Schweizer 1-35 and other flapped sailplanes

Our local DE had a 1-35 on the line, which he mentioned to me when I
mentioned my plans to buy an HP-11. He gave me some advice then, and
in retrospect it was very good advice.

First off, flaps for glideslope control are not an issue. Really no
big deal at all. Sure, a little different, but not difficult.

The issue with my HP-11, and the HP-18 my friend had, and the 1-35 the
local DE had, was weak aileron control on takeoff. On a wide grass
field with a powerful tow plane and all tows into the wind, it's not
much of an issue - you rudder it around until the ailerons come alive,
and then all is well. On a narrow paved runway, with lights on posts
giving the wingtips just a few feet of clearance, a weak tow plane, and
a habit of towing slightly downwind to avoid the inconvenience of
moving, it's a much bigger deal.

Michael

Do Piks HPs and 1-35 flaps create too much drag to leave out in the
flair?

Shawn

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~

As a PIK 20B driver:

It's not that they create too much drag, it's that it floats for quite a
long way even if your approach isn't fast, and in that float it is
_VERY_ pitch sensitive. The other problem is that once you are down on
the ground there is very little aeleron control and any brake will put
the aircraft on its nose, so it's much easier to complete the initial
part of the flare and then slowly wind in the flap so that the tail
comes down and it settles onto the ground, winding the flaps all the way
to negative allows use of the wheel brake and gives some aeleron
control.=20

Rgds,

Derrick Steed

Derrick Steed wrote:
Do Piks HPs and 1-35 flaps create too much drag to leave out in the
flair?
no
As a PIK 20B driver:
It's not that they create too much drag, it's that it floats for quite a
long way even if your approach isn't fast, and in that float it is
_VERY_ pitch sensitive. The other problem is that once you are down on
the ground there is very little aeleron control and any brake will put
the aircraft on its nose, so it's much easier to complete the initial
part of the flare and then slowly wind in the flap so that the tail
comes down and it settles onto the ground, winding the flaps all the way
to negative allows use of the wheel brake and gives some aeleron
control.=20

I'll second all of that on the PIK20b. First, I think the PIK, 1-35,
and the HP series are all different.

You will float too far in the PIKb using any reasonable speed over the
threshold. Since I learned CC soaring and outlandings in this ship,
precise touchdowns were required. The previous owner, an experienced
racing pilot, taught me the the "wind up the flaps as you flare"
technique after I had 'mastered the float'. I would almost always use
the full 90 deg position on final and wind it to neg 6 deg in the flare
- about 2.5 cranks as I recall. As you cranked, you pulled back and
landed 2 point. Very easy to hit any spot and very easy to do the flare
once you learned to coordinate cranking with one hand while pulling on
the other. You ended up being the afternoon's entertainment in the
meantime. That cranking motion invariably found it's way into your
right hand resulting in pitch PIOs.

If you don't touch the flaps, you would simply sit in ground effect and
wait for the energy to bleed off. Every gust or nudge of the stick
would cause excursions until the wait was over. Coming in on final with
minimum energy was unsafe. A unforseen drop in wind would leave you
without options....

....and that is the main problem with flaps. Once you have them out and
your energy is down, there's little recourse. With spoilers, you can
always slap them closed and return to high performance configuration.

Flaps are great but spoilers are better. Both is best.

Maule Driver wrote:

Flaps are great but spoilers are better. Both is best.

That's one of the reasons I prefer Schleicher gliders like the ASW 20,
and now a ASH 26 E.
--
Change "netto" to "net" to email me directly

Eric Greenwell
Washington State
USA

Jack wrote:
If I can survive 140 hours in a flapped
ship and not just survive but love it... so can you. They're not
dangerous, just different.

I have had similar good experiences with a flaps-only for
glide-path-control ship. In this case an RS-15. After only 22 hours
of flying anything I took my first flight in the RS. I found the ship
very easy to fly with almost docile handling characteristics,
especially at low speed. Several good things happen when the flaps are
deployed during the landing pattern: 1) stall speed decreases, 2) pitch
stability increases due to the increase in "longitudinal dihedral", 3)
any tendency to tip stall decreases due to the effective increase in
washout. Also, I have never forgotten to connect my spoilers nor have
I ever had spoilers accidently deploy while in flight. I'm not
knocking spoilers, they work just fine. But a flaps-only ship can also
be a real pleasure to fly.

Regards,

-Doug

I would have to agree with most of the comments made here, including
the one about there being better ships out there for about the same
money. After all, when I put my money down, I didn't buy a 1-35.

I have never had the PIO problem that someone pointed out, but then
with the primary-subject sailplane, the landing flap is just pulled
back as the stick is moved forward.

I never had the float problem, either. I guess I have always used
enough flap and slowed her down to nothing before dumping any of it
off.

The comment about narrow runways with a slight downwind takeoff roll
and a weak towplane... That's asking for trouble in any sailplane, and
perhaps more so in one of tese ships, but I would think an SZD-55
wouldn't be any easier.

One comment that stuck out was the set 'em and forget 'em thoery. I was
taught to modulate these flaps just like spoilers. If the airspeed is
maintained, there's no appreciable loss of altitude in leveling the
nose while removing the flap. I have had 2 instances where I wasn't
seen in the pattern and was VERY glad to be able to back the flaps off
to 0 and extend about 400' and continue my final. This was of course
followed by a debriefing of the offenders about scouring the pattern
for approaching ships. So far, I've had 12 hours in my PIK, interrupted
for the summer by a surgery, but I've had no problems in modulating my
flap input throughout the pattern to maintain proper speeds and
altitudes.

