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Model Forum / Radio Controlled / Air Models / May 20061/2scale r/c Japanese navy zero fighter
Yeah I know I'm addicted to watching these videos online, but hey it's midnight I'm at work and have nothing else to do at the time so hey. Anyways you all know I like R/C planes and this is a beautifull model of a 1/2 scale Japanese Zero. Manufacturing costs 2500000yen (about $22000) Length 4,8m Width 6m Weight 150kg Engine 250cc Time period for manufacturing 3 and half years http://www.youtube.com/watch?v=K9w00A6e478 I wont spoil the video with my comments Cheers, Chris sh.t happens... > Yeah I know I'm addicted to watching these videos online, but hey it's > midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 17 lines] > Cheers, > Chris "dingo" wrote: > "Dude" schreef... > [quoted text clipped - 16 lines] > > sh.t happens... Appears the plane is underpowered, wing stalled after leaving ground effect and dorked in. IMHO, perhaps tweaking both ailerons up a little would mimic washout and prevent tip stalling. He was having engine problems earlier on. May need more power. Accident isn't as bad as it appears. There is some rebuilding, but plane isn't totaled. Anyway, enough monday morning quarterbacking (or sumo coaching?) .... Would like to see it fly again successfully. Now if the AMA .... heh  SignatureHPT > Yeah I know I'm addicted to watching these videos online, but hey it's > midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 4 lines] > > Engine 250cc What was he thinking? It was way obvious taxiing that thing around that it was horribly underpowered. >> Yeah I know I'm addicted to watching these videos online, but hey it's >> midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 7 lines] >What was he thinking? It was way obvious taxiing that thing around that >it was horribly underpowered. And the B-29 was horribly overpowered. They should have worked out some sort of deal on power-sharing. Ken I didn't think it was under powered, just under flown. Red S. >> Yeah I know I'm addicted to watching these videos online, but hey it's >> midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 7 lines] > What was he thinking? It was way obvious taxiing that thing around that > it was horribly underpowered. > I didn't think it was under powered, just under flown. It climbed out pretty flat, then dropped a wing. There just wasn't enough power. It would seem that should have been enough motor for it, but either it wasn't making enough power or it was overpropped trying to get a scale look. >I didn't think it was under powered, just under flown. > >Red S. It is hard to tell sometimes just what the prop speed is on some engines, and then there is the pitch question. So, the rpm could sound low and still have plenty of thrust...but the model did not accelerate like it should when the rpm was at a constant level. The tail was never completely flying at lift off. The engine was having a hard time clearing itself on four of the lengths of the runway. I assumed that was full speed and either it was underpowered or the pitch/diameter was incorrect and gave the model insufficient low-speed thrust...as with a direct drive-motor on a two-meter model. In that case, the rpm is up but the drag doesn't let the model accelerate to an air-speed to produce sufficient lift. We are assuming that was the model's first flight. There was a pretty good head wind which should have helped him some. If it had been in still air, I do not think the tail would have come off the ground. He could have immediately raised the gear and put some down in but then, he might not have thought of that at the time. I am used to flying under-powdered models. Ken >>> Yeah I know I'm addicted to watching these videos online, but hey it's >>> midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 7 lines] >> What was he thinking? It was way obvious taxiing that thing around that >> it was horribly underpowered. > >I didn't think it was under powered, just under flown. > > > >Red S. I agree with Red, it was probably a pilot problem, reversed ailerons or mechanical/radio malfunction. That slow left roll was not a tip stall. It flew all the way to the ground. >> >I didn't think it was under powered, just under flown. >> > [quoted text clipped - 3 lines] >mechanical/radio malfunction. That slow left roll was not a tip stall. >It flew all the way to the ground. It was a big, very heavy model and it was low. I would think the inertia of the model would slow down the apparent roll-rate of a tip stall. I would not expect the violent and abrupt tip stalls we see on the smaller and lighter models. I have seen the differences in roll rates even in the models I have flown. Lets hope the poor guy did not have the ailerons reversed. <g> I like scale flight from scale models...Kamikaze? I designed and built a Bogus Baka (published in MB) with an engine and big spinner on the front and another engine on the rear. I was asked if I was going for a scale flight. I told them, "I hope not!" <g> Ken > >> >I didn't think it was under powered, just under flown. > >> > [quoted text clipped - 3 lines] > >mechanical/radio malfunction. That slow left roll was not a tip stall. > >It flew all the way to the ground. I looked at the video several times. If you watch carefully, It looks as though the