Use of Flaps in the Pattern

I wonder how other pilots of flapped ships are using their flaps. I don't use any flap till I am aligned with the runway on final approach. Don't like the sluggish aileron control and the forward stick pressure required on the dreaded base to final turn. I switch to positive flap on final. Any comments ?
Dan G

On 10/12/2013 5:56 PM, wrote:
I wonder how other pilots of flapped ships are using their flaps. I don't
use any flap till I am aligned with the runway on final approach. Don't
like the sluggish aileron control and the forward stick pressure required
on the dreaded base to final turn. I switch to positive flap on final. Any
comments ? Dan G


Ummm...additional context would be helpful, he ship type; synopsis of your
experience (ships, hours), both overall and in the ship.

That said, I transitioned (1975) into a 15-meter glass, large deflection
landing flapped only (no spoilers) ship (Concept 70) with 128 prior total
hours, entirely in 2-33s, 2-22s and 1-26s; zero power experience.

I wanted a flatter gliding 1-26...as in I didn't want to give up the short
off-field-landing capabilities of a l-26, and considered large deflection
landing flaps just the ticket. Never saw reason to change my opinion in that
regard...flying the C-70 for 48 hours, an HP-14 for 196 hours and a Zuni for
2065 hours. Never had any 2-seat flap training (decades' later exposure to an
L-13 and an IS-28 were irrelevant in "flap use/training" terms in my opinion).

I considered myself a raw beginner, and, I considered the performance increase
step as significant as the change from spoilers to large deflection flaps. My
total knowledge of what to expect from flaps had come from reading ("Soaring"
magazine, various college textbooks).

My 1st-flight initial plan was to use no more than 30-degrees of landing flap,
in order to reduce exposure to "significant pitch changes", a plan based
entirely on book knowledge...and a plan discarded on final approach when it
became apparent an overshoot was in the cards if I didn't come up with lots
more drag, Real Soon Now. Eventually touched down about halfway down a 4,000'
strip, after using all 90-degrees of the flaps, and having zero practical
issues with so doing. I simply flew indicated airspeed (just like with
spoilers), and the pitch attitude fell out in the wash. Later - when I
eventually flew 1-34s and 2-32s (both ships with Vne-limiting dive brakes) -
it became apparent that Joe Pilot (i.e. me) couldn't tell the difference
between pitch changes due to flap pitching moment changes and (lots of) drag:
both require forward stick to maintain airspeed, and in the single-seat
gliders I've flown, stick pitch forces are minuscule...well except for
Schweizers at above trimmed speeds! :-)

As to your wondering "...how other pilots of flapped ships are using their
flaps," I generally used mine just like spoilers. Just as my goal - assuming I
wasn't practicing some specific landing technique - with spoilered ships was
to fly patterns allowing steady-state use of 50% of the spoilers, so it was
with landing flaps. By "50%" I mean I sought to fly my "routine patterns" in
the middle of my ship's descent cone (which isn't necessarily 50% flap
deflection. This conceptual goal was routinely modified for the HP-14, for
reasons noted 4 paragraphs below...but the modifications had zero to do with
flaps per-se, and 100% to do with how that ship's flaps were *actuated*.)

Coupla ship-specific notes here - since you note you're less than
happy/comfortable with the need for forward stick pressure and what seems to
you like sluggish aileron control with flap in...
- the C-70 had "PIK-20-like" rack and pinion actuated flaps, driven by a
multi-turn crank;
- my HP-14 had hydraulicly-actuated flaps, 5 pumps for full deflection;
- my Zuni has flaps actuated by pulling back on a pivoting handle (very little
mechanical advantage) through an arc of perhaps 45-degrees.

In none of those ships are stick pitch forces significant, flaps up or flaps
down. I never felt the C-70 or the Zuni sluggish in roll, regardless of flap
position. The HP *was* a slow roller, regardless of flap position (some HP-14s
have had the outer 3' of flaps turned into ailerons to address this
condition). Both HP and Zuni (side stick) have relatively high (in single-seat
glider terms) aileron forces, IMO, regardless of flap position.

Because my home field - shared with power traffic - has the glider pattern
inside the power pattern, enlarging the pattern to accommodate the HP-14's
slow-rolling, heavy-aileroned, tendencies wasn't an option, so I compensated
by flying a continuously turning pattern, varying the bank angle as required
while performing the 180 from downwind to final...it was a no-brainer and
physically-easier to do so than to horse on the stick for the sake of "a
pretty, textbook, rectangular pattern." Navy pilots do the same thing, though
for different reasons.

