BMW Fokker D.VII's

[Dave_Watts]

Hi Dan-San,

I don't believe it would be "F" for "Fokker" as the Albatros tag reads;

"FOK D7 F", why have the "F" after the "FOK D7" stand for Fokker, when you already have the first part of "FOK" for "FOKKER". The "F" certainly refers to the powerplant being a BMW installation.

I did some scratching and digging through some on-line translation dictionaries and as simple as it sounds, I think I may have found the answer...

"F" = Fachflugzeuge = Specialized airplane

In simple terms; "special airplane". A "D.VIIF" would be a "D.VII special"

I'll keep looking, but that may be it.

Very Happy New Year to you and Pattie,
Dave W.

[Frommherz]

Happy New Year to everybody!

I've never heard of the term "Fachflugzeuge" (plural) or "Fachflugzeug" (singular) and I seriously doubt that it exists. It just doesn't make sense in German. The word "Fach" means "topic" or "subject" or "profession" and is used in applications like

Facharzt - medical specialist
Fachanwalt - specialist solicitor
Fachgebiet - area of expertise
Fachgespräch - expert talk
and so on

but "Fachflugzeug" would be very, very odd. If you wanted to create a term like "special aircraft" you would call it "Spezialflugzeug" or "Sonderflugzeug".

Sorry Dave, but your idea is not the solution to the "F"-problem.

[Dave_Watts]

Hi all,

Frommherz,

You are correct, I was confused, the word more correctly means "'.... specialist", as you stated, so a "D.VII specialist" makes no sense.

Although I don't think this is correct, what do you think of the "F" could be for "Führer" meaning leader, captain, guide? Or in other words, best...not so good is it.

With that Albatros data plate having the "F" stamped on it and a BMW installed, I'm on the tack that the "F" no longer means "Fokker", but is directly tied to the BMW motor, but what word meaning I'm not certain about.

Another possibility I'm not happy with is "F" for Max Fritz the genius engineer who came up with the high altitude carburetor for the BMW IIIa making it so good.

The strange thing about this is Fokker applying the "F" to the aircraft designation directly on the side of the airplane, evidently without Armee approval or order, and Albatros/OAW not, except on their "in-house" data plates attached to the aircraft.

It appears to be a BMW thing, not a Fokker thing.

I wouldn't be surprised if the dispatch lists for the flug parks that listed the aircraft, had the "F" designations on them. Don't know if there is anyone out there with access to original documents that could give us insight?

As has already been pointed out, why didn't Fokker and Albatros/OAW utilize the D.VIIa and D.VIIb nomenclature as did L.F.G. Roland D.VIa (Mercedes) and D.VIb (Benz) to distinguish between Mercedes and BMW powered? Strange.

Best,
Dave W.

P.S. I bet Ol' Imrie knows! If he would only finish his D.VII book.

[Dan_San_Abbott]

Hi Dave;
It was almost always the case, when an engine change was done the aircraft type number was modified with a letter designator, Rol.D.VIa Mercedes and Rol.D.VIb Benz. There is another case of the use of the f, Pfalz D.XVf 8364/1 See, Pfalz Aircraft of World War I, by Jack Herris, photo top of page 106. In the caption, Jack states, "Pfalz D.XVf prototype. As with he D.VIIf, the f indicates that a 185 hp BMW IIIa engine is installed" Pfalz used the lower case f. What I now wonder, did the F,f designator come from Idflieg?
I suspect it did, but it was an odd way of doing it. I do believe the F designator started with a Fokker built D.VII. the f designator was a smaller type in Fokker aircraft serial numbers, the F was smaller.
Happy New Year Dave,
Dan-san

[Dave_Watts]

Hi all,

Dan-San,
We are in accordance on this "F" or "f" matter. I don't believe Fokker came up with the nomenclature as well.

For what it's worth, we have "Fok.D.VII 377/18F" coming out of Fokker with an acceptance flight of May 15th. The next BMW powered D.VII's are 378/18 and 404/18. I don't believe I've seen a photo of 378/18, but I believe I've seen 404/18 and it was a "D.VIIF". I know there was the coloring changing of the numbers from white to black, but there also appears to be an "F" change from the "Fok.D.VII 377/18F" to "Fok.D.VIIF 404/18". 404/18 was flight accepted on May 22nd. 378/18 was accepted the same day as 377/18, (May 15th).

