B-17 appendage

Definitely trailing aerial weight and its tube. It can be seen here in a preserved B-17G where it’s in the position described by B17Man.[ATTACH=CONFIG]225685[/ATTACH]

We are looking at the left hand side of the aircraft so it points rearward, not forward. This link shows another view with it on the right hand side (assuming the photo is not reversed), though the weight itself is missing.
http://b17warhorse.fws1.com/photo5.html
Here is an old ad for a NOS weight for sale.
http://amppowerwire.com/wwii-signal-corp-trailing-wire-antenna-weight-aircraft-radio-transmissions/

Don’t want to thrash this to death, but I still like the mirror proposal!

The trailing aerial, of which I have now seen about a hundred photos, is on the other side of the fuselage, is situated at the bottom, not halfway up, and is a different shape.
It also, as you would expect, trails back toward the tail. This thing points forward ! I think it is a pole with a mirror on the end stuck out of the waist gunner’s hatch (you can just see the shadow of the Browning) to assist the ball gunner, maybe during training or whatever – don’t see it as a permanent fixture otherwise it would be bound to show up on other B-17 photos.

Looks like the trailing aerial, but that is normally situated further down in the waist gun area, just before the step around the turret, in this photo it appears to be located in the radio room, also the shape looks a little different than what I have seen.

I think you are right.

Because the frequencies used required a long aerial. Trailing aerials were common on RAF types of the same period. What does surprise me is that this has not been more visible in other photos of B-17s.

I’m sure I’ve seen this on Sally B and I’m sure that someone on here would be able to post such a view to confirm.
How far out does it go? Surely this would get caught up in the other bombers in their tight formations?

Emergency oars. 😉

Because the frequencies used required a long aerial. Trailing aerials were common on RAF types of the same period. What does surprise me is that this has not been more visible in other photos of B-17s.

Looks like the trailing aerial, but that is normally situated further down in the waist gun area, just before the step around the turret, in this photo it appears to be located in the radio room, also the shape looks a little different than what I have seen.

It is the weight on the end of the retractable trailing aerial. The weight is egg shaped and fits into the socket when retracted.

I guess the obvious questions is, what is the retractable aerial for (and don’t say so the aerial can retract!) ?

It is the weight on the end of the retractable trailing aerial. The weight is egg shaped and fits into the socket when retracted.

Don’t think it’s an aerial – weird shape and it’s pointing forwards.

Trolley aux may be onto something with the mirror – the guy in the turret appears to be looking up at it……

.. Otherwise it has to be the pilot’s danglies.

Not likely.

Those guys had ENORMOUS ones made of tungsten steel.

Moggy

I’d say it’s the weight at the end of the retractable radio aerial.

Is it not a mirror to see if the turret is in correct position/retracted/ to see if crew member is ok?

Trailing aerial? Otherwise it has to be the pilot’s danglies.
Cees