S.E.5a Woes

[emely]

Great post Wolf, now let's lower the engine speed of Dr1 by 500 based on your own words ?

[ZachariasX]

3 hours ago, VeltroRoF said:

Sidenote: I also think you would need more proof of your numbers. I red somewhere there was an AB662C that had a pitch of 1800 but Wolseley printed the number 1750 on the blade.

I do not have proof of this as such, it is just the configurations I came across in places such as "the aerodrome" forum and I collect  what  I find. Also I occasionally find propellers for sale, and if they turn out to be originals, I take their numbers as well as info on the used configuration.

 

I'd much rather be asking more literate guys on this topic to provide links. All I can do is sanity check what the respective configuration can do.

 

3 hours ago, VeltroRoF said:

Another thing, who knows is Wolseley printing "effective pitch" on their blades?

Yes, all propeller have that, diameter and pitch stamped on them. Those numbers are semi correct, as for instance diameter (this can easily be checked and is stated as measured number in the item dimensions) sometimes varies a tiny bit, but in my experiene. those values fit rather precisely. Those guys knew what they were doing and the numbers are good enough for our purposes.

 

3 hours ago, VeltroRoF said:

it rather coincidental that 2100 RPM (which is the max from HagarTheHorrible's Acceptence Test) with a 1.75m pitch calculates almost exactly to 138 mph (which some people indicate as the max speed of the SE5a).

I get 136 mph as theoretical maximum. Personally from that, I'd make it a 132 mph or so. But it still fits the bracket where you want it to go. But in this case, we had a 220 hp aircraft, not a 200 hp one as we supposedly do have.

 

The main problem here is that we are presented with "maximum speeds" without any indication of prop and rpm. were they wringing out their AC at 2150 rpm? Or being test pilots, set 2000 rpm and marveled at the telemetry data later on? HP or torque matters less here, as in the end it's just the actual rpm that counts for respective flight speed, hp being always "sufficient", as the prop in fact turns at that speed.

 

3 hours ago, VeltroRoF said:

The Viper allowed for better performance at altitude because of the high compression ratio.

Conversely, you can mount a larger, slower turning propeller that should be better with accelleration, as with increased torque, you have more hp at same revs. But all later Hissos had 5.3 :1 compression, usually fitted to a 1500 rpm prop (2000 rpm engine). The increased torque made the four blade SE5a unpleasant to fly as they required lots of footwork to fly straight and were discontinued.

 

The SPAD XIII for instance used this propeller (among others) with a 200 hp Hisso (@2000 rpm I giess):

and this one has a pitch of 2.15 m. It is a lefthand prop, meaning it is geared, assuming 0.75 gearing this would also set it for ~120 mph @2'000 rpm.

Then again, there are Ratmanoff and Régy serial 361. Both were 2.50 meters long, with quite the same pitch (2.30 vs 2.55 meters) and blade width (200 vs 210 mm), making the SPAD go 127 mph or ~140 mph. Clearly, the latter requires a stronger engine with more torque, more than the 700 nM we have on the Viper.

 

 

Everything I know about our dear SE5a so far just statess one thing to me: wrong propeller selection.

 

So, anyone having deatils on the different propellers and engine types we could list them here to see what was really out there and try to check on what kind of aircraft is actually meant when talking of those "138 mph" or so as top speed.

 

I'm really trying to understand here and hopefully learning something new. I get shot down whether this will be patched or not, so that is no my concern.

 

3 hours ago, SeaW0lf said:

You should also test on the autumn map, which is, if I'm not mistaken, the International Standard Atmosphere. So the test you did during spring is not relevant, since in FC the speed varies according to the season (air density?).

It shouldn't matter, as rpm with fixed pitch prop directly results in a certain TAS. Airframe drag doesn't change over seasons in a way that would impact out tests. What it can influence is the rpm output of the engine, but this one you always take into account and normalize for specific rpm.

 

Besides, the idea of an aircraft NOT reaching full power rpm in a climb gives me the creeps, even though I've written it here many times. i just can't get over that. Imagine sitting in a GA aircraft and you want to climb away, but you cannot make your engine do 2500 rpm... ?

