Official Freewing MiG-29 Fulcrum Twin 80mm Thread

[GliderGuy]

PANCAKES AIN’T NO FUN!

Someone mentioned earlier in the thread about getting into a falling leaf situation. BEEEE CAREFUL!!!!

I was doing hammer head stall and didn’t get the nose around quick enough with the rudder. Next thing I knew....I was in the falling leaf situation.

The bird was totally unresponsive to ANY control input, but it was nose slightly up and wing-wobbling stable. FULL POWER WILL NOT GET YOU OUTA THIS. After falling several hundred feet with me trying everything, I think I chopped the power AND the nose fell down. Recovery was not very far off the ground, but she did recover.

Maybe full power is aggravating the situation???

My CG is on the mark, with a 6000 in the middle tray and one in the rear.

When someone else experiences this, let us know what method you used to recover. Now to go clean my shorts!!!

-GG

P.S. Check off the range check at low altitude and far distance = pass

[Evan D]

Wow! Good to know. You are not the first, or second, t0 report this...

[janmb]

Maybe full power is aggravating the situation???

When someone else experiences this, let us know what method you used to recover. Now to go clean my shorts!!!

-GG

Yes, it does! Power has a tendency of aggravating pretty much everything.


This sounds a lot like any other stable spin situation, where the model is locked into a pattern where it is stuck falling without picking up airspeed and thus without picking up control authority.

The cure for that is always this (assuming the model is still upright. If inverted, opposite inputs apply):

1. Zero throttle
2. Zero aileron
3. Hold full forward elevator (dive)
4. Hold full opposite rudder (opposite of whatever yaw rotation the model might be having)

If the situation is at all recoverable, this is what will get it done. As soon as the nose drops and rotation stops, center controls, feed in throttle carefully, let speed build, pull out gracefully.

This is standard spin recovery technique, and may or may not apply to your case. I bet a fair share it would though.

Any model is prone to this in more or less degree. I'm a bit surprised it gave you as much grievances as it did though, considering you were running a fairly nose heavy config, which typically helps avoid stuff like this, and also makes exiting it easier. Adding power is probably the main culprit in this case, almost sounds like you were in a high alpha/tail slide/high alpha/tail slide repetitive pattern.

Another huge benefit of thrust vectoring too obviously. As soon as mother nature goes "fooled you!", pilot simply says "nope".

[Evan D]

I'll bet it would too Jan.

It's my SOP for other models.

[GliderGuy]

Hi Jan - Great info.

For those reading, a bit more details....

- No yaw or nose rotation (not a spin per se)
- No pitch oscillation was seen / stable pitch attitude
- Wings were rocking back and forth....deep stall
- I did not hold forward stick like you say. I just punched it. My bad!

Likely when I chopped the power in preparation for impact, I lucked into the solution.

-GG

[janmb]

Hi Jan - Great info.

For those reading, a bit more details....

- No yaw or nose rotation (not a spin per se)
- No pitch oscillation was seen / stable pitch attitude
- Wings were rocking back and forth....deep stall
- I did not hold forward stick like you say. I just punched it. My bad!

Likely when I chopped the power in preparation for impact, I lucked into the solution.

-GG

So essentially a stable, flat fall then? Slightly positive nose, just plain falling?

In that case, kinda surprised you were not able to simply power out of it to be honest. But kinda hard to assess without having seen or felt what was going on.

As long as you have altitude to work with though, spin recovery is always your best bet. But on the other hand, if altitude is a luxury you don't have, power may indeed be a last resort, and may at the very least, combined with elevator pulling, make the flat fall as flat and slow as possible, to minimize impact damage.

If it is any comfort, I managed to put my Avanti into a locked spin the other day lol - so nasty situations can be achieved with the most forgiving models ever :D Fortunately remembered my spin exit 101 and got her out, but shouldn't been 15' lower...

[Lcacing]

On the maiden flight, second step after trimming, is to check the stall characteristics of the plane. As the AOA is increased, let’s say past 45 degrees, you start loosing authority of the control surfaces, specially the elevator up/down, is quite an estrange feeling, the stall is straight nose down. If you keep power on past a high AOA , the MiG will continue to raise the nose on its own. But if you take power off, relax the elevator, the nose will drop and elevon authority comes back.

When I did the tight loop/flip that’s how I entered the maneuver, slow high alpha, once it went past 45, lost elevator authority, added full power, at the top of the flip I added down elevator and once the nose dropped, neutral elevator and kept power on and slowly fed up elevator. It actually didn’t loose that much altitude but for sure its awkward. I also did some tail slides and tried doing the cobra, not much success. Overall the MiG is fun to fly and I’m pretty sure that if I still had the stock servos, I would have crashed the plane already. Some of the guys claiming that the stock servos are great are also the ones just flying the pattern.

[Evan D]

" Some of the guys claiming that the stock servos are great are also the ones just flying the pattern." is really an unfair statement...

There may people just flying the pattern but I have to think every person flying theirs with the stock servos has it in the back of their head to be cautious, or at least aware of the possibility of servo issues. I have to think most flying the F-18 and F-22 are too.

When I flew mine I didn't just fly the pattern but I did help the torque of the stock servo by moving the pushrod to the inner hole. Did it on ailerons too. I think it's a good thing to do anytime you have to reduce the ATV or travel in the radio to get the book throws. Moving the push rod in allows the servo to work easier and it also gives your throws more resolution.


Edit; my new FW servos are at the PO to be delivered tomorrow...

[Lcacing]

" Some of the guys claiming that the stock servos are great are also the ones just flying the pattern." is really an unfair statement...

