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From Jasons Q&A on Stormbirds blog, parts on FC


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On 4/11/2021 at 11:20 PM, Chill31 said:

Except for the Pfalz, those are plausible maximums.  The Bristol is probably a little on the high side, but I haven't collected any data on it.  Though I will probably get to fly one next year!

 

For the most part, although its pretty hard to believe the SE5a and Dolphin are falling apart at mid-6s. That's the acceptance loading for Central scouts later in war. Not known to be a frail plane the SE.

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6 hours ago, Avimimus said:

It is really great that they are considering engine variants.

 

It'd be good to have engine variants for the S.E.5, Camel, and Strutter someday... mainly the weaker engined variants which are a bit slower in order to have more balanced dogfights (yes, I'd fly the S.E.5 more if it was a bit slower)! I think the Strutter would actually be the highest priority - as it'd produce a relatively slow Allied two-seater (something which is completely lacking except for the F.E.2b). But a lot of these comments apply to FC3 obviously (not F.E.2, Strutter etc. in the currently announced plans)!


I still think engine variants is the answer to the "Balance Issue" in FC, so I was glad to hear that (at least) the D.IIIau is in the works for Central scouts. IMO, as it currently stands the SPAD outclasses all other Central scouts (provided it's in the right hands), and the D.VII F outclasses everything the Entente has. A D.IIIau powered D7 should do better against the currently-modeled 1917-spec SPAD XIII, and a SPAD with a higher compression 1918-spec engine (HS 8bd / 8be) would be a stronger match-up vs the D.VII F. 

You could then have maps where 200 HP SPAD / D7 IIIau are the 'top tier' planes on each side, and maps where the 220hp spad and D.VII F are the top tier, which would solve the current problem of the D.VII F being the apex fighter on every map rotation. 

I'm excited at the idea of the 'collector planes' as well - everyone's pretty convinced that it'll be a snipe, and maybe a siemens-shuckert to match, but honestly atm I think the game needs to fill the current gaps rather than inserting more uber-planes to further unbalance the 'upper tier' 

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39 minutes ago, Monostripezebra said:

 

oh, yeah, you are right.. I was allready wondering why that load case had such an emphasis.. 3 sounds a lot more reasonable.

 

Loadcase A, the getting out of a dive one, is probably the most relevant for the "wingshed" discussion.. so 6.5 was the official minium requirement as per DVL from the gouvernment.. and it seems different manufacturers worked with different safety factors, it seems to range from 1.3 to 2, so theoretically a dive pullout of german planes could have a terminal loadfactor somewhere between 8.45 and 12g which seems a bit higher then I would have anticipated, albeit I doubt 2 was really used much?

 

Yes, the pull out is probably the one that rips the wings off. About the safety factors: I was wondering about that as well but I think those are the acceptance limits with no safety factor meaning you pass if you in static ground tests sandbag up to that g-load as I understand it. TBH, I have not read through the whole NACA report but given that the RAE calculated a failure load of 5.4 g on the early Sopwith Camels (later beefed up as I understand it but to what level I don't know) I would not be surprised if 5-6 g was the limit in Germany. OTOH, the last thing you want is for your wings to go BOOM in static testing so one can suspect that there is a safety margin added by the maker. Later aviation industry standard is a safety factor of 1.5 that is applied to the expected in-service g-load so if you expect 6 in service you have to pass 9 in testing. So today you would probably dimension for maybe 9 times 1.1 or something, or translating that back to WW1 to 5 times a factor of 1.1-1.2 say 5.5 to 6. If the requirement is 5 and your plane can handle 10 g without failing then your engineer should be fired!

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34 minutes ago, Monostripezebra said:

however what we can safely say from the sources is that the requirement in the BVL went up from 5 for dive pullout for single seaters in 1916 to 6.5 in 1918.

Yeah in a number of the NACA reports there are 2 tables from BVL. My understanding from those was that in 1916 the requirement for Class V aircraft was 5.0, and in 1918 it became 6.5.

image.png.30c19aae3bd1da056516a7559b59d847.png

Edited by Hyun_Bin
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1 hour ago, US93_Larner said:

You could then have maps where 200 HP SPAD / D7 IIIau are the 'top tier' planes on each side, and maps where the 220hp spad and D.VII F are the top tier, which would solve the current problem of the D.VII F being the apex fighter on every map rotation.

 

If it's truly late war that people want, then we also need the Siemens-Schuckert D.IV, Rumpler C.VII (with oxygen tanks), Sopwith Snipe some kind of late 1918 SPAD XIII and the Bentley Camel, along with the existing Fokker D.VIII (soon), Pfalz D.XII (soon), Fokker D.VIIF, S.E.5a Viper and Bristol F2B F.III.