 

[SeaW0lf]

36 minutes ago, ZachariasX said:

It shouldn't matter, as rpm with fixed pitch prop directly results in a certain TAS. Airframe drag doesn't change over seasons in a way that would impact out tests. What it can influence is the rpm output of the engine, but this one you always take into account and normalize for specific rpm.

 

You are assuming the game is reproducing reality, which is not the case. So the game has its own universe and laws. Plus, if people want to compare both FC and ROF, it would be better to do tests with the same atmospheric conditions, otherwise people will be mentioning values that don't match, producing skewed comparisons.

[ZachariasX]

7 minutes ago, SeaW0lf said:

You are assuming the game is reproducing reality, which is not the case. So the game has its own universe and laws. Plus, if people want to compare both FC and ROF, it would be better to do tests with the same atmospheric conditions, otherwise people will be mentioning values that don't match, producing skewed comparisons.

 

It is my understanding that my rather crude guesstimates are basic propeller mechanics to which ANY flight simulator should adhere. I also don‘t think that the sim is having „alternate physics“ here. I have no indication for that.

Edited April 5, 2020 by ZachariasX

[SeaW0lf]

2 minutes ago, ZachariasX said:

 

It is my understanding that my rather crude guesstimates are basic propeller mechanics to which ANY flight simulator should adhere. I also don‘t think that the sim is having „alternate physics“ here. I have no indication for that.

 

I see no indication that the flight models are interacting in-game as it would in real life. That perhaps is still a decade or so ahead of us. So if people are comparing the ROF SE5a, would be better to keep equal settings. It also means that we can compare data knowing beforehand that it was tested under in-game ISA conditions.

[ZachariasX]

6 minutes ago, SeaW0lf said:

So if people are comparing the ROF SE5a, would be better to keep equal settings.

There is no real need to overcomplicate things. rpm is a (almost) direct function of TAS. You can the the SE5a in RoF and let is fly at whatever altitude and check rpm, then calculate TAS. All configuration give you  about the same pitch for the propeller., hence we know that in FC we have an 1.9 m pitch prop. You can do the same in RoF and see what you get. Any altitide, any season, as long as you make no coarse mistakes in calculating TAS, you get the same value for pitch. Here, in FC, I get  ~2% variation, which is in line with me not bothering too much for precision to get the numbers. The closer the numbers are, the less slip you can assume, meaning that the plane really follows the pitch. Propeler slip varies with rpm, air density etc. here, I get rather consistent numbers so far.

 

Once you know the propeller pitch, you can see to what it would correspond, lacking more detailed plane description. You know the how fast it would go at 2000 rpm.

 

If you don't find an exact match, then you know where they played a bit with the parameters to make the thing perform as intended. And to me, it appears that they fudged a bit with the prop parameters. Or would you know of a 1.9 m pitched prop?

[HagarTheHorrible]

Sorry I made a bit of a boo boo earlier, I wasn't rigerous enough with setting up the test, mixture was manual, I thought I had auto mix on, but had turned it off by mistake, so 1620, for the SE5a as max rpm is incorrect.  When I realised I went back and spent a bit more time making sure everything I could think of was optimal.

 

Kuban map.........Autumn........Airfield next to the sea.......manual mixture, adjusted for best rpm......aircraft prevented from moving by parking one wing against hanger

 

Max RPM;      Spad XIII =            2038

                        Dolphin =              1980

                        SE5a =                   1690

       

                        Pflaz D.IIIa =         1505

                        Albatros =             1480

                        Fokker D.VII  =      1470

                       

Just as an aside, the Pflaz and Albatros radiators were far more effective at stopping the engine from overheating.

 

I'll now go away and see what I get speed and rev's wise when flying auto level over the sea on the same map.

 

Same map, no wind or turb, 12 noon, 100m,  100 litres fuel or for the German aircraft 100%, auto level, auto rad, all speeds in metric, max speed and rev's

 

Spad XIII -                                                 214 kph  -  2080 rpm

SE5a -                                                        220 kph  -  1925 rpm

Dolphin -                                                    198 kph  -  2100 rpm

Camel -                                                      185 kph  -  1420 rpm

 

Albatros -                                                   168 kph  -  1500 rpm

Pflaz D.IIIa-                                                167 kph  -  1525 rpm

Fokker D.VII                                               188 kph  -  1555 rpm

Dr 1 -                                                           164 kph  -  1320 rpm

 

 

Edited April 5, 2020 by HagarTheHorrible

[HagarTheHorrible]

This looked like a real fun site ?

