Official Freewing B-2 Spirit Bomber 86" Twin 70mm EDF Jet

[GliderGuy]

Here’s a company that builds a position control box for the RV-10 type aircraft. They use the term REFLEX for negative (up) control surface position.

https://www.aircraftextras.com/FPS-PlusReflex.htm

Good ‘nuff for me as are the other posts which define reflex as up control position. I won’t hesitate to use the term going forward to indicate “up”.

Therefore, for the B-2…

Setting the inner surfaces to 8 mm reflex and the outer (non-clamshell) surfaces to 4 mm reflex as a starting point for a maiden is a perfectly acceptable use of the term REFLEX…IMHO.

-GG

[xviper]

Full-scale sailplane pilots use the less ambiguous terms “positive” and “negative” when discussing flap and aileron settings for take-off and landing configurations.

Flap down or aileron down with flap down = positive configuration

Flap up or aileron up with flap up = negative configuration

Sailplane aircraft owner’s manual often just say flaps down or flaps up.

Very often negative flap and negative aileron is called for in the POH the first part of then take-off roll to enhance aileron control. Going back to this configuration for the last part of the landing roll.

-GG

So true for a plane like a sailplane, which can have flaps and ailerons. However, this plane, being a flying wing, doesn't really have flaps and ailerons. They only used those terms to differentiate the inner and outer control surfaces. Regardless of them being "innies" or "outies", they are still elevons and they should have called them inner and outer elevons. That being the case, I've always considered "reflex" as being UP elevator and nothing really to do with flaps/ailerons. All my other flying wings have always referred to using some "reflex" to aid in launch. This was also suggested for the A-10 models.

[xviper]

I guess my thought with the steering gyro is to be able to adjust gains independently.

But I would definitely say I'm not familiar enough with the gyro yet.

The thing with the E-52 RUD gyro is that those who have connected the master gain have indicated that there is little difference between 100% and 0% on the "air" rudder. So, adjusting that gain on the gyro isn't really all that important for flying. What I'm sensing from those who have played with it, have suggested that perhaps the AIL gain could be lowered by a few % and the ELE gain could be raised by a few %. What happens with the RUD gain appears to be of little consequence to the "flying" rudders, only to the steering ground rudder. To be able to adjust the gains independently, one would need the programmer.

[GliderGuy]

I always thought that "reflex" was UP elevator.

Full-scale sailplane pilots use the less ambiguous terms “positive” and “negative” when discussing symmetrical flap and symmetrical aileron settings for take-off and landing configurations.

Flap down or aileron down with flap down = positive configuration

Flap up or aileron up with flap up = negative configuration

Sailplane aircraft owner’s manual often just say flaps down or flaps up.

Very often symmetrical negative flap and symmetrical negative aileron is called for in the POH the first part of then take-off roll to enhance aileron control. Going back to this configuration for the last part of the landing roll.

AND….many POH’s avoid the confusion all together. The POH simply lists 1, 2, 3, 4, 5, 6, flap position markers. 3 may be 0 or neutral flaps with 2 and 1 = symmetrical flap up/aileron up positions and 4, 5, 6 = symmetrical flaps down/aileron down.
-GG

[SanExup]

I guess my thought with the steering gyro is to be able to adjust gains independently.

But I would definitely say I'm not familiar enough with the gyro yet.

[xviper]

My understanding is they are the same? May need to research it. Wash out is twisting the wing to reduce AOA at the tips and reflex is adding up ailerons to do the same.

I always thought that "reflex" was UP elevator.

[Evan D]

My understanding is they are the same? May need to research it. Wash out is twisting the wing to reduce AOA at the tips and reflex is adding up ailerons to do the same.

[mongo]

Thanks for the enlightenment of the "reflex". It's just ingrained in my head and it's easier to say.
Agreed on the second point, but I have a couple laying around, I'll see how I feel about it after the maiden. (If I ever get mine. It's currently "lost in Yonkers [Singapore]".

isn't twisting the wing so as to have less AOA at the tip than the root called Washout?

