dazako]

10 hours ago, Volant_Eagle said:

 

 

After viewing the film I played around with both the Tomahawk and the Kittyhawk in CloD. I had no trouble doing both wheels or 3-point landings with either plane. Both flaps up and flaps down. I was using the the recommended approach speed from the training video of 115 mph. I didn’t run into any oscillations or control issues while airborne, but with the Kittyhawk there where considerable oscillations while taxiing. Was this what you were talking about in your post here Daz?

I was assuming you were meaning while airborne just prior to touchdown because that correlated with the “weak aileron authority” claim I’d heard. The lateral dipping I experienced while taxiing was very pronounced and at times the wingtips were striking the ground. This is definitely something I have not experienced with other aircraft in the game. I also did not experience this with the Tomahawk even though I was using the same airfield and taxiing in the same manner. I also tried an airfield on the Tobruk map using the trop variants and got the same results. Tomahawk taxied normally, Kittyhawk was flailing all over the place like I was driving over foot wide boulders. In my opinion there must be a bug with the gear/ground interface specifically on the Kittyhawk.

 

Yes this is my Kitty experience, during taxi and very aggressive after touchdown. Using the 'fly it on to the deck' approach is a much better method, holding the tailwheel and elevators up for longer until speed drops. The roll out is longer, but so long as you keep it straight all is good. It seems the tail down attitude is very twitchy, which is exaggerated at landing speed. Holding off this attitude until slower helps. I've not compared this with the Tomahawk.

 

Daz 

Edited May 10, 2023 by dazako

[FTC_Karaya]

Besides the shaking the Kittyhawk also starts to oscillate around the lateral axis if you dive it to very high speeds which is very odd.

Cannot recall any other aircraft doing that, the others just start to shake when nearing breakup speed.

[Dawson]

Like Volant Eagle, I recall hearing about Kittyhawks in RAF service being landed in two wheel fashion. If I remember it was because pilots who were used to landing three point style were breaking the landing gear. I don't recall where I saw this but it stuck in my mind when I started landing the 'hawks in Tobruk.

 

In the last year however I read "Flying American Combat Aircraft of WW2" (Robin Highham ed.) and there are three former pilots who wrote a chapter about the P-40. All three said they used three point landing.

 

Current day warbirds pilot Dave Hadfield has a Youtube video where he says he lands the Kittyhawk with a tail low two wheel landing.

 

Seems whatever works for you is the way to go. I find after touchdown that reducing the prop pitch way back shortens the runoff.

[Buzzsaw]

On 5/10/2023 at 11:22 AM, Karaya said:

Besides the shaking the Kittyhawk also starts to oscillate around the lateral axis if you dive it to very high speeds which is very odd.

Cannot recall any other aircraft doing that, the others just start to shake when nearing breakup speed.

The earlier Kittyhawks had a lateral stability issue... this was the reason the later versions had a lengthened tail section.

On 5/9/2023 at 8:50 PM, Volant_Eagle said:

The lateral dipping I experienced while taxiing was very pronounced and at times the wingtips were striking the ground. This is definitely something I have not experienced with other aircraft in the game. I also did not experience this with the Tomahawk even though I was using the same airfield and taxiing in the same manner. I also tried an airfield on the Tobruk map using the trop variants and got the same results. Tomahawk taxied normally, Kittyhawk was flailing all over the place like I was driving over foot wide boulders. In my opinion there must be a bug with the gear/ground interface specifically on the Kittyhawk.

Please post on the bugtracker.  ?

[NO.20_Krispy_Duck]

Same - I've experienced the flopping back and forth type instability while taxiing the Kittyhawk.