Wing span vs takeoff weight

I'm new to rc planes.In a previous post I expressed my opinion about Muliplex EZ Star.Now I'm ready to upgrade to something more durable.

I see people fly all kind of airplanes:slowflyers, acrobatic, gliders,hotliners,etc.

I felt in love with fiberglass hotliners.But they come in different sizes:1.5 to 3 meters span(even more).
I almost bought the plane shown here.It's a custom made 2800 mm by 1250 mm long.

My first concern was the wing span.Is it too long for me?Will it be difficult to fly?
Because I saw a relation between wing span/vs plane weight my questions are:
What is the best ratio wingspan/weight for an all purpose glider(plane) and what is the optimum wingspan to liftoff 1kg of payload(video camera and accesories)?

My conclusion is:2800mm is too much for me.The best size is around 1500mm.

Of course this is only my opinion.

To be more rigorous I found a link on wiki describing relation between wing span and plane weight:

The aspect ratio of a wing is the length of the wing compared with the breadth (chord) of the wing. A high aspect ratio indicates long, narrow wings, whereas a low aspect ratio indicates short, stubby wings

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  • I have a Sonic185 hot liner and she is a handful. landings take forever cause if you dont start using up your momentum, they will just glide by your landing spot. And durability in RC is much different than in full scale. EPP is very durable because of its impact resistance. I challenge you to take a piece of EPP and hit it reasonably hard with a hammer, now take a piece of CF and do the same. The EPP will absorb and disperse the impact force while maintaining structural integrity while the CF will more than likely shatter. That's why EPP planes are recommended for beginners. After a crash, they are more than likely repairable with some packing tape and hot melt glue. A CF model on the other hand will probably be a total loss. Also, I fly 3D. And i am way more comfortable to fly my bipe in an inverted Harrier 20 feet over my neighborhood than to fly my hot liner at 100ft. Quick reactions to problems that arise are not an option.
  • Developer
    I'm not sure why you were asking for advice if you'd already made up your mind.

    Best of luck with your new model - if you survive the learning curve, it looks like a lot of fun.
  • Also ,I remember I forgot my EasyStar in my car in full sun for several hours and it got deformed.Try you hairdrier on this elapor and you will see it will pop like bubbles.
    If EasyStar is so durable maybe Boeing should make their Dreamliner out of elapor foam,not carbon fiber.:)
    Also the new EasyStar should be filled with helium so nobody could crush them.Sorry for my black humor.
  • Michael:Your advice is wise,but...
    unfortunately I already bought my next plane:
    One reason is that we don't live forever to go all the steps to achieve something.
    I hope I made one good choice(it's made of fiberglass but it's not as slim as a hotliner).
    Now to describe my experience with EsyStar:Even an cave man can do it.When you get bored of flying or the situation gets windy you can simply crush it to the ground.This way you will learn bad habits.
  • Developer
    There's a lot of questionable information here.

    A better answer to your question starts by considering your first comment: "I'm new to rc planes", and then continues on by considering that so far you have been flying an EasyStar, and you are "looking for something more durable".

    There aren't very many planes "more durable" than the EasyStar. What sort of durability are you looking for? What other attributes do you want in the model? The Beginners forum on RCGroups is a good place to go if you want lots of suggestions.

    A composite hotliner is not a good second plane, in general. They are not "durable" in most senses of the word, and mistakes tend to be very expensive.

    You asked "My first concern was the wing span.Is it too long for me? Will it be difficult to fly?"

    None of us have seen you fly or know how confident you are. All other things being equal, a longer wing implies more roll damping (note, not necessarily stability). The issue of "difficult to fly" is tough to answer without knowing a lot more about the model; hotliners are frequently "difficult" to fly because they are capable of flying very fast, retain energy well (making landing difficult), and tend to be heavy and very highly powered, leading to complications during launching. In addition, the narrow aspect ratio and small frontal area make it quite easy to lose sight of this sort of airframe.

    If you're hoping for a concrete suggestion; based on reading between the lines above I would encourage you to look at the EasyGlider. It's robust, easy to build, easy to fly, and is a good intermediate step between the Easy* and an entry-level hotliner. You can also beef up the power system and add some weight (brass rod inside the wing spar is popular) to make it faster without spending very much money.
  • So generally, the glider profile will increase your time in the air while decreasing the distance you can cover. since distance you cover includes wind drift, it effectively constraints the operating envelope.

    If you want to provide persistence on calm days, a glider is great, if you want to survey a large area, a faster plane might have some advantages.
    For any wing length, the wider, thicker wing will provide more lift at the same airspeed with less drag.
    Glider are only more efficient because they travel slow, they are not the most efficient design for getting from a to b.
  • wing span is not as good as a tool to use for compairson as wing loading, or power loading. So wing loading is the total weight / wing area. Power load is the Total weight / max engine power.
    To give some info:
    Blanik L-23 Sailplane Wingspan: 16.2 m (53 ft 2 in) Wing area: 19.2 m² (206 ft²)
    max load, 2 passangers

    Piper PA-18 Normal Plane Wingspan: 35 ft 2½ in (10.73 m) Wing area: 178.5 sq ft (16.58 m²)
    Max takeoff weight: 1,750 lb (794 kg) so 820 lbs load.

    The PA-18 has shorter and smaller wings but a larger load, but the L-23 is built to be a glider and therefore more efficent.

    You also need to look at how to load is going to affect the air flow over the plane.
    If you just put a lead brick inside the airplane it might handel better than if you ducktape a camera to the wing.
  • Developer
    The bigger the wingspan the slow the turn radius becomes. Some like the calmer plane behavior, while others do not because of the control delay.
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