Puchacz reviews

[cuflyer]

Hello All,

I am looking for real world reviews of the Puchacz (or the newer Perkoz)
in the club / instructional environment.
How do they hold up to daily use/abuse?
Maintenance issues?
How are they for ab-initio?
Truth to the spin-eager rep?
Any bad habits?

Thanks,
Tim

[ASM]

Puchacz is an old glider. Go to the http://szd.com.pl/en/products/szd-50-3-puchacz web site and look at the published service bulletins. It is still being used as a primary trainer in many countries around the World. And since it was designed in the expanded aerobatic category it will spin quite happily. If flown as it supposed to be flown, it does not present any problems, but if someone flies it carelessly it will bite; eg. right rudder/left aileron. I have flown in the Puchacz in the very first prototype in 1977 and I still like it, but there are better gliders now-a-days.
In the "Gliding International" magazine there is an article about the SZD 54-2 Perkoz. If you can't get a copy, send me an email to jacek dot kobiesa at raypolandandsons dot com and I will get you a PDF copy of this article.
If you don't mine taking care of an old glider then the Puchacz (also known as the Ruchacz) is a OK, but if you prefer a modern glider designed and tested to the latest requirements, willing to have a flexible glider which is capable of almost full aerobatic capabilities and have a cross country machine (17.5 m for basic training with winglets, 17.5 m with standard tip for aerobatics, and 20 m for cross country), than the Perkoz is the way to go. Also, take a look at the PW-6U; its cost is about half of the Perkoz. Link to the Soaring Cafe article : http://soaringcafe.com/2012/04/world-class-sailplanes-dead/

[guy]

In this day and age I would not consider a Punchaz if you are planning
on acro. Look at the load limit/flight envelope chart and you will
see that it has a very low VNE and the limits to negative Gs gets
smaller as one approaches VNE. Any lack of attention in a blown
manuver and WATCH OUT. There is also quite a history of people not
recovering from spins. I participated in assembly of a Punchaz and it
was not pretty.
Guy

[Nick Hill[_3_]]

On 27/09/2012 13:36, cuflyer wrote:
> Hello All,
>
> I am looking for real world reviews of the Puchacz (or the newer Perkoz)
> in the club / instructional environment.
> How do they hold up to daily use/abuse?
> Maintenance issues?
> How are they for ab-initio?
> Truth to the spin-eager rep?
> Any bad habits?
>
> Thanks,
> Tim
>

Check the hours on the airframe. I think the current max lifetime hours
is 6750.



--

Nick Hill

[David Salmon[_2_]]

At 12:36 27 September 2012, cuflyer wrote:
>Hello All,
>
>I am looking for real world reviews of the Puchacz (or the newer Perkoz)
>in the club / instructional environment.
>How do they hold up to daily use/abuse?
>Maintenance issues?
>How are they for ab-initio?
>Truth to the spin-eager rep?
>Any bad habits?
>
>Thanks,
>Tim
>
Let me start by saying that I like the Puchacz very much. About 4000
instructional flights and over 1000 hours in them. Perhaps they have been
bettered now, but I always claimed that it was the best training glider
available, it would do exactly what the pilot told it to do. One exception,
that in spite of it's reputation, pre-solo pilots had difficulty making it
spin.
They hold up well in a club use/abuse situation, but a few issues.
Wheelbrakes are poor design and can stick on. I've known 2 wheels on Puchs
being towed on the ground, explode due to extreme overheating. Better to
change to Tost wheels.
U/C bungees were poor quality, we changed to UK supply.
Aileron and elevator drive connections will eventually wear.
Trim wires occasionally break, but easily replaced.
Tailplanes are a fiddle to put on, but normally you don't do it very often.
You have to learn the technique.
We have used them for many years as ab initio trainers and for first solo.
In my personal experience, I have never had an unexpected departure, though
there have been spin in accidents. But there have also been with Oly 2bs
and Skylarks. What is the point of training pilots in gliders that will not
spin, then putting them in single seaters that will?
They seem almost unaffected by rain, quite an asset. In rough, turbulent
conditions I'd rather be in a Puch than anything. Excellent brakes. Very
good visibility.
There is a Dick Johnson flight test, and Dean Carswell did further spinning
tests (1994). It is the only glider I'm aware of where they got a better
L/D than the manufacture claimed, 32 as opposed to 30.
Dave

[Andreas Maurer]

On Fri, 28 Sep 2012 10:53:11 +0000, David Salmon
> wrote:


>but I always claimed that it was the best training glider
>available, it would do exactly what the pilot told it to do. One exception,
>that in spite of it's reputation, pre-solo pilots had difficulty making it
>spin.

