The Pfalz DIIIa

[mik]

I've been gone for a bit but now I'm back. Still studying aircraft, the Pfalz is my favorite German aircraft. however even after buying books which shall remain nameless for the moment I find there is no really reliable info on German WW1 aircraft. You don't have to be an (engineer and I am) to work out the generally accepted info for the Pfalz D111a and other German aircraft varies from at best suspect to complete rubbish. Agree/disagree/point me to reliable info if you can.
mik.

[vossiewulf]

A little confused, what do you consider "reliable"? I'd certainly consider the info found in Pfalz Aircraft of World War I, Greg Van's Pfalz Scout Aces of World War I, Windsock's Datafiles #21 and 107, and the many various articles in WWI Aero and Cross and Cockade, etc. to be about as reliable as anything we're going to have from here on.

[totalspoon]

Here's what some of the pilots of the time thought of it...

George A. Vaughn, 84 Sqn RAF, 17th Aero Sqn, USAS:
“The early aircraft I ran into were Pfalz and Albatros. The Pfalz as a rule was a more or less cumbersome airplane and we didn’t worry about the Pfalz. The Albatros was a little bit better, but of course the best fighter that the Germans had was the Fokker D.VII. That’s the one that gave us the most trouble.”


McDonald 56 Sqdn: A formation of 12 SE’s from No. 56 Sqn took off at 12:35 on 24 March 1918. After a series of running fights, MacDonald recalled: “I found myself alone and almost immediately spotted a Hun. He was a single-seater Pfalz scout. I had seen a model of this machine and had been told that Pfalz scouts were slow and not of much account. I got in a burst on him at close range and he went down completely out of control."


Summary of Air Intelligence No. 17.
On 26 Feb 1918, Vzfw Hegeler of Jasta 15 was captured in Pfalz D.III 4184/17. The "Summary of Air Intelligence No. 17" reported that Hegeler stated, "Pfalz scout is not popular with pilots owing to its lack of speed and its bad manoeuvrability; an improved type is expected." The improved type was, of course, the D.IIIa which was already reaching the front.


Summary of Air Intelligence, General Staff of the AEF:
“April 1918 - Interrogation of pilot, Jasta 64: Pfalz D.III inferior to Albatros D.V, but one advantage, it climbs faster. It is equipped with 160 hp Mercedes, old model, but good with frequent defects in metal. 45 Hrs between overhauls,”…

May 1918 - Albatros D.V much liked, although Pfalz D.III probably faster and has better climb, but not in favor because maneuvering qualities are not so good.

“Jagdstaffeln 64 and 65 have about 10 Albatros D.V and Pfalz D.III aircraft apiece. Pilots not satisfied with machines especially Pfalz which climbs slowly and loses speed at high altitudes. They regard speed superior to Albatros D.V.”


Air Chief Marshal Sir Donald Hardman flew Dolphins with 19 Squadron and wrote, "The Pfalz unlike the Albatros was not a popular machine with the Hun Pilot; it was prone to catch fire, had little glide, and was not so strong as its predecessor, and therefore, although it actually came on the front later than the Albatros, it disappeared before it.
However it was rather more splitarse and had a slightly higher ceiling, 19 000ft or 20 000ft. It had one bay with "V"-shaped struts, extensions, a rather deep and narrow fish-shaped body with a square tail.
It was more or less regarded as "cold meat" by the British pilot and known as the foolish Pfalz fish. The Hun was always rather afraid of them and consequently didn't make the best of them."



1/Lt. Donald S. Poler, an American who flew SE5a’s with No. 40 Squadron RAF, described a fight he had on June 27: “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. No one was hurt…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. 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.”

Ltn. Van Ira a South African flyer in 74 Squadron gives this antidote of a fight between Mick Mannock and a well flown Pfalz on 21st May 1918.
"...the other Pfalz, a silver bird, and he had a fine set-to, while his patrol watched the master at work. It was a wonderful sight. First they waltzed around one another like a couple of turkey-cocks, Mick being tight on his adversary's tail. Then the Pfalz half rolled and fell a few hundred feet beneath him. Mick followed, firing as soon as he got into position. The Hun then looped - Mick looped too, coming out behind and above his opponent. The Pfalz then spun - Mick spun also, firing as he spun. This shooting appeared to me a waste of ammunition. The Hun eventually pulled out; Mick was fast on his tail - they were now down to 4,000 feet. The Pfalz now started twisting and turning which was a sure sign of 'wind-up'. After a sharp burst close up Mick administered the coup de grace, and the poor old fellow went down headlong and crashed."
"This was a remarkable exibition, a marvellous show. I felt sorry for the poor Pfalz pilot, for he put up a wonderful show of defensive fighting. Had he only kept spinning right down to the ground, I think he would have got away with it."


Lt John M. Griders diary, 85 Squadron RAF.
"They were Pfalz scouts and are easy meat for SEs"


Jasta 24, in a report dated 25th October 1917, expressed the following opinion...'It is slower than the Albatros D III; it is fast in a dive and is then faster than the Albatros D V. The climbing performance...varies greatly, sometimes almost as good as the average Albatros D V but never better'

These are not cherry picked accounts, but every single account I can find as a non-German speaker.

