Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[janmb]

Looks like my flights will include a rear wide-angle camera view to document any control surface behavior with flight anomalies ...

Very good idea indeed

[evensen007]

Yeah, that was a pretty dramatic crash. My nose attitude was a bit shallower than that, I estimate about 5 degrees or so less than what you see there; but same exact no-frills lawn dart into the ground :-(

DANG, ANOTHER ONE!? So sorry to hear Falcon... I got another 10 flights this weekend and it's hard not to shake the feeling of it being a ticking time-bomb. I'm using a Spektrum Ar637t alone in the front battery bay with no satellites. I did add the Ferrite chokes that GG linked to both ESC and rx wire. CG is on the money. +3mm of default elevator set. I've been pushing it pretty hard in maneuvers and the only 2 things I've even noticed: Default recommended aileron throws are pretty... EXTREMELY aggressive. When I do loops I notice it's a touch soft coming out of the bottom of the loop to level out. Really sad to hear this for you guys that have had this happen. I wonder how many more before we get to the bottom of it.

[Evan D]

Another 5 on mine yesterday. At 18 now. No issues. But as I have noted a number of times mine is re-wired and I have moved the better made elevator pushrods to the inner hole. I was not happy with roll rate but with the added tailerons I am. All my flights yesterday were with 5800-6200 packs so I was limited in battery movement. Some flights were 1/4" behind the marks and others were at about 3/8". Flies very well. Also flew 5 more on the F-22 with 8S, TVs, tailerons and a bunch of mixing. Good day.

Saturday was an old timer and Avanti.




Video- https://www.youtube.com/watch?v=Nfso...index=2&t=784s

[GliderGuy]

I took Friday off and flew the MiG all day, more on Sat and Sun mornings before the wind got up. Solid as a rock and hope it stays that way!

Hopefully, as Evenson007 noted, the use of RF chokes just might be one of the keys.

But...the one post-crash comment about the elevators ending up in the full up position has me perplexed as well.

CG on the mark
3-4 mm elevator trim
30 mm flap when down
negative 1 mm flap when up
factory throws on all other controls
no EXPO / No flap/elevator mix
typically fly on low rate
4 min flights / 3.8 V / could go longer or hot dog more
Admiral Pro 6000
Stronger elevator push rods and links
Futaba TX/RX - RX in front bay
upgraded factory-provided elevator servos
Y on elevator bypassing BB
all other wires go thru BB
new nose gear retract servo...replaced an intermittent one

A funny side note: I flew the AL37 Sunday evening. Haven’t flown it since I got the MiG. My first thought was, “Where did the power go?” LOL

-GG

[Lcacing]

I watched the video of the 3 crashes, looking closely at the first MiG, assuming he used factory CG, initial elevator trim was set at the fuse halves not bottom of fuse. That means from the get go, it was trimmed extremely nose down as much as 15mm, then add the possibility of the pushrod being in the wrong location, 17g servos, and full throttle. Maybe?
The second MiG also looks like the elevator trims is set at the wrong location, take off sure looks like he almost ran out of elevator, It jumped off instead of lifting up.
Can’t comment on the third flight, but the roll sure looked like it had a forward CG.
If all this were maiden flights, the one thing I didn’t hear were trim adjustments, and by looking at the initial elevator position, up trim was required for level flight.

Thoughts?

[Airguardian]

I'm not understanding how mine ended up needing 5-6mm between the LE of the elevator and the fusealge with the cg on the mark and others reporting theirs needed no elevator trim? Unless their is a big fluctuation in weight distrubution from model to model from the factory.

I think that is less likely because the CG mark is manufactured into the wing.

You are not getting it. Factory recommended CG is too nose heavy so people are shifting CG back to make the plane fly better.
Aft CG in turn requires less pitch-up trim.

Motion themselves commented the CG marks molded into the wings are just a reference starting point and you should trim and fine adjust it out from there.

I'm using a Spektrum Ar637t alone in the front battery bay with no satellites.

