Anyone flown a SHK-1?

On Sun, 21 May 2017 06:28:00 -0700, Bruce Hoult wrote:

On Sunday, May 21, 2017 at 4:00:05 PM UTC+3, Chris Rollings wrote:
At 11:24 21 May 2017, Martin Gregorie wrote:
On Sun, 21 May 2017 03:39:09 -0700, Bruce Hoult wrote:

On Sunday, May 21, 2017 at 1:00:07 PM UTC+3, Mike Oliver wrote:
I flew one for many years. 1000 hrs+ Can't add anything on the
technical side but what I would say is that it remains fantastic
value for money. Make sure you get or make good rigging aids, a
root trestle at rigging height and a tip trestle along with a wing
dolly at the
root
end and I could easily rig mine single handed without any lifting
of the wings.

Flew at least 8 flights over 500k here in the UK longest was 564k.
Climbs beautifully on the early thermals so could leave early in
the mornings. Longest flight time was over 8 hours and never found
any discomfort in the cockpit. I'm just under 6'0.

Brakes are weak if you have no headwind but a tip I was given
(which goes against all training)! was that if seriously too high
IN NO WIND conditions and NO TURBULENCE you can open the brakes
and raise the nose to take it to the back of the drag curve. It
comes down smoothly and rapidly. When back to the correct angle
lower the nose and
complete
approach as normal. It works. I'll bet people will want to come on
here
who have never flown one and say different but try it at altutude
first. I could even do this whilst playing with the rudder and it
showed no tendency to drop a wing.

Std Libelle brakes are similar. But a slip works better.

As Bruce says, its easy to do a full deflection, full-brake slip in a
Std

Libelle. This turns it into quite a satisfactory brick and compensates
nicely for its rather weak brakes if you're a bit high on finals or at
a field, such as Borders, that needs a higher descent rate.

How vigorously can you slip an SHK?

I ask because I've seen a comment that applying full rudder in an SH
affected its pitch trim. I've heard that many V-tail control systems
may limit the available deflections if deflections on more than one
axis are used and am wondering if that limits slipping in an SHK.
Disclaimer: I've never flown anything with a V tail.


--
martin@ | Martin Gregorie gregorie. | Essex, UK org |


It's interesting to note that many, possibly most, of the glider and
light aircraft types that started out with a V-tail, went over to a
conventional tail-plane and rudder if the went on to a mark 2 or other
later development
In the current context, the first Cirrus was essentially a glass SHK,
the prototype inherited the V-tail, the production versions went over
to the conventional tail-plane and elevator.

ITYM "all-flying tailplane"

Early ones, yes. After that they first got rather more washout twisted
into the wing and final versions had a conventional tailplane plus
elevators.

I've never flown any of them, but I have crawled round and sat in a late
one with normal elevators (VTC built G/81). Biggest cockpit I've ever sat
in and even more limited rear view than an SZD Junior.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

On Sunday, May 21, 2017 at 8:30:16 PM UTC+3, Martin Gregorie wrote:
On Sun, 21 May 2017 06:28:00 -0700, Bruce Hoult wrote:

On Sunday, May 21, 2017 at 4:00:05 PM UTC+3, Chris Rollings wrote:
At 11:24 21 May 2017, Martin Gregorie wrote:
On Sun, 21 May 2017 03:39:09 -0700, Bruce Hoult wrote:

On Sunday, May 21, 2017 at 1:00:07 PM UTC+3, Mike Oliver wrote:
I flew one for many years. 1000 hrs+ Can't add anything on the
technical side but what I would say is that it remains fantastic
value for money. Make sure you get or make good rigging aids, a
root trestle at rigging height and a tip trestle along with a wing
dolly at the
root
end and I could easily rig mine single handed without any lifting
of the wings.

Flew at least 8 flights over 500k here in the UK longest was 564k.
Climbs beautifully on the early thermals so could leave early in
the mornings. Longest flight time was over 8 hours and never found
any discomfort in the cockpit. I'm just under 6'0.