 

I still think the sweet spot is Spring 1918 and it requires very little to get there, mostly just the D.IIIaü 200hp (Albatros D.Va 200hp, Fokker D.VII 200hp) and a 1918 Central recon plane. Possibly a DFW C.V 220hp. The Pfalz D.XII 200hp should also be available, and really take precedence over the Pfalz D.IIIa 200hp,

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4 hours ago, Monostripezebra said:

 

to the best of my understanding (especially mid war) was deliberately up to destruction, so for every type of construction one was sacrificed. The origin of the so called "Baumusterprüfung" still existing today

 

now I don´t know how strict it was adhered to and if there where any exceptions, as towards later war it seems there is considerable effort to have calculations replace sandbag testing to a degree which was mandatory (and the destructive testing to terminal load) in order to facilitate and economize the introduction of new types but it kinda was expected that you pass the minimum BVL requirements with a safety factor because of in-service detoriation. 

 

however what we can safely say from the sources is that the requirement in the BVL went up from 5 for dive pullout for single seaters in 1916 to 6.5 in 1918.

 

3 hours ago, Hyun_Bin said:

Yeah in a number of the NACA reports there are 2 tables from BVL. My understanding from those was that in 1916 the requirement for Class V aircraft was 5.0, and in 1918 it became 6.5.

image.png.30c19aae3bd1da056516a7559b59d847.png

 

For sure, the requirements went up from 5 to 6.5 g in 1918 (Date?) but which designs were done according to which BVL requirements? If someone knows this would be interesting to know: What about the Fokker D.VII and E.V/D.VIII? Were those done targeting 5 or 6.5 g from the beginning (Design work probably started before 1918)? If not from which serial number was the change made? What about the Pfalz D.III & D.IIIa? Was the D.III dimensioned for 5 g and then later updated to 6.5 g in the D.IIIa beginning with serial number X or? So many questions.....

 

Anyway, destructive testing is almost always done AFAIK and 10 g sounds like a lot for a WW1 scout targeting 5-6.5 g even though I know a Fokker D.VII stood up to that (+10g) in testing. OTOH the safety factors from materials, loads and load path assumptions, assumptions about straightness in Euler beam buckling etc. all accumulate so that works in your favor. OTOH the Fokker D.VII handling 10 g may be been a high strength outlier or not. No way of knowing. However, expecting 10 g from a wing designed to meet a 5-6.5 g requirement is living dangerously to say the least.

 

PS: And yes, Comrade @=IRFC=Hbender, the scale bottoms out at 10 but as a loyal Apparatchik I realize that that COULD be the actual value and that is what I'm reporting since we do not want to dramatize things and upset the Nomenklatura do we?

 

Edited by Holtzauge
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That was interesting info @Monostripezebra and thanks for the link to the BVL! Still struggling reading the fraktur though: like the different s's in "eines" and "komission" Usw. About the Dreidekker wing: For sure, the box spar and D-cell torsion boxes are good concepts still used today on aerobatic aircraft but if a wing takes 6,8 or 10 g's is also a matter of how much material is used and bigger margins means more weight which is why I don't think even back then they added more than they needed because the added weight would hurt climb performance etc. The max g-load issue we are talking about now for WW1 aircraft is a bit like the max speed issue for WW2 aircraft I think: They had well recorded Vne speeds in the manuals back then but those include margins which are also included in the BoS modeling so you can go faster before ailerons get ripped off etc. However, the issue in both cases is how big is the margin? Anyway, my point was that the Pfalz D.IIIa seems to be able to take +10g in-game trailing WW2/jet era type condensation vortices from the wingtips while other designs seem to shed wings earlier and I don't quite see the logic there that's all.

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Well, today was a day of firsts.

 

I did some G load testing again on the Pfalz and she loses her wings pulling out of a dive somewhere between 9.5-10G. You still need to dive faster than the engine can take, but it can be done without applying aileron. Ninja edit? I checked Tacview but it doesn't register the ultimate G whenever I broke her, so all I could do was confirm that she can take 9G just fine. By comparison: the Dolphin can take around 6G safely. The wings appear to break off faster at altitude, though I suspect this has to do with IAS/TAS.

 

Then tonight whilst dogfighting in my stupid pink Dolphin I lost one of my machineguns to enemy fire and knocked one out myself due to overheating. Complete gun stoppage. Sure was interesting carrying on the fight with the Webley and accidentally making it home alive.

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36 minutes ago, Monostripezebra said:

Basically, whatever side and plane I play, it always seems like the enemy has it better ;=P

Unless you're in a DVIIf...

 

Joking aside, that is a pertinent point.  And, joking aside, the DVIIf was the "best fighter" of the war, so it ought to be the best in the sim.  Those who chose to fly exclusively or predominantly Entente really ought to accept that and move on.  Apart from me, since I reserve the right to shout, "Fucking clown car!" at my PC.

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13 hours ago, US93_Larner said:

I'm excited at the idea of the 'collector planes' as well

 

Looking at the different aircraft packages on sale in the store, at regular prices they seem to offer eight aircraft for USD 50, so $6.25 per plane, while the so-called collector planes work-out at more than three times the price.  Am I really the only one prepared to admit  that they find this system abhorrent?

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8 hours ago, CfC=76SQN-FatherTed said:

Unless you're in a DVIIf...

