Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[Airguardian]

Well the other thing is that when you are in Alpha lock pushing the elevator down does absolutely nothing if you are at full throttle. That is the crucial problem.

Only if your VT nozzles are switched off. :/

Does it also stay in alpha lock when inverted or does the airfoil help in preventing that?

Inverted high alpha with the 29 is not really stable (unlike the F-22 and Su-35) and it wing rocks terribly.
Maybe a gyro cures it. I haven't tested yet. I don't recommend doing that maneuver with the MiG. At least not for starters.

So now when in alpha lock:
1. Reduce throttle until nose comes down
2. Push elevator and pick up speed by going downward
3. Have at least 30 meters of height - that's what the cool videos seem to indicate

With VT off, just cut throttle completely. The thrustline of the stock nozzles is off and will push the nose up when thrust is added. If you are still stuck after completely cutting throttle (it can happen) then apply short duration bursts of full throttle with full pitch down to break the plane out of the alpha lock, then, as soon as you do, reduce throttle and keep nose'down stick pressure until the plane regains speed.

But you don't need to do any of that because you have VT nozzles. Just leave them on. Full throttle and apply forward stick. End of the problem. ( :
Backflip works too but is not needed.

Switch on VT, pull elevator, do a backward flip and go off throttle when the nose is pointing down. And switch off the VT immediately when nose is pointing down until you're in stable flight. Accelerate level and / or a bit downwards. I found pushing the VT down results in a massive loss of height if you are too late in going level (which is tricky when using the VT). Keeping VT on would make the elevator stick just too sensitive for a saving manoeuvre once you are out of alpha lock, especially after some extra adrenalin.

I disagree. Switching TV off is a terrible move. Just increase your expo values and get used to it.

[Airguardian]

Is the High Alpha problem solved with the FMS 80mm EDFs? I mean at least to be able to accelerate out of High Alpha.

You should get the Freewing Su-35 with FMS 1900kv EDFs. That's the ideal scale 3D jet for 'low to the ground' extreme aerobatics.
I love the MiG, but it's not a model you want to be pulling certain shenanigans 2m from the tarmac...

Example here, jump to 1:11 and 2:30 for reference:

And some more here:

The MiG just came out too heavy as it is to do this kind of flying. Some like to hate on EPS, but... IDK, I'd choose it over EPO any day just for the better mechanical properties at a lighter weight! ^^
That's half the secret of the Su-35's great performance features.

Actually I wanted the MIG-29 for some close to ground aerobatics.

Well... this jet isn't probably the best for that unless you go through a hardcore bikini op, remove a ton of weight and switch to a 12S high power system.

So I am just wondering what the best route is.

I'd certainly suggest trying to upgrade to FMS fans to gain a bit of thrust edge, but don't expect that change to be enough to get the plane into 'Su-35 aerobatics' realm.

Instead, I think the MiG offers a great platform to experiment with more 'scale' inertia driven maneuvers, ass-drifting through the air at moderate speeds, where smaller, lightly wing-loaded planes fail to give a scale appearance. But that's better flown at some altitude.

I'd also suggest you test new batteries first and foremost. I wouldn't expect SLS 4Ah to perform. You may be losing a great amount of thrust due to using subpar batts.

Since you are in EU, you may find it difficult to get the best packs around ATM for EDF flight (SMCs) but if you contact Danny, the company owner, I'm pretty sure he should be able now to ship directly to you. If you are interested, send a PM and I'll give you the contact e-mail.

Otherwise, I'd probably try CNHL 5Ah or 4Ah, but those are heavier. For the most part, I've had the best luck in performance with the MiG using powerful 600g 4Ah packs, but then don't expect them to live long lives. You'll be puffing packs left and right in about 20-40 cycles depending on the chemistry of the pack and your level of abuse.

[JetFun]

@ Evan D: If you control your descent with throttle thats obviously fine. I fly next to a forest (lee conditions sometimes) and landing conditions are different every time. And next to the field there is some lift when coming in - depending on the wind direction.