Again, I wasn't knocking spoilers, either, but I do wish those knocking
flaps only ships would really look at the situation or just be quiet...

Jack Womack

Jack wrote:
I would have to agree with most of the comments made here, including
the one about there being better ships out there for about the same
money. After all, when I put my money down, I didn't buy a 1-35.

I have never had the PIO problem that someone pointed out, but then
with the primary-subject sailplane, the landing flap is just pulled
back as the stick is moved forward.

I never had the float problem, either. I guess I have always used
enough flap and slowed her down to nothing before dumping any of it
off.

The comment about narrow runways with a slight downwind takeoff roll
and a weak towplane... That's asking for trouble in any sailplane, and
perhaps more so in one of tese ships, but I would think an SZD-55
wouldn't be any easier.

One comment that stuck out was the set 'em and forget 'em thoery.

That was my comment with regard to the trailing edge dive brake/flap
system of the the Ventus and Mosquito. My comment was that once on
*short* final i.e. runway made and on glide for my planned touchdown
point I pull full brakes/flaps and use the stick to control the
remainder of the flight. If the brakes/flaps aren't fully deployed in
the flair, more can be added. I've never found the trailing edge system
to be easily modulated near the ground. My experience has been that if
I try to put them away in the flair I drop onto the runway very inelegantly.

Shawn

and that is the main problem with flaps. Once you have them out and
your energy is down, there's little recourse. With spoilers, you can
always slap them closed and return to high performance configuration.


Flaps are great but spoilers are better.

This is the mentality we are talking about. The "spoilers are better"
mentality. What I see wrong with this is the energy shouldn't be blead
off until flair, just like spoilers. The flaps can be dumped if the
airspeed is still there, just like spoilers. The float will be minimal
if the flaps are cranked in as they should be. If you're using 45
degrees... yep... it's gonna float all the way down the runway. The
flaps should be pulled to max during flair if they're not there
already, and should be dumped only at ground contact to facilitate
aileron control for the rest of the landing run - which should be short
if you used the flaps and slowed during flair. Better than spoilers?
Not in my opinion. Spoilers better than flaps? No to that one as well.

Again, I would stress that either one can be used effectively, with the
flaps having a short field advantage for outlandings.

Both is best. You'll get no argument from anyone on that one.

Jack Womack

As a former long time PIK owner, I am partial to flaps-only. They are
great, and flexible, and facilitate lower energy landings. Fun like a
tailwheel.

But I've landed in extremely gusty/wind shear conditions on several
occassions. That is, with T-storms over or on the airport (stupid?
Yes.) Flying with spoilers and flaps saved the day. Upon reflection if
given a choice between the 2, it would have to be spoilers. In those
admittedly extreme conditions, airspeed excursions are not entirely in
one's control and spoilers-only are better than flaps-only no matter the
level of pilot proficiency.

I would just add that flap-only techniques appear to be very aircraft
specific. The Pik will float in ground effect all day long with 90
degrees cranked in. If you wait until ground contact to start
retracting them, you will not be able to meet a 10 foot spot standard.
Not applicable to similar types.

Mauledriver, aka Foureyes, aka Bill Watson
....I guess you can figure out why I now fly a Maule - Composite
construction, reflex flaps, no racing class, a tailwheel to enforce
proficiency and an engine to land where the Tstorms aren't....

Jack wrote:
and that is the main problem with flaps. Once you have them out and

your energy is down, there's little recourse. With spoilers, you can
always slap them closed and return to high performance configuration.

Flaps are great but spoilers are better.

This is the mentality we are talking about. The "spoilers are better"
mentality. What I see wrong with this is the energy shouldn't be blead
off until flair, just like spoilers. The flaps can be dumped if the
airspeed is still there, just like spoilers. The float will be minimal
if the flaps are cranked in as they should be. If you're using 45
degrees... yep... it's gonna float all the way down the runway. The
flaps should be pulled to max during flair if they're not there
already, and should be dumped only at ground contact to facilitate
aileron control for the rest of the landing run - which should be short
if you used the flaps and slowed during flair. Better than spoilers?
Not in my opinion. Spoilers better than flaps? No to that one as well.

Again, I would stress that either one can be used effectively, with the
flaps having a short field advantage for outlandings.


Both is best. You'll get no argument from anyone on that one.


Jack Womack

I have a 1-35, the one with retract gear and nose skid, and have been
flying it for 9 years but not enough to justify continuing to own it.
So it is for sale. If I thought I'd ever buy another similar glider, I'd
keep this one.
However, I learned from the beginning to operate the flaps and stick in
unison but opposite - pull flaps down, push nose down. It then becomes
second nature. Other than the 30 deg initial flap setting, one can only
lock the flaps in full down position. When landing on grass and have
the the field and landing spot made, I lock the flaps full down and then
have my left hand on the brake for short stops after touch down. One
concern with full flaps is that if your speed is too fast, you touch
down on the nose skid first. So maintaining appropriate speed is of
course essential.
The other thing I like about it is that the aluminum glider is Orange
and not white!
Cheers,
Jim
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