Couple of letal spin accidents during winch launches in Germany with
instructors on board.
Pretty sure that the instructors did not tell the Puchacz to spin and
kill them and the student.

My 2 cents on the Puchacz.

Andreas

[[email protected]]

One of my clubs has been using a Puchacz as its basic trainer for more than a decade now, with excellent results. Compared to the Blaniks we used before, the pupils need a few more hours before solo, but the ship is much more comfortable. It makes the transition to a glass single seater like the Astir CS a bit easier (but we usually have the pupils doing some doubles on a Twin just to be sure).

Spinning issues: the Puchacz spins beautifully and stops spinning correctly, but one needs to effectively apply the controls to terminate the spin, especially if centred slightly rearward. In most circumstances, it won’t stop spinning if you don’t push hard on the opposite pedal and put the stick forward, while a Blanik usually seems to stop as soon as you release the back pressure on the stick. The Puchacz flight manual describes the different spinning modes in function of the centre of gravity and aileron position, so it pays to read it.

Maintenance: the automatic connection of the controls has a downside. The connectors must have a very tight fit to avoid creating excessive play. So there are two extreme situations: tight fit making the glider rather difficult to assemble, or glider easy to assemble but with too much play in the controls… One also has to regularly check the bungee cords in the main wheel suspension system.

Another issue is the very inefficient wheelbrake system. It only functions (and not very efficiently at that) if the wheel axle is perfectly smooth and slippery, as the wheel has to be pushed sideways on it by the mobile braking disk, against the fixed braking disk. There is not much leverage, as you have to pull on a small ball at the end of a very long cable. Without the benefit of a Bowden cable, your hand moves to and fro with the movements from the sprung undercarriage…

[David Salmon[_2_]]

At 14:24 28 September 2012, Andreas Maurer wrote:
>On Fri, 28 Sep 2012 10:53:11 +0000, David Salmon
> wrote:
>
>
>>but I always claimed that it was the best training glider
>>available, it would do exactly what the pilot told it to do. One
>exception,
>>that in spite of it's reputation, pre-solo pilots had difficulty making
it
>>spin.
>
>Couple of letal spin accidents during winch launches in Germany with
>instructors on board.
>Pretty sure that the instructors did not tell the Puchacz to spin and
>kill them and the student.
>
>My 2 cents on the Puchacz.
>
>Andreas
>
I really don't want to start this running, but many other glider types have
done exactly the same, when unfortunately the winch launch is not handled
correctly. See the BGA website, and what has been done in the UK to try to
eliminate this type of accident. I have seen it happen to an ASW20, know
the pilot of a Mosquito, who survived, and knew an ASW19 pilot who didn't.
Sorry, but don't blame the glider. BTW, the Mosquito accident in Germany
was the subject of a widely distributed video.
Dave

[6PK]

On Friday, September 28, 2012 10:15:04 AM UTC-7, David Salmon wrote:
> At 14:24 28 September 2012, Andreas Maurer wrote: >On Fri, 28 Sep 2012 10:53:11 +0000, David Salmon > wrote: > > >>but I always claimed that it was the best training glider >>available, it would do exactly what the pilot told it to do. One >exception, >>that in spite of it's reputation, pre-solo pilots had difficulty making it >>spin. > >Couple of letal spin accidents during winch launches in Germany with >instructors on board. >Pretty sure that the instructors did not tell the Puchacz to spin and >kill them and the student. > >My 2 cents on the Puchacz. > >Andreas > I really don't want to start this running, but many other glider types have done exactly the same, when unfortunately the winch launch is not handled correctly. See the BGA website, and what has been done in the UK to try to eliminate this type of accident. I have seen it happen to an ASW20, know the pilot of a Mosquito, who survived, and knew an ASW19 pilot who didn't. Sorry, but don't blame the glider. BTW, the Mosquito accident in Germany was the subject of a widely distributed video. Dave