right aileron drops (left roll) just after the wing starts to drop a bit on climb out. However not standing there and watching in person (knowing the models weight, HP, prop etc) videos can be a bit deceptive. rick markel >I looked at the video several times. If you watch carefully, It looks >as though the right aileron drops (left roll) just after the wing >starts to drop a bit on climb out. However not standing there and >watching in person (knowing the models weight, HP, prop etc) videos can >be a bit deceptive. My first impression was "reversed ailerons," too. I can't believe they would do that! Someone knows, but they speak Japanese and I don't. ;o) Marty >>> I didn't think it was under powered, just under flown. >>> [quoted text clipped - 3 lines] > mechanical/radio malfunction. That slow left roll was not a tip stall. > It flew all the way to the ground. Looks like full aileron deflection for a left turn just after take off, radio failure seems the most probable cause. SignatureRick -- >Looks like full aileron deflection for a left >turn just after take off, radio failure >seems the most probable cause. About a year and a half ago, there was a whole spate of similar incidents involving a new version of Berg receivers. This happened to a friend of mine, an experienced RC pilot, maidening a Fliton Quiet Storm with the aforementioned Berg Rx. At takeoff, all controls froze, the throttle frozen at takeoff setting; the plane does a slow roll to the left and plows into the pavement inverted. There was absolutely no control, with all controls frozen. Afterward, the Rx checked OK, and was even sent in and checked by Mr. Berg himself who pronounced it OK. My friend's Tx supported several other planes with no problems ever. RC Groups (EZone) carried a thread about similar incidents around the same time. The issue appears resolved now that Castle Creations has taken over the Berg line. Anybody know what Rx was in the big Zero? Bill(oc) Dude Wrote: > Yeah I know I'm addicted to watching these videos online, but hey it's > midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 17 lines] > Cheers, > Chris Interesting, but pointless isn't it? You could build a full scal replica of the real thing for a lot less than that -- spinnett >Yeah I know I'm addicted to watching these videos online, but hey it's >midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 12 lines] >Time period for manufacturing 3 and half years >http://www.youtube.com/watch?v=K9w00A6e478 WOW! Probably should have used rudder rather than ailerons to correct the roll? He certainly didn't horse it off the ground. I'm sure they'll do better next time! Marty >>Yeah I know I'm addicted to watching these videos online, but hey it's >>midnight I'm at work and have nothing else to do at the time so hey. [quoted text clipped - 22 lines] > > Marty Nah, it was probably that 3/16" of full aileron travel that got him. <G> Ed Cregger Maybe it would help if he plugged in his ailerons before flight. ??? But you are right, maybe some rudder would have compensated. It is kind of amazing that while they continue to build bigger models their basic flying, pre-flight and maintenance skills don't seem to keep up. Red S. > WOW! > [quoted text clipped - 5 lines] > > Marty Red, I find that 'symptom' astoundingly common. Too bad... > Maybe it would help if he plugged in his ailerons before flight. ??? But > you are right, maybe some rudder would have compensated. It is kind of [quoted text clipped - 13 lines] >> >> Marty >Maybe it would help if he plugged in his ailerons before flight. ??? But you >are right, maybe some rudder would have compensated. It is kind of amazing >that while they continue to build bigger models their basic flying, >pre-flight and maintenance skills don't seem to keep up. I asked a friend with good eyes to watch the video and tell me what he saw. Looks to him (and now looks to me) like the ailerons must have been reversed: http://moleski.net/rc/zero.htm Marty > >Maybe it would help if he plugged in his ailerons before flight. ??? But you > >are right, maybe some rudder would have compensated. It is kind of amazing [quoted text clipped - 10 lines] > > Marty After another look at the video IMHO it does appear that the ailerons are reversed. If one looks closely at the video as the plane banks to the left I think I can see the right aileron drop. I know the video is not of great quality but watch the lower trailing edge of the right wing. Hard to believe that someone would not preflight a 50% plane. Equally hard to believe the pilot would move the stick in the wrong direction. Maybe there is another reasonable explanation? >After another look at the video IMHO it does appear that the ailerons are >reversed. If one looks closely at the video as the plane banks to the >left I think I can see the right aileron drop. I think I can see it dropping, too. I put a couple of frames on this page: http://moleski.net/rc/zero.htm >I know the video is not of >great quality but watch the lower trailing edge of the right wing. Yep. And the left wing looks "thinner" at the same time--the left aileron would be edge-on to the camera. >Hard to >believe that someone would not preflight a 50% plane. Equally hard to >believe the pilot would move the stick in the wrong direction. Maybe there >is another reasonable explanation? Inadequate