how to do a 2g turn? help please~

[hyunmi1027]

hello, i'm a newbie and i would like to know how to manipulate the control to do a 2g turn without losing power or altitude in a small general aviation aircraft. i'm learning this in school but dont really have a clear understanding. I know you have to do something like get the airplane to roll 60 degrees by turing the yoke while pulling the yoke and using the pedals that control the rudder, step on the side you are turning. but i would like to know more specifically how to use the control to do this. Thanks alot!

[john_tullamarine]

.. you appear to have the basics .. now a demo with your instructor, some practice and you're away ..

(a) 60 deg bank - balanced level turn

(b) yoke/stick to maintain the bank - stick load will vary among aircraft

(c) yoke/stick back load to maintain the turn - stick load as above

(d) rudder depends on the aircraft but, for most recent light aircraft, will be a touch of "bottom" rudder

(e) extra power to maintain speed - the load factor results in increased drag so you need more thrust

Now see how much practice before you can keep the turn ± 20 feet on the altimeter.

Also fun if you descend ever so slightly and catch up with your own slipstream.

[mstram]

HY,

JT gave you a good descriptiion of the manouever.

Just to add to what he said, and possibly what your instructor has told you.

When the plane banks more than about 20-30 deg, you'll find that you need increasing amounts of back pressure to maintain altitude, as the bank angle increases.

You'll also need increasing amounts of power as the bank angle increases and therefore the drag.

A "touch" of bottom rudder is probably all you''l need in a light trainer, and while co-ordiinated flying is an important habit to develop, the rudder input will probably have the least amount of effect on your steep turn, especially in a 172/piper, etc where adverse yaw is almost non-existent :)

Hopefully your instructor has also emphasized that you should be flying this manouver at Va speed, to avoid exceeding the load factor.

Also hopefully you have been shown stalls, accelerated stalls and spiral dive recovery ?

Have you started ground school yet? Have you covered the aerodynamics of the turn yet ?

Mike

Some further info :

http://142.26.194.131/aerodynamics1/Lift/Page10.html
http://www.pilotsweb.com/principle/load.htm

http://www.av8n.com/how/

[john_tullamarine]

Limiting yourself to Va for normal steep turns in a light aircraft probably is a bit conservative.

The current rules for load design are at FAR 23.333 (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=eeadceca504f8b1f881cb943f8d0888e&rgn=div8&view=text&node=14:1.0.1.3.9.3.70.8&idno=14) (and the envelope picture is a bit easier to read in this (http://a257.g.akamaitech.net/7/257/2422/04mar20050800/www.access.gpo.gov/ecfr/graphics/pdfs/ec28se91.001.pdf) download) while the required positive load factor is given at FAR 23.337 (http://ecfr.gpoaccess.gov/cgi/t/text/text-idx?c=ecfr&sid=eeadceca504f8b1f881cb943f8d0888e&rgn=div8&view=text&node=14:1.0.1.3.9.3.70.10&idno=14).

Given that the typical light aircraft has trouble maintaining a level turn at bank in excess of 60 degrees, I think that the risk of a structural overload probably is not great ....

[rekop]

Just a quick comment.

Seems a little strange to me to be asking this question here. Off course all questions are welcome but isn't your instructor able to give you enough instruction to do the 60deg 2g turn?

[jayteeto]

He doesn't say he is actually flying yet. Learning in school could be fltsim maybe??

[ProfChrisReed]

You could go to a gliding club, where 2g (60 degree) turns would be quite normal in a narrow thermal.

The procedure in my 18m glider is a little different from a powered a/c:

1. Increase airspeed to 55 kt (50 kt is possible, but might make the handling a little sluggish). More likely, pull back from 75 kt to 55 kt as I climb into the turn.

2. Full into turn rudder while banking to 60 degrees.

3. Increased back pressure on stick (nearly to backstop) as bank increases.

4. Once in the turn reduce rudder - a little out of turn rudder might even be required to maintain balanced flight.

At this point I should be a comfortable 2-5 kt above stall speed.

To maintain height in this turn I would need to be in a 2-3kt thermal - but if I turned this tightly I'd hope it was 4-10 kts!

[DragonflyDH90]

I a level balanced turn, there should be almost no requirement for rudder at all.
Rudder is only required when using the ailerons as this is when adverse aileron drag and the associated yaw is present.
You should not need to provide a continuous rudder input at all.
If any continuous input is required, as ProfChrisReed has mentioned, it may be the smallest (read very small) out of turn rudder, as most aircraft tend to want to roll into the turn you tend to stop this with a little out of turn aileron and as already mention any time you use aileron to balance a little rudder is required in that direstion also.

Sorry to get all technical but too many people leave a continuous input on the rudder in a turn putting the aircraft out of balance, and then proceed to wonder why, or just plain ignore it.

[andyb79]

Can i just say with regards to this. "I should be a comfortable 2-5 kt above stall speed."

:eek: :eek: :eek: :eek: :eek: :eek: :eek:

[shortstripper]

Just a quick thought ... do you really mean a "2g turn"? or do you mean a "rate 2" turn?

SS

[stiknruda]

One of the hidden benefits of the biplane type that I campaign is that when the cabane strut is parallel with the horizon, the aircraft is at 60 degrees aob.

So all I have to do is pull OR push until the G meter says +2 or -2 and as long as I'm doing anything between 90 and 150mph and I keep cabane in the right place I should fly a level turn, erect or inverted.

Due to precession and p-factor the outside turn can be flown feet off.

Stik

[ProfChrisReed]

Apologies to andyb79 if my "2-5 kts above the stall" reference caused concern. In gliders, you won't be able to soar if you're not comfortable flying this slow - a common thermalling technique is to pull back until you feel the pre-stall buffet and then relax the stick pressure slightly. Every knot above the minimum possible speed means you fly a larger diameter circle, and thus fly in less good lift.

Bear in mind that (a) glider pilots are trained for this, and (b) recovery in a glider from an *expected* (more accurately in these circumstance, incipient) stall simply requires a relaxation of back pressure with no loss of height (because you're flying in lift). Even if you get caught out and stall fully (e.g. through a gust), recovery should be almost immediate with a height loss of well under 100 ft.

I imagine that someone who flies with a large lump of metal in front might want a greater margin of speed - never tried it myself.

The challenge in steep turns is flying co-ordinated - with long wings adverse yaw is really noticeable - but once you've got it a 60 degree turn is no harder than a 30 degree turn.

[BigEndBob]

In typical Cessna/Piper you will also find that a liitle more backpressure is required in left turn as opposed to right, due to slipstream effect...usually results in overspeeding in right turn because increase in power conterbalances the need for rudder to maintain balance and there is a component of lift from prop..all reduces drag therefore easier to maintain speed.