I'd drop at least one satellite...

[Reaper911]

DANG, ANOTHER ONE!? So sorry to hear Falcon... I got another 10 flights this weekend and it's hard not to shake the feeling of it being a ticking time-bomb. I'm using a Spektrum Ar637t alone in the front battery bay with no satellites. I did add the Ferrite chokes that GG linked to both ESC and rx wire. CG is on the money. +3mm of default elevator set. I've been pushing it pretty hard in maneuvers and the only 2 things I've even noticed: Default recommended aileron throws are pretty... EXTREMELY aggressive. When I do loops I notice it's a touch soft coming out of the bottom of the loop to level out. Really sad to hear this for you guys that have had this happen. I wonder how many more before we get to the bottom of it.

When I do loops I notice it's a touch soft coming out of the bottom of the loop to level out. Agree I had the same impression on mine coming out of a Split S.

[janmb]

Going back to my flight, on maiden flights, after trim, pitch and roll, and CG check, I always, always check stall charactersitics regardless of plane type. The MiG behaved quite differently and recovery was even more interesting. Once I reached about 3-4 mistakes high, I slowed the MiG, reducing throttle and adding elevator, as the AOA increased, lets say past 50 degrees, there was no elevator response, the only way the nose would move was by throttle, the more throttle I added the nose kept going up, adding down elevator did noting. I maxed the throttle and the plane "flipped" and once the nose pointed down and speed increased, I regained elevator control. I did the same maneuver a few more times and it reacted the same way.
If during the "flip" you keep adding up elevator and reduce throttle, the MiG will enter another stall and the dreaded falling leave, at this point there are two viable options, elevator to neutral and zero throttle and allow the plane to drop the nose on its own. Once the nose drops, add a little throttle to increase speed and gently add elevator. The second option that I like is to reduce elevator input but max throttle, the nose will go up and it will "flip" again and once the nose points down add throttle/elevator and fly away. I think the safest way, with less altitude loss, is zero throttle/neutral elevator. One thing to keep in mind is that my MiG is set up with tailerons and ailerons so I do have more roll control than standard configuration.

If you watch the video of the F22, it sort does the same inputs, also note how it uses up flaps to help get out of it. Maybe a mix to explore

Not sure I see anything "dreaded" about a tail slide at all to be honest. It is a damn cool maneuver, but nothing I would dread.

As for the F-22, it does nothing in that video that it needs to "get out of" as such. It is in perfect control absolutely all the time, and nowhere near being otherwise either. Using flaps as an active flight surface is completely standard on that aircraft btw, and not a special case at all. The flight computer on the F-22 is quite simply insane. For those interested in a glimpse into that, I can highly recommend this one: https://youtu.be/Evhrk5tY-Yo

[Nickc2023]

I watched the video of the 3 crashes, looking closely at the first MiG, assuming he used factory CG, initial elevator trim was set at the fuse halves not bottom of fuse. That means from the get go, it was trimmed extremely nose down as much as 15mm, then add the possibility of the pushrod being in the wrong location, 17g servos, and full throttle. Maybe?
The second MiG also looks like the elevator trims is set at the wrong location, take off sure looks like he almost ran out of elevator, It jumped off instead of lifting up.
Can’t comment on the third flight, but the roll sure looked like it had a forward CG.
If all this were maiden flights, the one thing I didn’t hear were trim adjustments, and by looking at the initial elevator position, up trim was required for level flight.

Thoughts?

Definitely could be an improperly setup elevator. A buddy of mine got the eflight 80mm f18 and in his haste to get out and fly it he neglected to properly set up the elevator and had it set level. He also prefers a nose heavy setup for madens. Long story short he didn't even get off the ground. Cost him a nose gear on the curb about 450ft away but probably saved the plane in the end.

[Reaper911]

I took Friday off and flew the MiG all day, more on Sat and Sun mornings before the wind got up. Solid as a rock and hope it stays that way!

