Slip slidin' away.

For fun. If you get the chance to fly a Janus up high. Play with slips. It will 'lock over' to either side, dropping like a set of car keys (Thanks for that image JS) and the canopy mounted yaw string (s) will be pointing..... well, you'll see.
I started playing with this about the time that Jonkers broke a rudder cable and the guy had to bail. Having read Derek Piggot's warning about the Janus, and realizing it really took a LOT of pedal force to straighten up, I started thinking about 'recovery' if one of my 30+ year old rudder cables broke. Turns out it IS recoverable, but involves a lot of elevator, and eats a lot of altitude. From a mile AGL, it's doable.

Wondering how long my wandering will persist.

Just to address the reference to the JS1 accident, according to
Uys Jonker speaking at the BGA conference, what happened
there was not a broken rudder cable but similar to what you
describe in the Janus (and various other gliders) i.e. a situation
of a high pedal force required to overcome a locked-over rudder
in a side slip.

This scenario is described in the JS1 flight manual as:

"WARNING: If an excessive slip angle is not corrected with
opposite rudder input, the secondary effect of yaw may cause
the sailplane to roll and enter a spiral dive. It is not possible to
prevent roll by applying full opposite aileron during excessive
sideslip.

CAUTION: The rudder control input force to recover from a side
slip exceeding 20° is high (approximately 20daN) and increases
if the speed is allowed to build up during the resulting spiral
dive. Apply sufficient rudder input to recover from the sideslip to
prevent spiral dive."

John Galloway

At 07:45 30 August 2013, Uncle Fuzzy wrote:
For fun. If you get the chance to fly a Janus up high. Play
with slips.
I=
t will 'lock over' to either side, dropping like a set of car keys
(Thanks
=
for that image JS) and the canopy mounted yaw string (s) will
be
pointing..=
... well, you'll see.
I started playing with this about the time that Jonkers broke a
rudder
cabl=
e and the guy had to bail. Having read Derek Piggot's warning
about the
Jan=
us, and realizing it really took a LOT of pedal force to
straighten up, I
s=
tarted thinking about 'recovery' if one of my 30+ year old
rudder cables
br=
oke. Turns out it IS recoverable, but involves a lot of elevator,
and eats
=
a lot of altitude. From a mile AGL, it's doable.=20

Wondering how long my wandering will persist.

Is that right?

The sister ship also at the same field had the same problem. Luckily it failed on the ground. I was shown the frayed cable prior to its complete failure.

Mike

On Friday, August 30, 2013 8:30:42 AM UTC-6, John Galloway wrote:
Just to address the reference to the JS1 accident, according to

Uys Jonker speaking at the BGA conference, what happened

there was not a broken rudder cable but similar to what you

describe in the Janus (and various other gliders) i.e. a situation

of a high pedal force required to overcome a locked-over rudder

in a side slip.



This scenario is described in the JS1 flight manual as:



"WARNING: If an excessive slip angle is not corrected with

opposite rudder input, the secondary effect of yaw may cause

the sailplane to roll and enter a spiral dive. It is not possible to

prevent roll by applying full opposite aileron during excessive

sideslip.



CAUTION: The rudder control input force to recover from a side

slip exceeding 20° is high (approximately 20daN) and increases

if the speed is allowed to build up during the resulting spiral

dive. Apply sufficient rudder input to recover from the sideslip to

prevent spiral dive."



John Galloway



At 07:45 30 August 2013, Uncle Fuzzy wrote:

For fun. If you get the chance to fly a Janus up high. Play

with slips.

I=

t will 'lock over' to either side, dropping like a set of car keys

(Thanks

=

for that image JS) and the canopy mounted yaw string (s) will

be

pointing..=

... well, you'll see.