 

Joking aside, that is a pertinent point.  And, joking aside, the DVIIf was the "best fighter" of the war, so it ought to be the best in the sim.  Those who chose to fly exclusively or predominantly Entente really ought to accept that and move on.  Apart from me, since I reserve the right to shout, "Fucking clown car!" at my PC.

 

"Only plane mentioned by name in the armistice..."  Dunno man, this isn't War Thunder. Simplifying relative performance helps no-one, and certainly doesn't help improve the Sim. The DM has serious issues which affects all player groups, its not an Entente or Central thing. The Albatros is rendered almost useless and the CL2 not much better by the same wing issues. Then there is the crazy high frequency of control 'jams'. If all these are addressed it will greatly help the Sim and all who use it.

 

The D7f was already the 'best' in the Sim before a DM based on wing spar size was created and the D7's wing spar size increased by 300%. The forums were not full of pilots expressing their dissatisfaction with the D7f performance or damage model prior to 4.005 right?

 

Edited by US28_Baer
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22 hours ago, Monostripezebra said:

 

oh, yeah, you are right.. I was allready wondering why that load case had such an emphasis.. 3 sounds a lot more reasonable.

 

Loadcase A, the getting out of a dive one, is probably the most relevant for the "wingshed" discussion.. so 6.5 was the official minium requirement as per DVL from the gouvernment.. and it seems different manufacturers worked with different safety factors, it seems to range from 1.3 to 2, so theoretically a dive pullout of german planes could have a terminal loadfactor somewhere between 8.45 and 12g which seems a bit higher then I would have anticipated, albeit I doubt 2 was really used much?

 

This 1.3 to 2 safety factor meaning German planes can handle 8.45 to 12 g sounds intriguing: Where have you come across this information and which manufacturer used which safety factor?

 

10 hours ago, Monostripezebra said:

 

In the end, I just don´t know.. and in the end the point I was trying to make is just that a generic "WW1 planes are all about 5G" maybe too "catch all" as WW1 was a time of really rapid technological advancement and towards the end somewhat radically different in terms of design care and testing.. it is kind of the birthplace of methodical aircraft engineering. But in practice, the "load-question" of realistic plane behaviour maybe even a lot more complex with hastened production, in-service deterioration and even how the damage affects things, D-box wings are known to be very sensitive to damage to the plywood nose.. while maybe the chance of hitting something important in a more truss-like dolphin wing would be a lot less per surface area, who knows?

 

I would assume, that it is relatively impossible to have that "completely realistic" in any game, so I am fine with using these greyzones for a bit of balance, and while I think FC is doing it tendentially right with some planes beeing more sturdy, my pure, subjective feeling is that some allied wings are really a bit too frail compared to central tanky Pfalzes and Fokkers and that the possible long distance shooting often leads to frustrating situations for the allies that after a hit and run pass you get a felt single bullet that at 400-500m distance just pops your cables on the egress.. when you thought you did a really clean run. But then again, as central, one has to deal with Spad-crimes and their devastating balloon guns

 

Basically, whatever side and plane I play, it always seems like the enemy has it better ;=P

 

Deterioration due to service conditions is a bit like engine wear is it not? That would open up a big can of worms and I don't think that should be modeled. About the DM model I completely agree: Control loss and conventional wire braced versus cantilever wing DM should be reworked: Loss due to controls shot out should be extremely rare and there should not be as large a difference in the number of rounds needed to shed wings as there is today.

 

Regarding Entente/Central airplane undamaged strength I completely agree: That some German scouts can pull 10 g without breaking seems over the top but then that is connected to the above safety factors you mentioned is it not?

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37 minutes ago, Holtzauge said:

Regarding Entente/Central airplane undamaged strength I completely agree: That some German scouts can pull 10 g without breaking seems over the top but then that is connected to the above safety factors you mentioned is it not?

I think it is problematic taking the best of all cases as reference to the whole. AFAIK, any structure exposed to dynamic load is on a timer, be it a ship (where, if you are a great naval engeneer, you know how many waves it can sail before it WILL break apart) or an aircraft. I would argue, that if, say, you had a collapse of the structure at 9 g, then repeatedly doing 8 g will make it break at 8 g at some point (or even less than that). And I understand this is why aircraft are operated way below their crush loads, just to ensure that they stay inact over within specified loads over the specified flight time.

 

Now, wings of these birds are also built by talented pianomakers or less accurate workers and my differ in breakup loads. We have strong wings and some that come off on their own. (I'm looking at you, Antony!) I'd say if you were to sandbag a squadron of fighters, they all would differ considerably in breakup point.

 

I am not sure if giving the damage models a timer by using load cycles, as this had to be adjusted for all aircraft that are due to their different construction most likely different in resilience over time. But by all means, I do not think that a theoretical best case will have a place for wooden aircraft that are basically abused insteas of used that are stored mostly outside in the mud when not flown and getting shot at.

