Wng loading (Full Version)

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rctt -> Wng loading (7/8/2002 7:29:47 AM)

What is typical wing loading of 1/4 scale acrobatic sport planes //// caps ,edges / extras in oz per sq feet

When does the plane become noticeably heavy ?

How so ? Thanks Ron

I have to shave weight from my extra // need to know how far /// Thanks Ron



WS -> Re: Wng loading (7/8/2002 8:09:21 AM)

[QUOTE]Originally posted by rctt
What is typical wing loading of 1/4 scale acrobatic sport planes //// caps ,edges / extras in oz per sq feet

30-35

quote:

When does the plane become noticeably heavy ?


When you have no power or run out of airspeed. Don't worry about wing loading, it's power loading that's important



rctt -> loading (7/8/2002 4:50:15 PM)

Thanks !
I Should not be shy of power /I took a chance and bought a Fuji BT 50 /Got 100 bucks off to boot in early April !
Since have ran and HAND started many times Starts reliable and is swinging a ZINGER Pro 22 -8 at 6800 not bad !
Should be close to 30 LBS Thrust !

But I''m at 31 oz per sq. Most outhers are in the 27 -29 Range /

Thanks for post Ron



Rodney -> Wng loading (7/8/2002 8:00:54 PM)

Wing loading on big aircraft is not very indicative of how they will fly; a much better measure is wing volume loading.



rctt -> reply (7/8/2002 8:24:11 PM)

Can you explain wing volume loading in laymans terms?
Thanks for the time!!



Ollie -> Wing Loading (7/8/2002 9:10:23 PM)

In horizontal flight lift is equal and opposite to weight. Lift varies as the square of the airspeed so it takes only about a 5% increase in airspeed to accomodate a 10% increase in weight (or wing loading) at a given coefficient of lift or angle of atack.

In vertical flight thrust is opposed to weight and drag but lift is zero. The plane will be accelerated vertically by how much thrust exceeds the sum of weight and drag. In this case a reduction in weight of 10 % will result in a 10% increase in initial vertical acceleration.

Weight reductions will produce much more noticable improvement in vertical flight than in horizontal flight.



rctt -> Reply (7/8/2002 9:27:35 PM)

Thanks ollie !
That makes since ! I'm not now so concerned about flyabilty
But more so to landing speeds /I don't want to have to bring her in to hot!!

In figuring wing volume loading /from rodey earler post // do I
multiply wing area in ft by 1.5 or .5 /he called it power of???
thanks ron



Ollie -> Landing Speed (7/8/2002 10:09:54 PM)

The landing speed is determined by the stall speed plus a stall margin to allow for gusts and wind shear. Lets say that the stall speed is 25.5 MPH at a wing loading of 32 ounces per square foot (corresponding to a maximum lift coefficient of 1.2). A reduction of wing loading to 29 ounces per square foot would result in a reduction of stall speed to about 24.25 MPH.

If this small reduction in stalling speed doesn't do it for you, consider adding split flaps. This is probably a lot easier modification than a much bigger reduction in weight.



rctt -> Small amount (7/8/2002 10:31:30 PM)

Seems like such a small differance for a oz or two !!



Geistware -> Wng loading (7/8/2002 10:40:40 PM)

I have flown planes that are considered heavy and had to be careful because they would float the length of the runway during landings. While I am not sure I understand the downside of a heavy plane, if you have the power and correct CG the plane should handle quite well.



can773 -> Wng loading (7/9/2002 10:18:44 AM)

[QUOTE]Originally posted by Geistware
I have flown planes that are considered heavy and had to be careful because they would float the length of the runway during landings. While I am not sure I understand the downside of a heavy plane, if you have the power and correct CG the plane should handle quite well. [/QUOTE]

For aerobatics lighter planes have many advantages, they will accelerate and decelerate faster into and out of manuvers, they snap and spin more consistently, and over a wider range of airspeeds, they are less critical of correct throttle management, they have better downline breaking, and better upline power, they are easier to fly at constant airspeed, beleive it or not they handle the wind better. In general a lighter plane will outfly a heavier one.

It is possible to get too light though, in which case you have a glider :) For modern pattern models which are not too much smaller than a 1/4 scale Cap, etc. you shoot for 1lb / 100 sq in wing area, that seems to work very well.



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