I was checked out in one, the club I belonged to at the time purchased about 10-12 years ago.
I was told prior it had a very benine spin characheristic. Boy was I in for a surprise!
Entered in a regular conventional way and she wound up like a mama!!
It did recover no problem through. I been told that if you really wanted a great surprise just cross it up and wach out. I never did tried this entery method throuh.
Our chief pilot did a deep slip once at altitude and it went over the top.
Later in a checkout it killed an instructor and the pilot being checked out from what we think was an intentional practice spin entry from altitude.
6PK

[Eric Munk]

Hello Tim,

As an instructor I have about 2000 launches in the Puch, as a technician I
serviced four of them for 10+ years. A delight to fly, if proper spin
training is done in the club environment and the aircraft's flight envelope
is respected. As an ab-initio it is perhaps not ideal due to is spinning
ability (the reason we sold ours and converted to ASK-21s). Dick Johnson
wrote a good article on its pros and cons in spinning. Your questions:

>How do they hold up to daily use/abuse?
Very well. We do 7-days a week flying, on an often wet airfield, with about
2000 flights a year per glider. A strong glider, that stands up to a lot of
abuse and has a very well sprung undercarriage that is an instructor's
delight. Spacious back cockpit. Getting the airbrakes extended from the
front cockpit is a bit awkward, but you get used to it. Aerobatics are not
really advisable, given low VNe, small margins for error, etc. Replace the
canopy cable (which stops the canopy from opening further than needed) with
a different design: they snap and it'll cost you a canopy. Don t buy one
with a skid but go for a tailwheel (less change of damage). The wheelbrake
sucks, but there's a mod for Tost brakes which we had and works wonderful.
Puchs (like e.g. ASK-13s) suffer from relatively low max. cockpit loads.
Check yours before buying. Respect airspeeds (we overstressed one in
repeated highspeed winch launches, with structural wing damage that needed
repair). Teach people to be careful with the tail in hangars. They are
ceconite covered control surfaces and prone to hangar rash. Airbrake caps
raise themselves at airspeeds in excess of 180 km/h or a bit lower with
high G. No issue, but scares the living daylight out of you if you do not
know this ;-)

>Maintenance issues?
See the factory SB-overview for weak points (if you buy one make sure it
has the new design front wing attachments: this'll save a lot of hassle and
costs due to hairline cracking). Mainwheel bungees deteriorate with age.
Have a spare set available at all times. Easy to replace by technician.
Tailwheel tyres sometimes go off the rim with traversed landings. All
control cables have to be replaced every 12 years/1500 hours according to
SB 007/94 (lots of work). Canopy closing levers sometimes work loose when
lock rings are worn. Play on elevator after ca. 1500 hours is normal
(replace t-lever in the tail), play on stabilizer occurs as well (the
limits for play are enormous compared to German gliders, so that'll easy
your mind). We had one jammed bevel gear in the airbrake system due to
dirt, they are not an ideal design. Wear in the gears will cause asymmetric
opening and play. Trim tab actuator rods snap if lubrication is not carried
out regularly. Also, the lower rudder attachment ply and its vertical
support are prone to damage. This really should be an AD imho, but is not.
Check the horizontal ply for cracks, and the joint between vertical and
horizontal for disbonding at every DI to be sure.
All in all the Puch is a bit more work on maintenance than say an ASK-21,
but not too bad/costly if you have club technicians available for the brunt
of the work. Inspection schedule is every 50 flying hours, with a bigger
one every 250 (equal to an annual, which it has as well). A major
inspection/servicing every 1000 hours. Airframe lifetime is 6000 hours, but
may now be extended to 6750 and is expected to be more in some years time
as design life is 11000 hours. Parts supply and service is excellent from
Allstar.

>How are they for ab-initio?
OK, provided you have a good spintraining programme that is mandatory for
all instructors who fly on it, to pass the information/skills on to their
students.

>Truth to the spin-eager rep?
See the Johnson article. Aircraft has tendency to flatten out in a spin
rather quickly if back pressure is applied with low cockpit loads. Also:
with asymmetric stall from a turn with relatively little nose-up (but low
speed) wing will drop and with little warming go into spin. Other than this
it is very predictable, and gives ample warning.

>Any bad habits?
I don't have any I am aware of.

No info on the Perkoz, sorry, only did one flight in it.