There may people just flying the pattern but I have to think every person flying theirs with the stock servos has it in the back of their head to be cautious, or at least aware of the possibility of servo issues. I have to think most flying the F-18 and F-22 are too.

When I flew mine I didn't just fly the pattern but I did help the torque of the stock servo by moving the pushrod to the inner hole. Did it on ailerons too. I think it's a good thing to do anytime you have to reduce the ATV or travel in the radio to get the book throws. Moving the push rod in allows the servo to work easier and it also gives your throws more resolution.


Edit; my new FW servos are at the PO to be delivered tomorrow...

There is nothing wrong with flying conservative because of the possibility of the servo failing, but claiming that the servos are great and have plenty of power, as to suggest there is nothing wrong with them, is a whole different story. That’s what I was referring to. When I first got my F-14 I was flying very conservative because even then, I thought the 17g servos were borderline, once I upgrade to Hitecs, I started to have fun flying it.

Ive also set up the linkages to achieve best geometry and mechanical advantage, but moving a linkage one position out should not be enough to over stress the servo.
I did say some, not all so that’s me get out jail free card

[Evan D]

Uh hu...

[Itgordon00]

This jet will be my Christmas gift. In the meantime we have three of them at the field already. One pilot is VERY comfortable with his Mig 29. Turning and burning at 2 ft off the ground is what keeps his juices flowing.

[mshagg]

You never want to beat the record for lowest pass lol.

We'd get a stern talking to flying that close to the flight line but goodness me it's impressive up close isn't it :)

[crxmanpat]

Finally went down to Home Depot and got some color match paint for the base gray, and it came out perfect! So with that I got some detailing done on the Mig today. I painted and glued on the antenna array and the bird slicers, and then I masked out and painted the false canopy on the bottom (I used Apple Barrel Country Grey for this). Attached is the paint mask I drew up in CAD and used. I also cut the signal wires for the main doors (first white wire from the pos/neg wires on the ribbon cable) and soldered them together to an old servo plug. I removed the pos/neg wires from the servo plug so all that was left was signal (the door servos still get power through the ribbon cable). This saved having to run servo extensions from the wing to the blue box. Now my doors close after the main gear extends. Tomorrow she gets packed up for the trip to St George.

[ATTACH]n275651[/ATTACH]

[crxmanpat]

I also put the finishing touches on the missile decals and got one of each done. Now I need to put together the application guides and then they'll be ready for sale when I get back home next week. Here is the R-73 from all sides.

[crxmanpat]

Here's both together, and then the R-27 from all sides. I hand painted the fins with a combination of gunmetal and steel, then painted the exhaust cone with brown that I cut with some black to make a little darker.

[Dirty Dee]

Those look great!

[Bmccormick]

So here is my observation and questions; after about a dozen flights now on my Mig and gaining trust with the elevators And dialing in my preferred rates I have found full throttle passes tend to suck this plane in a down Elevator manner. The faster you go the exponentially worse it gets to the point of taking 1/3 up elevator to keep it level. Cg Changes have had no effect on this. So I can only image in a terminal velocity down line under power how some of these crashes have happened when the mechanical advantage of the elevator servos is taken away. Were the servo rods beefed up after the fact, was something found in testing? Does this thing reach a point where the air pressure is so great on the elevator stabs the servo linkage bent/flexes? So why the pull to gear at full throttle, is it the servo still getting over powered and the fix more needed servo power to correct because this is an inherent trait or this thing just needs to be corrected with a mix or gyro.
ANYONE ELSE EXPERIENCE FULL THROTTLE DOWN PUSH?

[crxmanpat]

Oops, almost forgot to install the ACL! I have it on a strobe port. Used a light housing and light from a crashed 90mm F-16. There's also an ACL on the bottom of the left engine duct, right about where the EDF hatch cover is. Not sure yet whether or not I'm going to do that one, or the white marker on the left vertical.

[Lcacing]

Bmccormick I only have 6 flights on mine, I’ve concentrating more on CG, about 13mm back from stock, and how it handles at low speed and high alpha. I’m using Hitec 5085 servos, linkage at second hole from center, this position is further inn than Freewing servo arms, elevators statically balanced and running CC BEC at 5.6v. With that said, today I did do a couple of full throttle passes, 15mph tail wind, and did not notice any downward pull at speed. I don’t think a mix is the answer, that would just cover an issue, specially if it’s a servo/linkage not holding up to the task.
HSD likes to add throttle to elevators mix in their jets,up elevator when throttle is added, I found that with a correct CG that mix is not needed.

[JLambCWU]

So here is my observation and questions; after about a dozen flights now on my Mig and gaining trust with the elevators And dialing in my preferred rates I have found full throttle passes tend to suck this plane in a down Elevator manner. The faster you go the exponentially worse it gets to the point of taking 1/3 up elevator to keep it level. Cg Changes have had no effect on this. So I can only image in a terminal velocity down line under power how some of these crashes have happened when the mechanical advantage of the elevator servos is taken...
ANYONE ELSE EXPERIENCE FULL THROTTLE DOWN PUSH?

It does do this a bit, but is not something exclusive to this model.

There is a CHANCE that your neutral flap and aileron positions are slightly too low at the trailing edge of the surface. Mine took some fine tuning and both ailerons in neutral are slightly above being inline with the wingtip, and the flaps are even with the aileron. Otherwise you’re adding a remarkable amount of camber on the wing aft of the CG causing the nose down pitch as speed increases.

Try turning your control linkage turn buckles out a couple turns on the flaps and ailerons and recheck this up high until your comfortable with it.

Solid chance mine has more flights on it now than everyone except James from Motion, and the stock 17g servos have worked fine, being pushed very hard, possibly thanks to where I have my surfaces set. 👍🏼