Pflaz DIIIa - how good or bad it really was?

[Kwiatek]

I read some books, internet sites about Pflaz DIII. I spot really different opinions about these planes. Some descirbe it beside its better dive ability as worse then Albatros V fighters good only in balloon mission. Here is some of such opinion:

"German pilots variously criticized the Pfalz’s heavy controls, low speed, lack of power, or low rate of climb compared to the Albatros. The D.III slipped in turns, leading to crashes when unwary pilots turned at very low altitudes. Moreover, the Pfalz stalled sharply and spun readily. Recovery from the resulting flat spin was difficult, though some pilots took advantage of this trait to descend quickly or evade enemy aircraft"

Probably worse opinion about these plane cames from first version of Pflaz III with 160 HP Mercedes which was underpower.

Some said that was more manouverable then ALbatros and could be generally better plane.

In example in ROF game Pflaz DIII a is very good plane. It is manouverable, with very good turn rate, medium climb rate , good dive and rather poor speed ( comparing to Allied planes). It is even better in turn and climb then Fokker DVII and much better then Albatros DVa.

I put some data from game ( and RL):

Wingloading for PflazIIIa- 41kg/m2, DVa - 44 kg/m2, Fokker - 41 kg/m2

Powerloading for PflazIIIa- 0,197 HP/kg, DVa - 0,192 HP/kg, Fokker - 0,20

( all with 180 HP Mercedes)

Speed: Pflaz DIIIa - 180 km/h, Dva -186 km/h, Fokker DVII - 188 km/h

climb to 2km: Pflaz -7:26 min, DVa- 8:48 min, Fokker DVII- 8:36 min

Pflaz IIIA has better wingloading, powerloading and Clmax then Albatros and similar to the Fokker DVII

Here are CLmax for these planes :

1.462 - Pfalz D.IIIa
1.370 - Fokker D.VII
1.313 - Albatros D.V

Analyzing Pflaz wing airfoil i see that even if it get high critical AoA ~ 16 deg. it lose very quickly lift without so much warning and has sharp polar Clmax/AoA. From charts it look that e.x Fokker airfoil get critical AoA ~ 17 deg but also has much more gentle polar. Albatros airfoil get lower critical AoA ~ 14,5 deg but also polar is more gentle then Pflaz. Also longer wingspan of Plfaz DIII could result worse roll rate and the same worse manouverbility in change directions of flight.

So whats is expert opinion about Pflaz DIIIa? It was really such bad like general opinion of these planes or it was such close in performance to Fokker DVII and much better then Albatros DVa?

[YavorD]

Hi Kwiatek!
What is the source of such CLmax data? I am curious how relatively thin airfoils with low curvature and relatively sharp leading edge got such a high CLmax (Pfalz, Albatros)?
Regards,
Yavor

[MiG-77]

Kwiatek, as you probably know that Fokker climb time is wrong and devs have said they will evaluate it in future.

Also in game Pfalz DIIIa dont go 180km/h (more like 165km/h). It seems to have DIII speed.

[Brad]

Remember that a game is just that... a game.

As for the Pfalz "slipping" in a turn- that's the pilot's fault if that is so.

The DVII will out-climb either the Pfalz or the Albatros, by a pretty big margin. It is also easier to fly, and doesn't have as sharp of a stall. Appearances can be deceiving- a thinner wing with a sharp leading edge is NOT better at the speeds these planes fly at... and just because it looks sleeker doesn't mean it is less draggy- the wings (due to the thin, heavily undercambered wing) add a lot of drag... hence the higher speed of the DVII. Looks like a box, but the wing is more efficient.

Pfalz hard to recover from a spin? I can see that, given the relatively small rudder.

Overall the Pfalz wasn't "that bad" it was just... mediocre.

The Fokker DVII is considered by many to be the best fighter of the war, period, from either side. It was SO effective it was actually specifically named in the Armastice terms that all of them had to be surrendered.

[Chock]

I think you have to bear in mind that many reports from pilots in the era of WW1 were tainted by a lack of knowledge. A good many modern pilots who have flown aircraft with genuine WW1 engines have reported that the original estimates of their horsepower are wildly inaccurate, so you have the problem of the internal combustion engine being a relatively new device, in combination with the infancy of practical aerodynamics. The design choices for both often being as much a case of trial and error as sound theory. Witness the classic example of that happening, with the Germans copying the sesquiplane layout of the Nieuport in an attempt to match its maneuverability, but neglecting to include the variable incidence feature of its lower wing, instead sticking two spars in the wing, but not bothering to attach the second spar to the fuselage. Not to mention doing all that with a much heavier aeroplane.

Additionally, WW1 performance reports are sometime best treated with suspicion for other reasons, as there were occasionally ulterior motives for them. One well known example of that phenomenon is Albert Ball, who declared the SE5 to be 'a dud aeroplane', and indulged in installing ridiculous things on it such as a machine gun firing through the floor, which could not have been in any way practical. Yet his opinion on aircraft design was sought by Austin, who designed a singularly ugly fighter based on his suggestions. His attempts to dismiss the SE5 as a poor design were clearly motivated by attempting to promote his own fighter design. The same thing occurred in Germany and in France, with several big pilot names being involved with aircraft manufacturers, influencing, or attempting to influence, production and purchasing decisions.

