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Old Jan 14, 2013, 01:06 PM
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Originally Posted by rcoconut View Post
Went to the AMA Convention in Ontario, CA today & I tried and tried to get "something" out of John Redman & Quique Somenzini regarding another micro EDF release in the future....... no words said but lots of smiles from both! We'll see what's next!!!
Wish list in order of preference:
F-104(the REAL bird DEFINITELY could use UMX)
F-100
P-80/T-33
F/A 18

Now on to the real reason I'm here. Had a "controllability issue"(one misset rate
switch) and need to know if "dunking" can fix it or not, and should it be 3-5 min
at simmer? Or is it new plane time?
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Old Jan 14, 2013, 01:25 PM
Do you see what I see?
rcoconut's Avatar
Rancho Cucamonga, CA
Joined Sep 2006
1,776 Posts
Sorry for your incident, take a look at this & hope this helps ya, you could always try the hot water method first & if it doesn't work pick up a new fuse??

Good luck

MIG 15 Hot water Crash Fix (4 min 30 sec)
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Old Jan 14, 2013, 01:31 PM
LiPo-Sucker & Airframe EMT
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Charlottesville, Virginia, USA
Joined Aug 2010
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Originally Posted by Valkpilot View Post
...... Or is it new plane time?
How's the rest of it?

If everything else is in good shape -- especially the control surfaces -- just repair the nose as best you can and keep flying! (You may have to ignore occasional snarky comments, from low-lifes who probably also kick dogs.)

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Old Jan 14, 2013, 01:43 PM
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Joined Feb 2012
108 Posts
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Originally Posted by pugsam View Post
Brilliant technical achievement!

Clearly, the bar is set higher here than in all entires heretofore submitted.

The ending credits need work.

To evaluate this entry, Judge 'Sup will have his work cut out for him.

TRX, your thoughts?



My thoughts Pugs?

Well Lemme see. As th eunofficial judge:

Beautifully executed, and an all around achievement!

The lights! The sounds! The ACTION!

OVERALL GOOD JOB!

Creativity and amusement +100

There were a couple glaring faux pas that brought negative points to my attention:

1) The use of a three point disk rotary wing aircraft. Waffleman that thing has more discs than than a Frisbee golf competition!

2) The limbo rig.... that a UH-60 could fly through!

This still isn't bad I am only levying - 480 and in accordance with prophecy, you are still in 2nd place!

Grand total of -380
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Old Jan 14, 2013, 02:04 PM
when down=up, up=expensive
whichwaysup's Avatar
United States, VA, Roanoke
Joined Apr 2012
3,075 Posts
Quote:
Originally Posted by Valkpilot View Post
Wish list in order of preference:
F-104(the REAL bird DEFINITELY could use UMX)
F-100
P-80/T-33
F/A 18

Now on to the real reason I'm here. Had a "controllability issue"(one misset rate
switch) and need to know if "dunking" can fix it or not, and should it be 3-5 min
at simmer? Or is it new plane time?
You'll find that a little hot water and a nostril massage and she'll be feeling up to her old self again. One warning if you do the hot water dunk and happen to have a gas stove - TURN OFF THE GAS BEFORE YOU DUNK HER. I sort of left the gas on under the pot (on very low) and the next thing I knew, my wing was blistering. The heat from the burner was creeping up the side of the pan and hitting the wing. She's a little blistered, but still flies well. I'd imagine this could happen on an electric stove too, if the burner were still hot.



Okay - I need help. I've had this issue consistently with my Mig and I want to know if it's specific to MY airframe, or if it's a swept wing/EDF/Mig 15 thing. EVERY time I give significant up elevator (with any speed at all), I get a REALLY nasty roll that often ends up causing my Mig's nose to look like his Mig's nose. I'm not even talking full deflection - coming out of a loop, if I don't ease off the elevator as the speed increases, she'll roll right out of the loop and straight into the ground. Before you begin postulating, here are a few things you can eliminate:

1) Wings - yes i know i mentioned scorching one of them, but this happened long before that. Wings are level, ailerons are operating normally.
2) Rudder - I already thought of this and discovered that the rudder halves were not operating together and that one of them had too much play in it. I got all excited and thought I'd fixed it, but alas, no change in performance.
3) Elevator/horizontal stab - reinforced, level, no play in either of the push rods.