The dates may shed some light on when the "official" orders came down specifying the nomenclature and letter order, it that is the case.

Best,
Dave W.

[Laserlloyd]

Not sure what importance it is but I have to ask why then 377/18 is just listed as D.VII 377 on the acceptance report? On April and May's there no listing of the "f" so I wounder the if this was either a after thought or not part of the Idflieg doing.

Dave,

I can cut the photo of the data plate and past it here but I'm waiting on permission from WW1 Aero.

Lloyd...

[Dave_Watts]

Hi all,

I'm getting back to the total number of BMW powered D.VIIF's made.

On the total number of motors made we now have from observed motor numbers and the numbers from Die Flugmotoren-Erzeugung, sämtlicher Fabriken und samtlicher typen von 1 August 1914 bis 1 November 1918 from Pete Grosz, (published in WW1 Aero) and kindly posted on Aerodrome by Dan-San with his added observed data we can set the numbers pretty firmly.

From known serial numbers 1207 (from an OAW built D.VIIF) - 1682 = 486, I speculated the BMW IIIa production to be sn. 1200 - 1699 = 500, so the cited 540 from the recorded sheet, looks good, as do the other numbers from Opel and Mana observed serial numbers.

BMW IIIa = 540
Opel BMW IIIaO = 194
Mana III = 73

This gives us a total of 807 "BMW" type/performance motors built.

We established Fokker recieved 220 BMW motors installed/accepted into 247/245 aircraft. 41 Opel BMW motors into 41 aircraft. 3 Mana motors installed into 3 aircraft, 2 accepted.

Total Fokker output of "F" aircraft = 291 made/ 288 accepted.

This leaves a pool of 543 "BMW" type motors for the rest of the aircraft utilizing this powerplant, such as;

Fokker D.VIIF Alb.
Fokker D.VIIF OAW
Pfalz D.XII
Pfalz D.XV
Rumpler D.I
Dornier D.I
As well as many various prototypes from several manufacturers.

I have to cut out, but now we will try to calculate the number of BMW powered aircraft non-Fokker D.VIIF.

Best,
Dave W.

P.S. Along with the motor manufacturing list, Grosz had a performance sheet for many of the motors. I found it interesting that the weights for the Daimler D.IIIa vs the BMW IIIa is;

D.IIIa = 265 kg.
BMW IIIa = 285 kg.

I wasn't aware of the weight difference of 20 kilos. I wonder if the motor was located exactly the same as each other in the D.VII fuselage?

[Dave_Watts]

Laserlloyd,

Good point on the Fokker Armee acceptance sheets not "notating" the "F" designation. I agree it points to Idflieg.

Best,
Dave W.

[Dave_Watts]

Hi All,

Continuing on the BMW powered aircraft and production numbers.

This leaves a pool of 543 "BMW" type motors for the rest of the aircraft utilizing this powerplant, such as;

Fokker D.VIIF Alb.
Fokker D.VIIF OAW
Hannover CL.IIa + CL.V = 60 motors
Junkers D.I = 41 motors
Pfalz D.XII = 1 motor (at 2nd D Trials)
Pfalz D.XV = 5 motor (1 at 3rd D Trials)
Rumpler D.I = 1 motor (at 3rd Trials)
Zepplin D.I = 1 motor (at 3rd Trials)
As well as many other various aircraft (mostly prototypes) from several manufacturers. = approximately 14.
Such as; Albatros D.Va/ 1st Fighter Trials, Albatros D.XII 3rd Trials, Fokker V.29 3rd Trials, Fokker V.36 3rd Trials, Junkers D.I 3rd Trials, LFG D.XVII 3rd Trials, and Pfalz D.XVf 3rd Trials.

Utilized motors = 123.

543 - 123 = 420 available.

Fokker may have had a couple of BMW's around for prototype development. We know BMW sn. V5 was accepted in 231/18F, and this number falls outside of the normal number range and is in fact an experimental motor #5. I don't believe there were too many of these experimental motors that were utilized in aircraft, so I will not worry about them, other than this one sn. V5 as it was accepted.

= 421 motors available for Albatros and OAW.
I believe it is just as possible that some of the motors could have been salvaged and reused by Alb. & OAW, most likely at the same rate as Fokker. On the other hand using the same logic, the 60 Hannovers and 41 Junkers could have utilized salvaged motors as well. The licensed Opel and Mana motors came too late to be salvaged to any degree.