I started playing with this about the time that Jonkers broke a

rudder

cabl=

e and the guy had to bail. Having read Derek Piggot's warning

about the

Jan=

us, and realizing it really took a LOT of pedal force to

straighten up, I

s=

tarted thinking about 'recovery' if one of my 30+ year old

rudder cables

br=

oke. Turns out it IS recoverable, but involves a lot of elevator,

and eats

=

a lot of altitude. From a mile AGL, it's doable.=20



Wondering how long my wandering will persist.



The FAA inspected the sailplane and found a worn through rudder cable. The sister ship, at the same field, had the same problem and failed on the ground.

It is certainly right insofar as that was what was described in
the Jonker Sailplanes presentation to the BGA conference and
has also been added to the flight manual V3. As someone on
the JS1 waiting list I was listening attentively and I knew that
the original suspicion had been of a broken rudder cable and
also that JS1 rudder cable S tubes had been modified after the
accident.

Has an accident investigation report been published in the US?

John Galloway




At 15:29 30 August 2013, mike wrote:
Is that right?

The sister ship also at the same field had the same problem.
Luckily it
fa=
iled on the ground. I was shown the frayed cable prior to its
complete
fail=
ure.

Mike

On Friday, August 30, 2013 8:30:42 AM UTC-6, John Galloway
wrote:
Just to address the reference to the JS1 accident, according
to=20
=20
Uys Jonker speaking at the BGA conference, what
happened=20
=20
there was not a broken rudder cable but similar to what
you=20
=20
describe in the Janus (and various other gliders) i.e. a
situation=20
=20
of a high pedal force required to overcome a locked-over
rudder=20
=20
in a side slip. =20
=20
=20
=20
This scenario is described in the JS1 flight manual as:
=20
=20
=20
"WARNING: If an excessive slip angle is not corrected
with=20
=20
opposite rudder input, the secondary effect of yaw may
cause=20
=20
the sailplane to roll and enter a spiral dive. It is not possible
to=20
=20
prevent roll by applying full opposite aileron during
excessive=20
=20
sideslip.
=20
=20
=20
CAUTION: The rudder control input force to recover from a
side=20
=20
slip exceeding 20=B0 is high (approximately 20daN) and
increases=20
=20
if the speed is allowed to build up during the resulting
spiral=20
=20
dive. Apply sufficient rudder input to recover from the
sideslip to=20
=20
prevent spiral dive."
=20
=20
=20
John Galloway
=20
=20
=20
At 07:45 30 August 2013, Uncle Fuzzy wrote:
=20
For fun. If you get the chance to fly a Janus up high.
Play=20
=20
with slips.
=20
I=3D
=20
t will 'lock over' to either side, dropping like a set of car
keys=20
=20
(Thanks
=20
=3D
=20
for that image JS) and the canopy mounted yaw string (s)
will=20
=20
be
=20
pointing..=3D
=20
... well, you'll see.
=20
I started playing with this about the time that Jonkers
broke a=20
=20
rudder
=20
cabl=3D
=20
e and the guy had to bail. Having read Derek Piggot's
warning=20
=20
about the
=20
Jan=3D
=20
us, and realizing it really took a LOT of pedal force to=20
=20
straighten up, I
=20
s=3D
=20
tarted thinking about 'recovery' if one of my 30+ year
old=20
=20
rudder cables
=20
br=3D
=20
oke. Turns out it IS recoverable, but involves a lot of
elevator,=20
=20
and eats
=20
=3D
=20
a lot of altitude. From a mile AGL, it's doable.=3D20
=20

=20
Wondering how long my wandering will persist.
=20


The FAA inspected the sailplane and found a worn through
rudder cable. The
=
sister ship, at the same field, had the same problem and failed
on the
grou=
nd.

In article ,
Uncle Fuzzy wrote:

For fun. If you get the chance to fly a Janus up high. Play with slips. It
will 'lock over' to either side, dropping like a set of car keys (Thanks for
that image JS) and the canopy mounted yaw string (s) will be pointing....
well, you'll see.
I started playing with this about the time that Jonkers broke a rudder cable
and the guy had to bail. Having read Derek Piggot's warning about the Janus,
and realizing it really took a LOT of pedal force to straighten up, I started
thinking about 'recovery' if one of my 30+ year old rudder cables broke.
Turns out it IS recoverable, but involves a lot of elevator, and eats a lot
of altitude. From a mile AGL, it's doable.

