Did some structural weaknesses show up in the Spectre at the IHLGF? If so have they been corrected?

I seem to remember a comment that something showed up but it would be easy to correct.

From : Don Stackhouse

Well, not exactly. The folks we sent a Spectre VR (the flaperon version) for a beta test had some problems with it. They have never bothered to give us ANY direct feedback after the IHLGF, but a little over three weeks later posted a report on RCSE about it. If you saw that, then you know about as much about it as we do. Needless to say, we won't be using them for beta testing any more.

NOTE: the issues they raised apply ONLY to the initial production version of the flaperon-equipped Spectre VR, NOT TO THE POLYHEDRAL SPECTRE HLG.

They had some problems with the Spectre VR in strong winds and with very strong arms. We'd tested it here in winds, and in both flight and launching tests never got the production version to flutter, but apparently it did out there. There were also some questions about some stress concentrations in the vicinity of the center section and servo cutouts that we're looking into. NONE of these have been a problem in the less windy portions of the country.

They were involved in midairs, and raised some questions about durability of lighter models like the Spectre, implying that the supposedly lighter wing skins can't hold up. In fact, the wing skins of the entire Spectre series of HLG's is the SAME thickness and material as what we used on the Monarch D-lite and Wizard Lite, neither of which are percieved as having a problem with this.

Now it is true that in a collision between two objects of different weights, the lighter object will see a greater acceleration than the heavy one. However, the FORCE between the two objects (the thing that causes the damage) will be the SAME for both objects, and in fact that force will be less than for a collision between two heavy objects. If the skin durability of the objects is the same (which in this case they are), if anything, the lighter object will see, on average, LESS damage than a heavier design.

Note, this is NOT applicable to the small car/larger car safety debate where the factor in question is the acceleration forces imposed on the soft, fragile human beings inside the car. The higher accelerations imposed on the lighter car ARE a factor in THAT case. This is NOT a significant concern in collisions of our models, unless you've somehow managed to hire Tom Thumb as your on-board pilot. In the vast majority of cases, the accelerations imposed in a midair collision involving HLG's, regardless of whether it's a heavy model or a light one, are not severe enough to damage radio gear.

Midairs are strange and nupredictable events, and the damage that occurs depends tremendously on the details of each individual event, such as impact angles and attitudes, exactly where on each model the impact occurred, relative velocities, etc. Engineering theory does not support any such presumed greater vulnerability for lighter models like the Spectre series, and the physical evidence is so far so limited and so anecdotal that at this point it would have to be considered here-say and wild speculation at best.

As I stated above, the poly Spectre HLG does not have flaperons cut in its wings, is therefore stiffer in both torsion and bending, and does not have any of the flaperon-associated stress concentrations around the center section. From all the data we've seen it does NOT have any flutter problems, even with strong arms in strong winds. Likewise, the prototype of a 2-channel poly version of the Spectre VR (the one that Joe Hahn flew at the Nats) has no stress concentrations or flutter, because it also does not have flaperons cut out of the wing.

According to the evidence available to us, the Spectre VR only has flutter problems in very severe conditions. Even so, we have stopped taking orders for the Spectre VR for the time being. It will be re-introduced as soon as we finish increasing the flutter resistance of its wings, strengthen a few key spots in the center section, and re-engineer the VR to allow for wingtip throwing. We're also working on a new calibrated launching system for flight testing here, that will allow us to duplicate in still air the launch speeds that the folks at IHLGF were encountering in the strong SoCal winds.

The poly Spectre is still an extraordinarily good HLG for light and moderate winds, and still does well in strong winds if you add some ballast. It is still available.

Don Stackhouse
DJ Aerotech