Out of the pool of 544, (added 1 back for sn V5), left over are;
321 are from BMW
153 from Opel
70 from Mana

Let's say Junkers and Hannover ran at the same 12% salvage rate as did Fokker and we'll use the percentages of Opel and Mana the same as Fokker.

Fokker BMW IIIa =
85% BMW (including 12% reuse salvage rate)
14% Opel
1 % Mana

Junkers needs 41 =
30 (with reuse rate of 12% = 34)
6 Opel
1 Mana

Hannover needs 60 =
45 (with reuse rate of 12% = 51)
8 Opel
1 Mana

Others need 23 =
18 (with reuse rate of 12% = 20)
2 Opel
1 Mana

This leaves us with;
228 are from BMW
137 from Opel
67 from Mana

With this given pool of BMW type motors left over for Albatros and OAW, if we use the same percentages of motors utilized by Fokker we should see something like the following.

228 BMW + 12% reuse = 255
137 Opel
67 Mana
= 459 "F" aircraft for Albatros and OAW.

Total Fokker output of "F" aircraft = 291 made/ 288 accepted out of approximately 800 D.VII's delivered by Fokker. That's right at .36% or let's say just over 1/3rd were "F"s.

I speculate this would make for a total of 459 + 291 made/288 accepted = 750 "F" made/747 "F" accepted (approxiamtely).

If we apply the ratios of "F" to non-"F" from Fokker's production we get the following;

Albatros Fokker D.VII overall production was very close to 1200 out of 1350 ordered.

Using Fokker's ratios, we should have come up with 432 "F" aircraft, but that appears to not be the case.

OAW Fokker D.VII overall production was very likely 1300 out of 1300 ordered.

Using Fokker's ratios, we should have come up with 468 "F" aircraft,, but that appears to not be the case.

If we divide up the left over "F" aircraft respectively to Albatros and OAW we have the following.

Fokker D.VIIF = 291 made/288 accepted.
Albatros D.VIIF = approximately 220.
OAW D.VIIF = approximately 239.

Total D.VIIF's = approximately 750 out of approximately 3300 D.VII's made = 23% about 1/4th or a quarter.

Now you guys can gang up on me and beat up the numbers so we can get this closer. At least it's a point to start from.

In a posting from "Terry" earlier in the year I read where he posted something like 80 BMW's for Pfalz as cited from Ed Harris, but I don't believe that is correct. Everything I read says the production D.XII's all got Mercedes, with only one being fitted for the Adlershof D Competition, along with a single D.XV (out of three) fitted with one BMW.

If these numbers, (which are speculative) are close, Fokker certainly got preference over Albatros and OAW on BMW deliveries. To reitterate;

Fokker is at 36% of all his D.VII's being "F"s.
Albatros/OAW is at 23% of all their D.VII's being "F"s.

A big factor is how many total BMW motors were made and delivered. My number of 540 from BMW out of a total of approximately 800, is what is critical. I know Dan-San has reported documents showing both 540 and a higher number of 747.

Interesting results. Has anyone else speculated this close on these numbers?

Best wishes,
Dave W/

[YavorD]

Anlage 17 : Flugmotorenbau (Bauprogramm 15.1.1918) Januar bis Oktober 1918 (Deutsches Reich)

1918 / BMW IIIa 185 P.S. / BMW IIIa Opel / BMW II 120 P.S. / Standmotore insgesamt
January ......... - ....................... - ................. - ...................... 1415
February ....... 5 ....................... - ................. - .................. 1297 (990 actual deliveries)
March ......... 15 ....................... - ................. - .................. 1455 (1140)
April ............ 30 ...................... - ................. 5 .................. 1635 (1390)
May ............ 50 ...................... - ................ 20 .................. 1785 (1230)
June ........... 60 ..................... 50 ................ 30 .................. 1895 (1310)
July ............ 70 ..................... 80 ................ 30 .................. 1965 (1260)
August ...... 100 .................... 100 ............... 50 .................. 2035 (1440)
September .... - ....................... - ................. - ...................... 1660
October ........ - ....................... - ................. - ...................... 1680

Source:
Jakob A. Gilles (1971)
Flugmotoren 1910 bis 1918
E. S. Mittler & Sohn GmbH, Frankfurt/Main, S. 203 + XXVII + 35 Bildtafeln.

Regards,
Yavor

P.S. Mana III from MAN Augsburg may be a different engine!