I am eyeing the F-22 or Jas39. Simply because I am very happy with the Avanti. Perhaps the Jas 39 is too similar to the Avanti. Seems to me the MIG-29 is for days where you really want to fly MIG-29. Also takes up a lot of space in the car. Think TV is absolutely necessary if you like to do slow aerobatics. It's like someone pulls the handbrake during flight and you just have to deal with it.

[Evan D]

You'll figure out what you like best with this just like any aircraft, they are all a little different.

I come in on "my" mid rates and I have my TVs on all the time. descent is controlled with throttle and I do not cut throttle until the mains have touched or just slightly before.


My thoughts on alpha lock... There is something in the airframe that causes this. You will never stop it from happening. I know others will say you won't have it if you have TVs, I say it will still happen, but TVs will help you get out of it. Flew both the big MiG and FW F-14 yesterday. Amazing how different they are. Both are a bit stressful for totally different reasons.

[JetFun]

Just tested what I mentioned above:

I always fly with 3 phases, normal (1), flaps half down (2)and flaps full (3) down. (A 4th phase on gliders with reflex up for speed, but not on the MIG-29) I always land with no flaps when windy, half flaps if a bit windy and full flaps with no wind. And butterfly / crow on gliders.

I tried the setup of about 50% TV and 50% elevator in all three phases. While flying it's fine.

The problem is during landing when you come in with a mix of elevator and thrust. With the 50% TV and 50% elevator you only have half elevator function (pitch) if the thrust is off. And if thrust is on for small corrections the pitch function is very effective. But as the elevator is limited during thrust off there is just not enough pitch function. Another result is that it's hardly possible to come in with high alpha during a landing without thrust. And there is simply not enough pitch if thrust is off. A small correction with thrust instantly moves the nose up and messes up the glide path.

With the 50% elevator / TV setup it takes longer to get out of locked high alpha. I actually intended to make lock alpha nonexistant that way. But the downside is during landing with varying pitch function. So that I had to use the programmed switch for 100% TV and elevator.


It would be possible to have some TV / elevator mix in the normal (1) phase but if windy that would make a landing more tricky.

So what happened to my today is I came in on a perfect glide path, added some thrust to come closer but as I had some up elevator the TV added more when I gave some thrust. Nose went up a bit so I corrected down with elevator and no thrust to glide the last bit before touchdown. As the aeroplane had reacted so directly I did not pull the elevator as much as I should have. Landed a bit hard. Then the nose gear conked in after touchdown. I simply had not thought about the pitch having little reaction when thrust is off. Well, should have thought about that. The landing before that one was perfect.

Also during flight when I turned off the thrust just to glide the pitch function (elevator but not thrust) has half the effect than flying with thrust. So I suddenly needed to pull a lot more as the ground was coming closer fast. Thrust added and it bounces upwards. Does not really look nice.

So It seems to me the best is a setup in all phases without TV in all phases because it makes landing (and gliding without thrust) so much trickier. And add full TV / elevator via switch.

Just adding 20% TV in all phases would be an option, but it does affect the glide path if you add power a few times during landing. It actually think it may explain why so many TV videos end with a pretty hard landing.

It seems to me with full TV movement via switch the stock EDFs are enough to get out of alpha lock. So other EDFs with more power are nice but not a must.

[Evan D]

Sebart and FreeWing

[JetFun]

What is SA and FW?

[xviper]

Still, some interesting observations. I've never even considered the Arrows Mig since I already had the SA and the FW. I had no idea that it was powered by 6s. A 6s in a little airframe like that could be a real exciting model to fly. I may have to take a serious look at one now.

[Evan D]

The Arrows is quite a bit smaller, about the size of the FW (or EF) 70mm F-16, maybe a tiny bit larger. I did some basic measuring a long time ago of the FW and Arrows to compare them within their scale percentages, Things like length to span and CG location that I decided on after flying (not book CG). Visually the wing angle of attack to fuselage line to thrust line all look different between the two and because of that the neutral spot for the stabs look different. That said I have no quantitative data.