So, it's not the control surfaces, I have to think it's an airframe issue. Is anyone else's Mig doing this?
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Old Jan 14, 2013, 02:17 PM
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Originally Posted by whichwaysup View Post
You'll find that a little hot water and a nostril massage and she'll be feeling up to her old self again. One warning if you do the hot water dunk and happen to have a gas stove - TURN OFF THE GAS BEFORE YOU DUNK HER. I sort of left the gas on under the pot (on very low) and the next thing I knew, my wing was blistering. The heat from the burner was creeping up the side of the pan and hitting the wing. She's a little blistered, but still flies well. I'd imagine this could happen on an electric stove too, if the burner were still hot.



Okay - I need help. I've had this issue consistently with my Mig and I want to know if it's specific to MY airframe, or if it's a swept wing/EDF/Mig 15 thing. EVERY time I give significant up elevator (with any speed at all), I get a REALLY nasty roll that often ends up causing my Mig's nose to look like his Mig's nose. I'm not even talking full deflection - coming out of a loop, if I don't ease off the elevator as the speed increases, she'll roll right out of the loop and straight into the ground. Before you begin postulating, here are a few things you can eliminate:

1) Wings - yes i know i mentioned scorching one of them, but this happened long before that. Wings are level, ailerons are operating normally.
2) Rudder - I already thought of this and discovered that the rudder halves were not operating together and that one of them had too much play in it. I got all excited and thought I'd fixed it, but alas, no change in performance.
3) Elevator/horizontal stab - reinforced, level, no play in either of the push rods.

So, it's not the control surfaces, I have to think it's an airframe issue. Is anyone else's Mig doing this?

I had a similar issue last week. During my second flight ever, I rolled out of the loop (was supposed to be an Immelman but it snuck up on me real quick!) as I came to the bottom of the loop I rolled hard and as the bottom of the loop was quite low, I willl be firing up the water pot tonight!

I have been noticing momentary aileron sticking. Just a brief stick that correct with opposing stick movement. I think its a bad servo and plan to inquire with the LHS that specializes in parkflyers.

I would check your MiG in hand several time with full quick oscillating movements left and right. If this is a common issue, I would love to know!

Good luck WWU!
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Old Jan 14, 2013, 02:19 PM
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United States, PA, Archbald
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I've also experienced this same abrupt roll after giving elevator input. In my case I need to pull up pretty hard to induce it though. Makes me think it is the airframe, I have heard others mention the same roll with up elevator behavior.
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Old Jan 14, 2013, 02:46 PM
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East Bethel, MN USA
Joined Jul 2009
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Pulling the stick back abruptly on any plane will often cause an accelerated stall. If one wing stalls first (which is often the case), the usual result is an abrupt roll toward the stalled wing. It has nothing to do with the airframe, per se. It's simply physics. Pulling positive Gs increases wing-loading, which increases stall-speed. Misaligned elevator halves will also cause a roll with elevator input. Flexing of the horizontal stab can also cause it. So can a heavy wing.

Joel
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Old Jan 14, 2013, 02:57 PM
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Agreed. That being said I do have some airframes where I can not, no matter how much elevator I use, induce this behavior no matter how hard I try. I get more of a pivot around the wing as opposed to a wing stall. Or maybe an equal stall on both wings? Airfoil /Airframe seems to in at least some way make a plane more/less susceptible to this behavior.
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Old Jan 14, 2013, 03:05 PM
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Charlottesville, Virginia, USA
Joined Aug 2010
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Also, can the MiG's horizontal stab/elevator lose authority if their air flow is blocked by the wing in a sharp nose-up attitude?

