Pflaz DIIIa - how good or bad it really was?

[Chock]

Not so much in the actual construction (although doubtless that too played a part), more a case of the level of skill used in making the components and how they were fitted, as well as some indirect inspirational thinking.

Comparable water-cooled stationary engines in craft such as the SE5a, DH4 and SPAD, i.e the Hispano-Suiza, the Wolseley Python (aka, the British built Hispano-Suiza), the Wolseley Viper and the numerous FIAT and Peugeot engines shoehorned into the DH4, were often beset by problems. This was especially true with the SE5 and SE5a, with the Hispano-Suiza geared-down versions fitted into them being notorious for having badly-tempered gears and similarly dodgy crankshafts, which was something which prompted RAF to try a direct-drive engine. Many of those engines also suffering from general cooling problems which exacerbated the failure of those parts.

It's worth noting that the SE5a was often run with the cowlings removed when in the warmer US climate, specifically to get around cooling issues. By contrast, most German types did not have a closely-cowled engine even when powered by a water cooled engine, a design feature which showed up on the DH9 in comparison to the enclosed engine of the DH4.

That aside, you can learn a lot about production methods of engines simply by looking at the thing, to see how parts have been cast and what revisions have taken place on later iterations. But other things can also occur.

Immediately following the Great War, there was a general feeling that because the DVII had a water cooled engine, and because it was highly regarded as one of the best fighters of the war, that water-cooled engines must be the way to go. It was Frederick Brant Rentschler, who had been the head honcho at Wright Aeronautical who was an advocate of developing an air-cooled radial, but he was flying in the face of that general opinion about the superiority of water-cooled types. Also adding to the problem was the fact that there were literally thousands of spare water-cooled Liberty V-12 engines sat in warehouses in the US waiting to be used, and nobody wanted to admit they were largely obselete, because they had such a poor power to weight ratio.

Rentschler left Wright Aero when they could not be persuaded to build an air cooled radial, and instead teamed up with Pratt and Whitney to make the Wasp Radial, with Wrights later using some of his ideas to make the similarly air-cooled Wright Cyclone. But both of these engines had been born out of studying the water-cooled engines of the DVII and coming to the conclusion of 'why carry water, when you can carry extra payload?' Thus the study of the water-cooled engine led to the development of the air cooled engine, since the goal of Rentschler when creating the Wasp radial, was a one-to-one power to weight ratio, as opposed to the V-12 water-cooled Liberty, which had around half that performance, delivering approximately half a hoesepower for every pound of weight, much of that weight being the cooling system and bulk of the water cooled system jacketing the cylinders and other parts.

The other thing of course is that, as with the Mustang, bf109 and Spitfire etc of WW2, it was the glycol coolant system which left them more vulnerable to combat damage when air-cooled types would not risk the same potential problem.

Al

[Gregvan]

Hi,

Well, as Greybeard mentions the book "The Pfalz Aces" and as I am the author of Osprey's Pfalz Fighter Aces of World War 1, I suppose I should step up here (I really thought I did find "someone to mention"?). Since I wrote that book, I have found additional information on the Pfalz D.III flown by Rudolf Berthold, and the D.IIIa fighters flown by Otto Kissenberth and some of the aces of Jasta 29.

First, I must state that I am neither an engineer nor a pilot. I don't even know what a PflazIIIa is, nor do I know anything about computer games or flight simulations crafted by techy types. I have researched quite a few accounts by pilots who flew in the Pfalz D.IIIa, or who flew against it. That will have to do.

Yes, there are plenty of accounts by German pilots who found the Pfalz mediocre at best. These especially come to the fore when they were comparing the Pfalz D.IIIa against the much-more-desired Fokker D.VII, or against later generations of Allied fighters and two-seaters. One can also easily find plenty of accounts from Allied fighter pilots who had very low opinions of the Pfalz D.IIIa as a foe (see Winged Victory). Yet, I have found some bits of evidence that seem to show it wasn't a complete dud, especially when flown by competent pilots who knew how best to maximize its strengths and minimize its weaknesses.