 

http://www.aircraftinvestigation.info/

 

......and about the Viper

 

http://www.aircraftinvestigation.info/airplanes/Wolseley Viper webvesrion 09dec2018.html

 

I had a thought.  When did the Viper II come out ?  I wonder if the engine acceptance form above is from a Viper II even if it doesn't specify.

[VeltroRoF]

@ZachariasX

I have done some searching... but just on the internet I could not find other propellers used for the SE5a either.

Some numbers and codes that I found on auction sites and such:

- Wolseley Viper SESA 180HP 1800 Revs, AB662 BRH G102 N60 D2400 P1750, length approx. 240cm.
- DRG No AB8080LH, D2514 P2850 200HP HISPANO-SUIZA 3/4 G669N54 and production number 10289
- G1433N54, AB 662 G.R.H. , WOLESLEY VIPER , HISPANO SUIZA , D 2400 P 1750
- G720N59 - AB7673 RH D2414 P1710 242cm
- G.761.N.22, SE.5. A.VIPER DG.AB.7673.RH, D.2414, P.1710
- A.B. 662 CRH Hispano-Suiza Woolsey Viper D-2400 P-1750 SPAD
- G 1669 NO 90 DRG AB 662 CRH HISPANO SUIZA, WOLDSLEY VIPER D2400 M/M p 1750 2400mm
- ETOILE Dg AB 765 RH 180 HP HISPANO SUIZA D2414 P1710

 

This one says AB662 "B":
Wolseley Viper SESA 180HP 1800 Revs, AB662 BRH G102 N60 D2400 P1750, length approx. 240cm
- https://www.the-saleroom.com/en-us/auction-catalogues/biddle-and-webb/catalogue-id-srbid10066/lot-dcebf864-211c-45ce-b2b7-a5c000fcfa8b

 

However this person says there are 15 AB662 variants and no records of a "B":
- http://www.theaerodrome.com/forum/showthread.php?t=24634

 

This person talks about a variant AB662 "C":
G1433N54, AB 662 G.R.H. , WOLESLEY VIPER , HISPANO SUIZA , D 2400 P 1750
- http://woodenpropeller.com/forumvB/showthread.php?t=1759

 

Other prop numbers I have found:
AB765 : 180 HP Hispano Suiza RAF SE5a (British/ French prop boss)
AB767 : "

[emely]

In any case, the technical specialist who put such a propeller on the fighter of his country, in which this fighter can realize its power only in deep dive, is a traitor to the Motherland, and the military court should consider its actions.

Edited April 5, 2020 by emely

[ZachariasX]

8 hours ago, HagarTheHorrible said:

This looked like a real fun site ?

 

http://www.aircraftinvestigation.info/

 

 

I see he calculates prop pitch the way I did above, where he lacked info. Giving pitch angle instead of travel is impractical though.

 

What I found interesting, he gives 2100 rpm for top speed in case of the Hissos and 2005 in case of the Viper.

[HagarTheHorrible]

On 4/4/2020 at 5:33 PM, ZachariasX said:

Something is odd with the SE5a and I am trying to find out how the FM comes up withe the speeds and accelleration we are seeing. For this I made a chart with all the engine/prop combinations that I am familiar with. If you know other configurations, please let me know.

 

For this I compiled a small chart:

 

I suppose we have a W.4a Viper direct drive engine cranking a A.B.662 prop. This is what comes closest to the performance when using the speeds @US93_Larner just posted above. You stated TAS, right?

 

Correction, you used IAS, right?

 

Back at my rig, I get the following speeds ~131 mph (212 km/h) TAS at seal level @1900 rpm, ~107 mph IAS (~125 mph / 202.5 km/h

TAS) @1900 rpm, 3000 m.

 

So then what I said initially doesn't make sense. Here's my (rough) measurements:

 

 

This means, the airspeed would correspond to a prop pitch of (theoretically) of 1.86 m or 1.88 m respectively. This means we have a prop steeper than the A.B.662. Is there a prop with ~1.9 meters pitch?

