Vickers gunsight in french fittings

[Greybeard]

I wonder how french pilots of Nieuport 17 did aim at their targets. Photos and drawings shows actually lack of aiming systems. Only an essential clue (a la Lee-Enfield rifle, so to speak) is always built-in, but I think virtually invisible from pilot's seat. Also Mark Miller did remain unsure:

Mark Miller's 3-D Nieuport

"But, despite all the help, I still had to do a considerable amount of guessing, particularly on the synch device and gunsight."

[YavorD]

The only clue I have is shown above. From what I can see, only built-in Vickers aiming equipment is shown, "infantry style". This detail comes from 1917 Nieuport-Macchi Ni 17000 manual (source: paolomiana web site). Parts for Vickers and Lewis installation were shown, no aiming instruments.
Regards,
Yavor

[Greybeard]

Thank you very much, Yavor, for your kind help. Unfortunately, italian manual seems only to confirm lack of proper aiming devices.

BTW, since you've this document, does it mention Nieuport 17 ailerons displacements (I mean full angular deflections, up and down)? I would really appreciate it.

Best regards,
GB

[YavorD]

Originally Posted by Greybeard

...
BTW, since you've this document, does it mention Nieuport 17 ailerons displacements (I mean full angular deflections, up and down)? I would really appreciate it.

Best regards,
GB

No data about aileron displacement, as much as I am able to read Italian
All the components of wing cellule and empennage are marked with part numbers within 11,000 series. In my opinion, such parts were identical for both Nie.11 and Nie.17, Macchi version at least. Fuselage and control column are, probably, Nie.17 specific, marked 17,000. May be this observation helps a bit.
Regards,
Yavor

P.S. There should be enough data available from Nie.17 drawings to calculate aileron deflection using simple geometry considerations (rigid-body kinematics). Stick forces will be a bit harder to calculate.

[Greybeard]

<<...to calculate aileron deflection using simple geometry considerations...>>

I already did, but getting about 15° up and 10° down, which seem to me too poor. Maybe drawing I used , although seemingly genuine, wasn't correctly scaled. Do yo have (or find) something better?

Thank you very much.
GB

[YavorD]

On the basis of Rozendaal drawings (Internet wersion with not very good resolution) and above mentioned manual my crude estimation is about +/- 20 degrees. I do not see reasons for too much difference up/down, may be about one degree.
Regards,
Yavor

[Greybeard]

Originally Posted by YavorD

...my crude estimation is about +/- 20 degrees. I do not see reasons for too much difference up/down, may be about one degree.

Thanks, Yavor for your kind help. Indeed, about 20° up and 20° down is the average of that time, with a minimum (AFAIK) of 14° for SE5a and a maximum of 32° for Fokker D VII. Unfortunately, also a few degree difference matters significantly. According to drawing I referred to, up angle should be higher than down one; this allows to compensate for induced yaw (that caused by increased air drag by lowering aileron and reduced by raising one), anticipating what would become common practice much later, on the contrary of what done by Nieuport contemporaries (down displacement could be even 50% more than up deflection).

GB

[YavorD]

Originally Posted by Greybeard

...
According to drawing I referred to, up angle should be higher than down one; this allows to compensate for induced yaw (that caused by increased air drag by lowering aileron and reduced by raising one), anticipating what would become common practice much later, on the contrary of what done by Nieuport contemporaries (down displacement could be even 50% more than up deflection).

GB

There are aerodynamics reasons for uneven up/down aileron displacement. Aileron control mechanism should be designed for uneven displacement. My conclusion is, Nie.17 kinematics does not provide any significant up/down difference (my estimation is about one degree).
Regards,
Yavor

[Greybeard]

Thanks Yavor. I think I'll go with the +/-20°. The drawing I referred to should be scaled uncorrectly.

GB

[YavorD]

There was, actually, an aiming device, fixed below the upper wing. It was shown with details of Lewis installation (1917 Nieuport-Macchi Ni 17000 manual mentioned in an earlier post).



Regards,
Yavor