Sliding Tube? A Trailing Aerial Question
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Sliding Tube? A Trailing Aerial Question
Hi All
A very specific questions and one suited for W/Os. Attached are two pics one shows the W/O position with the trailing aerial partly fed into a tube, the lead balls can be seen clearly. The other picture shows what I believe is a tube corresponding to the one inside the A/C. It is from this tube that I think the trailing aerial would be coming out.
I think that the tube is there to keep the lead balls and the aerial wire away from the fuselage while being paid out and probably while being used, otherwise there would be quite a bit of slapping against the metal work.
However you don't always see the external tube on photos - why is this? Is it because:
a) The tube is broken off?
b) It wasn't fitted to all Marks of the A/C?
c) It is possible (and indeed practice) to pull the tube back into the A/C after the aerial has been used?
Cheers
James
A very specific questions and one suited for W/Os. Attached are two pics one shows the W/O position with the trailing aerial partly fed into a tube, the lead balls can be seen clearly. The other picture shows what I believe is a tube corresponding to the one inside the A/C. It is from this tube that I think the trailing aerial would be coming out.
I think that the tube is there to keep the lead balls and the aerial wire away from the fuselage while being paid out and probably while being used, otherwise there would be quite a bit of slapping against the metal work.
However you don't always see the external tube on photos - why is this? Is it because:
a) The tube is broken off?
b) It wasn't fitted to all Marks of the A/C?
c) It is possible (and indeed practice) to pull the tube back into the A/C after the aerial has been used?
Cheers
James
- Attachments
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- pipe.jpg (127.8 KiB) Viewed 4776 times
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- Inside.jpg (47.58 KiB) Viewed 4776 times
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- Group Captain
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Re: Sliding Tube? A Trailing Aerial Question
Hi James
Logic would dictate that in the former photo the tube is in the lowered position whereas the latter is the stowed position. I would think that the tube would be raised when not in use to prevent drag, ice acretion and possible damage in the air flow. Other photos of the installation seem to show that the orientation of the winch and the funnel down which the lead balls are lowered would be better served if the tube was lowered into the air flow
John L
Logic would dictate that in the former photo the tube is in the lowered position whereas the latter is the stowed position. I would think that the tube would be raised when not in use to prevent drag, ice acretion and possible damage in the air flow. Other photos of the installation seem to show that the orientation of the winch and the funnel down which the lead balls are lowered would be better served if the tube was lowered into the air flow
John L
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Re: Sliding Tube? A Trailing Aerial Question
Thanks John
That's one vote for a retractable tube, that's my vote too but is there anyone out there who has instructions for use, has actually used one or possibly has a pic of the tube extended but from inside the A/C?
The tube at one end gets thicker at the tip, could be a rubber seal to stop the tube rattling when retracted possibly? How might the tube be locked into place is another question.
Cheers
James
That's one vote for a retractable tube, that's my vote too but is there anyone out there who has instructions for use, has actually used one or possibly has a pic of the tube extended but from inside the A/C?
The tube at one end gets thicker at the tip, could be a rubber seal to stop the tube rattling when retracted possibly? How might the tube be locked into place is another question.
Cheers
James
- K4KittyCrew
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Re: Sliding Tube? A Trailing Aerial Question
Wish I could assist James but your already speaking to our Head Engineer!
Cheers,
Kitty
Cheers,
Kitty
K for Kitty Crew - Winthorpe, 1661 HCU's - stirlingaircraftsoc.raf38group.org/
630 Squadron - East Kirkby
" There is nothing glorious about war with the exception of those who served us so valiantly"
630 Squadron - East Kirkby
" There is nothing glorious about war with the exception of those who served us so valiantly"
Re: Sliding Tube? A Trailing Aerial Question
I only know one wartime wireless operator who is on emails, he operated on Lancs but might have encountered a Stirling in training. I've asked him and will report back..
Adam
Adam
Remembering the crew of 467 Sqn Lancaster LM475 PO-B Jan-May 1944
www.somethingverybig.com
www.somethingverybig.com
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Re: Sliding Tube? A Trailing Aerial Question
Thanks Adam
James
James
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Re: Sliding Tube? A Trailing Aerial Question
Hi All - update...
Been digging around and it appears that this tubular device is called a 'fairlead'. I have found another photo of the inside of the Stirling looking back at the mid spar but while it looks lowered it is very hard to be certain - but I believe that I will be able to confirm things when I get to model the item.
There were various designs apparently but the general idea is to feed the trailing aerial lead out of the aircraft without touching the fuselage as this would short out the transmitter output and any incoming signals. This means that the tube would have been made from an insulating material.
In a description of another system the fairlead was pushed out through a spring flap in the skin being sealed by a rubber grommet - it looks as if there is a flap in one photo - it's a shame that there are so few high definition pics of the Stirling taken close up.
The Lancaster at one point was fitted with a fairing to protect the fairlead from icing up, in one other aircraft installation the aerial was paid out by a motor with a nice indicator on to show how long the wire was - varying the length would 'tune' the radio for best reception (American).
The Stirlings trailing aerial winder had a control with a 'ratchet' position and what looks like a 'brake', I would be guessing but it may have been that each 'click' represented a given length of wire allowing it to be tuned, though it might have been quite a high number of clicks to count if the ratchet came on frequently!
One particular reason for the tube being retractable was to avoid or clear any icing that might occur.
Cheers
James
Been digging around and it appears that this tubular device is called a 'fairlead'. I have found another photo of the inside of the Stirling looking back at the mid spar but while it looks lowered it is very hard to be certain - but I believe that I will be able to confirm things when I get to model the item.
There were various designs apparently but the general idea is to feed the trailing aerial lead out of the aircraft without touching the fuselage as this would short out the transmitter output and any incoming signals. This means that the tube would have been made from an insulating material.
In a description of another system the fairlead was pushed out through a spring flap in the skin being sealed by a rubber grommet - it looks as if there is a flap in one photo - it's a shame that there are so few high definition pics of the Stirling taken close up.
The Lancaster at one point was fitted with a fairing to protect the fairlead from icing up, in one other aircraft installation the aerial was paid out by a motor with a nice indicator on to show how long the wire was - varying the length would 'tune' the radio for best reception (American).
The Stirlings trailing aerial winder had a control with a 'ratchet' position and what looks like a 'brake', I would be guessing but it may have been that each 'click' represented a given length of wire allowing it to be tuned, though it might have been quite a high number of clicks to count if the ratchet came on frequently!
One particular reason for the tube being retractable was to avoid or clear any icing that might occur.
Cheers
James
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Re: Sliding Tube? A Trailing Aerial Question
Hi James
Noted something from the Vol 1 jacking and trestling instructions; it states that the trailing aerial fairlead should be retracted (if lowered) before the jacking tube is installed transversely across the bomb bay. From that it would seem that there's no hard and fast rule for the position of the fairlead on the ground
John
Noted something from the Vol 1 jacking and trestling instructions; it states that the trailing aerial fairlead should be retracted (if lowered) before the jacking tube is installed transversely across the bomb bay. From that it would seem that there's no hard and fast rule for the position of the fairlead on the ground
John
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Re: Sliding Tube? A Trailing Aerial Question
Hi John
That's pretty conclusive - thanks for pointing it out! I'll make a few drawings to see which bits were likely to move and how far, etc.
James
That's pretty conclusive - thanks for pointing it out! I'll make a few drawings to see which bits were likely to move and how far, etc.
James