It's no secret that Manfred Von Richthofen was not the world's best in terms of piloting skill, being much more a tactician than an aerial artist, yet he was often consulted by Fokker when it came to aircraft design. And whilst it is often supposed that such designers as Fokker could do very little wrong, Anthony Fokker produced numerous ridiculously poor designs alongside his more well known successes, including the preposterous V8 quintuplane, with five wings set in a group of three near the nose and two more halfway down the fuselage, the entire theory being based on nothing more than the ill-thought out notion that if a plane with three wings was good, then surely one with even more wings would be better.

Such things were not limited to the drawing boards either. If you read James McCudden's Flying Fury biography, you find that McCudden was made an assistant flight instructor at a flying school after having made just a few flights in the pilot's seat. The first time he spun an aircraft, he didn't even know it was a spin, and simply got lucky in applying rudder to recover the thing, yet he is regarded as one of the Great War's better pilots. There is no doubt he was a good pilot by the time of his death, but that anecdote gives one an idea of how little genuine science and knowledge there was around in the early years of WW1.

So it is hardly surprising that a fighter which was easily spun should be regarded with derision in a era where a good many pilots were terrified of even trying to spin an aeroplane, since a lot of them hadn't the first clue about how to effect a recovery.

Javier Arango, who owned the Pfalz DIII replica built for the movie The Blue Max, is on record as stating that it is nice to fly, but is heavy on the ailerons (like most WW1 aircraft), but it is not particularly stable. Of course that is not a real Pfalz, being based on a Tiger Moth, but it did have new wings and a new tail assembly built to make it look like one, so it is more or less like the original Pfalz DIII in a good many respects.

Nevertheless, there is rarely smoke without fire, and many pilots berated the Pfalz as not one of the better craft of the war. But then again, the Sopwith Camel was not that great an aeroplane in many respects either; it was hard to fly, slower than almost every other aircraft in the sky (including two seaters and bombers), and all but useless above 12,000 feet. But it managed to nail hundreds of German aircraft. Maybe the Pfalz could have done so too had it not gained the reputation it did, which I suspect is probably not so deserved as one might imagine when looking at the bigger picture.

Al

[Kwiatek]

Originally Posted by YavorD

Hi Kwiatek!
What is the source of such CLmax data? I am curious how relatively thin airfoils with low curvature and relatively sharp leading edge got such a high CLmax (Pfalz, Albatros)?
Regards,
Yavor

I got it from Rise of the Flight team member. I also check these data in Profili program ( unfortunately it shown only Clmax for 13 deg Aoa) and by these site:

worldofkrauss.com/foils/search

Airfoils names:

- Pflaz DIIIa - Geottingen 79 ( Pflaz 11)
- Albatros DVa - Geottingen 173 ( ALbatros 6020)
- Fokker DVII - Geottingen 367

You could check it on the site which i wrote above. Just serach profile by name then click on it - You will get polars. ( but only for small Reynolds number)

I was also suprised that such airfoils like Pflaz and Albatros had have such high Clmax.

[Kwiatek]

Originally Posted by YavorD

Hi Kwiatek!
What is the source of such CLmax data? I am curious how relatively thin airfoils with low curvature and relatively sharp leading edge got such a high CLmax (Pfalz, Albatros)?
Regards,
Yavor

After making some more analyz there is definitly something wrong.

Polars Clmax/AoA which i used before from Profili or other sources were not reliable beacuse there were for RC models and for small Reynolds numbers.

I rechecked charts which i got for some of these planes and i found that i made mistake and wrong read values from chart. Is it possible that developers of these game also made such mistake?

Here are their Clmax values:

1.462 - Pfalz D.IIIa
1.370 - Fokker D.VII
1.313 - Albatros D.V

Here are valuse which i read directly from charts ( for airfoils):

Plflaz - Clmax - 0,78, AoA - 16 deg
Fokker - Clmax - 0,67, AoA - 16 deg
Albatros -Clmax- 0,68, AoA - 14 deg
SpadXIII -Clmax- 0,52, AoA - 14 deg

They look somewhere very low but are quite possible.

Chart for Pflaz:

[Greybeard]

It's always pleasant debating about technical details and flight reports of famous aircrafts. But when wondering if this or that scout was really worse than others and what it could have made having better opportunities, I think intervenes that famous "motto":<<One fact weighs much more than a mountain of words>>.

I think Pfalz D III was exactly what it was known for: a fair plane. If it would have been better, it wouldn't have serviced only six months in first line and author of book "The Pfalz aces" would have found someone to mention.

On the contrary, Albatros D series prolonged service, number of victories got on it, not to mention the famous allied request to seize Fokker D VII, speak theirself to state a clear superiority.

Regards,
GB

[Chock]

I don't think you can always read too much into the superiority of a design based on it being around longer than another one, even with early to mid war designs, which appeared at a time when developments and discoveries were coming thick and fast. With the speedy turnaround of WW1 designs, a plane that was superior one week could literally be outclassed the following week, but such types weren't always destined to become hangar queens.