 

Another prop to add to your list; 

A Royal Aircraft Factory SE5a twin bladed wooden propeller, circa 1918,

for Wolseley Viper powered late WWI variant, laminated wooden construction, with remains of olive green painted cloth covered tips, the hub stamped G763 N77, SE5A VIPER, DG AB 7673 RH, D2414, P1710, also stamped 2 2634 with 99CTV marks, 241cm diameter, (after years of dry storage there is some de-lamination and cracking, cloth covered tips worn with loss to material).

[HagarTheHorrible]

"Airscrews: Four-blade airscrews T.28096 were usually used on S.E.5a’s with French engines with 24:41 gears. The majority of aircraft had two-blade airscrews A.B.8080 or T.28137M on Wolseley built 200hp geared engines or French Hispanos with 21:28 gears. With Viper engines A.B.7673 or A.D.662. "

 

From here, pages 78/79/80 ;  file:///C:/Users/tombr/Downloads/WWIAircraftPerformance.pdf 

 

 

 

[emely]

Then the guys wrote already that the pilot on the SE receives more damage than on other aircraft.  I flew a little on it and agree with their opinion.  On a dolphin, and even more so on P3, I never had such that one hit caused 98% wounding the pilot, and the plane’s damage was 100%.  Or they put machine guns with a caliber of 20 mm on German planes and did I miss this news? ? After this, it’s funny to read the enthusiasm of some players about the fact that DM in the circus is much better than in RoF.

[Tycoon]

6 minutes ago, emely said:

Then the guys wrote already that the pilot on the SE receives more damage than on other aircraft.  I flew a little on it and agree with their opinion.  On a dolphin, and even more so on P3, I never had such that one hit caused 98% wounding the pilot, and the plane’s damage was 100%.  Or they put machine guns with a caliber of 20 mm on German planes and did I miss this news? ? After this, it’s funny to read the enthusiasm of some players about the fact that DM in the circus is much better than in RoF.

Yeah I like the idea of the new pilot wounding system the problem is it's half baked and obviously still using the same hitboxes that were designed for 4 hits kill. At the end of the day it's fundamentally flawed.

[HagarTheHorrible]

4 hours ago, emely said:

Then the guys wrote already that the pilot on the SE receives more damage than on other aircraft.  I flew a little on it and agree with their opinion.  On a dolphin, and even more so on P3, I never had such that one hit caused 98% wounding the pilot, and the plane’s damage was 100%.  Or they put machine guns with a caliber of 20 mm on German planes and did I miss this news? ? After this, it’s funny to read the enthusiasm of some players about the fact that DM in the circus is much better than in RoF.

 

The “enthusiasm” with the DM in FC is almost entirely centred around the robustness of the wings.  In RoF, some aircraft would have a habit of shedding wings after minimal battle damage, the Dolphin and Pup if I recall, to name but two.  Combined with the “shotgun” type effect of the bullet dispersion model there was a lot of dissatisfaction with the Damage model.  Another source of dissatisfaction was the disparity between FM damage and visual damage, the Dr 1 could lose it’s entire top wing, for example, but, it’s FM was entirely undiminished.by this minor trifle.

[1PL-Husar-1Esk]

6 hours ago, Tycoon said:

Yeah I like the idea of the new pilot wounding system the problem is it's half baked and obviously still using the same hitboxes that were designed for 4 hits kill. At the end of the day it's fundamentally flawed.

 

You can be killed by one bullet strigh into head.

[Tycoon]

3 minutes ago, 1PL-Husar-1Esk said:

 

You can be killed by one bullet strigh into head.

I know, what I'm saying is the hitboxes were designed gameplay wise for 4 hits to kill, changing it to 1 shot kills using (what i assume is) the same hitbox makes for killing to happen too often and from way, way too far.

[SeaW0lf]

But it is not related to a particular plane. At least on the Camel and Dr1, a hit means a long blackout most of the times, perhaps 99%. Maybe some planes have the armor effect due to wooden fuselage, but the one hit one long blackout is not exclusive to the SE5a.