Eric

[Andreas Maurer]

On Thu, 27 Sep 2012 05:36:30 -0700 (PDT), cuflyer >
wrote:

>Hello All,
>
>I am looking for real world reviews of the Puchacz (or the newer Perkoz)
>in the club / instructional environment.
>How do they hold up to daily use/abuse?
>Maintenance issues?
>How are they for ab-initio?
>Truth to the spin-eager rep?
>Any bad habits?

Just a small addition since the same topic is just being discussed in
the German gliding board segelflug.de.


Since August of 2009, five letal accidents of Puchacz gliders with
nine people being killed an one injured badly.

Each time an instructor was on board.

http://aviation-safety.net/wikibase/wiki.php?id=137025
http://www.abc.net.au/news/2012-04-0...cident/3925952
http://aviation-safety.net/wikibase/wiki.php?id=144869
http://aviation-safety.net/wikibase/wiki.php?id=146849
http://aviation-safety.net/wikibase/wiki.php?id=137365
http://aviation-safety.net/wikibase/wiki.php?id=68075

Note that nearly all accident reports contain the word "spin" or
"stall".

Google "puchacz accident" - there's hardly a year where there was not
a Puchacz accident that killed both student and instructor.

Draw your own conclusions.


Andreas

[cuflyer]

On Thursday, September 27, 2012 8:36:31 AM UTC-4, cuflyer wrote:
> Hello All,
>
>
>
> I am looking for real world reviews of the Puchacz (or the newer Perkoz)
>
> in the club / instructional environment.
>
> How do they hold up to daily use/abuse?
>
> Maintenance issues?
>
> How are they for ab-initio?
>
> Truth to the spin-eager rep?
>
> Any bad habits?
>
>
>
> Thanks,
>
> Tim

Thanks for all your comments, folks. Very helpful.

Cheers,
Tim
1FL

[[email protected]]

Andreas's list is probably mainly stalls/spins (though 2 of the 6 are during the climb out on aerotow, which seems to me the least likely phase of flight for such an occurrence). But I wouldn't automatically say the Puchacz is unsafe, even though it has proportionately more stall/spin accidents than most other trainers.

My experience is in being trained as a UK Basic Instructor, a large proportion of which included stalls and spins. I find that it stalls or spins only when expected, normally with lots of warning, and recovers immediately with the correct control inputs more crisply and reliably than other trainers I've flown.

However, the Puchacz loses lots of height in these manoeuvres - for a one-turn spin around 800 ft compared to 350 ft or so in a K13. This gives a lower margin for errors. As an example, one of the accidents:

http://aviation-safety.net/wikibase/wiki.php?id=137365

is a spin off a practice aerotow rope break at 150m/500 ft. At that height, if the instructor doesn't prevent spin entry then the departure is almost certainly irrecoverable.

For that reason I wouldn't want to use a Puchacz for all aspects of basic training, at least unless the instructors were able to take special care in these no-margin situations and were prepared to take over control early. For upper air work, however, it's excellent .

The biggest concern I'd have is winch launching. The BGA recommendation is that minimum launch speed should be 1.5 x Vs, or 55kt. Max winch speed is 59kt, and a previous poster has written of damage from overspeed on winch launching. That 4kt window is very narrow!

As an advanced trainer, launching mainly by aerotow, I reckon the Puchacz is very good indeed.

[Dave Martin[_3_]]

The Puchacz handles very well on a winch launch, I have done
hundreds.

The biggest problem with the Puchaz is the a lack of orders, its
old technology (1970's) replacement the Perkoz is around the
£100,000 ready to go with trailer etc. The ASK 21 £110,000 for
the similar option.

Other than second hand there are no cheap gliders around.

