Hello

I bombed airports in Alsace - I'm flying the Caudron G-4.
A new sight was installed in it. Unfortunately, its calibration is wrong.

In the center there is a 100 km / h wheel. However, the next ones are marked as 95.90.85.
Yes, but this only applies when the plane is flying at a speed of 95-85 km / h and we look at the target through the lower parts of the sight - below the value of 100 km / h, because when flying slowly we have to wait before dropping the bombs.
Where the speed is greater, the upper part of the scale should be 105,110 and 115 km / h, respectively.

I tested the sight several times and I must say that it is a very flexible device. After a few tries, I hit the track as I was flying across the train station!
Since the G-4 is not a fast machine, all you need to do is set the engine power to 70% and keep the front of the machine raised to an angle of about 5 degrees (100 km / h). Guaranteed success.

Regards

I don't quite follow Taal. Could you draw what you mean?

Surely if you fly at 95 mph you use the part of the ring that is marked 95. - but use the lower intersection of the circle. I assume the numbers on the upper screen so it's clearer.

It would have been drawn as horizontal lines each with a number otherwise if they wanted a full range, rather than a circle?

It depends on altitude too of course.

You can hit the target every time so I don't understand the problem.

You find what works and then use it repeatedly at the same speed and altitude, and bingo.

An example in training ...

Hello

Maybe I was misunderstood.

A / The center of the sight determines the moment of dropping the bomb when we fly at a speed of 100 km / h.

B / But if we fly slower, e.g. 95 km / h, the later the bomb should be released. Then you only need to use the part of the circle below the center point - at the intersection of the 95 km / h circle and the vertical line of sight. We just need to "prove" our bomb.

C / If, however, we fly faster than 100 km / h, e.g. 105 km / h, then the bomb has more energy and will fly further. When we use the central point, it will fly over the target and fall behind it.

Therefore, it must be dropped earlier (somewhat in front of the target, before the center of the sight coincides with the target). Therefore, we only use the upper part of the circle.
So its top should be labeled 105, 110 and 115 km / h if we are flying +5, + 10 or + 15 km more than 100 km / h.

To sum up, the viewfinder should have the following numbers marked from bottom to top:

75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125.

This is how all bomb sights work. The faster the plane flies, the more "forward" the bombardier looks.

Regards

Ok that is what I thought you meant, thanks Taal. However, the circles are only for going slower. It just happens the numbers are drawn above for each circle.

I have not seen a sight with the numbers you indicate but if you have some photos of one we can look at that. But basically fly at 100 and all is well.

Welcome back

I know how hard you try to gather authentic material from the Great War period. For example, this is the photo you presented. Unfortunately, I do not have photos of such a viewfinder.

You are probably right, the sight circles have been described in such a way as to allow it to be used at speeds lower than 100 km / h, which is not surprising, with the performance of the Coudron G-IV, a reconnaissance machine suddenly burdened with two bombs (who thought about it before?) .
Therefore, it did not pay attention to the fact that the inscriptions were placed above the center of the sight. It was probably obvious to them.
As I am more interested in strike missions than hunting missions, I immediately noticed a certain inconsistency in the marking. As I wrote, the crosshair (if properly understood) is a very flexible attack tool. You don't have to keep moving the throttle.

By the way - do you have any publications about the Great War air sights?

greetings