A Different Chute Question

[Steve Leonard[_2_]]

So, I am well aware of the drag chutes supplied by Walter Kostelezky, K.G. of Germany. I am aware of the rings and swivels at the connection to the aircraft, and that the aircraft end is a release somewhat resembling a Tost style release. But, I have a plane that has a different sort of interface with the airplane.

On the plane I have, the release is at the front end of a tube that is about 10 mm in inside diameter. It was just large enough for me to put my borescope camera inside. At the front of this hole, about 4-5 inches forward, is something that sticks in from one side, and goes maybe 1/3rd of the way across the diameter of the hole. I was not able to verify operation by pulling on the jettison handle, as I was the only one at the airport on that cold day.

Near as I can tell, it looks like this particular jettison mechanism would interface with something that looks like the end of a microphone plug. I am guessing this would be roughly 9 mm OD, tapered end, then a near 90 degree cut in or maybe even a o-ring style groove that the visible retaining feature would drop into to lock and hold the chute to the airframe until the jettison lever is pulled. My best guess is that there is a 5 inch or so long steel ferrel that is swaged onto the rope that goes back to the chute.

This tube exits the fuselage aft of the tailwheel and below the bottom of the rudder. From what I can tell, the rope went outside the airframe from attach point into the cover that is on the bottom of the rudder.

Any of you seen anything like that? The plane was built between 1962 and 1967 in Switzerland.

Thanks in advance for any assistance!

Steve Leonard
HB-723 soon to be N723HB

[John DeRosa OHM Ω http://aviation.derosaweb.net]

On Sunday, February 14, 2021 at 4:18:45 PM UTC-6, Steve Leonard wrote:
> So, I am well aware of the drag chutes supplied by Walter Kostelezky, K.G.. of Germany. I am aware of the rings and swivels at the connection to the aircraft, and that the aircraft end is a release somewhat resembling a Tost style release. But, I have a plane that has a different sort of interface with the airplane.
>
> On the plane I have, the release is at the front end of a tube that is about 10 mm in inside diameter. It was just large enough for me to put my borescope camera inside. At the front of this hole, about 4-5 inches forward, is something that sticks in from one side, and goes maybe 1/3rd of the way across the diameter of the hole. I was not able to verify operation by pulling on the jettison handle, as I was the only one at the airport on that cold day.
>
> Near as I can tell, it looks like this particular jettison mechanism would interface with something that looks like the end of a microphone plug. I am guessing this would be roughly 9 mm OD, tapered end, then a near 90 degree cut in or maybe even a o-ring style groove that the visible retaining feature would drop into to lock and hold the chute to the airframe until the jettison lever is pulled. My best guess is that there is a 5 inch or so long steel ferrel that is swaged onto the rope that goes back to the chute.
>
> This tube exits the fuselage aft of the tailwheel and below the bottom of the rudder. From what I can tell, the rope went outside the airframe from attach point into the cover that is on the bottom of the rudder.
>
> Any of you seen anything like that? The plane was built between 1962 and 1967 in Switzerland.
>
> Thanks in advance for any assistance!
>
> Steve Leonard
> HB-723 soon to be N723HB

Steve,

No answers...just questions.

- What aircraft is this for? The "HB-723 soon to be N723HB"? HB-723 doesn't Google.
- Can I assume (!) that this is a drag/drogue chute for landing in lieu of airbrakes? Can I then further assume that the 10mm tube and the rope (cable?) inside that you speak of triggers the release of a cover of where the chute is packed into?
- Do you have pictures taken with your borescope? Other pics?
- I see Walter Kostelezky's company's web site but not much info. http://www.kostelezky.de/ Any other information you can share?
- There are some pictures found when I Googled "Walter Kostelezky parachute" which look drag/drogue like. https://www.google.com/search?sxsrf=ALeKk00qknFvbA2iowzAmZhQOGFoK3_9Xg:16 13409308565&source=univ&tbm=isch&q=Walter+Kostelezky+parachute&client=firefox-b-1-d&sa=X&ved=2ahUKEwjai9uFsuzuAhWOXc0KHRqjC1MQjJkEegQIBRAB&biw=1481&bih=836

Expiring minds want to know.

Best of luck, John

[Stéphane Vander Veken]

Would that be an Elfe? I filmed one back in 1978 in Switzerland, landing with a drag chute after an aerobatic display. You can see it here: https://vimeo.com/160379590 (bad quality, I know, copied from Super 8 movie). The chute seems not to open fully.

[Stéphane Vander Veken]

At about 4 min 10...

[Steve Leonard[_2_]]

Thank you for the link, Stéphane. I wonder how many Elfe's got the shark mouth painted on the nose? I have a "trading card" with an Elfe with the shark mouth on it.

John, the plane is question is an Akaflieg Braunschweig SB-7. There are two handles in the cockpit for operating the chute. There is the deploy, which drops the chute cover (bottom of the rudder) with the chute. The chute is probably a 1.3 meter diameter, ribbon type chute. There is a second handle, on the opposite side of the cockpit, which allows you to jettison the chute if it is making too much drag and you will come up short if you don't do something.

The particular SB-7 also has trailing edge dive brakes like what Irv Prue used on the Prue Standard. They are also like what is used on the Elfe. Hinged on the upper surface at roughly 90% chord, the lower surface leading edge is at about 80% chord. So, sort of like an inverted SH trailing edge air brake. But it doesn't go from wing root to aileron, but is only about 6 feet long.

