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ThanasisK
05-22-2004, 09:36 PM
Hi,
this may sound a bit silly but how exactly you perform a barrel roll in il2?
-training: roll + full opposite rudder
- online tip #1: roll + pushback + little opposite rudder
- tailspin: roll 45 pull up roll 90
- online tip #2 : just roll + little pushback no rudder
-online tip #3: roll + same direction rudder.

Im a bit confused as of what a barrel roll is. Any input guys? Thanks in advance for your patience

ThanasisK
05-22-2004, 09:36 PM
Hi,
this may sound a bit silly but how exactly you perform a barrel roll in il2?
-training: roll + full opposite rudder
- online tip #1: roll + pushback + little opposite rudder
- tailspin: roll 45 pull up roll 90
- online tip #2 : just roll + little pushback no rudder
-online tip #3: roll + same direction rudder.

Im a bit confused as of what a barrel roll is. Any input guys? Thanks in advance for your patience

lil_labbit
05-22-2004, 09:52 PM
a barrel roll is a ....

Imagine a cylinder above the runway paralel to it...
you come in over the runway... (with ENOUGH SPEED but not too much)
you bank right (like 45 deg) (that would make you go right-turn
do a pull up on the stick too... that would make you go up-rightway - THATS 45deg to your right and ALSO 45 deg up...
NOW when you reach THAT
do a PULL BACK (Center stick- but back!) and keep that stick there WITHOUT rudder...

BARREL ROLL

adjust your rudder to keep the trajectory (vector) over the runway....

It's NOT easy - but ya CAN do it...

http://members.home.nl/lil.labbit/lilseesya.jpg
Night is better than Day

Blottogg
05-23-2004, 12:14 AM
Thanasisk, a barrel roll is a combination of roll and backstick pressure, and called a barrel roll because the resulting flightpath looks like it's wrapped around an imaginary barrel. By comparison, an aileron roll is a roll without any backstick pressure, and just spins the aircraft around its longitudinal axis (the line going from the prop to the tail.)

We'd instruct barrel rolls by breaking them up into quarters. Start wings level on the horizon, and pick a point on the horizon to the left or right of the aircraft that you want to roll around. Pick a point just outside the canopy bow...closer to the nose for tight barrel rolls, closer to the wingtip for wider ones. Clouds and mountains work well IRL, just pick something distant. During the maneuver, you'll try to hold this point in the same place on your canopy (I'm assuming you're flying cockpit on.)

For the first quarter, pull back on the stick, and roll towards your point. The first quarter requires a lot of pull, and little roll, because gravity is pulling through your seat to start with. Towards the top, you can start easing off the pull, and adding more roll.

The second quarter needs less pull and more roll to compensate for gravity, now pulling through the canopy. Try to hit wings inverted as you pass through the horizon.

In the third quarter you need to start feeding in more back pressure, while keeping a fairly high roll rate. This is where new students get into trouble, either rolling too fast/pulling too softly and "dishing out", or rolling too slowly/pulling too hard and "burying the nose". Try to get the nose as low on the downside as it was high on the upside (remembering to keep your reference point at the same spot on the canopy will help.)

The last quarter requires you to start reducing roll rate, and increasing pull until you start approaching the horizon. If everything else has gone right, your reference point should end up in the same spot on the canopy as it was when you started.

Aside from being a good aircraft control exercise, barrel rolls are a good way to keep from being shot. Rolling and pulling targets are harder to keep a pipper on than targets that just pull straight, or aileron roll only.

We taught jet students not to use rudder, but it might be acceptable to use top rudder (left rudder in a right bank, right rudder in a left bank) to help keep the nose up in props. Eco-Dragon would know more about that than I.

Sorry for the long reply. Hope this helps.

Blotto

"Speed is life." - Anon
"Sight is life. Speed is merely groovy." - "Junior"

El Turo
05-23-2004, 12:40 AM
Blotto's got it nailed down nicely.


Here is a little article I dug up from another forum wherein I responded to something similar.



=====================

Barrell roll: The magical manuever.

Used either offensively or defensively. Primary use is
to slow horizontal progress by introducing vertical
elements to forward travel. By "corkscrewing" you will
be forcing your plane to travel a greater distance to
move forward than someone who is flying straight and
level.

Maneuver is initiated by pulling back on the stick and
including an element of roll to either left or right.
The farther to the side you move your stick, the
tighter the roll will be. The farther back you pull
the stick, the wider your roll will be. The farther
from center you pull the stick, the more violent the
manuever will be.