Max Holtzem flew the Pfalz D.III and D.IIIa considerably in Jasta 16b in 1918. Of course, he came to the unit with unusually extensive experience as a Pfalz company test pilot. When interviewed circa 1970, Max had fond memories of the Pfalz D.III/IIIa. To quote an interview: "Building up combat operational flight time in the Pfalz D.III(a) fighter, Max developed a keen admiration and respect for it. Its ability to spin beautifully to the left saved his life more than once. Several times, as tracers burned past his head in a dogfight, his agile Pfalz snapped over into a tight left spin, literally flying him out of trouble. He believes that the Pfalz, at full power, could outdive most of the Allied and German fighters at the front at that time...Max flew the Pfalz with complete confidence that it would not shed its wings in combat maneuvers. With full power, he recalls, you had to keep slight forward stick pressure, as it wanted to go into a slight climb. Power off, it got nose heavy and dropped off to the right in a shallow dive. Max claims, "You flew this little bird. It was a real pilot's airplane."

"Like most aircraft of the period, it was inherently unstable and could not be flown hands-off, the mark of a flying machine. It did all of the combat maneuvers well, and was a delight to land. According to Max, it glided in at 55 mph, with a flareout at 45 mph for a perfect 3-point touchdown. It was so stable at slow airspeed that Max recalls he often wheel-landed his Pfalz to save his tail skid from damage in rough terrain."

"The D.IIIa could take a lot of punishment, was a stable gun platform...Max insists that the Pfalz D.IIIa was a better aircraft that the Albatros D.III series...While admitting the Albatros climbed better, Max terms the Pfalz "a great airplane on low level missions such as trench strafing and ground attack." Diving was its forte and although performance did fall off slightly over 10,000 feet, in the hands of a competent pilot the Pfalz D.III could hold its own..."

[Gregvan]

Hi Again,

Here's a few begrudging positive comments from the Allied side:

Gordon Taylor, a Sopwith Pup pilot in No. 66 Sqn RFC, wrote of an encounter on 31 August 1917 - which means he must have encountered some of the very first Pfalz D.III's at the front: “I watched them grow into the full shape of aeroplanes: all silver, but not the Albatros. The tail-plane was different; more rectangular than the spade shape of the Albatros…They looked lighter, and even slimmer than our usual opponents...They were the Pfalz Scouts. It was said that they weren’t as good as the Albatros. But they were obviously still much faster than our machines…”

Flight Commander E D Crundall of No. 210 Sqn, flying Camels, wrote on 4 July 1918: “I saw 5 Pfalz scouts over Armentières and Lille and about 3,000 feet above us. I decided to attack these enemy aircraft…The formation of Pfalz scouts were heading towards the north so when I got to about 50 yards from the hindermost one on the left I opened fire and my other pilots opened fire soon afterwards. Immediately all five Pfalz went into a very steep dive and soon left us a long way behind. The last we saw of them they were in good formation so we could not have done any serious damage.

Crundall, again, on 19 July 1918: “Led an OP of five Camels from Ghistelles to Ostende at 16,000 feet. When over Ostende we were taken completely by surprise because seven Pfalz scouts dived out of the sun and our first intimation of their presence was heavy bursts of machine gun firing. We swung round to the left in a steep climbing turn but after that one burst of heavy firing all the Pfalz dived steeply away. By the time we had recovered from this shock the Pfalz were a long way from us and we lost sight of them. On our return it was found that all our Camels had been hit by bullets but luckily no vital parts were hit.”

1/Lt. Donald S. Poler, an American who flew SE5a’s with No. 40 Squadron RAF, described a fight he had - on 27 June 1918: “At a 1:30 patrol we engaged two Huns. One, our first Fokker D.VII, and a Pfalz with wings painted red and fuselage yellow. I had a wonderful dogfight with the last down to 7,000 feet, away over the lines.…I fought with that fellow from about 14,000 feet down to 6,000 feet. Evidently the S.E.5 and that Pfalz were pretty closely matched (my emphasis - GVW). I’d try a maneuver and he’d try a maneuver and I’d try another maneuver and I couldn’t get any tighter and he couldn’t get any tighter to me. I’d pull away and get in a few shots without results. When we got down to 6,000 feet (and this is always the case up on the British sectors) the wind had carried us several miles over German held territory. …When we got down that far I decided I had better call it quits, so I beat it. Well, he wouldn’t let me beat it….all the time he was following he was firing. I looked back at the fellow and could see his bullets following me all the way. They looked like fountains of smoke. …I finally got away.”

Capt. Gwilym H. Lewis, No. 40 Sqn, described the same fight: “Two very sporty Hun scouts attacked a straggler of our formation. One with a very bright red top plane and yellow body, and the other a mottled brown. I turned round on them and had a shot at the brown lad, but this time had trouble with the engine. Bolo (Poler) had an excellent fight with the red fellow, who fought with equal determination, finally leaving each other at a few thousand feet."