Dave



At 18:21 07 October 2012,
wrote:
>Andreas's list is probably mainly stalls/spins (though 2 of the 6
are
>durin=
>g the climb out on aerotow, which seems to me the least likely
phase of
>fli=
>ght for such an occurrence). But I wouldn't automatically say
the Puchacz
>i=
>s unsafe, even though it has proportionately more stall/spin
accidents
>than=
> most other trainers.
>
>My experience is in being trained as a UK Basic Instructor, a
large
>proport=
>ion of which included stalls and spins. I find that it stalls or
spins
>only=
> when expected, normally with lots of warning, and recovers
immediately
>wit=
>h the correct control inputs more crisply and reliably than other
trainers
>=
>I've flown.
>
>However, the Puchacz loses lots of height in these manoeuvres
- for a
>one-t=
>urn spin around 800 ft compared to 350 ft or so in a K13. This
gives a
>lowe=
>r margin for errors. As an example, one of the accidents:
>
>http://aviation-safety.net/wikibase/wiki.php?id=3D137365
>
>is a spin off a practice aerotow rope break at 150m/500 ft. At
that
>height,=
> if the instructor doesn't prevent spin entry then the departure
is almost
>=
>certainly irrecoverable.
>
>For that reason I wouldn't want to use a Puchacz for all aspects
of basic
>t=
>raining, at least unless the instructors were able to take special
care in
>=
>these no-margin situations and were prepared to take over
control early.
>Fo=
>r upper air work, however, it's excellent .
>
>The biggest concern I'd have is winch launching. The BGA
recommendation is
>=
>that minimum launch speed should be 1.5 x Vs, or 55kt. Max
winch speed is
>5=
>9kt, and a previous poster has written of damage from
overspeed on winch
>la=
>unching. That 4kt window is very narrow!
>
>As an advanced trainer, launching mainly by aerotow, I reckon
the Puchacz
>i=
>s very good indeed.
>
>

[Eric Munk]

>The biggest concern I'd have is winch launching. The BGA recommendation is
that minimum launch speed should be 1.5 x Vs, or 55kt. Max winch speed is
59kt, and a previous poster has written of damage from overspeed on winch
launching. That 4kt window is very narrow!

Like posted here, winch launching is usually uneventful. I did wonder why
BGA promote 55 Kt (100 kmh). Manufacturer says 90kmh min, which is fine.
Still only gives you 20 kmh margin, not too much. Structural damage
occurred to a glider that routinely did 110-140 kmh, on a black weaklink.
Asking for trouble, but yes, it can happen.

[Marc]

On Oct 8, 6:15*am, Eric Munk > wrote:
> Like posted here, winch launching is usually uneventful. I did wonder why
> BGA promote 55 Kt (100 kmh). Manufacturer says 90kmh min, which is fine.
> Still only gives you 20 kmh margin, not too much. Structural damage
> occurred to a glider that routinely did 110-140 kmh, on a black weaklink.
> Asking for trouble, but yes, it can happen.

Not all of us have heard of this incident. Conventional (including
BGA) wisdom is that as long as the glider is structurally sound, and
the correct weak link is in use, exceeding max winch speed should not
result in structural damage, as the weak link should break well before
structural limits are reached. The specified weak link strength for
the Puchacz is 750 daN (red), it should be obvious that using a 1000
daN weak link (black) is an accident waiting to happen. What did
happen?

Marc

[Eric Munk]

>Not all of us have heard of this incident. Conventional (including
>BGA) wisdom is that as long as the glider is structurally sound, and
>the correct weak link is in use, exceeding max winch speed should not
>result in structural damage, as the weak link should break well before
>structural limits are reached. The specified weak link strength for
>the Puchacz is 750 daN (red), it should be obvious that using a 1000
>daN weak link (black) is an accident waiting to happen. What did
>happen?

Like I said: glider was routinely flown above max winch speed on too-high
strength weak links. Mainly human factors involved ('but we've been doing
this for some years now and it's still allright isn't it?'), some national
regulations getting in each others' way (Dutch glider flying only on
off-home airfield on a German airfield where they only use red and black
weaklinks versus the usual Dutch blue/brown which are lower max strength),
and a winch drivers' mentality (and training) that overemphasized the risk
of stalls on winchlaunch (under underestimating the danger over overloading
gliders), leading to excessive winch launch speeds. Combined with
instructor experience (complacency) and some other factors (peer pressure,
pressure to fly the airplane, lack of understanding of the risk of
overstress) this eventually (after some months) led to structural damage
that became visible as spanwise cracks along the leading edge of the wing
which I noticed when the aircraft came in for an annual. The underlying
structure was compromised, leading to extensive GRP repairs to the D-nose
of both wings (at the factory).

[Roel Baardman]

In reply to the list of accidents with spinning:

Recently there was spin training (on a Fox) in The Netherlands. Out
of 20 instructors, only one got the Fox out of a spin without any
unintended maneuvers. Many instructors pulled to early after
stopping the rotation (and recovering the stall), causing a
spin/flick maneuver.
The one instructor that did it right the first time had extensive
aerobatic experience.