Brakes are weak if you have no headwind but a tip I was given
(which goes against all training)! was that if seriously too high
IN NO WIND conditions and NO TURBULENCE you can open the brakes
and raise the nose to take it to the back of the drag curve. It
comes down smoothly and rapidly. When back to the correct angle
lower the nose and
complete
approach as normal. It works. I'll bet people will want to come on
here
who have never flown one and say different but try it at altutude
first. I could even do this whilst playing with the rudder and it
showed no tendency to drop a wing.

Std Libelle brakes are similar. But a slip works better.

As Bruce says, its easy to do a full deflection, full-brake slip in a
Std

Libelle. This turns it into quite a satisfactory brick and compensates
nicely for its rather weak brakes if you're a bit high on finals or at
a field, such as Borders, that needs a higher descent rate.

How vigorously can you slip an SHK?

I ask because I've seen a comment that applying full rudder in an SH
affected its pitch trim. I've heard that many V-tail control systems
may limit the available deflections if deflections on more than one
axis are used and am wondering if that limits slipping in an SHK.
Disclaimer: I've never flown anything with a V tail.


--
martin@ | Martin Gregorie gregorie. | Essex, UK org |


It's interesting to note that many, possibly most, of the glider and
light aircraft types that started out with a V-tail, went over to a
conventional tail-plane and rudder if the went on to a mark 2 or other
later development
In the current context, the first Cirrus was essentially a glass SHK,
the prototype inherited the V-tail, the production versions went over
to the conventional tail-plane and elevator.

ITYM "all-flying tailplane"

Early ones, yes. After that they first got rather more washout twisted
into the wing and final versions had a conventional tailplane plus
elevators.

When someone says "the first Cirrus was essentially a glass SHK, the prototype inherited the V-tail, the production versions went over to the conventional tail-plane and elevator" I tend to the assumption they're talking about "early" ones -- which are the vast majority of examples in NZ.

On Sun, 21 May 2017 13:39:31 -0700, Bruce Hoult wrote:

When someone says "the first Cirrus was essentially a glass SHK, the
prototype inherited the V-tail, the production versions went over to the
conventional tail-plane and elevator" I tend to the assumption they're
talking about "early" ones -- which are the vast majority of examples in
NZ.

Understood: apparently only the first prototype had a V-tail, so I'd
expect the "early" Cirruses in NZ to be T-tailed with all flying tails.

I also know that the first production Std Cirrii had 1.5 degrees washout
on the wing and were a bit prone to tip stalling and spinning. Later Std
Cirrii had 3 degrees of washout which, apparently cost them some
performance but killed the tip stalling tendency, but I have no idea what
Wrk.Nr this change applied to. It would be interesting to know which
group most NZ-registered Std Cirri fall in.

I've heard it said that Std Cirri dominated Club Class until the ones
with 1.5 degrees of washout had all been broken and that after that Std
Libelles took over. Make what you will of that!



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

At 22:36 21 May 2017, Martin Gregorie wrote:
On Sun, 21 May 2017 13:39:31 -0700, Bruce Hoult wrote:

When someone says "the first Cirrus was essentially a glass
SHK, the
prototype inherited the V-tail, the production versions went over
to the
conventional tail-plane and elevator" I tend to the assumption
they're
talking about "early" ones -- which are the vast majority of
examples in
NZ.

Understood: apparently only the first prototype had a V-tail, so I'd
expect the "early" Cirruses in NZ to be T-tailed with all flying
tails.

I also know that the first production Std Cirrii had 1.5 degrees
washout
on the wing and were a bit prone to tip stalling and spinning.
Later Std
Cirrii had 3 degrees of washout which, apparently cost them some
performance but killed the tip stalling tendency, but I have no idea
what
Wrk.Nr this change applied to. It would be interesting to know
which
group most NZ-registered Std Cirri fall in.

I've heard it said that Std Cirri dominated Club Class until the ones
with 1.5 degrees of washout had all been broken and that after
that Std
Libelles took over. Make what you will of that!



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

The change over came in the spring/summer of 1972 as I was
working at S-H as a summer student. I helped lay up the first sets
of increased twist wings. Sorry, I don't recall the serial numbers.
If you want to buy a pre-1972 Std Cirrus, make sure you determine
the turning stall/spin characteristics and speeds (at altitude) before
you buy it. If it behaves differently (one direction compared to the
other) don't buy it.

