HUNGARIAN AIR FORCE MIG-15 RED 047 MUSEUM SCALE 1/4
08-31-2015, 10:32 AM
#327
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Just a Heads Up on this.... as I am just back home (from the JWM 2015).
1 of these was lost at the JWM 2015, and 1 more was lost in test flying for the JWM 2015. Seems to be an issue with asymmetric flap deployment (jamming) with the production configuration. Please stay in touch with your peers on this! I wish the owners of this plane success in sorting this out so they can enjoy it!
David
1 of these was lost at the JWM 2015, and 1 more was lost in test flying for the JWM 2015. Seems to be an issue with asymmetric flap deployment (jamming) with the production configuration. Please stay in touch with your peers on this! I wish the owners of this plane success in sorting this out so they can enjoy it!
David
Last edited by dribbe; 08-31-2015 at 11:41 AM.
08-31-2015, 11:40 AM
#329
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David
08-31-2015, 11:52 AM
#330
Hey Mike
Both Craig's and Brian's planes had the new resigned flaps. I have email Agoston several times after Craig's plane went down a couple keep of months ago and after Brian's went down at wjm. Agoston is aware of the problem an is to my knowledge looking into a solution.
Both Craig's and Brian's planes had the new resigned flaps. I have email Agoston several times after Craig's plane went down a couple keep of months ago and after Brian's went down at wjm. Agoston is aware of the problem an is to my knowledge looking into a solution.
08-31-2015, 05:39 PM
#332
Having spoken with Craig, it sounded to me like the trailing edge of the flap might have jammed against the trailing edge recess in the wing under aerodynamic loading, thus causing the hang up of one flap. Have to take a close look at mine.
09-07-2015, 02:02 AM
#333
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In recent weeks regarding the issues raised flaps investigated. I checked the structure again and made a synthetic test, which I recorded with photographs and video footage. These well-established that the structure and the servos are perfectly suited to the task. The servos are able to move a load of nearly half the flaps, the wing structure in spite of the higher than necessary load performed well.
The weather was not favourable. Gale-force cross wind and 24 Celsius. During the test the wing was fixed top of my car. This is significantly higher stress on the wing like on a model, as this because on the inflexible car we lost elasticity and softness of the air. On the attached recordings clearly see that the flaps work smoothly and perfectly over 120 km/h. This speed is more than double that the stall speed of the models.
Raised in the two cases are just assumptions because I did not see any records and I was not at the scene, I was not involved in the ready building of the model. Based on the foregoing, it appears that the clearances were not sufficient to free movement under load, and the pair of servo was inadequate. So in both cases, a steering jammed. This could lead to accidents.
https://www.dropbox.com/sh/p63o5gg6l...sF9jRwIka?dl=0
The weather was not favourable. Gale-force cross wind and 24 Celsius. During the test the wing was fixed top of my car. This is significantly higher stress on the wing like on a model, as this because on the inflexible car we lost elasticity and softness of the air. On the attached recordings clearly see that the flaps work smoothly and perfectly over 120 km/h. This speed is more than double that the stall speed of the models.
Raised in the two cases are just assumptions because I did not see any records and I was not at the scene, I was not involved in the ready building of the model. Based on the foregoing, it appears that the clearances were not sufficient to free movement under load, and the pair of servo was inadequate. So in both cases, a steering jammed. This could lead to accidents.
https://www.dropbox.com/sh/p63o5gg6l...sF9jRwIka?dl=0
09-10-2015, 02:52 PM
#334
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I have ofcourse checked the flaps functions many times and all seems fine. I have moved the fuction to a trim lever so that I immediately can feel if one of the flaps are stuck and trim them back at once.Rolf
09-10-2015, 03:34 PM
#336
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Thankyou George. I was going to use a M 140 at first, but chickened out in the end and put in a M 160 instead. If it is too much power I can always reconsider. About the jet , the only thing I am looking for now are a set of wing tanks. I think the Mig looks great with them and they can be good to skid on in case of some retract problems. I dread the thought of grinding away the belly of this beautiful plane on the tarmac
Rolf
Rolf
09-30-2015, 07:24 PM
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Hi all,
I had planned to stay off here re my crash but after a few emails with Agoston I believe there is a broader explanation required than in previous post for everyone building this model. I would hate to see anyone else throw 15k to 20k away with the same issues that two models have suffered to date.
To confirm I lost my Mig weeks before leaving on a trip to Europe to attend the Jet World Masters in Germany. Upon arriving at the JWM on the Monday I was told by a few of the pilots that Brian, the lone ranger from Malta, had lost his model due to a flap lockup – he was the first flight of the event. One flap had locked in the up position and other had extended to full down - the same as mine. From both crashes this was a pretty easy to diagnosis as the actuators stay locked in position versus a servo operated surface which would move on impact.
