Dr.I Dilemma

Hi all,

Here's one for you Dr.I experts.

While on a recent thread pertaining to Voss' FI 102/17, the subject of if an Oberursel or a Le Rhone was fitted to the aircraft was disscussed. This lead me to looking into the early Dr.I "FI" triplanes, and made me come up with more questions that I would like to resolve. Any help appreciated.


Referencing The Fokker Triplane by Alex Imrie states on page 39,


"The British found that 103/17 was powered by 110hp Le Rhone No. T6247J, the engine that had been fitted to Nieuport 17 A6693 flown by Lieutenant E. J. D. Townsend of No 60 Squadron, RFC, who was reported missing on 5 April 1917."

Now to "change gears", I've been having trouble understanding the difference between the Fokker V.5 and F I 102/17. Anyone's input of clarification would be appreciated.

You may want to take another read on the Imrie book on page 31. It gets a bit confusing. He mentions different nomenclature designations such as, V.4, V.5, V.6, D.VI, D.VII, F.I, and Dr.I and gives a smattering of assorted Fokker factory Werk numbers.

My take on it is, (without digging into other references), as follows;

Fokker in anticipation of contracts being given out of three triplanes to different manufacturers began development. When he received his contract, he already had the D.VI, (later V.4) completed, (recognizable from the lack of struts and balanced ailerons), and utilized it as one of the aircraft for the contract.

D.VI, V.4, werk number 1661 Later modified with struts and balanced ailerons and elevator. Mistakenly designated/identified as V.5 on photographs in the Fokker archives. Aircraft sent to Matyasföld, Hungary.

D.VI, V.5, werk number 1697 Military designated FI 101/17. First true prototype Dr.I.

D.VII, V.6, werk number 1698 Mercedes powered triplane prototype. Third triplane prototype filling Idflieg's contract.

Based on the V.4's performance work began on two pre-production triplanes for front-line evaluation.

FI 102/17, werk number 1729

FI 103/17, werk number 1730

My confusion comes form the fact that Imrie states on page 22, photo caption 23.; "Voss's mechanics, Gefreiter (lance-corporal) Ruser and Flieger (private) Karl Timm, with 103/17 at Marcke aerodrome near Courtai shortly after the arrival of this aircraft in August 1917. Note the lack of wingtip skids, one of the features by which Fokker V 4 triplanes can be identified."

Later he states Voss flying 102/17 may have returned to Schwerin, (see page 37), to fly the production Fokker V.5 and see what improvements had been made over his V.4.

Was it only the first six triplanes that were lacking wing struts?

What are their Bestell numbers, 101/17 ?, 102/17, 103/17 and ? ?

On page 39, Imrie brings up the possibility that Voss ran out of fuel on the day of his demise, and goes into the comparisons of V.4 to V.5 triplane.

Does he "group/designate" the early triplanes as V.4s and all of the production triplanes as V.5s?

Thanks for any clarification.

Best,
Dave Watts

[rammjaeger]

David,

I have not the time to read my whole source currently but a SONDERHEFT of the German magazine "Flugzeug" from the series "Flugzeug profile" with title "Fokker V.5 / Dr.I" by Wolfgang Schuster and Achim Sven Engels could maybe answer some of your questions.

Schuster/Engels discussed the modifications of the airplanes of the first order compared with the prototypes. The following modification was called the main reason for the change of the term V.4 into V.5 in the internal system of the enterprise Fokker (now the German original text):

"Die drei Prototypen waren nur nach maßhaltigen 1:10 Skizzen angefertigt worden. Erst nach der Abnahme durch die ZAK wurden ordentliche Werkszeichnungen erstellt. Eine Zeichnung vom 15. August 1917 bestätigt, daß die Flügeltiefe spätestens ab diesem Datum 1000 mm betrug. Demnach wurde 104/17 (WN 1772, Baubeginn 13.September 1917) auch so gebaut, während die Flügeltiefe der Prototypen nachweislich (bestätigt anhand der durch die Flugmeisterei während des Typentests von 101/17 angefertigten Dokumente) 980 mm betrug."

I think its possible to order this magazine via Internet-homepage of "Flugzeug" too. I will check the Internet-address for you.

Hannes

[rammjaeger]

Look at

http://www.flugzeug-publikation.de/n.../profiles.php3

It needs an endless long time to built the site up - be patient and you will see the Dr.I-magazine (DM 19,95).

Thanks Hannes,

I think I have it sorted out after consulting Engel's V.5/Dr.I book.

He states Fokker started the first triplane prototype, (the strutless "D.VI"), in anticipation of forthcoming orders from Idflieg for triplanes. This D.VI, (later designated V.4 became FI 101/17 and was sent to M.A.G. in Hungary in anticipation of future orders from the Austro-Hungarian air force, (which never materialized).

He states FI 102/17 and 103/17 were made to fufill formal acceptance requirements of Idflieg. (Imrie contradicts this by stating they were for field trials). These two aircraft were built to the standard of the final modified form FI 101/17. These three "pre-production" aircraft were accepted as the first three aircraft against the contract order of twenty from Idflieg.

Construction began on Dr.I 104/17, (first designated V.5 by Fokker, then officially designated Dr.I), on September 13th. Kurt Wolff had fallen in FI 102/17 on September 15th soon followed by Voss on the 23rd in FI 103/17. After investigation into the crash of Wolff all subsequent Dr.Is, (beginning with 104/17), had their wings beefed up along with all of the other familiar changes such as a straightened leading edge on the horizontal stabilizer, etc.

This is the way I see it.

Best,
Dave