 

I mean, raise hands if you were willing to try 7 g's in a real SE5 or a Pfalz (and you have no chute).

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26 minutes ago, ZachariasX said:

I think it is problematic taking the best of all cases as reference to the whole. AFAIK, any structure exposed to dynamic load is on a timer, be it a ship (where, if you are a great naval engeneer, you know how many waves it can sail before it WILL break apart) or an aircraft. I would argue, that if, say, you had a collapse of the structure at 9 g, then repeatedly doing 8 g will make it break at 8 g at some point (or even less than that). And I understand this is why aircraft are operated way below their crush loads, just to ensure that they stay inact over within specified loads over the specified flight time.

 

Now, wings of these birds are also built by talented pianomakers or less accurate workers and my differ in breakup loads. We have strong wings and some that come off on their own. (I'm looking at you, Antony!) I'd say if you were to sandbag a squadron of fighters, they all would differ considerably in breakup point.

 

I am not sure if giving the damage models a timer by using load cycles, as this had to be adjusted for all aircraft that are due to their different construction most likely different in resilience over time. But by all means, I do not think that a theoretical best case will have a place for wooden aircraft that are basically abused insteas of used that are stored mostly outside in the mud when not flown and getting shot at.

 

I mean, raise hands if you were willing to try 7 g's in a real SE5 or a Pfalz (and you have no chute).

 

What you are talking about is fatigue strength and is actually something that not only naval engineers but also aeronautical engineers battle with. Have been involved in some fatigue testing on structures in the tail section of a fighter aircraft myself but that is strictly GEKADOS! :ph34r:

 

However, in WW1 I would say that no one looked at fatigue when designing planes. In addition, in WW1 the planes as we know were done in wood which has the intriguing property that it has basically no fatigue limit. Steel on the other hand has a so-called fatigue threshold limit (Compare steel and Al in linked figure) meaning that if you stay below that load the structure will hold together until hell freezes over. On the other end of the scale is aluminium which is nasty stuff: Al has no fatigue limit meaning that if you cycle a load on a piece of Al it does no matter how low the load is eventually break so all surviving Spitfires, Mustangs and Me-109’s etc. WILL eventually be grounded no matter how much you baby them.

 

But to be practical: I don’t think fatigue was an issue in the wood structures in WW1. Maybe in some engine parts though. Very doubtful that fittings and bracing etc. would reach enough cycles as well. However, water, moisture and sunlight sure were enemies but like engine wear how are you going to model that in FC?

 

As an interesting side note Mikael Carlson was very reluctant to leave his airplanes (covered with lozenge fabric) out in the open longer than absolutely necessary. Why? Well since they are only doped with no protection against ultra-violet radiation they are living on borrowed time. However, yet again like fatigue this was not an issue back in WW1 where chances were that you would be shot down tomorrow anyway!

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1 hour ago, Holtzauge said:

But to be practical: I don’t think fatigue was an issue in the wood structures in WW1. Maybe in some engine parts though. Very doubtful that fittings and bracing etc. would reach enough cycles as well.

Thanks for more details on all of that!

 

I did know that wood is a very particular material, but then again, you still limit the loads on "oldtimer aircraft" to preserve them longer, this inludes the airframe. A Bücker 131 (from what I know) can tolerate up to 12 g theoretially before it would break up. It is a very aerobatic aircraft and it is built for that. Then again, I wouldn't know of anyone flying such an aircrat today in excess of 4.5g. Wood does also have a significant downside as a material, you cannot tell exactly if it is damaged. The crack has to be large to see it, but the state of the wooden frame below the canvas is guessing at best. Last example I heard of such was when a guy ground looped the Cub of his local flying club. They simply have not much of an idea how much there is to repair. There are large parts that "look good", but find someone betting his life on that wing.

 

 

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For sure, and as you say who would pull 7 g in a WW1 aircraft with no chute! And saying wood has no fatigue limit is a bit of a simplification for WW1 kites since there is an impact with a large number of cycles but it's not as pronounced as for the metals and then there are the glue joints to take into consideration as well. In Sweden a lot of gliders built pre-war with perfectly good wooden parts had to be scrapped in the 60's because many where built with bad glue that became brittle. Some where taken apart and re-glued with new resins but for the most part people did not think it worth the effort. Anyway, I'm still sceptical that Entente scouts should break up at 6-8 g and Central at 10-12 g so I hope @Monostripezebra will come back with some more info on the 1.3 to 2 safety factors he mentioned earlier.

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1 hour ago, Holtzauge said:

For sure, and as you say who would pull 7 g in a WW1 aircraft with no chute! And saying wood has no fatigue limit is a bit of a simplification for WW1 kites since there is an impact with a large number of cycles but it's not as pronounced as for the metals and then there are the glue joints to take into consideration as well. In Sweden a lot of gliders built pre-war with perfectly good wooden parts had to be scrapped in the 60's because many where built with bad glue that became brittle. Some where taken apart and re-glued with new resins but for the most part people did not think it worth the effort. Anyway, I'm still sceptical that Entente scouts should break up at 6-8 g and Central at 10-12 g so I hope @Monostripezebra will come back with some more info on the 1.3 to 2 safety factors he mentioned earlier.