I find the above account interesting because it seems to show that, as late as 27 June 1918, when Fokker D.VIIs were increasing in number, a good Pfalz D.IIIa pilot could still put up a great show against an SE5a.

A patrol of No. 56 Sqn SE5a’s led by Capt. W.S. Fielding-Johnson,MC, on 7 March 1918, engaged a formation of enemy scouts, concentrating on two Pfalz D.IIIa's which had become detached from their comrades. The SEs drove the Pfalz down over Cambrai, but Fielding-Johnson commented, ‘These were stunt pilots and it was impossible to get a shot at them. They were last seen at about 3000 feet over Cambrai under control.”

Even good old Taffy Jones, whose books are full of lurid accounts of Mick Mannock blasting 'dud' Pfalz aircraft out of the sky, could occasionally muster a scrap of respect for the occasional competent Pfalz pilot. From Tiger Squadron p. 107): “ The enemies were Pfalz scouts, well-flown and most aggressive. Quite a change to find Huns who will fight, I thought. …I thought this would be a good opportunity to give Nicky (Nixon) a chance to draw his first blood. I fired a few shots at him, then zoomed up to watch Nicky have a go… but when I had finished my zoom and had steadied myself to look for Nicky on the Hun’s tail, I saw to my horror quite the reverse picture. The Hun was pumping lead into Nicky, who was diving in a straight line away from him. Before I could help, my dear old machine with my mascot and poor old Nicky was enveloped in flames." Jones had lent the neophyte Lt.M "Nicky" Nixon his own favorite SE5a for the flight; the well-flown and aggressive Pfalz pilot in this case was Gefreiter Marat Schumm of Jasta 52, gaining his first victory.

Later on 1 June 1918, Jasta 52 again encountered No. 74 Squadron, led by Mannock. Jones wrote (again, the emphasis is mine): "The fight with Mick in the afternoon turned out to be the hottest dog-fight I’ve been in for a few days. Mick led A and C Flights on to seven Pfalz scouts, camouflaged dark, with white tails. It was cloudless where we fought – over Estaires, between 4:24 and 4:35 pm, at 13,000 feet.

“For ten minutes the ten S.E.5s engaged the seven Pfalz; and when the battle ended one enemy had gone down in flames, one had crashed, and one had gone down out of control -all to Mick’s guns -while we had lost our flight commander (Cairnes). A determined Pfalz got to within 25 yards of him and gave him the gun. His right wing was suddenly seen to break up, the nose of his S.E. dipped viciously, then downwards he spun at a terrific rate. I watched him for a short while, sickness overcoming me. It is a terrible thing to see a pal going to his death.”

Capt. W.J. Cairnes of No. 74 Sqn, a Flight CO with six victories, was shot down by Ltn Paul Billik of Jasta 52. His SE5a C6443 broke up northeast of Estaires at 16.25. Billik claimed an SE5a east of Merville at 4:40 PM. Mannock shot down Ltn. Saint Mont of Jasta 52, who was KIA (he took to his parachute, but it tore); there were no other recorded Jasta 52 casualties.

[Gregvan]

Hi,

The following quotations from Carl Degelow are well-known: "When I arrived at Jasta 40 in May 1918, the Staffel was equipped with Albatros D.Va and Pfalz D.IIIa aircraft...Given the choice, I selected a Pfalz D.IIIa, a type I had flown in Jasta 7. The Pfalz was a bit underpowered and it did not climb as well as the Albatros, but I felt it was a safer aircraft. For some time the Albatros D.Va had a structural problem with the lower wing spar, which had a tendency to break under stress, causing the bottom wing to part company with the rest of the airplane!...Suffice to say, this did little to install confidence in the Albatros fighter planes. So, in my case, I took the second-rate Pfalz and, having learned its limitations, made the best of a bad job."

Hardly a ringing endorsement, but again - the last sentence re-emphasizes that if you learned its limitations, a Pfalz D.IIIa could do all right in the hands of an experienced and clever pilot. That's not to deny that every Pfalz (and Albatros) pilot wasn't very happy to exchange their machines for Fokker D.VII's as soon as they became available.

As I said, there are also plenty of comments from German pilots who disliked the Pfalz - particularly Paul Straehle and Heinrich Kroll, among others. On the other hand, it would seem from photographic evidence that Rudolf Berthold of Jasta 18/later 15, apparently preferred the Pfalz D.III and D.IIIa to the Albatros - as he certainly could have had his pick of either. Of course, he probably wasn't doing a whole lot of flying during some of these periods.