I am hoping to get information on the type of fitting that was on the end of the rope or lines that connect the chute to the airframe. I need to make a new cover/lower rudder, as the original appears to have been lost somewhere in the 30+ years since it last flew. Unfortunately, so has the drag chute. Would be nice to know how to make something so I could have the drag chute available.

Steve Leonard

[Tango Whisky]

You might want to contact the Akaflieg Braunschweig. I think the original SB7 is still flown by a group of former members.
I don't remember it to have trailing edge brakes though, but I've flown it only once, and that was30+ years ago.

Le mercredi 17 février 2021 Ã* 07:20:41 UTC+1, Steve Leonard a écritÂ*:
> Thank you for the link, Stéphane. I wonder how many Elfe's got the shark mouth painted on the nose? I have a "trading card" with an Elfe with the shark mouth on it.
>
> John, the plane is question is an Akaflieg Braunschweig SB-7. There are two handles in the cockpit for operating the chute. There is the deploy, which drops the chute cover (bottom of the rudder) with the chute. The chute is probably a 1.3 meter diameter, ribbon type chute. There is a second handle, on the opposite side of the cockpit, which allows you to jettison the chute if it is making too much drag and you will come up short if you don't do something.
>
> The particular SB-7 also has trailing edge dive brakes like what Irv Prue used on the Prue Standard. They are also like what is used on the Elfe. Hinged on the upper surface at roughly 90% chord, the lower surface leading edge is at about 80% chord. So, sort of like an inverted SH trailing edge air brake. But it doesn't go from wing root to aileron, but is only about 6 feet long.
>
> I am hoping to get information on the type of fitting that was on the end of the rope or lines that connect the chute to the airframe. I need to make a new cover/lower rudder, as the original appears to have been lost somewhere in the 30+ years since it last flew. Unfortunately, so has the drag chute. Would be nice to know how to make something so I could have the drag chute available.
>
> Steve Leonard

[AS]

On Wednesday, February 17, 2021 at 4:41:26 AM UTC-5, Tango Whisky wrote:
> You might want to contact the Akaflieg Braunschweig. I think the original SB7 is still flown by a group of former members.
> I don't remember it to have trailing edge brakes though, but I've flown it only once, and that was30+ years ago.
> Le mercredi 17 février 2021 Ã* 07:20:41 UTC+1, Steve Leonard a écrit :
> > Thank you for the link, Stéphane. I wonder how many Elfe's got the shark mouth painted on the nose? I have a "trading card" with an Elfe with the shark mouth on it.
> >
> > John, the plane is question is an Akaflieg Braunschweig SB-7. There are two handles in the cockpit for operating the chute. There is the deploy, which drops the chute cover (bottom of the rudder) with the chute. The chute is probably a 1.3 meter diameter, ribbon type chute. There is a second handle, on the opposite side of the cockpit, which allows you to jettison the chute if it is making too much drag and you will come up short if you don't do something.
> >
> > The particular SB-7 also has trailing edge dive brakes like what Irv Prue used on the Prue Standard. They are also like what is used on the Elfe. Hinged on the upper surface at roughly 90% chord, the lower surface leading edge is at about 80% chord. So, sort of like an inverted SH trailing edge air brake. But it doesn't go from wing root to aileron, but is only about 6 feet long.
> >
> > I am hoping to get information on the type of fitting that was on the end of the rope or lines that connect the chute to the airframe. I need to make a new cover/lower rudder, as the original appears to have been lost somewhere in the 30+ years since it last flew. Unfortunately, so has the drag chute. Would be nice to know how to make something so I could have the drag chute available.
> >
> > Steve Leonard

Not exactly the SB7 Steve mentioned but still a pretty interesting design for its time by the AKAFLIEG Braunschweig! Four of them were built in Switzerland apparently with some artistic liberties, hence the air brake system Steve is describing.
https://www.akaflieg-braunschweig.de/projekte/sb7/
Google Translate is your friend .... ;-)

Uli
'AS'

[Dave Nadler]

On 2/17/2021 1:20 AM, Steve Leonard wrote:
> ...so I could have the drag chute available.

Oh Steve, don't be a wimp...

[Steve Leonard[_2_]]

On Wednesday, February 17, 2021 at 2:36:48 PM UTC-6, wrote:
> On 2/17/2021 1:20 AM, Steve Leonard wrote:
> > ...so I could have the drag chute available.
>
> Oh Steve, don't be a wimp...

You are right, Dave. I want the increased flap deflection in my ASW12 so I don't need the drag chute, so why am I being such a whiner and wanting the drag chute on this plane? :-)

Two pictures of this particular plane on page 71 of "SB 5 - SB 15 Segelflugzeug Braunschweig". It has a 16.5 meter span with Eppler E 417 airfoil section for the wing.

And, thank you, Bert. I will check with them, but I am not sure what they will know. Maybe someone there remembers the style of drag chute connection?

Steve Leonard

[Steve Leonard[_2_]]

On Wednesday, February 17, 2021 at 10:22:15 PM UTC-6, Steve Leonard wrote:
>
> And, thank you, Bert. I will check with them, but I am not sure what they will know. Maybe someone there remembers the style of drag chute connection?
>
> Steve Leonard

Best suggestion ever, Bert! Our soaring community never fails to impress me in good ways. The message has been forwarded, as most students at the Akaflieg are likely children, or maybe even grandchildren of those involved initially with the project over 50 years ago. However, the message has been forwarded, and I am in contact with owners of other SB7s, and have leads and information to share on this interesting sailplane.

Steve Leonard

PS: Anyone have an Ilec SB7 vario they would like to donate to an SB7 sailplane? :-) Mine currently has a Cambridge with a speed director and a 10 m/sec. log scale winter vario.