Not sure if this is relevant to the current discussion, but according to the book "French Aircraft of the First World War" "An STAe memo noted that there had been criticism of Bleriot's method of contruction.  To evaluate these complaints, a SPAD 7 built by Bleriot was given a static test in which it supported 4,870kg with a coefficient of 7.9.  As the required coefficient for fighters was 6.0, this was more than enough to enable the bleriot-built SPAD 7s to enter service."  

 

Note that doing the math myself The SPAD 7's own loaded weight of 705kg (which is 1g right?) must be added to 4,870kg in order to get 7.9. So I would assume the 4,870 was in addition to the weight of the aircraft.

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8 minutes ago, Garven said:

Not sure if this is relevant to the current discussion, but according to the book "French Aircraft of the First World War" "An STAe memo noted that there had been criticism of Bleriot's method of contruction.  To evaluate these complaints, a SPAD 7 built by Bleriot was given a static test in which it supported 4,870kg with a coefficient of 7.9.  As the required coefficient for fighters was 6.0, this was more than enough to enable the bleriot-built SPAD 7s to enter service."  

 

Note that doing the math myself The SPAD 7's own loaded weight of 705kg (which is 1g right?) must be added to 4,870kg in order to get 7.9. So I would assume the 4,870 was in addition to the weight of the aircraft.

 

Very relevant info I would say so thanks for posting! Would be interesting to see the test setup but even so, the figures as you interpreted them makes sense I think so that is a good piece in the puzzle and indicates that the French engineers that did the design knew what they were doing since just as @ZachariasXpointed out, you will always have a spread in produced airplanes and cutting it too close could prove embarrassing in testing if the testing was done on a "lemon".

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12 hours ago, ST_Catchov said:

Oh for God's sake, Jason please just give him the Hanriot.  

 

I've no idea how much it costs to port each RoF plane, but I'm certain one sale won't cover it.

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15 hours ago, Cynic_Al said:

 

Looking at the different aircraft packages on sale in the store, at regular prices they seem to offer eight aircraft for USD 50, so $6.25 per plane, while the so-called collector planes work-out at more than three times the price.  Am I really the only one prepared to admit  that they find this system abhorrent?


I'll clarify: 

I'm excited at the prospect of, after a very long period, the creators of RoF / FC looking at finally adding planes we've not had the chance to fly before (at least in 777 / 1C titles). 

The flogging of the planes at unreasonable prices, however, is something I'm definitely not excited about. 
 

17 hours ago, Monostripezebra said:

my pure, subjective feeling is that some allied wings are really a bit too frail compared to central tanky Pfalzes and Fokkers and that the possible long distance shooting often leads to frustrating situations for the allies that after a hit and run pass you get a felt single bullet that at 400-500m distance just pops your cables on the egress.. when you thought you did a really clean run. But then again, as central, one has to deal with Spad-crimes and their devastating balloon guns


Agreed here. The Alb / CL.II also suffer from frail wing syndrome. In terms of Gameplay, I still think the Pfalz D.III seems like a reasonable "Baseline" for the FC plane-set. It's sturdy and robust, able to sustain hits and stay in a fight, but if she takes a severe beating she's liable to break up. 

As a point of interest (I believe Talbot's mentioned this a few times in the past), at least from the 3rd P.G. perspective the preference of 11mms is actually a response to the DM. As it stands, an unlucky SPAD pilot can find their wings suddenly shearing off during a fight or later in a sortie after taking very minimal damage, whereas most German types don't, so our guys try to "level the playing field" by outfitting their SPADs with the big war crime hoses 😉. With the old DM, the vast majority of our guys swore by .303s. 

Can't speak for other SPAD pilots, though! 

EDIT: also, the Control Cable fiasco, imo, needs a serious rework. It wasn't impossible to have a control wire shot out, but it certainly wasn't as frequent as it is in FC.  

 

17 hours ago, Monostripezebra said:

Basically, whatever side and plane I play, it always seems like the enemy has it better ;=P


I feel like this is the basis of most forum spats regarding FMs / DMs 😆

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7 minutes ago, Monostripezebra said:

 

I got no hard data.. other then all the stuff that points out that using safety factors became standard practice at the time.. and that the range varied before 1.5 became like the "cultural" standard in aviation., like in the first book I linked, where you can find 1.5 and 2 as recomended values.. elsewhere you find even 1.3 etc.. but how far manufacturers adhered to that would have been up to the constructors in the companies. It would probably be clearer, since the calculations had to be included in the request to have a type approved if someone with archieve access could dig that up, I would assume some must have survived. I am not anymore in any academic context and have not readily access. 

 

Was the glider in Sweden casein glue? (a milk based wood glue)

 

Maybe animal glue. Who thought that the SPAD was a two trick pony?