 

Engine damage and fuel leak are also common on these planes. The Camel still have fragile wings and you have to be careful after some hits. Perhaps there are some particular planes out there with strong frames, but I flew them all, perhaps beside the Pfalz, Albatros and Spad, and they just look fine. Then I would be mindful when mentioning these things, because the results can be disastrous.

 

And I'm praying that they won't bring back the folding wings.

[1PL-Husar-1Esk]

1 hour ago, SeaW0lf said:

But it is not related to a particular plane. At least on the Camel and Dr1, a hit means a long blackout most of the times, perhaps 99%. Maybe some planes have the armor effect due to wooden fuselage, but the one hit one long blackout is not exclusive to the SE5a.

 

Engine damage and fuel leak are also common on these planes. The Camel still have fragile wings and you have to be careful after some hits. Perhaps there are some particular planes out there with strong frames, but I flew them all, perhaps beside the Pfalz, Albatros and Spad, and they just look fine. Then I would be mindful when mentioning these things, because the results can be disastrous.

 

And I'm praying that they won't bring back the folding wings.

For sure some things mention above will change in the near future.

[SeaW0lf]

20 minutes ago, 1PL-Husar-1Esk said:

For sure some things mention above will change in the near future.

 

Oh, boy... Fingers crossed.

[Izra-il]

On 3/26/2020 at 7:51 PM, =CfC=FatherTed said:

I pretty much only fly the SE when on the Entente side, and reading this thread has made me feel much happier about myself as a virtual pilot.  Because, yes, I find the only way to engage and survive is to bounce very accurately on unsuspecting prey.  If you do not cripple in the first pass, then you just have to keep trucking on down.  Any sort of a dogfight almost invariably ends in your demise.  So you keep diving  down, and down.  Assuming  you don't get followed, you may then begin to climb back to repeat the process.

 

Whether this represents the RL experience of SE pilots v  DVa,  DVII or Dr1, I don't know.  I suppose the caveat is that IRL these machines were flown in formations, and we're not doing that in FC (as other threads have pointed out).

Spot on my friend! That is as it should be done in this B&Z plane...Or any other B&Z plane for that matter. Dogfights are the result of a badly performed attack and is not a form of tactics.

Edited April 7, 2020 by J5_JosefMai

[emely]

3 hours ago, 1PL-Husar-1Esk said:

 

You can be killed by one bullet strigh into head.

And you can also kill by hitting the heart, liver and many more in what places.  But our pilots do not have a liver, heart, or even a head :-)) In the old IL2 it was different, the wound was distributed to parts of the body - arms of the leg, head.  There was even a regimen of bleeding, with a deterioration in well-being, vision, and even death at the end.  This was not the case in RoF!  And whatever our enthusiasts would fantasize about, in the circus DM has exactly the same scheme as in RoF.  Differences are only in setting the strength of hit boxes!  Maybe someone has sclerosis, but I remember very well that during the early access, the wings broke like in the RoF, and the aircraft of the bots exploded from a short hit.  Then they increased the durability of some hit boxes and that’s it!  These changes have occurred only in the shooting system!

[VeltroRoF]

32 minutes ago, J5_JosefMai said:

Spot on my friend! That is as it should be done in this B&Z plane...

Nonsense, he is basically describing he can only Boom without a Zoom!  The necessity to have the element of surprise, being extremely precise and  'crippling the enemy'  should not be strict requirements to be able to B&Z. "Any sort of a dogfight almost invariably ends in your demise" hints to the SE5a to be entirely incapable of anything.

 

Edited April 7, 2020 by VeltroRoF
correction typo

[HagarTheHorrible]

48 minutes ago, J5_JosefMai said:

Spot on my friend! That is as it should be done in this B&Z plane...Or any other B&Z plane for that matter. Dogfights are the result of a badly performed attack and is not a form of tactics.

 

Not really “spot on” at all.   It might be true in WW2 but is boll**ks in WW 1.