Wondering how long my wandering will persist.

Would love to fly a Janus sometime. Never even seen one in person.

I have played with full rudder slips in a 301 Libelle and a Standard
Cirrus above 6000 ft agl, at around 50 knots starting airspeed. Nothing
happened in the Libelle except for flying fairly sideways and generating
a pretty good sink rate. Tried gradually pulling the nose up to see at
what attitude/airspeed it would start to misbehave. Airspeed was not
reading due to the extreme slip. Thought it would depart and spin before
the nose got too high. I chickened and relaxed the stick when I felt
more buffeting and the controls started getting slack. It flew ok in a
slip with the nose at an attitude I would consider highly alarming close
to the ground. Slipping the Cirrus, the rudder would go hard over to the
right if I got close to full right rudder. Surprised me a bit the first
time it happened. Felt like I was suddenly flying directly sideways. Did
not take inordinate effort to recenter the rudder and the glider behaved
itself just fine. Should try it with the nose up sometime.

If there is one good thing about training in Schweizers, it's that one
learns to slip for glidepath control.

WB (who has also slipped Cezznas with full flaps).

On Friday, August 30, 2013 10:10:53 AM UTC-6, John Galloway wrote:
It is certainly right insofar as that was what was described in

the Jonker Sailplanes presentation to the BGA conference and

has also been added to the flight manual V3. As someone on

the JS1 waiting list I was listening attentively and I knew that

the original suspicion had been of a broken rudder cable and

also that JS1 rudder cable S tubes had been modified after the

accident.



Has an accident investigation report been published in the US?



John Galloway


NTSB Identification: CEN12LA265

At 18:19 30 August 2013, Bill D wrote:

NTSB Identification: CEN12LA265

Thanks Bill but that link only consists of the initial pilot's report.

On Friday, August 30, 2013 9:45:29 AM UTC-7, WB wrote:

If there is one good thing about training in Schweizers, it's that one

learns to slip for glidepath control.



WB (who has also slipped Cezznas with full flaps).

In glass, it's not the slip that is the problem - it's trying to land afterwards without using dive brakes that can be really interesting (and expensive)!

Unfortunately, that is not a problem in a Schweizer, so bad habits can (and have) transfer - and lead to broken gliders.

Kirk (who has also tried the dreaded Cezzna full flap slip)
66

I find it disturbing that no follow up that I am aware off was published yet about the cause of this incident by the pilot or anyone else who knows about it. If I was flying a JS1 I would be even more disturbed. Now we all know we can't trust the NTSB to teach us anything about the cause of glider accidents, but one would hope that at least we will be sharing information among ourselves, so we don't have yet another one of those "too bad he wasn't aware of this".

Ramy

I too would like to see a full report into the US accident but I
doubt that JS1 pilots will be at all disturbed now when they are
flying:

If the US accident was the result of the rudder cable fraying
(which clearly was a design issue) and then breaking in flight
then that should be fixed by the modification to the rudder
pedal S tube design by adding bell ends and sleeve inserts to
protect the cables (Technical Note TN.JS-010 06 July 2012).

If it was due to misinterpretation of the rudder over-locking in a
side slip then that aspect has been highlighted in the flight
manual.

John Galloway


At 07:51 31 August 2013, Ramy wrote:
I find it disturbing that no follow up that I am aware off was
published
ye=
t about the cause of this incident by the pilot or anyone else
who knows
ab=
out it. If I was flying a JS1 I would be even more disturbed.
Now we all
kn=
ow we can't trust the NTSB to teach us anything about the
cause of glider
a=
ccidents, but one would hope that at least we will be sharing
information
a=
mong ourselves, so we don't have yet another one of those
"too bad he
wasn'=
t aware of this".

Ramy