Oeffag C.II dimensions

[ReducedAirFact]

I was planning on modeling an Oeffag C.II, but I've hit a snag. In Austro-Hungarian Army Aircraft of World War One, it's listed as having an upper wingspan of 12.71m=41.7' (88.26mm at 1/144) and length of 8.40m=27.56' (58.33mm), not counting the propeller. However, when I match those sizes against the drawing in the same book, the plane is too long (or the wingspan too short). The pink box shows a rectangle of the dimensions listed, and it clearly doesn't fit the drawing. So either the drawing is wrong or the dimensions are wrong. Does anyone have a more definitive source, different drawings, or different dimensions listed?

[flash]

Trawling about the net the dimensions you have appear to be correct https://it.wikipedia.org/wiki/Oeffag_C.II http://www.samolotypolskie.pl/samolo...26/Oeffag-C-II
Lower wing given as 11.8m & upper as 12.7 in German & Austro-Hungarian Aircraft Manufacturers 1908-1919 the preview of which is here & available as an ebook. You have to scroll down to find the entry.
Maybe the image you have is not correct to scale ?

[Lt. S.Kafloc]

From a Polish site:

Dane taktyczno-techniczne samolotu Oeffag C.II

Rozpiętość (width?)	12,71 m
Długość (legth)	8,40 m
Wysokość (height?)	3,27 m
Powierzchnia nośna (Surface area)	38,0 m2
Masa całkowita (Max weight)	1205 kg
Prędkość maksymalna (Speed)	140 km/h
Czas wznoszenia na 1000 m (Climb to)	6 min 19 s
Pułap praktyczny (altitude)	3200 m
Zasięg (range)	400 km

[ReducedAirFact]

Maybe the image you have is not correct to scale ?

With the DD8, we've seen evidence in the past of a bad transcription of a dimension getting copied around to various places until the error is more common than the "correct value". On the other hand, there are not a lot of original drawings of the Oeffag C.II, so it could be that some draftsman made a mistake in their 3-view and everyone has been copying that faulty drawing ever since.

I think it's an elegant-looking plane, even if it wasn't a very popular type. Someone did an amazing computer model of it a few years back: link here

[flash]

A ticklish problem, but with no other measurements coming up you'd have to say it's likely the picture is wrong. Does the lower wing match to 11.8m ?

[Zoe Brain]

With the DD8, we've seen evidence in the past of a bad transcription of a dimension getting copied around to various places until the error is more common than the "correct value".

Yes, solving that one took a bit of historical sleuthing, didn't it?

[ReducedAirFact]

A ticklish problem, but with no other measurements coming up you'd have to say it's likely the picture is wrong. Does the lower wing match to 11.8m ?

Yes it does. So the question is whether the listed length is wrong or the drawing's length is wrong.

Yes, solving that one took a bit of historical sleuthing, didn't it?

Indeed! Thanks for that. There seems to be no shortage of such mysteries.

[flash]

Just looking at your pic again, I wondered whether the 8.4m measurement given is just a fuselage length, ie not the overall length counting prop,or, rudder/elevators ?
If you slide the pink box up a tad it appears it might fit the fuselage length in the diagram.
Another way to see if the image has been stretched might be to check the chord of the wings if you have that measurement.

A further rummage in the polish link I posted "...wingspan 12.71 (according to [2] - 12.7 ) m ...length- 8.4 (according to [2] - 9.0 ) m..."
[2] being: Sankowski W. ”Oeffag C.II”. Lotnictwo z szachownicą nr 11.

Would 9m length fit the entire length on the diagram ? If so then [2] maybe correct !

[ReducedAirFact]

Just looking at your pic again, I wondered whether the 8.4m measurement given is just a fuselage length, ie not the overall length counting prop,or, rudder/elevators ?
If you slide the pink box up a tad it appears it might fit the fuselage length in the diagram.
Another way to see if the image has been stretched might be to check the chord of the wings if you have that measurement.

A further rummage in the polish link I posted "...wingspan 12.71 (according to [2] - 12.7 ) m ...length- 8.4 (according to [2] - 9.0 ) m..."
[2] being: Sankowski W. ”Oeffag C.II”. Lotnictwo z szachownicą nr 11.

Would 9m length fit the entire length on the diagram ? If so then [2] maybe correct !

By George I think you've got it! In the picture below, the pink box is the correct wingspan and it covers the fuselage exactly. The blue box is the lower wing in width and the chord (of both wings) -- again, a good match. And finally the green box is the 9m length -- again, an excellent match. A tip of the hat to Sankowski (and to Dave)!

Once again proving this forum's combined aeroplane IQ is off the charts.



A theory: there is another way both measurements could be correct: The Oeffag C.II was produced in two series (52 and 52.5). Though none of the sources I have say so, they could have lengthened the fuselage between series. So it could be that the drawing is of the 9m-length plane (Series 52.5, presumably) and the statistics that are commonly quoted are of the 8.4m plane (Series 52, presumably). I have no evidence of this, but it seems plausible.

[flash]

I think our work here is done !