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18 minutes ago, Monostripezebra said:

 

I got no hard data.. other then all the stuff that points out that using safety factors became standard practice at the time.. and that the range varied before 1.5 became like the "cultural" standard in aviation., like in the first book I linked, where you can find 1.5 and 2 as recomended values.. elsewhere you find even 1.3 etc.. but how far manufacturers adhered to that would have been up to the constructors in the companies. It would probably be clearer, since the calculations had to be included in the request to have a type approved if someone with archieve access could dig that up, I would assume some must have survived. I am not anymore in any academic context and have not readily access. 

 

Was the glider in Sweden casein glue? (a milk based wood glue). I remember there where issues here as well, but before my time.. I only ever saw wooden wing gliders with later glues but the water damage on one wing we restored from inadequate drainholes was pretty harsh.. luckly it was in a very limited area, mostly only the drilled through wood bits the manufacturer had used in a pipey fashion, but the plywood around that had gotten layer delamination etc. so yeah, water and wooden wings is something to be cautionous off. I can´t find the pictures anymore, but there used to be someone from florida (I think) who had kept his Ka-8 in a trailer and in the climate the wings had gotten rotten and in flight the whole outer wing fell off.. I remember he had written something on the web page among the lines of "if I had had a chute, I would have bailed" but since he had not, he successfully landed that thing and put pictures up as warning.

 

That is what I ment with "in-service deterioration" was mostly water.. planes where not exatly stored dry on the western front and tent hangars only helped a bit but where not always available and in anectotal pilot evidence you can occasionally find that as concern

 

Yep, after googling a bit I found the answer: It was casein glue: apparently the SwAF after WW2 phased out gliders (SG-38 & Weihe) for pilot training and they were then absorbed in the civilian glider clubs. Then some guy flying thermals in clouds (was allowed in Sweden up to the turn of the century or thereabouts) pulled the wings off a Weihe and the accident board partly blamed the glue and that was that for the Swedish WW2 era wooden glider fleet which apparently to 99% barring museum pieces ended up making a nice bonfire.

 

About the safety factors: If there is no data supporting 1.5-2 being applied to the BVL requirements then I think we are talking about different safety factors: The modern 1.5 aviation standard factor is applied on the service g-load not the ultimate test strength g-load. So say the A/C manual says max 6 g this means that to pass the test for ultimate strength you need to go over 1.5*6=9 g. So once you pass 9.01 g in the static loading you are good to go. However, as an engineer you know you need to pass 9 g so you structurally dimension your kite for say 9*1.1= 9.9 g.

 

Now as I read the BVL requirement you need to pass 5 or 6.5 g in static tests depending on design year so applying 1.5 to 2 on top of that is a bit of an overkill which was why I wondered if there was any data suggesting setting the bar so high. Since there does not seem to be so, I would guess that the German engineers were no worse than the French who passed a 6 g requirement with with 7.9 g according to @Garven's data so applying that factor of safety to the 5 or 6.5 g BVL requirement we end up at 6.6 to 8.6 g for the German scouts meaning no significantly higher total strength which also seems reasonable. With this I mean that until such time that solid historical evidence is uncovered that Central scouts could in fact handle +10 g trailing wing tip vortices as in-game then this should immediately be reduced to something more reasonable like 6.6-8.6 g max.

 

Grabs hat starts running!

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If the Pfalz stays the way it is now, or all other planes don't get in line with it, the 200hp variant is going to be bonkers. Worse than RoF's old Pfalzcopter.

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41 minutes ago, Monostripezebra said:

hmm. Did you calculate the loadfactor or the weight? which was given? I am confused.

Everything in quotations was taken directly from the book.  I was only checking how the source came up with a coefficient of 7.9 because a while back I posted the same quote in a different thread and someone mentioned that 7.9 didn't seem correct, but that same source also lists the loaded weight of a 150hp SPAD 7 at 704kg and a 180hp SPAD 7 at 705kg and I can obtain a load factor of 7.9 when I added it the 4,870kg So I came to the conclusion that the 4,870kg load that was stated wasn't including the weight of the aircraft which by itself would be a load factor of 1.   So my math looks like this to match the numbers given in the source: (4870+705=5575kg) (5575/705=7.9078)

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12 minutes ago, Garven said:

Everything in quotations was taken directly from the book.  I was only checking how the source came up with a coefficient of 7.9 because a while back I posted the same quote in a different thread and someone mentioned that 7.9 didn't seem correct, but that same source also lists the loaded weight of a 150hp SPAD 7 at 704kg and a 180hp SPAD 7 at 705kg and I can obtain a load factor of 7.9 when I added it the 4,870kg So I came to the conclusion that the 4,870kg load that was stated wasn't including the weight of the aircraft which by itself would be a load factor of 1.   So my math looks like this to match the numbers given in the source: (4870+705=5575kg) (5575/705=7.9078)

 

Yes, the math looks good but I think @US28_Baer's post above makes sense and I also remember reading about the reduction of the wing weight when doing static testing which makes sense if one thinks about it: In flight the fuselage will needs to be lifted by the wings but the weight of the wings is actually "accelerated" by g in the other direction cancelling that force meaning the wings in actuality has to carry the fuselage only. In addition things are even more complicated: In a bi-plane the upper and lower wings do not carry load in proportion to the wing area (the upper wing carries more according to circulation theory) meaning you would need to take that into account as well when sandbagging the load. Anyway, however they did it, I would be inclined to think they knew what they were doing and focus on the 7.9 g figure.

