Albatros higher top wing

[VieuxCharles]

Evening all,

the over day I was reading through "Albatros Aces of WW1" by Norman Franks (great book by the way) and at some point the author explains the differences between the Albatros DI and DII fighters i.e. the top wing of the DII being closer to the fuselage to improve the upward vision of the pilot. My question is this:

- why was the change reversed in the DIII where the top wing looks much higher compare with the DII. Was it for structural integrity or did they just forget?

Be interested to hear any theories or concrete facts that any of you can come up with.

Kind Regards Alex

[Flying Helmut]

Theory - difficulty in visually following a target.

When the D.II top wing was lowered (compared to the D.I), it was supported on outwardly-splayed 'N' struts (which were out of the way of the pilot's line of vision laterally) but the lowered top wing, much closer to his head, restricted vision centrally/vertically.
The early D.IIs had the same side-mounted fuselage "Windhoff" 'ear' radiators as the earlier D.Is, the structure and pipes of which did not affect the pilot's vision.
Part way through the D.II production run, the 'ear' radiators were replaced by a single upper-wing-mounted "Teves and Braun" radiator, the feed pipes of which dropped down to the engine right across the pilot's eyeline.
The narrow space under the top wing was now quite congested, by the two machine guns and the coolant pipes.

I suspect that pilots had difficulty following target aircraft, and so on the D.III the wing was raised (but nowhere near as high as on the D.I) to reduce the congestion and improve the forward view.

Even this was not good enough, since later on in 1917 the "Teves and Braun" radiator was moved to the right, taking the water pipes with it out of the pilot's forward eyeline, following the complaints of several pilots.

[flash]

The two types had different wing systems, the latter being sesquiplane, so there may be issues over lift involved and they maybe found a 'sweet spot' on the D.III between the two heights used on the D.I & D.II to achieve acceptable visibility forward & upwards without compromising the aero-dynamics.
I thought the reason the rads were offset from the centre line was because of the risk of scalding to the pilots if they leaked or were damaged in combat but getting rid of anything from the sight line would help.

[Flying Helmut]

I thought the reason the rads were offset from the centre line was because of the risk of scalding to the pilots if they leaked or were damaged in combat....

Often cited, but without any evidence.
The newer Osprey books discredit this as the reason for the move to the right, principally because the Albatros two-seaters continued with a dead-centre radiator right up to the war's end - if a scalding problem existed, they would surely have moved radiator in the same way.
If any plane was more likely to receive incoming bullets, it's a two-seater rather than a Scout. No two-seater crews are recorded as having scalding issues; the scalding issue appears to be an assumed problem, rather than a recorded one.

[flash]

... the Albatros two-seaters continued with a dead-centre radiator right up to the war's end - if a scalding problem existed, they would surely have moved radiator in the same way....

Ach so, though the greater height of the tandems wings compared to the single seaters could've meant it wouldn't have been an issue for them anyway.