B-17 Aiming Lines/Drift Lines?

[fubar57]

This photo was posted on another forum (and Imgur, Pinterest etc) and there was no positive outcome as to what they are for. The ones on the stabilizers do line up with the waist gunners rear firing positions but the ones on the wings only kinda sorta do. The ones on the stabs are also reminiscent Japanese drift lines. Thoughts?

 

[Crimea_River]

Interesting. I can only guess they have something to do with the gunners.

 

[Airframes]

I've see something about this, somewhere, years ago. As far as I remember, they're 'arcs of fire' markers for the waist gunners.

 

[fubar57]

Thanks guys. That was the general feeling on the other forum as well. I lined up the wing lines with the waist gunners positions and to my eye, in the above photo they didn't look like they lined up, this shows they were almost bang on. I wonder if it was a warning not to shoot inside the line which may cause an accidental engine hot due to over zealous gun tracking

 

[Airframes]

Yep, to prevent hitting an engine or prop - keep the arc of fire between the lines on the wings and tail planes.

 

[Crimea_River]

Maybe but that doesn't explain 2 lines on the horizontal stabs.

 

[nuuumannn]

Maybe but that doesn't explain 2 lines on the horizontal stabs.

It kinda does and kinda doesn't. Looking at the Fort from the rear, the tailplane is actually above the line of the guns on the fuselage, this makes their importance more relevant, as, because of the way the guns are mounted, if you fire inboard of the innermost line and outboard of the outermost line your arc of fire is clear when firing rearwards at a shallow angle, but if you fire within the two lines, you'll hit the tailplane. Problem is, they are not so visible from the waist gunner's position because the tailplane is higher on the fuselage, but looking from the radio operator's position and the top turret, you would be able to see them. Hmm...

 

[Capt. Vick]

What a conundrum. (Always wanted to use that word)