Hopefully, as Evenson007 noted, the use of RF chokes just might be one of the keys.

But...the one post-crash comment about the elevators ending up in the full up position has me perplexed as well.

CG on the mark
3-4 mm elevator trim
30 mm flap when down
negative 1 mm flap when up
factory throws on all other controls
no EXPO / No flap/elevator mix
typically fly on low rate
4 min flights / 3.8 V / could go longer or hot dog more
Admiral Pro 6000
Stronger elevator push rods and links
Futaba TX/RX - RX in front bay
upgraded factory-provided elevator servos
Y on elevator bypassing BB
all other wires go thru BB
new nose gear retract servo...replaced an intermittent one

A funny side note: I flew the AL37 Sunday evening. Haven’t flown it since I got the MiG. My first thought was, “Where did the power go?” LOL

-GG

"negative 1 mm flap when up". Where does the flap trailing edge end up in reference to the fuselage?

[Lcacing]

Not sure I see anything "dreaded" about a tail slide at all to be honest. It is a damn cool maneuver, but nothing I would dread.

As for the F-22, it does nothing in that video that it needs to "get out of" as such. It is in perfect control absolutely all the time, and nowhere near being otherwise either. Using flaps as an active flight surface is completely standard on that aircraft btw, and not a special case at all. The flight computer on the F-22 is quite simply insane. For those interested in a glimpse into that, I can highly recommend this one: https://youtu.be/Evhrk5tY-Yo

My reference to “dreaded” was to the falling leaf on the MiG not the F-22 video, I personally don’t think is dreaded or an issue at all. In reference to the F-22 video, it was to show the control inputs I use during stall/falling leaf. The fact that flaps are used to help coming out of the maneuver could help on the MiG, I think a lot can be taken from the video as to what control inputs can potentially be used to get out of the stall.

[janmb]

My reference to “dreaded” was to the falling leaf on the MiG not the F-22 video, I personally don’t think is dreaded or an issue at all. In reference to the F-22 video, it was to show the control inputs I use during stall/falling leaf. The fact that flaps are used to help coming out of the maneuver could help on the MiG, I think a lot can be taken from the video as to what control inputs can potentially be used to get out of the stall.

Well, since it is being offered, I would say the #1 solution to any such concerns, and which happens to be exactly why the F-22 is never in any sort of trouble in that video, is VT.

I'm not going to fear any high alpha "locked" situation anyway, but VT is certainly the get out of jail for free card that pilots of any level would greatly benefit from in such situations.

Which is the only real reason I will be getting VT for my Gripen as well: When flying in significant high alpha, the rudder authority on that model is at some point going down the drain. And that's when it is really nice to have yaw VT to maintain authority.

[leithalweapon]

[QUOTE=Airguardian;n278927]



You are not getting it. Factory recommended CG is too nose heavy so people are shifting CG back to make the plane fly better.
Aft CG in turn requires less pitch-up trim.

Motion themselves commented the CG marks molded into the wings are just a reference starting point and you should trim and fine adjust it out from there.



I'd drop at least one satellite...

I understand what a cg is. If everyone starts out with it on the pre marked location why do some report not needing any up trim and others, me included, need a ton? Someone else said it's probably because not everybody is getring it exactly in the same location. He is probably right.

So far am I the only one that recovered from one of these loss of elevator events? I lost elevator, planes nose dipped and headed for the dirt. I was able to roll and chop power, but absolutely no elevator control. In hind site I remember thinking I was disoriented and got inverted because i was giving up elevator and the plane was going down. I started to roll and rerealized i was right side up.
Knowing what I know now, the plane was very nose heavy so it makes sense that when i lost elevator, before I had the plane trimmed, the nose dropped considerably.

[GliderGuy]

LW——What did you next that saved you from the dive? How did you get control back?
-GG

[Jdcrow]

My buddy maidened his Mig-29 this weekend. HRB 5000's center and rear. His Balance Bias was rear of the CG marks. That meaning, in Flight Ready condition, when lifting the aircraft at molded balance point, the tail sags and static remains nose high. Elevators at 4mm below chime line. All settings at book rates. Flew fantastic. Rolls, loops, inverted, slow full flaps, long off power glides. no issues.

