Hang bolt safety cable...do you have control?

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Bundy
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Hang bolt safety cable...do you have control?

Postby Bundy » Mon Apr 23, 2012 7:56 am

During the stripdown, I had a careful look at this cable.

I understand it's purpose...... but I'm interested to hear if someone has ever had a hang point failure and "needed" to be saved by this cable. Once hanging on the cable....do you have sufficient control? (Pitch/roll). How does the undercarriage behave when hanging and swinging freely?

Just interested to hear if anyone has ever expierienced this and is still alive to tell us :roll:

Topic heading edited:
Last edited by Bundy on Mon Apr 23, 2012 10:29 am, edited 1 time in total.
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Re: Jesus Cable...do you have control?

Postby Asterix » Mon Apr 23, 2012 9:24 am

I am under correction - but I don't think it has ever been tested. An old, bold pilot once told me when I asked him if it works - "Nobody knows.. because nobody has ever lost their hangbolt!"

As I said - I can't verify this.
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Re: Hang bolt safety cable...do you have control?

Postby Bundy » Mon Apr 23, 2012 10:38 am

My apologies if I offended anyone by reffering to this cable as the "J" cable. It's just the only term for it I've ever heard when described by others :roll:

No harm meant....appreciate your inputs....

James...I tried to picture in my mind what would happen if the cable came into use... :shock: I cannot see how you can remain in any sort of control. The undercarriage will be free to pivot left and right, all you energy will be used just to keep the cart pointed in the direction of travel! Then you still have to control the pitch inputs during all of this.... :shock: :shock:
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Re: Hang bolt safety cable...do you have control?

Postby Asterix » Mon Apr 23, 2012 11:00 am

Agreed - I don't think you will have a great deal of control - the best would probably be just to glide towards the ground in the direction you are facing, with as little input as possible to maintain enough airspeed, and do a "controlled prang."

Point is - I have never read of a correctly fitted and "made-for-the-job" hangbolt failing - except where the failure was as a result of a crash - not the cause of it. There was a guy in America ("Ed" something) who lost his hangbolt - because he married a wing to a trike and went to buy a nice shiny bolt at his hardware store, the diameter of which didn't fit through the holes (too small). The bolt subsequently seared of, but remained stuck through the two hangplates and the wing didn't part. He "crashed succesfully" and survived with serious injuries.

I think the most telling testament to the hangbolt is tumble-accidents - which are extremely high G situations, where the wing rotates through 300 degrees per second! :shock: In these accidents, where the wing actually parted, it was found that the keel itself ripped of, and the section of the keel where the hangpoint assembly is situated, was found with hangplates and bolt intact.

Even in tumble accidents, the wing doesn't always part - it tends to break up nearer to the point where your fly wires connect to the leading edge, breaking of your outer leading edge. Or the spreader cables part and the wing folds up.

IMHO - there are other parts of your wing that will break long before the hangbolt! More important probably is to make sure the safety clip is in.. :roll:

My 2 cents
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Re: Hang bolt safety cable...do you have control?

Postby Stan » Mon Apr 23, 2012 1:55 pm

That cable is just there to keep all the bits together on the way to the crash site when the hang bolt breaks. :lol: The cops and CAA cant walk far to look for reasons why you pranged. :lol: I have never heard of one of these bolts breaking. Probably just to give you peace of mind.
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Re: Hang bolt safety cable...do you have control?

Postby Bugwar » Mon Apr 23, 2012 2:18 pm

The "Hang Bolt" is quite a serious piece of metal and yet it is backed up by a cable. What amuses me is that the flying wires are bolted to the bar with a bonsai little bolt and it has no back-up. I contemplated many times putting a bracket on the cable with a second bolt fastened to the control bar (**)
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Re: Hang bolt safety cable...do you have control?

Postby skybound® » Mon Apr 23, 2012 2:37 pm

I actually think you will have quite a bit of control. Not much in it if you compare as to how a hanglider pilot attaches himself to the wing.
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Re: Hang bolt safety cable...do you have control?

Postby Asterix » Mon Apr 23, 2012 3:15 pm

I attach a very nice extract from an article about the workings of a trike. See page 151, under par 3. The author mentions there that at the time of writing the breaking of hangbolts is unknown...

(Sorry - too big to upload, but here is the link)

http://bura.brunel.ac.uk/bitstream/2438 ... tshift.pdf
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Re: Hang bolt safety cable...do you have control?

Postby Kalahari » Mon Apr 23, 2012 9:15 pm

There was a case here in SA 8yrs ago on a Windlass where the Hang bolt had torn out of the pylon, no safety cable installed, both 21yr pilot and 10yr old pax died in crash. Google Fraser Carey, you will find it. You will not have controll when hanging on safety cable as there will be a 90degr difference in the direction between the cart and the wing due to the way the cable is mounted on the Pylon.
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Re: Hang bolt safety cable...do you have control?

Postby John.com » Mon Apr 23, 2012 10:03 pm

Bundy wrote:During the stripdown, I had a careful look at this cable.