The magic ingredient to the Barrell Roll is to include
just a touch of OPPOSITE rudder
to keep your nose "up" in the topmost
portion of your roll.

Generally, you want to make a barrel roll with more
elevator than aileron so that the corkscrewing effect
has a bigger radius to exaggerate the diference
between straight/level flight and your barrel roll.

Usually, you want to use more elevator (back pressure)
as you come on the "up" side of the roll, and more
aileron roll (left/right on stick) as you come "down"
(inverted) side of the roll. This will keep your nose
relatively above the horizon. If your nose dips below
the horizon more than 50% of the time you will begin
descending and building up speed which is contrary to
what the barrell roll is supposed to do for you.

In a defensive situation, where you have a bad guy on
your six, you want to use the barrell roll to spoil
his guns solution and to try to force an overshoot.
Unless he does the same thing you are, he will try to
get a gun solution on you and will be too fast to stay
behind you.

The severity/sharpness with which you decide to
perform the manuever depends on one major factor...
how much closing speed does your bad guy have? Keep in
mind the faster he is RELATIVE to you, the less
violent of a manuever you need to use because the
faster he is flying, the less manueverable he is going
to be to begin with. If your bad guy is relatively the
SAME speed as you, then you should elect to perform a
stronger manuever to shake him. I recommend that you
use more elevator than aileron to make the manuever a
"bigger" corkscrew. Watch your opponent and see what
they do. If after a time they pull up and away, then
you may stop the manuever and try to get into an
offensive position. If they are too fast to stay with
you (like in a bounce from above), then they will most
likely pull up and away from you to begin another
bounce.

Using the barrell roll on offense:

You are coming down on your target from above and
behind at too fast of a closure speed to stick with
them and/or get a firing solution.

Instead of wasting all your built-up energy by cutting
power and/or dropping flaps to just slow down, use the
barrel roll to conserve that energy and still stay
behind them!

A nice big (high)lazy roll will trade your speed for
altitude, give you a great view of your target below
you as you go inverted at the top of the roll, and
still allow you to convert that gained altitude back
into speed to close on your target again. By trading
your excess speed for altitude, you still retain the
energy advantage and have more options than your
opponent who is forced to remain defensive.

Be patient, and always strive to use as little energy
as you can and still pull off the manuever. Sometimes
the least amount of energy you can afford to pull is A
LOT, but often times it is much, much less than a
maximum performance turn.

More on the Offensive Barrel Roll:

If you are coming down on your opponent with superior
energy (lots of speed) and you recognize that you are
going to overshoot him, you can elect to use a barrel
roll to conserve your energy by trading altitude
(using the vertical) to slow your horizontal progress
down, establish yourself above and behind your
opponent once more, and still have a great visual
acquisition on them (because you are inverted at the
top of your roll).

The idea is that you are looking to achieve a gun
solution much faster than just zooming back up into
the sky back on your perch to set up for another BnZ
pass. This move is a calculated risk and a decision
you must make. You are trading safety for the
opportunity to score a killing blow.

This would be an especially valuable manuever if you
have *already* scored hits on your target and damaged
them severely... because they aren't going to be doing
much more other than just trying to stay airborne, let
alone get a firing solution on YOU.

This is also a good manuever to use on bombers that
are relatively unmanueverable as well. You can get
multiple gun passes on your bad guy in rapid
succession by using this.

Note: You'll have to make a judgement call on just
how much rudder you're going to want to use...
remembering that the more rudder you use, the more
energy you are going to burn. If you are concerned
about the amount of E-bleed, use more aileron (and
more vertical) than rudder to get yourself around the
top of your roll. By exchanging speed for altitude
you have a more efficient retention of energy.

==========================

HI/LO Yo-Yo: An energy conserving manuever designed to
allow a faster, lesser-turning plane to "cut" the
corner and turn inside an opponent.

Initiated by banking the aircraft and pulling back on
the stick. (Anything but wings level or perpendicular
to the horizon works) Small corrections can be made to
ensure that the turn does not flatten out into a
purely horizontal turn.

Instead of a flat turn, an vertical element is added
into the maneuver to make the path of the aircraft
become eliptical or "egg shaped". The aircraft becomes
slower as it comes nose high into the turn, shortening
turn radius while exchanging speed for altitude which
makes for the smaller radius turn at the top of the
"egg". On the inverted "down" side of the turn the
aircraft exchanges the built up altitude for speed
which will make your turn a big wider at the bottom of
the "egg" curve. As the pilot continues to pull
through the turn, the nose will rise and fall below
the horizon, thus the term "yo-yo".

