|
The following extracts from the CGC pilot handling notes
for the IS-30 and IS-29D might be of interest to those involved in the
debate on spinning their "cousin", the IS-28. The notes were drafted
to assist pilots with conversion to type.
IS-30
The Incipient Spin
Being a mild mannered trainer, the Blanik
usually has to be provoked into dropping a wing and it is usually accompanied by
a recognisable pre stall warning in the form of mild buffeting. It also
becomes noticeably quiet.
The I.S.30, on the other hand, can sneak up on
the unwary pilot without any obvious warning. One minute you are
thermalling happily, the next you are pointing at the ground and the inside wing
has started to tuck under. Left unchecked, auto rotation will commence or
a transition to a spiral dive may occur. In this aircraft SPIN RECOVERY
MUST BE BY THE BOOK. Where the docile behaviour of the Blanik will
tolerate a less than perfect recovery technique, the I.S.30 will not.
Again this is a level of competency above the basic trainer that readies you for
the transition into more advanced aircraft.
The Full Spin
Depending on entry mode, the fully developed
spin varies from predictable and conventional through to abrupt and steep.
Entry from a normal thermalling attitude by steady backward movement of the
stick combined with coarse use of the rudder results in a predictable departure
about the stalled wing followed by auto rotation if full control travel is
maintained. Normal recovery procedures are immediately effective.
If a more enthusiastic effort is made resulting
in an "over the top" or very nose high entry then the wing drop is more sudden
and the attitude appears steeper. If the spin is prolonged, the nose down
attitude may oscillate past the vertical. In this situation when you apply
the spin recovery control inputs there may be a brief pause before the recovery
commences. This may be a little disconcerting at first, but as long as you
maintain the recovery inputs, all will be well.
A note of caution: Once the rotation has stopped, you may
find yourself in an extreme nose down attitude. During the pull out speed
and/or structural ("g") limitations could easily be reached, hence the
requirement for the correct recovery technique. Height loss can also be
dramatic, so if fully developed spins are intended then make sure you have
sufficient height.
IS-29 (Single seat)
Spins
The I.S.29 has a fairly abrupt stall whilst turning
at low speed and will produce a definite wing drop. If conditions are
turbulent then an incipient spin is not to be unexpected whilst thermalling if
your speed is too low. If the back pressure is not immediately released
the instant an uncommanded roll in the direction of turn occurs then the glider
will rotate into a steep nose down attitude. If it is the pilot's
intention to enter a full spin then the controls should be held against their
respective stops (ie full back stick + full rudder) otherwise the glider may not
stall the inside wing fully and auto rotation may not develop. The glider
is liable to enter a spiral dive with very rapid speed and "g' load build
up. This condition is unacceptable and can potentially lead to structural
failure if left unchecked. The recovery is conventional though
considerable forward stick movement may be needed. Insufficient forward
stick movement with opposite rudder applied may result in a brief pause followed
by a spin in the opposite direction, which can be quite disconcerting if that
was not your intention.
Fully developed
spins.
The first turn is typically very
steep with a moderate to high rate of rotation. Once established in the
spin subsequent turns produce a significant oscillation in pitch and the rate of
rotation appears to stabilise at a slightly slower rate. Aileron position
has a marked effect on the spin characteristics with "into spin" aileron tending
to produce a more predictable outcome. This aircraft demands text book
spin recovery technique to be applied! The recovery may vary as a result
of the continual change in pitch from steep to near vertical throughout each
rotation, depending at which point the recovery is initiated. If the
recovery control inputs are applied as the nose is pitching down then the spin
rotation may be halted with the aircraft left in an extreme nose down
attitude. Acceleration in this instance will be very rapid, so watch the
exit speed. Mild buffeting around the tail plane may also be felt as the
rotation is stopped with application of full opposite rudder. As
previously noted, significant forward movement of the stick is also required
otherwise there is a risk that the glider will try to flick into a spin in the
opposite direction whilst full opposite rudder is applied. This aircraft
is not as docile as a Blanik and should not be intentionally spun unless you are
very confident of your spin recovery technique.