 

I don’t think I’ve read anywhere, that the SE5a was only good at bouncing and running.  Tactics, at the time, were not universally understood, and as we know from our own flight sim experience “New Pilots” tend to try and dogfight, it was true then, as it is now, even with all the accumulated experience between then and now, and yet the SE5a was considered  one of the best late war aircraft.  The RFC/RAF was also known for it’s “aggressive” attitude, being encouraged to enter combat wherever and whenever opportunity presented and not just when a perfect bounce presented itself.   If anyone can be said to be hitting and running, it was the German pilots.  Well trained, disciplined  and with good, sensible tactics.  They avoided combat when they could if the situation allowed and they were at a disadvantage , attacked in strength and disengaged if events turned sour.  The weight of fire, of a typical WW 1 scout, was not ideal for a single devastating style attack and most combat resulted in much ambiguity as to results, but then again, simply driving an opponent away was often “enough” to claim a tactical victory.  That is very much not the case in FC.

 

FC is not an ideal environment for a singe bounce type of “hunting”.  Flights tend to be short, boredom, cold and physical effort don’t sap a pilots concentration, flying is confined within a rather defined time, space, distance and altitude.  Clouds, whilst present, are not a good representation of the real thing and have issues that tend to increase object visibility rather than provide a source of cover.  Visibility is imperfect and tools, such as TrackIR allow for effortless checking for approaching bogies.  The only thing that aids boom and zoom in FC, is the distance (excessive in my view) that it is possible to accurately shoot at.

 

The SE5a was a generation ahead of aircraft such as the Albatros and Pfalz D.III,  It is probable that it was as capable as the D.VII if not slightly better, in the right hands. I would have thought that,  performance wise, the SE would have the same level of capability as that demonstrated by the “f” over the likes of the Dolphin and SE5a, but over the Albatros and Pfalz.

Edited April 7, 2020 by HagarTheHorrible

[SeaW0lf]

I might use the stay at home discount to create a side account to test the SE5a again. From recollection at the Kuban Flugpark, I could keep Pfalzes and Albatroses and Dr1s at bay below. The D7 Vanilla was especially helpless on the deck if I'm not mistaken. Things might have changed, since nowadays we have real squadron aces on the Central side flying every day, but at least from my side of the spectrum flying DrIs, I do hate the sight of SE5as and Spads. It is not really fun to face them, so the talks that the SE5a is a dog and that it should be empowered somehow is taken with a pinch of salt from my side. I think the D7F is giving people wrong impressions.

 

I might be wrong, but these models are tricky and people have been developing defensive maneuvers for years. If you make a mistake, you have to duck and run.

[emely]

Such a fight in the circus is impossible.  Albatross will go up and leave no chance for SeVa.  In the circus, if you saw an albatross above yourself - you have one way - to run away

 

Sometimes it is surprising how easy and with what an important appearance some people talk about things in which they clearly do not understand ?

[SeaW0lf]

34 minutes ago, emely said:

Sometimes it is surprising how easy and with what an important appearance some people talk about things in which they clearly do not understand

 

I'll give you the benefit of the doubt, but I'm flying in Flying Circus since day one, early 2018, and I flew all kinds of planes, especially in furball servers, when you have dozens of engagements in a short period of time. Since when are you flying in Flying Circus? A couple of months? From October to December of 2019 you have 7 hours combined of flight on J5. You just really started in January 2020. 

 

As I said, I might be wrong and I'm just raising concerns, but it is extremely uneducated and pretentious to say that I'm saying things that I don't understand.

[emely]

Honestly, I do not keep records in my flight book, in general, I have been doing this nonsense for about fifteen years, more precisely, I can not say.  If my memory doesn’t fail me, the game was released on November 15, 19th, I bought it on pre-order, and tried all the planes as users received it.  The first stupid pair of Dr1 and Spad caused only a lot of laughs, it was well remembered ? But at the time of release there was a big update and a lot has changed in the game.  I tried SeVa, I absolutely did not like it in the new version.  I would never play the circus if all the events had not passed into it.  The last straw was the FiF transition.  So this is a forced decision.  Even today, I find RoF a more interesting flight simulator than a circus.

[J2_Trupobaw]

S.E.5a and Albie were last scouts to be released, and appear to be rushed jobs both (Albie was released with the oil overheat bug killing the engine, S.E.5a seems to suffer from BoX engine induced bad energy retention even more then previous planes.).