RO

On Sunday, May 21, 2017 at 5:40:06 PM UTC-5, Martin Gregorie wrote:
On Sun, 21 May 2017 13:39:31 -0700, Bruce Hoult wrote:

When someone says "the first Cirrus was essentially a glass SHK, the
prototype inherited the V-tail, the production versions went over to the
conventional tail-plane and elevator" I tend to the assumption they're
talking about "early" ones -- which are the vast majority of examples in
NZ.

Understood: apparently only the first prototype had a V-tail, so I'd
expect the "early" Cirruses in NZ to be T-tailed with all flying tails.

I also know that the first production Std Cirrii had 1.5 degrees washout
on the wing and were a bit prone to tip stalling and spinning. Later Std
Cirrii had 3 degrees of washout which, apparently cost them some
performance but killed the tip stalling tendency, but I have no idea what
Wrk.Nr this change applied to. It would be interesting to know which
group most NZ-registered Std Cirri fall in.

I've heard it said that Std Cirri dominated Club Class until the ones
with 1.5 degrees of washout had all been broken and that after that Std
Libelles took over. Make what you will of that!



--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

What Scott said, and then some. Martin, I think you have confused the Cirrus (17.74 meter) with the Std Cirrus (15 meter).

Also,to imply the Cirrus is "basically a fiberglass SHK" is comparable to saying "the Corvette is just a fiberglass body on a Monte Carlo." Two ENTIRELY different sailplanes. The ONLY similarity is that the prototype Cirrus had an SHK tail on it. Different wing span, airfoil sections and aspect ratios. different cockpit layout and geometry. They came from the same manufacturer, but other than that...

Just my 2 cents worth,
Steve Leonard

At 03:05 22 May 2017, Steve Leonard wrote:
On Sunday, May 21, 2017 at 5:40:06 PM UTC-5, Martin Gregorie
wrote:
On Sun, 21 May 2017 13:39:31 -0700, Bruce Hoult wrote:
=20
When someone says "the first Cirrus was essentially a glass
SHK, the
prototype inherited the V-tail, the production versions went
over to
th=
e
conventional tail-plane and elevator" I tend to the assumption
they're
talking about "early" ones -- which are the vast majority of
examples
i=
n
NZ.
=20
Understood: apparently only the first prototype had a V-tail, so
I'd=20
expect the "early" Cirruses in NZ to be T-tailed with all flying
tails.=
=20
=20
I also know that the first production Std Cirrii had 1.5 degrees
washout=
=20
on the wing and were a bit prone to tip stalling and spinning.
Later Std=
=20
Cirrii had 3 degrees of washout which, apparently cost them
some=20
performance but killed the tip stalling tendency, but I have no
idea
what=
=20
Wrk.Nr this change applied to. It would be interesting to know
which=20
group most NZ-registered Std Cirri fall in.
=20
I've heard it said that Std Cirri dominated Club Class until the
ones=20
with 1.5 degrees of washout had all been broken and that after
that Std=
=20
Libelles took over. Make what you will of that!
=20
=20
=20
--=20
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

What Scott said, and then some. Martin, I think you have
confused the
Cirr=
us (17.74 meter) with the Std Cirrus (15 meter).

Also,to imply the Cirrus is "basically a fiberglass SHK" is
comparable to
s=
aying "the Corvette is just a fiberglass body on a Monte Carlo."
Two
ENTIR=
ELY different sailplanes. The ONLY similarity is that the prototype
Cirrus=
had an SHK tail on it. Different wing span, airfoil sections and
aspect
r=
atios. different cockpit layout and geometry. They came from the
same
man=
ufacturer, but other than that...

Just my 2 cents worth,
Steve Leonard

Steve is entirely correct. The SHK was derived from the HKS-3
which was designed by Haase, Kensche, and Schemmp. E.G. Haase
flew and won the WGC in 1958 (Poland) with it. It used wing
warping as opposed to ailerons for increased performance. The
HKS design was modified for series production as the SHK.

Later, when Klaus Holighaus came to S-H straight out of Akaflieg
Darmstadt, he brought along design/constuction ideas and concepts
that he had learned and used (along with Waibel and Lemke) when
they built the D-36 at the university. The Open Cirrus was Klaus'
first venture as the new owner and glider designer of S-H. It is a
totally different glider than the SHK.

RO