I understand it's purpose...... but I'm interested to hear if someone has ever had a hang point failure and "needed" to be saved by this cable. Once hanging on the cable....do you have sufficient control? (Pitch/roll). How does the undercarriage behave when hanging and swinging freely?

Just interested to hear if anyone has ever expierienced this and is still alive to tell us :roll:

Topic heading edited:
Agreed, in normal flight this bolt should NEVER fail!!!

However, taking an "engineering view" on the results of such a failure, my humble opinion is as follows:

The most important thing is the event of a failure of this nature is where your "hang-point" ends up AFTER the hang-bolt failure. Hence the Wing Pre-Flight check list item that should read: "HANG BOLT SAFETY CABLE - check for TWO TURNS & IN FRONT of Hang-Block"!

Assuming, through the correct placement of the hang-bolt safety cable, your hang-point does not vary dramatically, your control will become less responsive, "mushy", and you will experience a somewhat "delayed" response to inputs, almost like walking with 2" jelly soles on your shoes, if that makes sense!! You will be able to walk, but more slowly and with greater concentration! :lol:

If the hang-point shifts forward, you will need to exert extreme forward pressure on the control bar to maintain level flight - luff lines will help recover from "steep decent", but still "manageable"!

If the hang-point shifts backwards, you will need to exert MASSIVE back pressure on the control bar (hard/impossible to maintain) to maintain level flight - the aircraft will tend to stall/recover all the way down to your landing!!

So, in summary, if your hang-point moves significantly either way you are in for a very difficult and physically exhausting decent!!

So, update your checklist with "HANG BOLT SAFETY CABLE - check for TWO TURNS & IN FRONT of Hang-Block"!

Safe Skies! (-)
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Re: Hang bolt safety cable...do you have control?

Postby John.com » Mon Apr 23, 2012 10:14 pm

Kalahari wrote:There was a case here in SA 8yrs ago on a Windlass where the Hang bolt had torn out of the pylon, no safety cable installed, both 21yr pilot and 10yr old pax died in crash. Google Fraser Carey, you will find it. You will not have controll when hanging on safety cable as there will be a 90degr difference in the direction between the cart and the wing due to the way the cable is mounted on the Pylon.
Not sure about this . . . . my safety cable takes two turns around the keel and bolts on either side of the pylon which would result is a fairly normal hanging orientation. Where does 90 degrees come from?

Can you share a picture of your hang block and safety cable??
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Re: Hang bolt safety cable...do you have control?

Postby skybound® » Mon Apr 23, 2012 11:11 pm

Considering that HG pilots do not end up swinging uncontrollably beneath their wings - why should we be any different?
Most trike safety cable installations I have seen do one turn on either side of the hangblock to lessen chances of the cable slipping either fore or aft of you CofG.

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Re: Hang bolt safety cable...do you have control?

Postby Kalahari » Tue Apr 24, 2012 9:19 am

John.com wrote:
Kalahari wrote:There was a case here in SA 8yrs ago on a Windlass where the Hang bolt had torn out of the pylon, no safety cable installed, both 21yr pilot and 10yr old pax died in crash. Google Fraser Carey, you will find it. You will not have controll when hanging on safety cable as there will be a 90degr difference in the direction between the cart and the wing due to the way the cable is mounted on the Pylon.
Not sure about this . . . . my safety cable takes two turns around the keel and bolts on either side of the pylon which would result is a fairly normal hanging orientation. Where does 90 degrees come from?

Can you share a picture of your hang block and safety cable??
Hi John

I do not have a photo now and I have sold the trike but the safety cable was definately bolted to the front and and the rear of the Pylon and not on the left and right hand side of the pylon like the hang plates are as one would have preferred it, from there the 90degr diffrence in direction. If I can find a photo of this somewhwere I will post it here.
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Re: Hang bolt safety cable...do you have control?

Postby John.com » Tue Apr 24, 2012 9:43 am

Kalahari wrote: Hi John

I do not have a photo now and I have sold the trike but the safety cable was definately bolted to the front and and the rear of the Pylon and not on the left and right hand side of the pylon like the hang plates are as one would have preferred it, from there the 90degr diffrence in direction. If I can find a photo of this somewhwere I will post it here.
WOW!!! That would scare the hell out of me!! So, hang-bolt fails and suddenly your trike is producing thrust at 90 degrees to the wing surface!!!! Not to mention trying to produce control inputs at 90 degrees to your seated position!! Not a healthy situation!! (**)

This would definitely be an occasion to pull the chute, assuming you had one!

Try to find a picture!! Someone needs to write to the manufacturer!! ## ## ##
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Kalahari
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Re: Hang bolt safety cable...do you have control?

Postby Kalahari » Tue Apr 24, 2012 10:00 am

Thanks John, that allways bothered me, I have checked some of the other aircraft in the hanger this morning, mine must have been the odd one out, the one end of my safety cable was attached inside the pylon as usual but the other end was attached to the 8mm bolt at the back of the pylon holding the top bracket of the aerofoil instead of an 8mm bolt some distance below the hang bolt and I assumed that all Windlass aircraft was like that, sorry to all Windlass owners for the confusion. :oops: Never too old to learn something new.
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