photography? Distortions in the images due to lighting conditions? Perceptual difficulties (i.e., it only looks like it's going down, but really it was going up)? I can't believe they made such a rookie mistake, but that's how the pictures look to me. <shrug> Marty >>After another look at the video IMHO it does appear that the ailerons are >>reversed. If one looks closely at the video as the plane banks to the [quoted text clipped - 25 lines] > > Marty That is how it looks to me too, Marty. What a shame. Ed Cregger >>>After another look at the video IMHO it does appear that the ailerons are >>>reversed. If one looks closely at the video as the plane banks to the >>>left I think I can see the right aileron drop. >> I think I can see it dropping, too. I put a couple of frames on this >> page: >> http://moleski.net/rc/zero.htm >> I can't believe they made such a rookie mistake, but that's how >> the pictures look to me. <shrug> >That is how it looks to me too, Marty. What a shame. Yes. No matter what the real cause was, I feel sorry for them. I installed a new servo once upon a time, switching from Futaba or Airtronics or something to Hitec. It was in 1995 or 1996. Or I made a mistake installing it. I haven't forgotten how it spoiled an otherwise great day to fly. When I'm at the top of my game, I remember to go through my pre-flight checklist: Controls--moving in the right direction and at the right speed. Antenna--fully extended. (Did that wrong once, too.) Trims--where they ought to be for this airplane. Switches--high or low rates; takeoff mode It all adds up to "CATS." Marty Marty, I think you nailed this one right on the spot. Good sleuthing. Red S. >>After another look at the video IMHO it does appear that the ailerons are >>reversed. If one looks closely at the video as the plane banks to the [quoted text clipped - 25 lines] > > Marty >Marty, I think you nailed this one right on the spot. >Good sleuthing. Thanks, Red. I have to give credit to my buddy. I asked him to look at it because he's got young eyes and plays around with Photoshop a lot. Once he told me what to look for, then I could see it myself. Marty >>>After another look at the video IMHO it does appear that the ailerons are >>>reversed. If one looks closely at the video as the plane banks to the [quoted text clipped - 4 lines] >> >> http://moleski.net/rc/zero.htm >>>>After another look at the video IMHO it does appear that the ailerons are >>>>reversed. If one looks closely at the video as the plane banks to the [quoted text clipped - 17 lines] > > Marty I've looked at this video countless times. I certainly see the ailerons do what I'd expect them to do when initiating a bank to the left. What I *don't* see is the ailerons ever return to neutral. Nor do I see them increase the left-bank rate. They moved once and never moved again as best as I can tell. And no obvious rudder or elevator input, either. I don't know about you folks but when I'm about to dig a post hole I usually do *something* with the sticks on the way down. So as long as we're guessing, I guess a radio failure, possibly caused by an rx or tx battery timing out, what with all the taxiing around that we saw plus all the probable pre-taxi futzing around in the pits that we didn't see. Once the Zero got a bit of distance from the tx it was all over. Cheers /daytripper >I've looked at this video countless times. I certainly see the ailerons do >what I'd expect them to do when initiating a bank to the left. What I *don't* >see is the ailerons ever return to neutral. Nor do I see them increase the >left-bank rate. They moved once and never moved again as best as I can tell. I thought I saw two movements. But I don't want to get into capturing the Flash movie and going through it frame-by-frame. The more I look, the less I see. :o( >And no obvious rudder or elevator input, either. I don't know about you folks >but when I'm about to dig a post hole I usually do *something* with the sticks >on the way down. I've managed to shut the engine down several times. Saves on cleanup afterward. :-O >So as long as we're guessing, I guess a radio failure, possibly caused by an >rx or tx battery timing out, what with all the taxiing around that we saw plus >all the probable pre-taxi futzing around in the pits that we didn't see. Once >the Zero got a bit of distance from the tx it was all over. That certainly would explain it. Or something shaking loose (a connector somewhere)? Marty >>I've looked at this video countless times. I certainly see the ailerons do >>what I'd expect them to do when initiating a bank to the left. What I [quoted text clipped - 28 lines] > > Marty Yeah, I ate a Gere Sport last summer about 20 seconds after take off . It was sickening. The bird broke ground and began a torque induced bank with the nose too high and there was NO control. No engine, no rudder, no ailerons, no nothing. This was NOT a first flight and the battery checked hot afterwards with a heavy load on it. It took me and several others a week of serious testing to discover the broken lead between the battery and the RX. It only showed up if you happened to move the wire in one particular direciton and it was not anywhere near and end nor was there any damage to the insulation. We just got very unlucky and had a bad chunk of wire. :( |
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