On the slope I’ve been fielding this question a lot. It is only natural as I think I was the only member of my local F3F racing club that didn’t get the memo “Not to purchase the Redshift”.
In my talks with the designer I learned that only about 30 of the redshifts were legally sold. And as I bought 3 (legally through his dealer network) I can say I have experience with 10% of the market. There are no other Redshifts flying in my area. If you want to learn the painful details of these models you can find then documented here.
https://forum.alofthobbies.com/index.php?tags/redshift/To save you from having to read all that here is a short synopsis. The OEM had a lot of quality issues with the manufacture of the airframe. The Redshift used Bowden tubes to drive the tails. The geometry of the tail surfaces forced to use of too small a control horn This in turn forced the use of sub 4mm servo arms. The called out servo did not fit the location in the wing and the killer was that the redshift exhibited sever directional instability as a result of far too small a tail volume and far too much forward area ahead of the center of pressure.
Now I loved how the 19:1 aspect ratio wing held its energy through a turn and how hard it was to initiate a stall. You might have read with the Redshift how much I loved the wing, the rest of the airframe not so much!
Let me state that I’m not nor have I ever been a member of Aeroic or sponsored Aeroic pilot. I have found my name and some of my art work in the Aeroic documentation. I’ve asked that my name and my artwork be removed from Aeroic’s documentation. And to date the owner has removed the offending references when I’ve asked that it be removed. Please let me know if you find and reference to myself in the Aeroic documentation as I will want it removed.
With that out of the way let's look at what we have with the Spada. I don’t know why the designer is shying away from calling the Spada an F3F racer. (Ok, I do and will go into that a bit later) So to tackle the first 800lb gorilla in the room it is a full fledged F3F racer!
Now luck would have it, I was at the USA importer when the first prototype landed in the USA destine for Aeroic’s test pilot. I only saw this bird for about 5 minutes and was not allowed to measure things or take photos. I was asked not to publish my opinions of what I saw until after Aeroic had posted their build on Aloft’s forum. As Red is on the Aeroic team and he has posted his build on Aloft’s forum. I’m assuming that this clears me to post my findings.
https://forum.alofthobbies.com/index.php?threads/spada-gofast-3m.3734/Well, a lot has changed and unfortunately a lot hasn’t changed. Let's try to go over the good points as I saw them. First the wings look real close to the same as the Redshift. That is they are basically what I think Wil Schuemann was describing in his paper on the inward span-wise flow as the wing stalls. This results in a rather straight taperedTE coming out almost perpendicular to the fuselage. Or put another way all the curve that keeps the wing compliant with the elliptical lift distribution is fond in the LE. I know nothing about the hinging the servo placement and the geometry used for the wing surface actuation. But it looks fairly close to what we saw with the Redshift.
The new fuselage is a mixed bag. The designer has done away with that grossly oversized Jimmy Durante nose. This looks like it is bringing the fuselage cross section in line with modern practices. It also looks line the side area ahead of the center of pressure is about 3/4 to 2/3 of the Redshift’s. All good things! I looks like the designer has chosen to ignore the benefits of the inverse pressure gradient we often get with straight parallel sides at the wing junction. Also the tail boom looks to be much too small to be practical. This is causing issues with the actuation of the V-tail. Now I did notice that the tail boom is sporting a rather triangle cross section. This is great news as historically the designer had used round tail booms thinking that the primary loads are torsional. The tail boom of this designed have historically performed rather poorly when it come to landing loads. Seeing how the triangular tail boom on the TUDm Freestyler 5 & 6 performs I’m happy to see Aeroic adopting it for their new 3 meter ship.
Now that I think Aeroic has addressed the area ahead of the center of pressure as well as can be expected and still house the radio I took a glance at the tail volume. It looks to me that the wetted area of the tail is much larger than the tails of the Redshift It looks to me that the designed did this by lengthening the span of the V-tail by 60mm. If this correct the wetted tail area of the Spada is close to that of the Freestyler tail (large option). Like I said I wasn’t allowed to measure anything so I can’t actually say much on the tail volume. But based of what has been published from Aeroic there might still be an issue with the tail volume as Aeroic has said that the V-tail junction was kept at a rather flat 100° for a wing with such a high aspect ratio! (I think I've said that for wing with over 16:1 aspec ratio that most will respond best with a V-tail junction of less than 100°.) You can see some loss of directional control at low speeds in some of the posted videos. Not having flown of set up a Spada this might not be a fair assesment as the source of the problem.
Now what really is concerning me is the actuation of the V-tail. First I have concerns with the way the spherical joints are added the V-tail arms. The hardware supplied is in my opinion inadequate in that it allows the sphere to move a lot (as a function of the total motion available) because of the thread clearance between the screw shaft and the sphere. The solution to this is to use a studded sphere. Now before anybody scream that there are still screw clearances, please remember that the thread installation torque will hold the stub centered on the pitch diameter of the threads. And the killer is the same as what we had this the Redshift. The V-tail arms are to short to stay inside the tail bulb of the fuselage. This will again force the builder to use servo arms that are 4mm or less. Why have done this is starting out with a clean sheet design?
Oh, and why Aeroic doesn’t want to market this as a F3F racer. Well, it is because if it is shown that Aeroic has again made a sub par F3F racer. The designer can claim no he hasn’t as the Spada isn’t an F3f racer, well not in the marketing literature!