Because the HP's flaps were essentially a "one-shot" (a consequence of how its
hydraulic system functioned and was installed), I generally put in one pump on
downwind (to verify they were going to work), a 2nd pump "somewhere on base"
(to bring on sufficient drag to actually begin descending from flap drag), a
3rd pump on longish final, and the last two pumps on short final (the ship
landed most gracefully/easily/shortly with full flaps). With full flaps, that
ship's fuselage angle was ~45-degrees nose down at approach speed...great
view, trivially easy to spot your roundout point, rock stable.

The Zuni's flaps are weenie, compared to the HP-14's, and in it I fly a
rectangular pattern and I really do generally try for the center of the
descent cone all the way down (aka a stabilized descent path), though I
usually wind up biasing that toward the upper half of the cone, since its 50%
approach path is so shallow (compared to the HP's and my "comfort zone"). In
the absence of strong crosswinds, I usually have full flap in on that ship
several hundred horizontal yards short of my roundout point; its fuselage
angle at pattern speeds is probably less than 30-degrees nose down.

Based on your ship, YMMV, of course. FWIW, assuming your ship has sufficient
drag to get you down where you're aiming at when you delay putting in any flap
until final approach, "More power to you!" Do what works.

Personally, If I flew a glider that could land vertically, I wouldn't use my
drag device until I was overhead my intended touchdown point. Why would I want
to? That's by way of suggesting that - assuming so doing doesn't introduce any
site-specific safety issues - "doing what works for you and your ship" is a
perfectly valid methodology for Joe Pilot to adopt. The point, after all, is
to be able to land consistently and safely. "The textbook pattern" is simply a
means to that end. (Flame suit on...)

As to your comment "Don't like the sluggish aileron control (with large
deflection flaps)...", flying the HP-14 with full flaps involved an
interesting (to me) effect (several, actually, but this post is long enough
already!). I was used to, as a glider pilot, seeing and "rating" my aileron
effects with the fuselage more or less horizontal. Pitched significantly nose
low, the visual - and actual - aileron effect on your path over the ground
differs, simply due to geometry. (Imagine descending vertically, rolling
90-degrees, and your new path relative to the ground.) In broad brush terms,
*the horizontal change* induced by aileron input to your path over the ground
reduces as your pitch angle increases, and the effect Joe Pilot perceives is
that his ailerons are becoming less and less effective, since we usually use
aileron to change our path over the ground...or at least that's the way my
thermalling glider brain thinks of aileron use. Aerobatic-rated pilots
probably know well what I'm talking about...

Anyhow...enjoy your landing flaps!

Bob W.

For an ASW20:
Thermal flap on downwind.
Landing flap on final.

What does the manual recommend for your glider?

On Sunday, October 13, 2013 10:22:16 AM UTC-4, chuck wrote:
For an ASW20:

Thermal flap on downwind.

Landing flap on final.



What does the manual recommend for your glider?

OOPs Ship is a Ventus C and the manual talks only about approach flap position which I take to be on Final. It recommends Landing flap or thermal flap. I Wonder why do you use thermal flaps on downwind ?
Dan G

Thank you Bob for the detailed post. I am flying a Ventus C with airbrake and flap combination.
Dan G
On Saturday, October 12, 2013 10:19:29 PM UTC-4, Bob Whelan wrote:
On 10/12/2013 5:56 PM, wrote:

I wonder how other pilots of flapped ships are using their flaps. I don't

use any flap till I am aligned with the runway on final approach. Don't

like the sluggish aileron control and the forward stick pressure required

on the dreaded base to final turn. I switch to positive flap on final. Any

comments ? Dan G





Ummm...additional context would be helpful, he ship type; synopsis of your

experience (ships, hours), both overall and in the ship.



That said, I transitioned (1975) into a 15-meter glass, large deflection

landing flapped only (no spoilers) ship (Concept 70) with 128 prior total

hours, entirely in 2-33s, 2-22s and 1-26s; zero power experience.



I wanted a flatter gliding 1-26...as in I didn't want to give up the short

off-field-landing capabilities of a l-26, and considered large deflection

landing flaps just the ticket. Never saw reason to change my opinion in that

regard...flying the C-70 for 48 hours, an HP-14 for 196 hours and a Zuni for

2065 hours. Never had any 2-seat flap training (decades' later exposure to an

L-13 and an IS-28 were irrelevant in "flap use/training" terms in my opinion).



I considered myself a raw beginner, and, I considered the performance increase

step as significant as the change from spoilers to large deflection flaps. My

total knowledge of what to expect from flaps had come from reading ("Soaring"

magazine, various college textbooks).