[Gravythe clown]

I think you might be mixed up about the gyro gain. High gain causes control surface induced oscillation as speed increases. Wind buffeting that causes your bouncing around should get worse as you lower gain, but that's another discussion.

I had the LX YF-23. Flew it twice and barely got it back in one piece. I gave up on it and gave it away to someone who kept it as a static model.

Yeah I got that, it was oscillating more than I liked last weekend even at low speed. So today I thought I would lower the gain off the git (bad day to play around with it because of wind). I really wont Know where my happy point is until I get a clean air day.

I will say the first flight on the YF-23 had me excited to fly it more. This let me know she is tamable.

Gravy

[xviper]

Good reports...

Reflex... We are using the term incorrectly. Reflex is twisting the wing to have a smaller angle of attack compared to the root. When we add up elevon we are just adding pitch up, we are not adding reflex.

I really like the Assan steering gyro. I have them in more than a few planes. That said the gyro in the B-2 does a good job of keeping it straight. I think that it has so much gain programmed in that it does a good job. It does so well I don't see any reason to bypass steering on this plane.

Thanks for the enlightenment of the "reflex". It's just ingrained in my head and it's easier to say.
Agreed on the second point, but I have a couple laying around, I'll see how I feel about it after the maiden. (If I ever get mine. It's currently "lost in Yonkers [Singapore]".

[Evan D]

I agree 100%.

I think you might be mixed up about the gyro gain. High gain causes control surface induced oscillation as speed increases. Wind buffeting that causes your bouncing around should get worse as you lower gain, but that's another discussion.

I had the LX YF-23. Flew it twice and barely got it back in one piece. I gave up on it and gave it away to someone who kept it as a static model.

[xviper]

Got 2 more today. Wind was choppy and switching between S and E. Take off going S into wind, 7 minutes later landing with E cross wind. While flying the thing bounced all over the place because of the choppy wind. I did lower my gain down to 60%, but she was still bouncing. The wind chop was even noticed on my mirage which usually cuts through with no issues.
One perfect landing one that had two small skips.
I was showing a buddy the difference in preloading the bank with rudder verses not. He could see the difference easily. She’s not a trickster or a hot rod, but man does she look good in the sky.
I do have my steering on a separate channel, but may try it back again off the gyro.
I haven’t had much issues until second flight today. And yep I over corrected and did a drifting take-off. If I had intended to do it, it would have been the coolest thing ever, however instead it left a little brown in boxers.

Also did a re-re-maiden on the YF-23. She’s still in one piece, but that’s another story.

Gravy

I think you might be mixed up about the gyro gain. High gain causes control surface induced oscillation as speed increases. Wind buffeting that causes your bouncing around should get worse as you lower gain, but that's another discussion.

I had the LX YF-23. Flew it twice and barely got it back in one piece. I gave up on it and gave it away to someone who kept it as a static model.

[Evan D]

Good reports...

Reflex... We are using the term incorrectly. Reflex is twisting the wing to have a smaller angle of attack compared to the root. When we add up elevon we are just adding pitch up, we are not adding reflex.

I really like the Assan steering gyro. I have them in more than a few planes. That said the gyro in the B-2 does a good job of keeping it straight. I think that it has so much gain programmed in that it does a good job. It does so well I don't see any reason to bypass steering on this plane.

[xviper]

The big difference is that the Assan is a heading hold gyro and the stock one is a rate gyro. Assan will track the centerline of the runway much better.

That explains why the Assan works better as a ground steering gyro. I should not have said "works" the same. However, the way the front wheel responds to the plane being yawed on the ground "looks" the same, except that the Assan returns to center much slower because of what you stated.

[radfordc]

No reason except that you're just substituting one by another. The one in the stock gyro works exactly like the Assan. My friend did his ground test this morning with his B-2 and the response is exactly the same.