All I'm trying to say is: while it might appear from the statistics
that the Puchacz is at fault, other factors can also play a role.

Roel

[Eric Munk]

> What did happen?

>Marc

- Lack of awareness of operational restrictions with the pilots (Vwinch
max)
- Local customs different than at homefield (black is standard in Germany.
In The Netherlands borwn is. As you state black is not within
manufacturer's specs)
- Complacency (on the instructors' part)
- Poor local winch driver training (highlighting the danger of slow
launches, but omitting dangers of overload during launch)
- Poor winch lay-out (small gas handle which made distributing the power
input difficult)
- And another couple of minor things, all combined make for a good
combination of overstressing a glider.

It was operated (very) regularly outside limits, and this came to light
during the next annual when I found significant spanwise cracking in the
wing nose structure. Went back to the factory for extensive GRP repairs to
both leadings edges before it was cleared for flight again.

[Chris Nicholas[_2_]]

1. As another (late) subscriber wrote, you will only find spin accidents in gliders that spin, and more frequently in those that spin easily when the inputs cause departure. Hence lots more spin fatalities in Puchacz than in K7/K13/K21. It does not mean that the Puchacz is in itself dangerous, but if abused, if not correct recovery, and if too low, yes it can kill. So can anything in one way or another if stupidly flown.


2. My understanding of the BGA guidance/advice about winch launch limitation speed is that IN THE LOWER AND MIDDLE PART of a winch launch, when the cabale is far from in line with the glider's weight and so adding only partly to the bending load on the wings, it is not dangerous to exceed the winch launch speed limit by a modest margin. IN THE TOP PART OF THE CLIMB however, when the cable is close to in line with the gravitational load and its vector is substantially additive, the winch launch speed should be respected. If too fast, at least lower the nose and reduce the load, or pull off. (Open to correction by current instructors etc., if the guidance is now pull off regardless.)

Chris N

[[email protected]]

Le mardi 9 octobre 2012 13:40:07 UTC+2, Roel Baardman a écrit*:
> In reply to the list of accidents with spinning:
>
>
>
> Recently there was spin training (on a Fox) in The Netherlands. Out
>
> of 20 instructors, only one got the Fox out of a spin without any
>
> unintended maneuvers. Many instructors pulled to early after
>
> stopping the rotation (and recovering the stall), causing a
>
> spin/flick maneuver.
>
> The one instructor that did it right the first time had extensive
>
> aerobatic experience.
>
>
>
> All I'm trying to say is: while it might appear from the statistics
>
> that the Puchacz is at fault, other factors can also play a role.
>
>
>
> Roel

Roel,

as an instructor, I would say that a double seater which tends to flick to the other side after spin recovery is a NoGo for basic instruction or first flight. With a Fox, it's ok - but it was designed for full aerobatics, and nbody would even think of using it as a basic trainer.

I have never flown the Puchaz, but looking at the statistics for spin accident with a FI on board, I tend to see an issue with this glider vs ASK's and the like.

[Eric Munk]

>as an instructor, I would say that a double seater which tends to flick
to
>=
>the other side after spin recovery is a NoGo for basic instruction or
>first=
> flight.

Agreed. But don't put the Puchacz 1, 2 and 3 on the same pile. The 3 is a
very different airplane than the 1 and 2, with longer rear fuse, larger
tail surfaces, larger tail controls, etc. Behaves quite differently in a
spin compared to the 1 and 2. I speak from experience.

>I have never flown the Puchaz, but looking at the statistics for spin
>accid=
>ent with a FI on board, I tend to see an issue with this glider vs ASK's
>an=
>d the like.

And an apple tastes wholly different than an orange and the like. My point:
don't compare a glider that will spin with a glider that practically
doesn't when it comes to accidents. ;-)

If you ever get the chance to fly the Puch, grab it. You'll get to enjoy
the positive and experience the negative aspects of it (there other things:
it is relatively slow to pick up speed after a stall due to drag; the
airbrake caps rattle over 180 kmh; when landing with full airbrakes and
misjudging the flare it has a tendency to settle firmly).

Judging by its reputation I understand if people decide against buying (or
even flying) it. I just love flying it and *respect* its flight envelop
limitations. Just like I do in any glider that spins very well.