Wright Stuff B

[a.novak]

Does anyone know if TSA will let you transport a big container with my plane on it as a carry on on the airplane? I am from Alaska so we have a ways to travel with it!

[coachchuckaahs]

If you want/need to carry on, I would suggest a removable wing and stab, much like Bill Gowen's Finney designs. Airline can deny boarding if carry-on is larger than their check stands, and a box large enough for an assembled plane surely would be. Stab can be made removable just like wing by having posts insert into tubes or sockets on the motor stick.

Or pack it really really well for checking.

Coach Chuck

[a.novak]

Thank you

[CMS AC]

Honestly I'm just worried about 1) Airport security, and 2) Air pressure difference at high altitudes?

[bjt4888]

Here's a link with pictures of the pros travel boxes:

http://www.hippocketaeronautics.com/hpa ... 2#msg42032

Of course, you don't need anything this elaborate, but this demonstrates the disassembly and packing. The clear plastic side "door" is to let TSA view the scientific equipment without opening the box and potentially damaging.

Brian T

[a.novak]

Thank you! Two years ago in the event elastic launched gliders I used a box similar to that design for transporting, but of course it was much smaller than the wright stuff planes. This really helps thank you

[jgrischow1]

Jgri,

Did removing 6" from the tailboom and moving the clay ballast cause the CG to be about 1.75" - 1.875" forward of the wing TE? If so, after setting the wing incidence to about 1/4", and the other trim settings per my earlier post, and winding the rubber fully (and backing off enough turns to keep off the ceiling), hopefully you'll be seeing flights in the 2:00 to 2:30 range.

Good luck. Be sure to post any other questions you might have.

Brian T.

Thank you.

We finally got some chances to run some tests. With your recommended settings, my kids could not get the plane to fly stable. However, after moving the wing forward an inch or so, it seemed to correct the issue. The CG is now only slightly in front of the TE, though, no where near 1.75 inches.

Our incidence is also more than 1/4 inches, and has always been (even with our old configuration). Not sure why, but the plane never seemed to climb unless it was 5/16 or more.

In any case, after seemingly getting it to fly in a stable manner, we had some interesting issues. At times, the plane would still fly in the manner I described pre-changes: it starts to climb and then descends after a half turn or so and hits the ground. However, this time it is only happening with a decent amount of torque. With less torque, this isn't an issue. Unfortunately, my kids have not recorded any torque data this week, so I only have visually observations to go by, but let me try to explain what I mean: We will launch the plane with, say, 1000 turns of .065, backed off 25. It does the half turn/go to ground thing. We then pick the plane up and re-launch it with remaining turns, no re-winding or anything, and it flies nice and stable for 45 more seconds. Not sure what's going on, but I've seen this several times, and it seems there is a relationship between launch torque and it flying erratically like this.

We have had another issue since re-configuration: At times, it will fly fine for a few turns, and then just suddenly stop turning, and fly straight into a wall. This didn't seem to happen pre-configuration.

Again, both of these issues only happen sometimes.

One more thing I just realized: our plane has no washin. It didn't before and it doesn't now. Would it help if they added some, should they add some, and how would they to an already built plane? Break the wing?

Thanks for all the help.

[coachchuckaahs]

The behavior sounds to me like too much torque or lack of stability. 50 unwinds may not be enough, depending on the prop you are using. We saw this behavior last year with the cut down Ikara non-flaring prop.

We are typically unwinding to about 0.2-0.25 oz-in this year. 50 unwinds on full rubber does not seem to be enough. We are using somewhat thinner rubber than that (maybe 0.056", or 0.372g/in), and that will wind somewhere around 3000 turns, and then unwind perhaps 200-250 turns. With your thicker rubber, its at even higher torque.

Just guessing, your rubber can probably take in the neighborhood of 2000 turns, and then back off at least 200 turns. Be sure to lube, and to stretch to about 7X nominal length. Wind about half at full stretch, then start walking in.

Can you describe the stability issues you had with the forward CG? By moving the wing forward, you reduce stability (moved CG back relative to the wing). SO maybe describe the stability issue you saw with the forward CG. Did you increase incidence until you got a stall on letdown, then decrease a little?

Your incidence would indicate a decent CG, unless you also have stab positive incidence. We are running 0 on the stab, about 9-10mm on the wing.

Coach Chuck

[bjt4888]

Jgri,

Yes, most likely you need about 1/16" to 1/8" of left wing washin to prevent rolling to the floor during the initial high-power portion of the climb. Yes, partially cut through the left LE spar near the wing mid point and gently crack and hold about twice as much washing as you want and apply a drop of CA. Hold for about 90 seconds (if fresh CA) and the spar will partially return to where it was and you will have a starting point for washin.

Agree with Chuck that a detailed description of what you are observing when the CG is set to 1.875" forward of the wing TE.

Winding to 90% full turns measuring max torque (should be about .8 or .85 in oz) and backing off to a reasonable launch torque (initially .25 in oz) are critical steps to testing. Winding to 1,000 turns and backing off 50 is massively underwinding and then significantly short of the correct backoff turns (depending upon the length of the 1/16" motor). It is possible that the winding they are currently doing is resulting in a launch torque in the .35 to .45 in oz range ( based upon our test results) and, without left wing washing, this much torque can easily result in a banking turn to the floor.

How much left wing offset, stab tilt, tailboom offset and thrustline offset does your airplane have?

Brian T

[bjt4888]

Jgri,

One more note on cracking LE to add washin; make partial cut through at a shallow angle relative to the spar lengthwise direction. The resulting scarf joint will be pretty strong.

Brian T