This got me to thinking. The thrust lines on this aircraft are down and out, which also drives the nose downward. Maybe the molded CG mark should be revised.

I know the default CG position for all aircraft tends to be Nose biased. But with the Mig-29, this may be overcompensated due to the amount of thrust and designed thrust lines of the twin.

[Airguardian]

In reference to the F-22 video, it was to show the control inputs I use during stall/falling leaf.

Mind that the F-22 in the video uses thrust vectoring while our MiG-29s don't (yet).
With TV on, it's a whole different story, of course :)

I understand what a cg is. If everyone starts out with it on the pre marked location why do some report not needing any up trim and others, me included, need a ton? Someone else said it's probably because not everybody is getring it exactly in the same location. He is probably right.

I think you missed that those reporting less pitch-up trim needed, also reported they set their CG behind the factory marks by at least a 10-15mm margin.

This got me to thinking. The thrust lines on this aircraft are down and out, which also drives the nose downward. Maybe the molded CG mark should be revised.

I'd swear the built-in thrustline on this model is pitch-up, not pitch down, as reported by many pilots (and from visual inspection of the nozzles). Nozzle thrustline will pitch the nose up (notice the jets flip over their back when attempted to hover!).

That still doesn't rule out a throttle pitch down contribution at speed due to pressure modification in the intake area.

[Jacckall]

I took Friday off and flew the MiG all day, more on Sat and Sun mornings before the wind got up. Solid as a rock and hope it stays that way!

Hopefully, as Evenson007 noted, the use of RF chokes just might be one of the keys.

But...the one post-crash comment about the elevators ending up in the full up position has me perplexed as well.

CG on the mark
3-4 mm elevator trim
30 mm flap when down
negative 1 mm flap when up
factory throws on all other controls
no EXPO / No flap/elevator mix
typically fly on low rate
4 min flights / 3.8 V / could go longer or hot dog more
Admiral Pro 6000
Stronger elevator push rods and links
Futaba TX/RX - RX in front bay
upgraded factory-provided elevator servos
Y on elevator bypassing BB
all other wires go thru BB
new nose gear retract servo...replaced an intermittent one

A funny side note: I flew the AL37 Sunday evening. Haven’t flown it since I got the MiG. My first thought was, “Where did the power go?” LOL

-GG

Hello, can you send some photo of your Admiral 6000 Pro placement? I want to use same batteries into this plane. Its cut of cabin bottom foam required for good battery placement?

[Jdcrow]

I'd swear the built-in thrustline on this model is pitch-up, not pitch down, as reported by many pilots (and from visual inspection of the nozzles). Nozzle thrustline will pitch the nose up (notice the jets flip over their back when attempted to hover!).

That still doesn't rule out a throttle pitch down contribution at speed due to pressure modification in the intake area.

its likely an optical illusion, as the profile of the aircraft has the cockpit riding high. or maybe its CG is nose heavy 🤣

Either way, i suspect the Mig-29 thrust lines play a role. Even if its a minor one.

[GliderGuy]

Hello, can you send some photo of your Admiral 6000 Pro placement? I want to use same batteries into this plane. Its cut of cabin bottom foam required for good battery placement?

No problem. A very small amount of foam removal allows for a better fit. Dab on some oily make-up on the battery corners and put the lid on to see where to trim (lip stick, etc.).

Suggest you use the RF chokes (search this forum for “ferrite”). Lots of discussion about these.

-GG

[Jacckall]

No problem. A very small amount of foam removal allows for a better fit. Dab on some oily make-up on the battery corners and put the lid on to see where to trim (lip stick, etc.).

Suggest you use the RF chokes (search this forum for “ferrite”). Lots of discussion about these.

-GG

Thank you for tips and photos!