Why does this work?

Visualize two hoops laying on the ground from a
top-down perspective. One hoop is slightly larger than
the other, representing a larger (or "worse") turn
radius comparatively.

Now, pinch the larger hoop slightly and lay it back
down over the smaller hoop. Whereas initially, the
larger hoop never crossed the smaller hoop (no firing
opportunities), this new "eliptical" hoop will cross
the smaller hoop in at least two places, maybe four.
These are your firing opportunities as you slash
through your opponent's turning circle.

The horizontal-flat turning pilot is pulling back on
his stick, burning energy as fast as he can to evade
you and/or get on your stick.

The yo-yo pilot is continually exchanging altitude and
speed for a more efficient manuever. This will
ultimately lead to the yo-yo pilot having the
advantage as the flat-turning pilot runs out of
airspeed and options.

Effectively, this allows a plane to out-turn a
supposedly superior turn-fighter and is a tactic
employed by many German pilots in WWIIOL to get the
edge on Allied pilots.

However, if you ALSO have a superior turn fighter AND
you are ALSO Yo-Yo turning, you will get the edge on
him anyway if he decides to turn with you.

Remember though, you do not necessarily want to pull
the stick back to your stomach and max-performance
turn.

You want to always try to keep your ride close to its
corner velocity. In the Hurricane and Spitfire, that
is right about 200-220mph (just a bit higher for the
Spitfire than the Hurricane). In the Hawk, around
250-300kph. If you get below this or above this
figure, you will not be turning at maximum efficiency.


This takes a LOT of patience and practice to pull off
because your instinct is to pull back as hard as you
can 100% of the time.

Watch your AoA and try not to exceed 10 degrees.

Watch your speed and try to keep it close to
200mph/300kph.

If you are above these speeds and blacking out in the
turn, and you just HAVE to keep turning harder for a
shot pull back the throttle and you should relax some
of the G-forces on your plane/pilot and be able to get
that snap shot.

Test this out offline or at a rear area:

Bank your plane to anything but wings level (loop)or
perpendicular to the horizon (flat turn).

Pull back on the stick moderately like you were going
to flat turn aggressively.

The nose of your plane will rise and fall above the
horizon without you doing ANYTHING else as you
continue to turn in this elliptical fashion.

Over time, your plane has a tendency to want to
flatten out its turn a little bit... which you offset
by inputting just a little bit left/right stick
pressure to increase or decrease the angle of your
turn.

Effectively, as you get slow at the top of your "turn"
you will be slow and have a small turning radius.

When you are at the bottom of the turn and fast you
will have a little wider turn radius...

Which is what gives you this "egg" shaped curve that
you are flying.

If your opponent continues to fly a flat turn you will
easily "cut the corner" on them and have multiple
firing opportunities.


*AS FOR RUDDER USE*

You don't want to use excessive amounts of rudder or
flaps in this manuever unless you've found yourself at
or approaching stall speeds at the top of your turn
(which you shouldn't be at anyway).

Rudder use should be limited to slip correction
(keeping this at or very near to zero will maximize
your turning ability and actually SAVE energy).
Anything more or less than zero slip means your plane
is flying slightly left or right of center, thus
increasing the amount of surface area it is presenting
to the oncoming air flow. Even just a couple degrees
of slip will rob you of a TON of energy.

You can kick in combat flaps at the top of your turn
if you are getting down to stall speed or dangerous
Angle of Attack limits (10+ degrees) to help you get
"over the hump".

Just make damn sure you raise them back up as you are
coming back "down" the manuever so that you get as
much speed and energy back as you can for the next
trip back "up".

Callsign "Turo" in IL2:FB & WWIIOL
______________________
Amidst morning clouds
Fork-tailed devil hunts its prey
Lightning strikes, süsse träume.

Henkie_
05-23-2004, 02:41 AM
Just pick a point on the horizon and draw a circel around that point with the gunsight.

That will make the barrel roll. http://ubbxforums.ubi.com/images/smiley/16x16_smiley-wink.gif

cu http://ubbxforums.ubi.com/infopop/emoticons/icon_smile.gif

EAF274_Henkie

ThanasisK
05-23-2004, 10:43 AM
Thanks for all the inputs guys, greatly appreciated. http://ubbxforums.ubi.com/infopop/emoticons/icon_cool.gif