 

Planes not working as expected / as they used to seem to be sad reality in flight sims. We had that with RoF Nieuport 28, D.Va, post-fix Camel and Tripehound, DH-2. 1946 Bf-109 pilots were complaining for years on its BoX performance (may still be at it). In FC, the Dr.I FM is just being proved wrong by Chill, I gave up my beloved D.Va because I no longer recognize the plane and Seawolf seems to have abandoned the Camel for Dr.I. It seems the S.E.5.a is last in this long line of mismatched performance. The switch is hardest for people who knew planes well in previous incarnation. I'd say the best way is to relearn the plane, but I am not really following that advice with D.Va ? . 

[emely]

Beard, you can joke as much as you like, but what did the fights on Bloody April turn into?  SE fly at an altitude of 10,000 feet, albatrosses jump vertically from below and try to get into them.  SE go to the right - to the left and carefully shoot at not careful albatrosses.  If the albatrosses occupy the same height that they have SE, then SE run away in a dive.  This shit, and not a war in the air, from such battles is no pleasure, only pulls puke.

[J2_Trupobaw]

I hear you. I'm out of town and was not flying BA, so have no idea what happened, but it sounds like BA 5 (where we went in Spads 150hp against Albies D.III) all over again. As old D.Va hand,  I'd still rather fly S.E.5.a than this "new" Albatros we're saddled with. I'm not joking at all (more like trying to skip straight to "acceptance" phase of grief and move on to other planes) and I agree that people who were most attached to old plane are hit hardest when it comes back wrong (which happens all the time, see the list above. It does no good to S.E lovers to say "your plane has been mangled like many before it, and likely many after it", but that's what happened  ). 

By reading the BA parser results, though, it seems to be much better at stopping Halbies than Albatros is at catching Bristols. No fun but wins the matches.

(BTW, it's Trup, it means the same thing as in Russian ;). Full name would be Tрупo-игрок or something close to that). 

Edited April 7, 2020 by J2_Trupobaw

[VeltroRoF]

On 4/5/2020 at 5:59 PM, ZachariasX said:

Everything I know about our dear SE5a so far just statess one thing to me: wrong propeller selection.

 

@ZachariasX

I sought for clarification here:

https://aviation.stackexchange.com/questions/76922/how-can-i-calculate-the-relationship-between-propeller-pitch-and-thrust

I spend quite some time playing around with this calculation (not been flying at all in the mean time :P).

[ZachariasX]

4 minutes ago, VeltroRoF said:

 

@ZachariasX

I sought for clarification here:

https://aviation.stackexchange.com/questions/76922/how-can-i-calculate-the-relationship-between-propeller-pitch-and-thrust

I spend quite some time playing around with this calculation (not been flying at all in the mean time :P).

 

One thing I can add regarding your reference. This „slip“ that creates the difference between geometric pitch and actual pitch varies. Generally speking, the faster you let the aircraft go, the more drag incrases, increasing your slip. the drag of the airframe is not that important here, as you will „gear“ your prop such that drag is not that high, hence slip is low. High slip means inefficient prop. The prop is an airfoil and as such it is sensitive to increased AoA.

 

I calculated the slip of Chills Dr.I and it is marginal, as the aircraft, even at top speed is still very slow. A Cessna with a prop for climb will have maybe 2% slip (guesstimate) and with a prop for cruise, the PN states it around 6%. This only around intended rpm, in case of the Cessna 2400 to 2500 rpm. Above and below that, prop efficiency drops quickly.

 

This is why 10% slip in the SE5a I find clearly excessive. 5% is a high guesstimate. Those aircraft are meant to be loaded to the gills with weapons and they still have to be able to reach high altitudes. With 10% slip in clean configuration, that wouldn‘t work. Hence I think 5% is a very high guess for aircraft with such big, slow turning propellers.

 

If you want to speculate for the performance of other engine/propeller types, then you can assume the propelles being ~70% efficient, meaning your 200 hp engine has „140 hp thrust“. Double in speed means eight times power required. You can now find out how fast a 300 hp engine can make your aircraft. Knowing this, you can calculate the prop pitch required for your given engine running at given rpm.

 

In principle, this sets most widely used rotary powered planes (~120 hp) in the 110 mph bracket (-+5 mph) and the 200 hp inline planes in the 125 mph bracket. It really requires a lot of power to go siginificantly faster.