The big difference is that the Assan is a heading hold gyro and the stock one is a rate gyro. Assan will track the centerline of the runway much better.

[Gravythe clown]

Got 2 more today. Wind was choppy and switching between S and E. Take off going S into wind, 7 minutes later landing with E cross wind. While flying the thing bounced all over the place because of the choppy wind. I did lower my gain down to 60%, but she was still bouncing. The wind chop was even noticed on my mirage which usually cuts through with no issues.
One perfect landing one that had two small skips.
I was showing a buddy the difference in preloading the bank with rudder verses not. He could see the difference easily. She’s not a trickster or a hot rod, but man does she look good in the sky.
I do have my steering on a separate channel, but may try it back again off the gyro.
I haven’t had much issues until second flight today. And yep I over corrected and did a drifting take-off. If I had intended to do it, it would have been the coolest thing ever, however instead it left a little brown in boxers.

Also did a re-re-maiden on the YF-23. She’s still in one piece, but that’s another story.

Gravy

[xviper]

Further to my edit in the previous post, my friend maidened his B-2 this morning and here are his thoughts. He doesn't post much on these forums so he asked me to do it for him.

His B-2 is bone stock right out of the box - did not have the "mode" or master gain hooked up, did not use the clear fin. He flew with both 5000mah and 6000mah CHL batteries going with the stock CG on the 5000mah and a little bit aft on the 6000mah. He used the 8mm and 4mm reflex and discovered that it had a hard time rotating off the GeoTex runway. After the trimming flight, he suggested that perhaps even more reflex would be useful OR a more rearward CG. The second flight was no problem getting off the deck with about 15 clicks of UP trim. He suggested that perhaps those who have difficulty getting off grass should give the amount of reflex or more aft CG some consideration or that some may simply be using crap batteries.
As I suspected, the B-2 flies like a really big EDF powered flying wing. Use of rudder through a banked turn made it perform and look much nicer, helping to pull the nose down. Landing was no problem as he has a lot of glider experience (both real ones and models). Doing no "stunts" like loops or rolls or high speed blasts, he got 3.5min with 30% left on the 5000 and over 4 minutes with the 6000, similar remaining.

Additional information ............... With regards to this plane's visibility, my buddy did mention that if you blinked and lost your train of thought at the same time, it is possible to forget which way it was going since it looks pretty much the same right side up and upside down. Therefore, at a distance, if you started to bank and turn and you had a "senior moment" and forgot which way you were banking, then yes, it is possible to "lose it". Eg. If we were banking right and a split second later, we forget we were banking right, our minds would ask ourselves, "Was I banking right or left?" However, most of us pay attention and remember which direction we were taking the plane just before we "blinked".

[xviper]

Any reason not to separate the steering and use an assan steering gyro?

No reason except that you're just substituting one by another. The one in the stock gyro works exactly like the Assan. My friend did his ground test this morning with his B-2 and the response is exactly the same. Perhaps the only advantage is that the Assan shuts down the steering servo when the retract is up.

Just discovered one reason to put the steering on an Assan. I watched my friend do ground handling with his just prior to his maiden. He said it was very easy to over correct the steering and have the B-2 veer off dramatically to one side or the other. An Assan steering gyro dumbs down the steering input a LOT so that it would make for smoother ground steering (almost like it has very high expo). He said the best way to take off is once it's running straight, just "give 'er" and get it off the ground quickly. Doing more of a "scale" take off can result in more chances of over-correction. I'm going to try having a high expo on the rudder for one of its rates (keeping it at 100%) purely for the ground roll.

[SanExup]

Any reason not to separate the steering and use an assan steering gyro?

[kallend]

Gyro toggles to the three settings (Basic Gain - Attitude Lock - Trainer)...details of each are explained in the second manual specific to the Gyro

TwistedGrin

Only until such time as people start experimenting with the programming card, now (apparently) being shipped.