Spoon

[mik]

thank you for your reply 9a very interesting read. Pfalz aircraft of WW1 is a great book but the info is suspect, see page 68. An albatross Dva has a speed of 116mph @ 3290ft on 180hp which is much slower than an SE5a at that altitude. The DVa might make 120-125mph @ 0ft. Page 68 says the Pfalz DIII on 160hp has the same speed as the DIIIa on 180hp of 180kph(112mph). The rates of climb also don't add up.

[Mogadeet]

The Pfalz D-III and Pfalz D-IIIA were actually very different machines, even though they looked nearly identical. The D-III was indeed a dog, very underpowered and with poor maneuverability. The D-IIIA, on the other hand, was more powerful, faster, and had a better climb. Experience with one could get you in hot water with the other. Fortunately for the German pilots the D-III was not the most numerous of the models. The Pfalz should never be treated as a D-III/D-IIIA.

The surest sign that not all the Pfalzs were dogmeat is the plane fact that the Entente fliers, in far better machines, available in far greater numbers, and engaged in a great deal of aerial activity, did not sweep the Germans from the skies when the Pfalz and the Albatros D-IIIA and D-V machines were pretty much all they faced. It should have been like the Zero vs the Buffalo if you listen to the fliers talk. But the numbers say that those "crappy" aircraft were holding their own. Simply put, if the Pfalz D-IIIA was that bad, why were they not only staying in the air, but shooting down Entente fliers and balloons? How many Buffalo aces did the Pacific war create?

A very successful method for a Pfalz getting away from a fast aircraft, like an SE-5A, was to drop like a rock. I'll bet there were many engagements where the SE-5A bounced the Pfalz, fired at it, watched the Pfalz drop like a rock, and the SE pilot declared "I got the blighter!" while the Pfalz flew back home secure in the knowledge that they didn't try and dogfight at a disadvantage. If the Entente claims were true the air war would have ended by June of 1918.

I think the best comparison of the D-IIIA as an air to air machine is that it is the P-40N of WW-I. Not the greatest, but dangerous for all that.

Mogadeet

[gavagai]

The "easy meat" quote supposedly from Grider's diary is apocryphal. A WW1 air-power historian I know says that no one has seen Grider's diary, not even Eliot Springs, who put that quote in his book.

In my opinion the Pfalz D.III(a) is a lot like the Hurricane. Rugged and successful, everyone who was shot down by one said it was an Albatros, just as Luftwaffe pilots claimed they were shot down by Spitfires in 1940.

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Mik,

Another friend of mine (an engineer who is also a pilot) has put together a spreadsheet for estimating the performance of WW1 biplanes. We started with the Mercedes D.IIIa powered Fokker D.VII because there is a lot of data available for it from France. Based on the aircraft dimensions and engine performance data (from a German test in a sealed chamber), the Pfalz D.IIIa performance does not come out so bad.

The reported 185km/h airspeed at sea level is reasonable (190km/h for the D.VII) provided you assume a prop pitch of at least 2000mm. It climbs a little better than the Albatros D.Va we modeled, but not quite as well as the D.VII.

Treat every figure you see for a WW1 scout with a healthy dose of skepticism. In addition to detailed technical specifications, unless they tell you the air temperature or air density on the day of the test (or at least the time of year!), the performance data could be highly skewed. For example, if I choose a temperature of 30 degrees C at sea level, our Pfalz D.IIIa model ceiling is only about 5200m. If I lower the temperature to 5 degrees C at sea level, the ceiling increases to over 6000m!

I suspect that a lot of the performance data we see that disagrees so sharply with combat reports is due to comparing one aircraft test at a cold temperature with another aircraft test at a warm temperature.

[vossiewulf]

I'm not aware of any WWI aircraft for which the performance data is consistent and anywhere close to accurate by modern standards. I don't see how the Pfalz is remarkable in that respect.

[sator]

I think alot depended on who was flying it. Jasta 10 used them and some pilots liked them and some didn,t. Voss flew one but i don,t know if he had any victories with it or what he thought of it. Maybe someone here on the forum can come up more info to share on this subject.

[mik]

I have a whole bunch of formula for estimating speed rates of climb ceiling etc, but they mostly apply to monoplanes. Biplanes are more difficult and I think there is something missing in my calculations. I calculated the top speed of a Pfaltz DIII at around 112mph @ 0ft but the calculated ceiling was way to low.
112mph @ 2055lb with a streamlined(relatively) aircraft seems to low relative to the RE8 doing 103mph with 10 less hp @ 2679lb and less streamlined.
Being lighter would allow a relatively small increase in speed and a much greater increase in rate of climb. 10hp should guarantee a noticeable increase in speed and ROC, plus the faster you try to go the more streamlining counts. My guess without calculations is I think the DIII should be good for 120mph @ 0ft.

[gavagai]

No, I don't see why the Pfalz or Albatros should do 120mph if the Fokker D.VII could only reach ~118mph with the same engine. Maybe with the Axial type 95 prop, which had a pitch of 2200mm, but I don't know if the engine would have sufficient torque to overcome the increased load.

See here for biplane theory:
Theory of flight - Richard von Mises - Google Books

The big adjustment you need to make when applying the above is to account for wings of unequal chord: multiply the wing gap by the upper:wing lower wing chord ratio. In the case of staggered wings, subtract the stagger from the lower wing chord.