Edited by Holtzauge
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On 4/14/2021 at 12:24 AM, US28_Baer said:

 

For the most part, although its pretty hard to believe the SE5a and Dolphin are falling apart at mid-6s. That's the acceptance loading for Central scouts later in war. Not known to be a frail plane the SE.

I posted this in the 4.007 DM thread. Additionally, I found reference for the Camel G limit at 5.4Gs.

 

 

I have been seeking information regarding G limits from from knowledgeable WWI historians. While my research is not exhaustive and complete with 100s of cases, I think it does paint a picture of WWI aircraft durability that we haven't really considered here.  Below I will lay out the data I have for ultimate G load (the G load where failure occurs) followed by a discussion of how those loads can be generated through diving and maneuvering.

 

(I have supporting docs for these things)

Fokker Dr.I --------------7.7Gs

Fokker D7 ------------ 10.7Gs

SPAD 13----------------- 6.8Gs

SPAD 7-------------------7.9Gs (6.9 based upon 4870kg/704.5 kg aircraft weight?)

Pfalz D3------------------6.5Gs

Sopwith Triplane-----~6Gs

SE5 ------------------------~6Gs

SE5a -------------------~6.5Gs

Edited by Chill31
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On 4/14/2021 at 6:26 AM, =IRFC=Hbender said:

S.E.5a Viper 

I have an original SE5a Viper propeller.  I don't think the Viper will be much improvement in performance over the 200hp geared Hisso (could be wrong if anyone can supply data) because the Viper is 200 hp direct drive and 2 bladed propeller. 

20201005_111046.jpg

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21 minutes ago, Chill31 said:

I have an original SE5a Viper propeller.  I don't think the Viper will be much improvement in performance over the 200hp geared Hisso (could be wrong if anyone can supply data) because the Viper is 200 hp direct drive and 2 bladed propeller. 

 

Probably the SE5a Viper retained better high altitude performance thanks to its higher compression carburettor. At sea level performance should really be the same.

 

In the sim this is clearly not the case. We don't have the SE5a Hisso, but we do have the Dolphin, which has a H-S V8 and was an all-round better performing machine, especially at high altitude. In the sim the speed difference at sea level between the Dolphin and SE5a Viper is around 20km/h, and the Dolphin even overtakes the SE5a at very high altitude.

 

 

From within the sim (these are old measurements though made before the propeller fix update, actual speed is about 5km/h lower — corrected measurements any year now😞

 

Dolphin:

 

8Vvmciy.jpg

 

SE5a Viper:

jXLngbf.jpg

 

 

In reality the Dolphin's top speed ASL was closer to 210km/h, but then again the H-S V8 in British service was notoriously unreliable in both the Dolphin and S.E.5a, so whatevs.

 

For those of you wondering (no one except me): no, Dolphins were never equipped with the Wolseley Viper. Let's not go the Pfalz D.XII "what iF"-direction.

Edited by =IRFC=Hbender
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6 hours ago, =IRFC=Hbender said:

If the Pfalz stays the way it is now, or all other planes don't get in line with it, the 200hp variant is going to be bonkers. Worse than RoF's old Pfalzcopter.

 

Unless you can show that the real 200hp Pfalz (if it was ever deployed) had such characteristics, you have just made an allegation of incorrect modelling in advance of the fact.

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19 hours ago, Cynic_Al said:

 

Unless you can show that the real 200hp Pfalz (if it was ever deployed) had such characteristics, you have just made an allegation of incorrect modelling in advance of the fact.


My opinion of all the “Albatros-like” Central planes in RoF/FC has remained unchanged since 2009-2010. That includes the Albatros D.II, D.III, D.Va, Pfalz D.IIIa (especially pre-RoF 1.034), Halberstadt D.II, CL.II, Roland C.IIa, DFW C.V, Brandenburg W.12 and Gotha G.V. Basically everything that isn’t a Fokker or a Pfalz D.XII. They turn too well for their relatively high wing loading and are unable to sharply stall, though they can enter very nasty nearly unrecoverable spins if you prophang them too long.

 

In other words they behave differently from Entente planes when nearing stall speed/critical AoA and this is apparently a feature of their thick wing design, even though history books and pilot reports disagree in this respect. The S.E.5a could easily outturn the Albatros D.Va (and Pfalz D.IIIa by extension), which has been demonstrated using reproductions. SPAD VII 150hp vs. Albatros D.III was an even match, except in terms of firepower. The Airco D.H.2 was much better at flat turning than the Albatros D.II, which is how Lanoe Hawker managed to survive MvR’s attacks for 20 minutes and was only gunned down when he tried to make a run for his own lines. All of this is difficult to explain with the current FM. I’m not an aircraft engineer, but I do understand that whoever originally designed the FMs for RoF is no longer working there, according to AnPetrovich. All I want to understand is why sustained turn is not primarily a function of wing loading. That’s what I was taught, and I may have been taught wrong. See also: the RoF N28.