--
Brian Wade
Personal Computer Concepts
Control SPAM with MailWasher Pro
Uniform Time
http://www.uniformtime.com.au
PO Box 114 INDOOROOPILLY QLD 4068
Ph: 07 3371 2944 Fax: 07
3870 4103
----- Original Message -----
Sent: Thursday, September 23, 2004 8:18
AM
Subject: Re: RE: [Aus-soaring] IS28 ADs
(was Reasons NOT to spin for fun)
I was trained on Southern Cross's IS28s. I remember the
first time a spin was demonstrated to me: I had no idea it would be so fast
and so (comparitively) violent. I recall putting my hands up onto the canopy
to brace myself -- all I could see out the front was the ground, rapidly
rotating. Of course, the instructor recovered at will and without drama. I
guess I've done a few dozen intentional spins since then -- and still can't
say I enjoy it.
Several times in this thread there has been reference
to IS-28s 'tucking' (in or under). What exactly is that? I remember when I did
my first 'unassisted' spin recovery, I pushed the stick forward FAR and FAST
(with full opposite rudder), and while we certainly recovered, the instructor
tells me that we went past the vertical for a moment. Is that a 'tuck', or is
it some other, uncommanded phenomenon.
----- Original Message
-----
From: McLean Richard <[EMAIL PROTECTED]>
Date:
Wednesday, September 22, 2004 11:38 pm
Subject: RE: [Aus-soaring] IS28 ADs
(was Reasons NOT to spin for fun)
> re: IS28 droping in
unintentionally from a thermal ..
> it definitely will, because I did
exactly that on an
> early solo! .. it also loses a fair bit of
height
> being on the heavy side .. I've never done it since
>
then though, so it must have scared me sufficiently ..
>
> ---
Derek Ruddock <[EMAIL PROTECTED]>
wrote:
> > Spin proof? Our new DG1000 spins like a top!
> >
> > I learnt to spin off the top of the winch in the UK,
>
> in a K7. It's a very different kettle of fish, as
> > Harry
notes, starting a spin at 1300 feet or so.
> > Perhaps some of the
accidents there were caused by
> > instructors expecting the Pooch to
recover like a
> > K13 or K7.
> >
> > Regarding
the IS28, I've spun them hundreds of
> > times, and only had it tuck
once. I've never been
> > concerned with the spin characteristics of
the 28,
> > and recovery is always immediate.
> > I've also
never had a 28 drop into an incipient spin
> > when thermalling,
unlike a Pooch.
> >
> >
> >
> >
> >
> >
> > -----Original
Message-----
> > From: [EMAIL PROTECTED]
>
> [EMAIL PROTECTED]
> > On Behalf Of
McLean Richard
> > Sent: Wednesday, 22 September 2004 01:04
AM
> > To: Discussion of issues relating to Soaring in
> >
Australia.
> > Subject: Re: [Aus-soaring] IS28 ADs (was Reasons
NOT
> > to spin for fun)
> >
> > Hi all - I
thought we trained people to recover from
> > spins because although
our nice shiny new trainers
> > are
> > "spin-proof" most of
our aging single seater fleet
> > that the majority of inexperienced
club pilots will
> > fly are not? I just spent the weekend
conducting
> > spin-training in a puchacz ... and I did my
own
> > ab-initio training in an IS-28 ..the puch is much
>
> nicer to spin =) i don't "enjoy" spinning, but I'm
> >
definitely a better pilot for it.
> >
> > - Richard
McLean
> >
> > --- Mark Newton <[EMAIL PROTECTED]> wrote:
> > > Harry Medlicott wrote:
> > >
> > >
> Spinning accidents don't normally happen at
> > > altitude,
it is the ones close
> > > > to the ground that cause the
accidents. Training
> > > at altitude undertaking a
> >
> > number of turns might be fun but I doubt if it
> > >
saves many lives. What is
> > > > needed is plenty of practice
at instantly taking
> > > the appropriate recovery
> >
> > action when a spin is developing and, yes,
> > >
preferably when and if the real
> > > > thing happens, you are
flying a docile glider.