[xviper]

Agreed. The Arrows is different too, no alpha lock

Can you give your assessment as to the design principles incorporated into the Arrows Mig as compared to the Freewing Mig that would make the Arrows resistant to alpha lock? As far as I can see, the Arrows is almost the same size as the SA but much heavier, no VT, flies on 6s.

[Evan D]

Agreed. The Arrows is different too, no alpha lock

[xviper]

Note the SA had no gear, had more than 1:1, and had TVs. And did not have a problem with alpha lock.

The Arrows Mig is a perfect comparison. No alpha lock issue, not quite 1:1, high alphas great and is able to get out of high alpha.

The SA is a different breed of Mig29. I believe it was designed specifically to hover and high alpha.

[xviper]

Well, if you have enough power to accelerate straight up it doesn't matter how far up the nose is pushed. When I had alpha lock during a takeoff the plane climbed vertically for a few meters but eventually ran out of climb performance. With enough thrust I assume it would have continued to climb to an altitude to effect a recovery.

You need enough thrust to hold the plane's weight in the air without losing altitude while the nozzles are tilting the plane to an attitude where it can get some forward airspeed, then the control surfaces can take over and "fly" the plane. This is how I get the SebArt to start flying out of a hover and/or high alpha.

[Evan D]

Note the SA had no gear, had more than 1:1, and had TVs. And did not have a problem with alpha lock.

The Arrows Mig is a perfect comparison. No alpha lock issue, not quite 1:1, high alphas great and is able to get out of high alpha.

[xviper]

Sounds like you are poo pooing the notion that deploying flaps causes the plane to pitch down uncontrollably? If so, I disagree. I was ready to land my plane and on the downwind leg at cruise speed hit the LG switch and without thinking also flipped the Flap switch. The plane instantly went into a steep dive and I could not recover using elevator control. Before I had time to realize what happened and retract the flaps the plane was in the ground. I'm now much more careful with my second Mig....I wait until the gear are out and the plane is slow before using flaps.

I assume your tests were done properly and your jet didn't pitch down with flaps, but I assure you that not all Mig-29s act like that.

I'm not "poo pooing" anything whatsoever. If it "sounds" like that to you, perhaps that's the way you interpreted it. All I'm doing is relating what was posted on the forums and on YouTube and what was said on the forums as a result of those early videos. I made no comments either way, just posting what theories and/or conclusions drawn by others. As far as showing that it did not happen to my Mig, that was my experience and I even got a video to prove it, which I posted early in this thread. I can only state what my experience is and I've never indicated what may or may not happen to others nor did I make any statements about any other Mig being like that or not being like that. You should not even make the assumption that I did the tests "properly", not knowing what your standards might be for "properly". I did it to see for myself and I shared that with those reading the forums. How they took it was and still is beyond my control.
PS. I've never stopped being careful with my Mig. It has characteristics that can be quite alarming and unpredictable. Your video shows that you went too vertical, too close to the ground. There was insufficient momentum to sustain that kind of attitude.

Insofar as powering this Mig enough to make it overcome it's own weight, that is going to be a very hefty project. It will never be able to do this:

It takes a tremendous amount of thrust to vertically lift a plane's weight and even more to get out alpha lock because then you're dealing with a plane already in motion and requesting a sudden and significant change in that motion.

[Evan D]

There is a big difference in thrust required at very low to zero airspeed AND in alpha lock (very draggy) and thrust required at very low to zero airspeed and NOT in alpha lock. Having more than 1:1 thrust is NOT a simple answer to the problem.

On mine I have triple rates for pitch and the TV is on all the time and also has triple rates. Each flight "mode", high speed, medium speed, post stall manuever requires it's own amount of surface and TV. In general the higher the airspeed the less stab and TV movement, in general. In zero airspeed alpha lock the stab movement is irrelevant and you want more TV throw and you are controlling pitch with throttle.

