Hawks Hobby Orbital Transport question <glider dihedral>

[George Rachor]

I've had a Hawks Hobby Orbital Transport for years. A hoppy shop owner built it. The glider has never flown well. I discovered that the glider wing is one piece forming both wings with no dihedral. Wasn't it suppose to be built with dihedral like the original Estes model?
George Rachor

 

[lr64]

A delta wing at a positive angle of attack has its own dihedral effect. That may be why he built it straight. Some delta wing airplanes even have anhedral to counteract excessive dihedral effect from the delta shape. So-called conical camber probably acts in a similar way, in addition to its other advantages. You can see it here:


Did he use the same amount of up elevator as the stock kit? The amount on the Estes looks like too much to me. I may know more soon, as I have the kit for the tiny Semroc version. (Not that I don't already have kits for a zillion other flying things.)

 

[OverTheTop]

Some aircraft have so much equivalent dihedral forces, due to airframe aerodynamics, they compensate with negative dihedral with the wings. The Harrier Jump Jet was a prime example of this:

 

[aerostadt]

The Orbiter wing on the original Estes Orbital Transport is dihedral. See Step 17 of the instructions.
https://www.spacemodeling.org/jimz/estes/001259_ORBITAL_TRANSPORT.pdf

 

[lr64]

Yes, and I wonder why it has so much dihedral and up elevator. I should think using less and maybe moving the cg back a bit would result in a better glide. Maybe even use conical camber in the glider? Note that the following design has a low wing, conical camber, and no dihedral, but presumably it flies ok.
https://outerzone.co.uk/plan_details.asp?ID=11545

Has anyone messed around with mods like these?

 

[Titan II]

Note that the following design has a low wing, conical camber, and no dihedral, but presumably it flies ok.

I have one and it flies great.

 

[lr64]

I have one and it flies great.

The F-102 Jetex model? Sounds like fun.

 

[ReynoldsSlumber]

An excess of roll stability may be desirable for quick, reliable transition into gliding flight after the ejection charge goes off. Likewise to be resistant to wind gusts. It's similar how it is with rubber band-launched gliders (Whitewings etc.): when the plane slows down to stall speed after the high-speed launch, it's vulnerable to going into a spin rather than settling out wings-level.

 

[DeWain]

I thought I remember the pictures on Hawk's Hobby's website showing dihedral and elevators on the Orbiter/glider.

This thread shows a model built with dihedral and elevators (so that it probably the way that the kit was designed):
https://www.rocketryforum.com/threads/hawks-hobby-super-orbital-transport.111544/

 

[lr64]

I'm wondering if the glider wiggles as it flies. That could be dutch roll, implying that there's too much dihedral or too little vertical stabilizer.

 

[Titan II]

The F-102 Jetex model? Sounds like fun.

Yes...from the OZ plans. I have several different models and use TSP motors.

 

[lr64]

Very nice. Does it pitch up under power? My leading candidate for a Jetex 50 test model is a modestly enlarged version of that wing with no fuselage, with the motor on top, and two fins instead of one.

 

[Titan II]

Does it pitch up under power?

No abrupt pitch up.