[Mogadeet]

I see Pfalz D III and Pfalz D IIIa used interchangeably in this thread. Often, when answering about the D IIIa, the D III keeps getting referred to. So...

The D III and D IIIa, while looking similar, were in fact very different in the air. The difference in engines was one part, and the tail structure was significantly different as well.

They should not be referred to interchangeably. What can be said about the D III applys to the D III. What can be said about the D IIIa, applies to the D IIIa.

The D III was indeed underpowered and not a real success. The D IIIa was a terrific improvement. The Pfalz D IIIa was the major heavy lifter in the German Air Service for a number of months, and didn't do a bad job. The Entente, though hugely outnumbering their German opponents, did not sweep the Germans from the skies during that time.

The D IIIa, though not a spectacular aircraft, was a very serviceable weapon and did not do badly.

And, though the Entente fliers considered it easy meat (it would just drop out of the sky when you fired on it), they were mostly being hornswaggled by the tactics. Plane dropping from the sky = kill. When it fact it was Plane dropping from the sky = got away from you.

Mogadeet

[Greybeard]

Originally Posted by Gregvan

Well, as Greybeard mentions the book "The Pfalz Aces" and as I am the author...

Sorry Greg, I would only emphasize Pfalz DIII got less victories than most successful contemporaries; absolutely, I wouldn't be critic in respect of your book.

I didn't say Pfalz DIII was completely outclassed by its adversaries: I meant it was, in the hand of an average pilot, less performing than Albatros DV and, later, Fokker DVII. Statistics may be arguable, but are the only way to asses the truth: it is for this reason, I think, politician must be elected by number of votes and not according to the best opinion of their fans.

Regards,
GB

[Kwiatek]

Thx All for these intetesting post.

I still think over Pflaz handling and stall characteristic.

As i wrote in my first post :

"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"

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."

Could be that Albatros was easier to fly and has better stall and spin characteristic then Pflaz? It could be that even modificated Pflaz DIIIa with more horsepower engine and larger rudder keep bad stall characteristic of his older brother? Both of them have the same wing profile and airfoil which could case such bad characteristic at high angle of attack?

So in hand of experience pilot it could do better then Albatros but with novice pilot it could make more problems in handling, turn and combat situation?

[Mogadeet]

Originally Posted by Kwiatek

Thx All for these intetesting post.
So in hand of experience pilot it could do better then Albatros but with novice pilot it could make more problems in handling, turn and combat situation?

From what I know, that is an accurate statement. But I would clarify that it was a case of the Pfalz D-IIIA was a more capable weapon overall, but it took a better pilot to get the best out of it because it was less forgiving.

Pfalzes were excellent divers. And I wonder just how hard they were to get out of spins, because that was such a common tactic for Pfalz pilots in a hot spot, and such a tactic would not be so common if it was real risky. Albatros pilots were far less willing to "drop out of control." Even if the Pfalz were less likely to break up at high speeds, if you were lucky to get it back under control, it is not a tactic the pilot would try a second time. And that tactic did not seem to be limited to experienced pilots.

My own books on Pfalzes describe them as having excellent dive characteristics and good high-speed handling (which you need in a dive) and good spin characteristics. The D-IIIA, with its improved tail, was better at pulling out than the D-III. However, they could be tricky at very low speeds and you had to be very alert to land one. One Squadron/Signal book mentioned high landing speed that was especially bad with the D-XII.

A lot of Pfalzes were claimed as kills that flew home just fine too.

Mogadeet

[SCMc]

Mogadeet wrote:

The D-IIIA, with its improved tail, was better at pulling out than the D-III. However, they could be tricky at very low speeds and you had to be very alert to land one. One Squadron/Signal book mentioned high landing speed that was especially bad with the D-XII.

In post 12, Greg van W. wrote about Max Holtzem (a Pfalz test pilot and a combat pilot in the D.III or D.IIIa):

It did all of the combat maneuvers well, and was a delight to land. According to Max, it glided in at 55 mph, with a flareout at 45 mph for a perfect 3-point touchdown. It was so stable at slow airspeed that Max recalls he often wheel-landed his Pfalz to save his tail skid from damage in rough terrain.

We seem to have contradictory opinions here, which is not surprizing for any discussion about the Pfalz D.III or D.IIIa.

Steve

[YavorD]

Originally Posted by Kwiatek

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.
...
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:

The above set of data was, probably, retrieved from the NACA reports. The scale factor is "twice dynamic pressure". In modern terms such values shall be multiplied by two. All the data come from a small scale test with a low Reynolds number.
Regards,
Yavor