My 1st-flight initial plan was to use no more than 30-degrees of landing flap,

in order to reduce exposure to "significant pitch changes", a plan based

entirely on book knowledge...and a plan discarded on final approach when it

became apparent an overshoot was in the cards if I didn't come up with lots

more drag, Real Soon Now. Eventually touched down about halfway down a 4,000'

strip, after using all 90-degrees of the flaps, and having zero practical

issues with so doing. I simply flew indicated airspeed (just like with

spoilers), and the pitch attitude fell out in the wash. Later - when I

eventually flew 1-34s and 2-32s (both ships with Vne-limiting dive brakes) -

it became apparent that Joe Pilot (i.e. me) couldn't tell the difference

between pitch changes due to flap pitching moment changes and (lots of) drag:

both require forward stick to maintain airspeed, and in the single-seat

gliders I've flown, stick pitch forces are minuscule...well except for

Schweizers at above trimmed speeds! :-)



As to your wondering "...how other pilots of flapped ships are using their

flaps," I generally used mine just like spoilers. Just as my goal - assuming I

wasn't practicing some specific landing technique - with spoilered ships was

to fly patterns allowing steady-state use of 50% of the spoilers, so it was

with landing flaps. By "50%" I mean I sought to fly my "routine patterns" in

the middle of my ship's descent cone (which isn't necessarily 50% flap

deflection. This conceptual goal was routinely modified for the HP-14, for

reasons noted 4 paragraphs below...but the modifications had zero to do with

flaps per-se, and 100% to do with how that ship's flaps were *actuated*.)



Coupla ship-specific notes here - since you note you're less than

happy/comfortable with the need for forward stick pressure and what seems to

you like sluggish aileron control with flap in...

- the C-70 had "PIK-20-like" rack and pinion actuated flaps, driven by a

multi-turn crank;

- my HP-14 had hydraulicly-actuated flaps, 5 pumps for full deflection;

- my Zuni has flaps actuated by pulling back on a pivoting handle (very little

mechanical advantage) through an arc of perhaps 45-degrees.



In none of those ships are stick pitch forces significant, flaps up or flaps

down. I never felt the C-70 or the Zuni sluggish in roll, regardless of flap

position. The HP *was* a slow roller, regardless of flap position (some HP-14s

have had the outer 3' of flaps turned into ailerons to address this

condition). Both HP and Zuni (side stick) have relatively high (in single-seat

glider terms) aileron forces, IMO, regardless of flap position.



Because my home field - shared with power traffic - has the glider pattern

inside the power pattern, enlarging the pattern to accommodate the HP-14's

slow-rolling, heavy-aileroned, tendencies wasn't an option, so I compensated

by flying a continuously turning pattern, varying the bank angle as required

while performing the 180 from downwind to final...it was a no-brainer and

physically-easier to do so than to horse on the stick for the sake of "a

pretty, textbook, rectangular pattern." Navy pilots do the same thing, though

for different reasons.



Because the HP's flaps were essentially a "one-shot" (a consequence of how its

hydraulic system functioned and was installed), I generally put in one pump on

downwind (to verify they were going to work), a 2nd pump "somewhere on base"

(to bring on sufficient drag to actually begin descending from flap drag), a

3rd pump on longish final, and the last two pumps on short final (the ship

landed most gracefully/easily/shortly with full flaps). With full flaps, that

ship's fuselage angle was ~45-degrees nose down at approach speed...great

view, trivially easy to spot your roundout point, rock stable.



The Zuni's flaps are weenie, compared to the HP-14's, and in it I fly a

rectangular pattern and I really do generally try for the center of the

descent cone all the way down (aka a stabilized descent path), though I

usually wind up biasing that toward the upper half of the cone, since its 50%

approach path is so shallow (compared to the HP's and my "comfort zone"). In

the absence of strong crosswinds, I usually have full flap in on that ship

several hundred horizontal yards short of my roundout point; its fuselage

angle at pattern speeds is probably less than 30-degrees nose down.



Based on your ship, YMMV, of course. FWIW, assuming your ship has sufficient

drag to get you down where you're aiming at when you delay putting in any flap

until final approach, "More power to you!" Do what works.



Personally, If I flew a glider that could land vertically, I wouldn't use my

drag device until I was overhead my intended touchdown point. Why would I want

to? That's by way of suggesting that - assuming so doing doesn't introduce any

site-specific safety issues - "doing what works for you and your ship" is a

perfectly valid methodology for Joe Pilot to adopt. The point, after all, is

to be able to land consistently and safely. "The textbook pattern" is simply a

means to that end. (Flame suit on...)