My favorite EDF is the Grippen, I just love it. I have three, on 8S repainted and with TV. One box stock no TV. And a spare in the box for when I lose either of my flying ones. I also like my F-22 and I've lightened it up, put in a Jet Fan/ HET 8S system using fairly light batteries and I put TVs on it. Another one I really like is the Arrows twin 6S 64mm MiG29, none of the issues that the FW MiG has, flies awesome. I am on my second one of those and also have a spare in the box in case.

[JetFun]

Pretty disastrous.

Yes enough power would have been the game changer. Because more power would be more speed. And more speed would mean that the elevators get enough air flow to actually be effective. Simple as that. Needs more thrust at low speed than aeroplane weight. The full speed thrust is not really relevant in alpha lock. Maybe the EDF needs a redesign for more thrust at lower speed and sacrifice some top speed. And more thrust would simply push the MIG forward to a safer altitude.

A bigger higher KV motor on the EDF which could handle the higher Ampere with a larger ESC would be a solution.

Just wondering if I am better off getting the F-22 and keep the MIG-29 as long as it lasts. Hope the F-22 does not do this similarly.

I had the EFlite Havoc and it had some very nasty stall characteristics. Sudden wing tip stalls at decent speed during landing and in the air. Tore it apart (before damaging retracts and electronics) and put the EDF and retracts into a printed F86 and got the Freewing Avanti. Rather move on than deal with frustration. Expected similar quality like that of the Avanti from the MIG-29.

Basicially to me the MIG-29 is a jet that always has to stay at minimum medium speed to be a safe aeroplane.

Just wondering now if I should adjust the Thrust Vector to minimal permanent deflection with smaller elevator deflection and go to full TV and elevator deflection via switch to do fun stuff. (higher elevator and TV dual rate via switch). That might prevent the situation as in the video above. So that the TV shares the work with the elevator during normal flight already. Think that seems to be the first most common sense solution to me. Think I will do that. Seems like the elevators need quite some speed to be effective and working. Look at the full size jet aeroplanes and see their massive stabilizer deflections. So there is a point about having to have EDFs will substantially more power to make a difference.

Thanks for posting that video!


We have to keep manufacturers accountable. We need to point these things out, so they improve what they sell to us. It's our money, our fun time. And give us good excuses to buy the next aeroplane.

[Evan D]

Do you honestly think ANYONE will ever get a pair of fans in the big Mig that can do that? Plus it'll take a lot of power, more than a normal plane in a normal high alpha state (think like a Mirage). The Mig would be just plowing through the air and need to overcome that natural high alpha lock that another plane doesn't have to fight. That other plane would not be in lock and still have pitch control and could use the extra thrust.

Either way until someone has a pair of fans that have 50% or more, maybe a lot more, thrust we won't know.

I'd be interested to see someone toss a couple 12S Jet Fans or Schubbies in...

[radfordc]

It doesn't do it inverted. I don't think additional power will be the solution at all, it'll just push you further into alpha lock.

Well, if you have enough power to accelerate straight up it doesn't matter how far up the nose is pushed. When I had alpha lock during a takeoff the plane climbed vertically for a few meters but eventually ran out of climb performance. With enough thrust I assume it would have continued to climb to an altitude to effect a recovery.

[radfordc]

BINGO!

Back when this plane was brand new, before the TV nozzles were even available, several crashes occurred in SE Asian - with videos. It was blamed on flying at high speed with the flaps deployed. First, why would anyone do that anyway? No matter. That was the assumption at the time. Before I got my VT nozzles, I did some tests to see what would happen if I slammed the flaps down at speed and see if the thing would fall out of the sky. This did NOT happen.

Sounds like you are poo pooing the notion that deploying flaps causes the plane to pitch down uncontrollably? If so, I disagree. I was ready to land my plane and on the downwind leg at cruise speed hit the LG switch and without thinking also flipped the Flap switch. The plane instantly went into a steep dive and I could not recover using elevator control. Before I had time to realize what happened and retract the flaps the plane was in the ground. I'm now much more careful with my second Mig....I wait until the gear are out and the plane is slow before using flaps.

I assume your tests were done properly and your jet didn't pitch down with flaps, but I assure you that not all Mig-29s act like that.