 

So without further judgment, all I can say about the Pfalz D.IIIa with a 200hp engine: it will be like the Pfalz we have now, but with more horsepower.

Edited by =IRFC=Hbender
Not the D.XII
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10 hours ago, Cynic_Al said:

Name one.

 

Pfalz D.IIIa.

 

 

10 hours ago, Cynic_Al said:

....

 

On 4/9/2021 at 10:48 AM, =IRFC=Hbender said:

In any case at sea level the Mercedes D.IIIa and D.IIIaü would have had close to identical performance. There's even a good argument to be made that the D.IIIaü performed slightly worse at sea level and it was simply not possible to go "full altitude throttle" and magically squeeze out an extra 10km/h as is now the case with the Halberstadt CL.II 200hp. If anything performance at sea level with the Mercedes D.IIIa should already be around 10-15km/h more on all current machines equipped with one (Albatros D.Va, Pfalz D.IIIa, Fokker D.VII and Halberstadt CL.II 180hp). With the D.IIIaü top speed should be slightly lower than that at sea level (~5km/h less than the D.IIIa), but then drop off far slower at altitude. TAS at 2000-3000m could easily be 185km/h (IAS 165km/h) with the D.IIIaü, but only 165km/h (IAS 145km/h) with the D.IIIa. 165km/h is the official figure from German Aircraft of the First World War (Gray and Thetford, 1962) which has the British performance data and some of the captured German data.

 

Edited by SYN_Haashashin
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10 hours ago, Chill31 said:

I have an original SE5a Viper propeller.

 

That's pretty amazing Chill. How on earth did you find that? Bet it cost a pretty penny. I wonder if we could fit a virtual copy onto FC's Se5a to correct the bleeding revs issue?

 

I presume you will be using this on your Se5a Viper build? Can't wait for that one! 

 

7 hours ago, =IRFC=Hbender said:

All I want to understand is why sustained turn is not primarily a function of wing loading.

 

Me too.

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11 hours ago, =IRFC=Hbender said:

All I want to understand is why sustained turn is not primarily a function of wing loading. That’s what I was taught, and I may have been taught wrong.

 

4 hours ago, ST_Catchov said:

Me too.

 

Snippet from page 4 in linked paper:

 

"In this table are two key metrics that usually indicate superiority in turning performance and these are the wing- and power loading. Both these are in the Dr.1’s favour: It has a more than 4% lower wing- and 12% lower power loading. However, even with these two advantages in the bag the simulations will show that the Dr.1 still comes up short at higher altitudes due to its very low aspect ratio and 10% higher effective span loading"

 

Enjoy!: https://www.dropbox.com/s/fw1eo270q4..._PA29.pdf?dl=0

Edited by Holtzauge
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7 minutes ago, Monostripezebra said:

 

Look, I think there may be a misunderstanding here.. there is clear data that safety factoring was contemporary standard practice in germany in aviation design from around 1916.. and 18-19 you´ll comonly find the famous 1.5 factor. That does however provide any hard data, in which design which engineers made which considerations, that is what would have to be pulled from the data on type certification and the likes.

 

Where is the "clear data" that can be "commonly" found? I have asked for something that substantiates this more than once now and the above is yet more supposition and speculation.

 

7 minutes ago, Monostripezebra said:

 

 But when Bleriots spads crush at near exactly 1.3 load, that kinda seems fairly in line with those assumptions.

 

No: The French REQUIREMENT is 6 g. It broke at 7.9 g giving the safety factor 1.3

 

The German REQUIREMENT is 5-6.5 g depending on time period. Applying 1.3 on that is not +10 g it is 6.5 g to 8.45 g

 

7 minutes ago, Monostripezebra said:

it is clear that the demand for more resistant structures goes up with the wars progression (logically, given higher speeds, too) and new construction methods, especially fokkers modern wing design with wireless thicker profiles make a significant difference that later war planes are infact able to withstand higher loads and in the 1918 end of the war, the german planes are somewhat more modern and resistant in that regard

 

Yes, the demands got higher and they went from 5 to 6.5 g. This we know. However, that the Germans used thicker wings and new construction methods does not support your argument: It all boils down to HOW MUCH material you use. You can built a Fokker D.VII design that fails at 3 g and a Sopwith Camel that can handle 12 g. It's ONLY a question of how much spar, strut, fitting and bracing wire material/dimensions you use.

 

7 minutes ago, Monostripezebra said:

But pulling individual aircraft numbers assumption out of that is about as silly in one way as in the other.

 

Totally agree: All this speculation about what safety factors were "commonly used" in Germany and how they were applied is silly since there seems to be no data.

 

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