I was in discussion with Agoston and importantly Brian after my crash as I new it was looking like he would be the second person to have his model in the air – also for the JWM. As far as I know there are no other customers flying the Mig with the scale flap system but happy to be corrected here. Post our discussions Brian added extra grease to his flap runners, opened the surface gaps and tolerances up a little further, and tested the system on the ground countless times – like me. But the facts are that the two Mig’s that have been flown to date with the scale flaps have been destroyed. For me it was pretty damn annoying to turn up at the JWM and see a second pile of honeycomb and glass after hardly being over my crash.
There were some differences in our flights. I took off with one notch of flap (both were down) and 50 seconds in to my test flight I thought I had a wheel hanging low. I went to cycle the gear and by mistake moved the flap switch to the full down position. I was flying at maybe half power, straight and level, and the aircraft went in to a large roll and straight in to the ground. My test flight was all over in around 1 min 10 seconds. I fed in full opposite aileron and rudder which had little effect. I suppose for me I wasn’t expecting the flaps to be coming down as I thought I had hit the gear switch so no chance of recovery. At the time I thought maybe if this had happened in a normal landing pattern I would have had time to put the flaps back up as the roll initiated and maybe i could have saved the model. Brian’s flight however was more traditional with one flap locking up on his downwind leg and the model rolled in. I suppose this proved that my machine was doomed either way. I think this was Brian’s fourth flight with his Mig - he had no issues on the first three. In fact he said the model flew beautifully.
I have had some email discussion with Agoston but no solutions or an admission than there could be an issue seem to be forthcoming. This is a true concern for the significant number of others out there building this aircraft and even for everyone attending events or in the surrounding areas where these models will be flown. My model crashed maybe 400 metres away in a field and Brian’s landed a similar distance away relatively close to a group of houses. In both cases there was a total loss of control. I know this really concerned Brian with the proximity to the houses and of course the shear umber of people attending the JWM.
As far as the testing goes - for me driving around with a wing attached to the roof of a car doesn’t prove a whole lot. I would rather see a prototype that was having it backside flown off to prove all was well with all design facets of this model. There is some frustration for me definitely and I must state that I don’t see much evidence that this system has been tested thoroughly on a working prototype model at all. I would suggest there needs to be more discussion and more testing before anyone else flys this model with the current scale flap system.
Many diagnosis' were being thrown around at the JWM. After my crash and a thorough review of the debris with my friends I put it down to increased pressure on the flap surface holding the surface in the wing flap pocket just a little longer and jamming at the rear. The actuators then do not have the torque to push the flaps through the lock up.
I have been building for 35 odd years and my mates joke about how much of a perfectionist I am – it drives me crazy but I like it done right. I believe my install was perfect and in line with the supplied images and I tested my system on the ground thoroughly. I had a look at Brian’s left overs too and it build / install was first class.
Good luck to all others with this model. I hope you are all chasing a solution to what I see as a real problem.
Thanks.
I had planned to stay off here re my crash but after a few emails with Agoston I believe there is a broader explanation required than in previous post for everyone building this model. I would hate to see anyone else throw 15k to 20k away with the same issues that two models have suffered to date.
To confirm I lost my Mig weeks before leaving on a trip to Europe to attend the Jet World Masters in Germany. Upon arriving at the JWM on the Monday I was told by a few of the pilots that Brian, the lone ranger from Malta, had lost his model due to a flap lockup – he was the first flight of the event. One flap had locked in the up position and other had extended to full down - the same as mine. From both crashes this was a pretty easy to diagnosis as the actuators stay locked in position versus a servo operated surface which would move on impact.
I was in discussion with Agoston and importantly Brian after my crash as I new it was looking like he would be the second person to have his model in the air – also for the JWM. As far as I know there are no other customers flying the Mig with the scale flap system but happy to be corrected here. Post our discussions Brian added extra grease to his flap runners, opened the surface gaps and tolerances up a little further, and tested the system on the ground countless times – like me. But the facts are that the two Mig’s that have been flown to date with the scale flaps have been destroyed. For me it was pretty damn annoying to turn up at the JWM and see a second pile of honeycomb and glass after hardly being over my crash.
There were some differences in our flights. I took off with one notch of flap (both were down) and 50 seconds in to my test flight I thought I had a wheel hanging low. I went to cycle the gear and by mistake moved the flap switch to the full down position. I was flying at maybe half power, straight and level, and the aircraft went in to a large roll and straight in to the ground. My test flight was all over in around 1 min 10 seconds. I fed in full opposite aileron and rudder which had little effect. I suppose for me I wasn’t expecting the flaps to be coming down as I thought I had hit the gear switch so no chance of recovery. At the time I thought maybe if this had happened in a normal landing pattern I would have had time to put the flaps back up as the roll initiated and maybe i could have saved the model. Brian’s flight however was more traditional with one flap locking up on his downwind leg and the model rolled in. I suppose this proved that my machine was doomed either way. I think this was Brian’s fourth flight with his Mig - he had no issues on the first three. In fact he said the model flew beautifully.