The classic example of that would be the Eindecker, which was by any standards a merely adequate monoplane. Under any normal circumstances the little Fokker monoplane would have been a relatively unknown type, and one that had many contemporary types which were certainly its equal as aircraft - but stick a forward firing MG on any of them and give them to innovators such as Boelcke and Immelman and you had a world-beater (for a time at least).

Boelcke and Richthofen had performed similar wonders with the early Albatroses, yet the Albatros was a design that was showing its age by 1917, but it was what they had at the time and was what they were set up to manufacture, and with fingers in various pies, thus it soldiered on. A not dissimilar situation occurred with Germany in WW2, where the bf109 became the warplane that was produced in greater numbers than any other, despite designer Kurt Tank's Fw190 being a much better fighter by 1943. Regardless, the 190 remained less well developed, and it came from a less-favoured manufacturer in the Nazis eyes, with a consequent lower priority for engine deliveries. It didn't help that it was more complex to build either, when Germany was reliant on forced labour for much of its manufacture. And many of its best brains had gone up the chimneys of places like Auschwitz, too, which was another problem when it came to innovative production.

There are often other factors involved too, such as which company is in favour with a particular Government department or person who gives the go ahead for something, and whether the company that makes a particular plane is well placed to meet large orders. Willy Messerschmitt was on the wrong end of that equation for a number of years prior to WW2, after several high ranking Nazi politicians were killed in Lufthansa aircraft made by bf (whom he was the designer for). A situation which Hugo Junkers used to his advantage for a good few years, being well aware of how knowing which way the political wind was blowing could affect things, since he had been forced to team up with Fokker during WW1 for a while. As a result, his rival Messerschmitt was often not even invited to enter designs to compete for aircraft contracts, in fact only being begrudgingly allowed to enter the contest for the contract which eventually saw the bf 109 win a fly-off competition for a front line fighter because those who wanted to keep Messerschmitt in his place arrogantly assumed he would lose the contest. It was this which turned things around for bf and Messerschmitt, and in a similar fashion to Fokker's purchase of Oberursel, Messerschmitt got his claws into bf when it became favoured once more.

Back in WW1, such scenarios were ones which the pragmatic Anthony Fokker realised, which prompted him to acquire a large share the rotary engine maker Oberursel. Over in Britain, a good example of similarly practical thinking, is the RAF SE5a, which is distinctly utilitarian in appearance, and it looks nowhere near as pretty as some other aeroplanes of the time, nor is it as aerodynamic, but it was designed that way so that it could be churned out in larger numbers, using a variety of engines with just a simple redesign. This at a time when the British aircraft industry was still dependent on traditional woodworking skills to make aeroplanes, and Henry Ford's 'production line' concept was still a very new idea. So anything that could speed manufacturing up was a plus, as Fokker found out with his metal-fuselage model DVII, which found rapid favour. He could have built the DVII from wood, and in fact did make one or two from wood on the offchance that metal might end up in short supply.

Thus, a large part of the desire for the DVII to be surrendered was very similar to the seizure of rockets and flying bombs at the end of WW2 by various allied nations, being not so much about the superiority of the craft itself, as the construction techniques and technology employed on the thing. In the case of the DVII airframe, it was the welding techniques used to create the fuselages, and the tempering of the metal in the engine parts that most of them were interested in looking at.

Perhaps the best example of that happening was the Boeing company, which had been founded by William Boeing to make seaplanes for the US Navy. William Boeing saw that as a suitable venture because he had previously made his fortune in the lumber business and was knowledgeable about wood. But when the Boeing company examined the DVII after the Great War, they started employing the metal fabrication techniques they learned about from examining the DVII. Most famously, this happened on the Boeing B40 (Boeing's first ever airliner), which was originally a flop with a wooden fuselage, but which ushered in the post war flying boom in the US when redesigned with more metal fabrication and re-engined with the Pratt and Whitney Wasp (the development of that engine was something William Boeing helped to fund). Despite being air-cooled, the P&W Wasp radial was an engine designed after the Wright company's boss (who left to form Pratt and Whitney) had taken a good look at the construction methods used in BMW and Mercedes engines - these being the ones which were fitted to those confiscated DVIIs. The power to weight ratio of the Wasp, combined with the B40's airframe using Fokker's construction methods, were what made Boeing a successful aircraft company.

So we have Reinhold Platz to thank for that in large part. Platz was Fokker's designer following the death of Martin Kreutzer in a flying accident in mid 1916, who previously held the post. Platz had been Fokker's chief welder, working with him as far back as 1912 on Fokker's Spider monoplane. Anthony Fokker might have been the guy who sketched out the ideas for aeroplane designs, but it was Platz who engineered them into physical form, with his practical knowledge of metallurgy and welding techniques. And that was the real secret to much of their success.

So we can see that there is often more to the success of an aircraft than simply what flies over the battlefield, or indeed what flies off the drawing board and ends up in the hangar.

Al

[Ransom E. Olds]

Chock: Do you see a commonality in construction methods between the BMW and Mercedes of 1918 and the P&W Wasp? What are they? Thanks, Ransom