[VeltroRoF]

@ZachariasX

In my question on this forum I intentionally exaggerated the slip a bit, to show my point that the "aircraft speed" has to be slower than the "speed calculated from pitch * slip" . Because what I am looking for is if the "geometric pitch" is indicative for the speed of the aircraft. The reply that I got was to look at the aircraft, engine and propeller as a whole.

 

Eventually the end-calculation does not take slip into account. It is merely a proof that the propeller can still perform under the specified conditions:

CDa < CDab

Where:

CDa = Drag coefficient aircraft

CDab = the back calculated  drag coefficient according to the last formula in the topic (CD = ..)

 

The calculation that I made based on the formulas from the replies that I got shows that the propeller can still perform:

 

So: "Everything I know about our dear SE5a so far just statess one thing to me: wrong propeller selection."

= not true (based on the calcuation that I made).

 

Best regards,

Veltro

 

Edited April 9, 2020 by VeltroRoF
correction typo

[ZachariasX]

6 minutes ago, VeltroRoF said:

So: "Everything I know about our dear SE5a so far just statess one thing to me: wrong propeller selection."

= not true (based on the calcuation that I made).

There's several ways to screw this up while still reaching intended speeds. They come down to a reduced accelleration, which is what we have in our FC SE5a in comparison to the other aircraft.

Edited April 9, 2020 by ZachariasX

[VeltroRoF]

That may be true, but that at least means 1C Studios got that one right

[ZachariasX]

37 minutes ago, VeltroRoF said:

That may be true, but that at least means 1C Studios got that one right

I'm not sure about the SE5a because it seems clear to me that we have a propeller with 1.9 m pitch of which I have no information that it ever existed for the SE5a. If this was the case, it would be really wrong. And that is what I meant. It is my hypothesis, because I think in principle the devs have a plausible system for FM. Else, there would be no point in doing these calculations.

 

A plane featuring a different propeller will not have the same performance charactersitics as the reference plane when you are doing things correct, and I repeat, I consider the FM mechanics in principle is correct enough for our purposes.

 

What we have however forces an engine to run at too low rpm, meaning it's actual power output is questionable. Thus, we have several parameters for our SE5a that I find odd. The flight speed is in principle reasonable, even a bit on the high side. Taken together, I'm inclined to say we have an over pitched prop on a 180 hp engine rather than a slightly under pitched prop on a 200 kp engine. The difference is just what the lamentations/woes are all about.

[VeltroRoF]

I hope that when I said:

So: "Everything I know about our dear SE5a so far just statess one thing to me: wrong propeller selection."

= not true (based on the calcuation that I made).

it was clear that I was talking about the airplane in 'real life'.

 

If it is what you are thinking is that the wrong propeller is selected in game I may actually be able to support this with the calculation sheet that I created:

So I've tinkered around with my calculation sheet again to try and support what you are saying.

Lowered RPM to 1900, Increased speed up to 132 mp

The calculated propeller pitch goes up to 1,85m.

Now here comes the interesting part, If I apply the same formulas that I got from aviation.stackexchange I can see I previously called CDab becomes 0,0405.

Meaning that the propeller efficiency goes down in comparison to the 'real life' values that I tried to calculate of 0,04578.

(It stays about equal to the CDa 0.0402 (zero lift) but goes well under the 0.0440 at max speed, that I found in one of the previous links).

___

CDa = Drag coefficient aircraft

CDab = the back calculated  drag coefficient (see previous posts)

 

edit:

4 hours ago, VeltroRoF said:

That may be true, but that at least means 1C Studios got that one right

I meant acceleration, I think it was not that good in real life either

Edited April 9, 2020 by VeltroRoF
added clarification - see edit

[Chill31]

The way the propellers are modeled in flight sims are not by simply inputting blade pitch and diameter.   You have to create a coefficient of power curve and an efficiency curve for thrust.  The power curve tells how much power is required to turn the propeller at a given angle of attack, which changes based upon rpm and airspeed and is given by the "advance ratio".  The efficiency curve is telling how much thrust is produced at a given angle of attack and airspeed (again, advance ratio).  

 

It is very difficult to model these things on WWI aircraft because we have no drag coefficients from testing.  If we knew the drag coefficients, it would be much easier to model the propeller.  This is where testing real airframes, regardless of the engine, can help us model them much better than we can now.