> > > > Why make life harder than we
need to?
> > >
> > > ANY flying activity close to the
ground is more
> > > hazardous than flying
> > > a
long way away from the ground.
> > >
> > > When
you're a long way away from the ground, the
> > > only things that
can
> > > hurt you are overstressing the aircraft, hitting
>
> > another aircraft, or
> > > climbing high enough to
become hypoxic (which
> > > usually causes one of
> >
> the other effects)
> > >
> > > When you're close
to the ground, there are all
> > > manner of other
> >
> miscalculations and bad judgement calls which can
> > > get
you in trouble
> > > by causing rapid height loss. If the
rapid height
> > > loss doesn't
> > > terminate
abruptly upon contact with geography,
> > the
> > >
pilots options
> > > are still limited by the loss, which might
result
> > in
> > > a high-risk,
> > >
badly-planned, unexpected outlanding.
> > >
> > > If
an aircraft's flight manual says it can spin, I
> > > see no
reason not
> > > to spin it -- And furthermore, I see no reason
not
> > > to enjoy it. Just
> > > like you can
enjoy loops, chandelles, steep turns
> > > and whatever
other
> > > aerobatic maneuver the flight manual says you
can
> > > do. However, as with
> > > any other
aerobatic maneuver, you should know your
> > > aircraft and
plan
> > > what you're doing with full appreciation of
your
> > > abilities and
> > > potential failings
before you start, and you
> > should
> > > conduct
those
> > > options with adequate, well thought-out safety
>
> > margins.
> > >
> > > (hmm - that isn't
actually limited to aerobatics,
> > is
> > > it
:-)
> > >
> > > We're "making life harder than we
need to" if we
> > > conduct any
> > > activity at all
which limits our options when
> > close
> > > to the
ground.
> > > I know a lot of people who have a great time
>
> > spinning gliders, but
> > > I don't know anyone who
would do it below 1,500',
> > > whether they're
> > >
in an IS-28, a Puchacz or anything else.
> > >
> > >
We teach pilots to perform turns at varying speeds
> > > and bank
angles,
> > > we stuff up their circuits, we simulate
cable
> > > breaks, we talk them
> > > through stalls
-- These are all things which
> > aren't
> > > part of
*normal*
> > > flight, but which teach the trainee that
when
> > things
> > > aren't normal
> > >
they can still extract themselves from the
> > situation
> >
> safely and
> > > confidently. Why doens't a multi-turn
spin at
> > > height fit into that
> > > mold?
And if it does, how can you say that you
> > > doubt it
saves
> > > many lives?
> > >
> >
> - mark
> >
> >
> >
> >
>
-------------------------------------------------------------------
>
-----------
> > This communication, including any attachments,
is
> > confidential. If
> > you are not the intended
recipient, you should not
> > read it - please
> >
contact me immediately, destroy it, and do not copy
> > or use any
part of
> > this communication or disclose anything about
it.
> >
> >
>
-------------------------------------------------------------------
>
-----------
> >
> >
> >
_______________________________________________
> > Aus-soaring
mailing list
> > [EMAIL PROTECTED]
>
> To check or change subscription details, visit:
> >
> http://lists.internode.on.net/mailman/listinfo/aus-soaring
>
>
>
> Find local movie times and trailers on Yahoo!
Movies.
> http://au.movies.yahoo.com
>
_______________________________________________
> Aus-soaring mailing
list
> [EMAIL PROTECTED]
>
To check or change subscription details, visit:
> http://lists.internode.on.net/mailman/listinfo/aus-soaring
>
_______________________________________________
Aus-soaring mailing
list
[EMAIL PROTECTED]
To
check or change subscription details, visit:
http://lists.internode.on.net/mailman/listinfo/aus-soaring
|