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Old Jan 14, 2013, 03:24 PM
when down=up, up=expensive
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United States, VA, Roanoke
Joined Apr 2012
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Okay - I think this answers my question. Unless someone says that this DOESN'T happen w/ their Mig, I'll associate it with the physics and the airframe. I've read that a swept wing increases the likelihood of a roll, and that the more swept, the more prone the airframe would be. Pug, given the fact that the tail is also swept, I'd assume it could also be subject to these same mysterious forces that people like me will go through life ever curious about, but never fully understanding.

Therefore, I hereby attribute ALL of my crashes of the MIg to this strange tendency - even the inverted landing when attempting inverted limbo. I have regained my status (in my own mind) of super thumbkin.
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Old Jan 14, 2013, 04:03 PM
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East Bethel, MN USA
Joined Jul 2009
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Quote:
Originally Posted by bob swika View Post
Agreed. That being said I do have some airframes where I can not, no matter how much elevator I use, induce this behavior no matter how hard I try. I get more of a pivot around the wing as opposed to a wing stall. Or maybe an equal stall on both wings? Airfoil /Airframe seems to in at least some way make a plane more/less susceptible to this behavior.
The airframe & airfoil definitely matter. However, most any conventional airframe can be put into an accelerated stall - given enough elevator authority, The finer points of a given plane's stall characteristics are largely dependent upon wing-loading & airfoil design. For instance, fatter airfoils with blunt leading edges typically have gentler stall characteristics than thinner airfoils with sharp leading edges. Lower wing-loadings reduce the tendency for accelerated stalls. CG placement also comes into play, as moving the CG aft increases elevator authority. A small variation in washout between the wings will also make one stall before the other, as will a lateral imbalance.

Quote:
Originally Posted by pugsam View Post
Also, can the MiG's horizontal stab/elevator lose authority if their air flow is blocked by the wing in a sharp nose-up attitude?

Horizontal stabilizer blanking is a concern with T-tails. However, it has nothing to do with the plane's attitude, per se, and it does not cause a roll of any kind. Stab blanking happens when the wing is already in a deep stall & the plane's nose-high attitude places the T-tail in the wing's wake. The result is often a total loss of pitch control combined with a strong pitch-up. This causes what is known as a locked-in stall, in which recovery is impossible - or nearly so: http://www.rbogash.com/Safety/deep_stall.html

Joel
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Old Jan 14, 2013, 04:36 PM
Chef Pilot: Planes vs Butter
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United States, VA, Hamilton
Joined Jul 2012
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I don't know about you, but I know that when I want to do a nice loop, all too often, I'm inputting some aileron at the same time, inadvertently of course.
I don't have all that much experience (9 months) but i have to be very deliberate about a loop or hammerhead as even the slightest aileron input while doing those maneuvers will yield a less than satisfactory result.
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Old Jan 14, 2013, 04:41 PM
LiPo-Sucker & Airframe EMT
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Charlottesville, Virginia, USA
Joined Aug 2010
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Deja vu, all over again!

http://www.rcgroups.com/forums/showp...postcount=1665

Deep stall for a T-tail = likely loss of directional stability.

The first thing to go may be pitch control (by definition, you're already high AOA!), but then roll and yaw oscillations probably follow.

(I'm not disagreeing with ANYONE, though.......)

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Old Jan 14, 2013, 04:58 PM
Gopher huntin' stick jockey
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East Bethel, MN USA
Joined Jul 2009
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Stab blanking simply doesn't happen when the wing is flying, and it never causes an abrupt roll. It is most definitely not the cause of the abrupt roll when pulling back abruptly on the stick that is currently being discussed. As we discussed 77 pages ago - the described behavior is classic 'high-speed stall'.

There is no mystery here...

Joel
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