I have had some email discussion with Agoston but no solutions or an admission than there could be an issue seem to be forthcoming. This is a true concern for the significant number of others out there building this aircraft and even for everyone attending events or in the surrounding areas where these models will be flown. My model crashed maybe 400 metres away in a field and Brian’s landed a similar distance away relatively close to a group of houses. In both cases there was a total loss of control. I know this really concerned Brian with the proximity to the houses and of course the shear umber of people attending the JWM.
As far as the testing goes - for me driving around with a wing attached to the roof of a car doesn’t prove a whole lot. I would rather see a prototype that was having it backside flown off to prove all was well with all design facets of this model. There is some frustration for me definitely and I must state that I don’t see much evidence that this system has been tested thoroughly on a working prototype model at all. I would suggest there needs to be more discussion and more testing before anyone else flys this model with the current scale flap system.
Many diagnosis' were being thrown around at the JWM. After my crash and a thorough review of the debris with my friends I put it down to increased pressure on the flap surface holding the surface in the wing flap pocket just a little longer and jamming at the rear. The actuators then do not have the torque to push the flaps through the lock up.
I have been building for 35 odd years and my mates joke about how much of a perfectionist I am – it drives me crazy but I like it done right. I believe my install was perfect and in line with the supplied images and I tested my system on the ground thoroughly. I had a look at Brian’s left overs too and it build / install was first class.
Good luck to all others with this model. I hope you are all chasing a solution to what I see as a real problem.
Thanks.
09-30-2015, 08:33 PM
#340
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Hey Roger - yep, there's a few expletives I could align to your asterisks. Tried emailing u the other day - seems I have an old address. Could you message me with your email addy...?
Hey Scott - I'm sure you could go backwards but it would be a bit of work. However this is what i would be doing. I started with the standard servo operated flaps but then dropped my wings back to JetPower to Agoston to fit the scale flaps system. Hindsight eh...!
Hey Scott - I'm sure you could go backwards but it would be a bit of work. However this is what i would be doing. I started with the standard servo operated flaps but then dropped my wings back to JetPower to Agoston to fit the scale flaps system. Hindsight eh...!
09-30-2015, 08:38 PM
#341
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Roger - you heading over for ANZAC?? I think its about time a few more Kiwis came in the other direction. Maybe next year with the 104 in a nice narrow box.
Just grabbed an Airworld F-100... hows your BVM version coming on?
Just grabbed an Airworld F-100... hows your BVM version coming on?
10-01-2015, 09:33 AM
#348
I don't think its been clearly demonstrated that there is a problem with the servos has it? From the fix instructions we received, it seems like it was the flap getting caught up in the recess in the wing.
Tobba, you said you accidentally hit the flap switch. Did the other crash happen with flaps deployed, or did one of them come out on its own? If the latter, I would think there is a servo problem.
It would be a shame to alter the mechanism that operates the flaps, they look outstanding.
I almost pulled my wings down last night. Need to clear a few more things off the bench.
Tobba, you said you accidentally hit the flap switch. Did the other crash happen with flaps deployed, or did one of them come out on its own? If the latter, I would think there is a servo problem.
It would be a shame to alter the mechanism that operates the flaps, they look outstanding.
I almost pulled my wings down last night. Need to clear a few more things off the bench.
10-01-2015, 03:12 PM
#349
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Second crash was the same as mine, one flapped locked in the up position when flaps were deployed.
Only difference being that Brian's happened on the downwind leg of a standard landing pattern, while mine was in normal flight.
Only difference being that Brian's happened on the downwind leg of a standard landing pattern, while mine was in normal flight.
10-24-2015, 12:20 PM
#350
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I finally got to fly the Mig this weekend and I must say that it flew very well. Very smooth handling with no surprices. The flaps worked as they should , no hitch at all.
My CG was set a bit far forward. It balances at 50 mm in front of the rear tube, with empty hopper tank. This was with a Merlin 160 engine and 180 grams of lead up front. When flying it felt a bit nose heavy, so the lead will be removed.
One problem I had was retracting the landing gear in flight. On the ground the gear retracts very convincingly. I am using the usual type of dual action electronic valve. But after take off there doesn't seam to be enough umpf to get them all up. I will have to make some changes to this setup
My CG was set a bit far forward. It balances at 50 mm in front of the rear tube, with empty hopper tank. This was with a Merlin 160 engine and 180 grams of lead up front. When flying it felt a bit nose heavy, so the lead will be removed.
One problem I had was retracting the landing gear in flight. On the ground the gear retracts very convincingly. I am using the usual type of dual action electronic valve. But after take off there doesn't seam to be enough umpf to get them all up. I will have to make some changes to this setup