As to your comment "Don't like the sluggish aileron control (with large

deflection flaps)...", flying the HP-14 with full flaps involved an

interesting (to me) effect (several, actually, but this post is long enough

already!). I was used to, as a glider pilot, seeing and "rating" my aileron

effects with the fuselage more or less horizontal. Pitched significantly nose

low, the visual - and actual - aileron effect on your path over the ground

differs, simply due to geometry. (Imagine descending vertically, rolling

90-degrees, and your new path relative to the ground.) In broad brush terms,

*the horizontal change* induced by aileron input to your path over the ground

reduces as your pitch angle increases, and the effect Joe Pilot perceives is

that his ailerons are becoming less and less effective, since we usually use

aileron to change our path over the ground...or at least that's the way my

thermalling glider brain thinks of aileron use. Aerobatic-rated pilots

probably know well what I'm talking about...



Anyhow...enjoy your landing flaps!



Bob W.

Why is the final turn "dreaded"? I find that THE most rewarding part of the
pattern!

I fly a LAK-17a which has flaps and upper surface spoilers/dive brakes. I
have 5 flap positions ranging from -1, 0, 1, 2, and L. Minus 1 is for high
speed cruise, zero is for normal cruise, 1 and 2 are for thermalling, though
there's not much difference in climb, only drag, and 3 is for landing.

It's very hard to slow my ship down from final glide since I'm very
conservative until there's no doubt that I've got the airport made, but I
usually accomplish slowing down with a climbing turn to below the white arc
on the airspeed indicator and then put flaps down to 1 as I enter downwind.
I progressively lower flaps to L (landing) and, just before beginning a
descending 180 to landing, I extend the gear and then open the dive brakes.
I hold a relatively constant airspeed by varying dive brake extension as I
maintain my aim point. I usually roll out on final over the numbers at
about 50 feet and gently modulate pitch and dive brake to achieve my
touchdown point.

On rollout, I relax the dive brakes and keep the flaps down to make it
easier to roll on the main tire. When my stopping point is assured (a wide
taxiway clear of the runway), I move flaps to -1. The tail comes down and
aileron control is improved as I roll to a stop. Dive brakes are now
ineffective and, since my wheel brake is on the stick grip, I leave the dive
brake handle alone.

Of course, your ship will have its own requirements.

wrote in message
...
I wonder how other pilots of flapped ships are using their flaps. I don't
use any flap till I am aligned with the runway on final approach. Don't like
the sluggish aileron control and the forward stick pressure required on the
dreaded base to final turn. I switch to positive flap on final. Any comments
?
Dan G

On Sunday, October 13, 2013 3:22:16 PM UTC+1, chuck wrote:
For an ASW20:

Thermal flap on downwind.
Landing flap on final.

Why would you want thermal flap downwind in a 20? You're probably flying at 55 kts - so neutral flap gives better performance and handling. Thermal flap or landing flap on final, sure, depending on the conditions and desired approach speed.

Personally I almost never use full landing flap - but position 5 instead. Having said that, I fly a 20F, and I think later versions of the 20 had less flap in the landing flap position.

Paul

On Sunday, October 13, 2013 12:27:30 PM UTC-4, wrote:
Thank you Bob for the detailed post. I am flying a Ventus C with
airbrake and flap combination.

Dan G

The answer to your original question varies immensely
depending on type of glider.

For your glider, first consult the manual...
Then, it depends on the type of wingtips fitted.
With the original tips you may find roll control
'uncomfortable' in landing configuration and
rough conditions, in which case don't use 'L'.
With winglets fitted (or short tips) this is
less of a problem in your glider...

Hope that helps !
Best Regards, Dave "YO electric"

At 16:55 13 October 2013, Dave Nadler wrote:

I completely agree with Dave's comments; on the PIK20E ( and
maybe D) the L position (16deg) degrades the roll control so much that I
never use it; landing sequence on downwind is gear down,
flaps to +12, trim for approach speed required.
JMF

On Sunday, October 13, 2013 12:27:30 PM UTC-4,
wrote:
Thank you Bob for the detailed post. I am flying a Ventus C with
airbrake and flap combination.

Dan G

The answer to your original question varies immensely
depending on type of glider.

For your glider, first consult the manual...
Then, it depends on the type of wingtips fitted.
With the original tips you may find roll control
'uncomfortable' in landing configuration and
rough conditions, in which case don't use 'L'.
With winglets fitted (or short tips) this is
less of a problem in your glider...

Hope that helps !
Best Regards, Dave "YO electric"

Hi, I hope your glider has a trim control, as that should be used to trim
off any unnecessary stick pressure after each change of configuration or
speed. You should not need to push the stick on the base/final turn.


At 23:56 12 October 2013, wrote:
I wonder how other pilots of flapped ships are using their flaps. I don't
u=
se any flap till I am aligned with the runway on final approach. Don't
like=
the sluggish aileron control and the forward stick pressure required on
th=
e dreaded base to final turn. I switch to positive flap on final. Any
comme=
nts ?
Dan G