How big is too big?
04-15-2013, 06:59 AM
#1
How big is too big?
This has been on my mind for, well, quite a while now, but today I just felt I needed to start to ask about it.
How big is too big when it comes to our models? I'm not talking the guys who build themselves and go huge and get inspections done so they are certified, that's a different ballgame. I'm talking from Manufactures who want to sell to the average guy. In many cases, the average American where the AMA weight limit is set at (I believe) 55lbs dry.
I have major concerns with the sizes of some of these airplanes.
Composite materials have certainly allowed for larger/lighter airplanes to come to the market. But where does size become unsafe? You can only build so big, at a specified weight, before you have to start removing weight from STRUCTURE. We saw this with Dantley's F14. Now I know it's not been proven what caused this airplane to crash, but the simple fact that a major structural area was built incorrectly with a material that was innappropriate for that area, is a genuine concern.
There are companies building RC Jets that 10 years ago would have weighed in at 100lbs, now they meet the 55lb requirement?
It is only a matter of time before one of these huge airplanes comes apart in flight and causes a major issue.
There are more concerns than simnply that of structure as well....
Perception. When airplanes become larger, they appear closer in, they appear slower etc. However, we are getting to the point where it's not inconceivable to think that these airplanes are getting to the point where they will be flown higher and farther out than ever before. I suppose that isn't really an issue so long as the area is wide open, and our radio's continue to be able to handle the distance (I don't feel range is an actual concern but....) I have seen many flying sites where populated area's are plenty far out that the average model will never come close to them. But when flying something huge that doesn't look that far away, it could be. Further to that, some of these jets today, doing 200mph only look like they're doing 100mph. Shui's firebird at 340mph looked crazy fast, that's by todays standards not a very big jet. But a 1/3 scale Hawk at 300mph wouldn't look anywhere near that fast, however, our human reaction time is still the same, and it's still covering just as much ground as any 300mph jet would. When does the average pilot reach their limits and not truly realize it due to the size perception?
Speed. I touched on it above, but in the US, with the 200mph speed restriction, how fast do you really think these 10' long jets are going? I bet 200mph is being broken with airplanes like these regularly without realizing it. Outside of the fact that rules are rules, that may not matter, so long as the structure is able to take it, and the area being flown in is open enough for those higher speeds.
My little Bobcat XL at 200mph looks and feels like a very fast airplane. My old Kingcat at the same speed looked and felt anemic, I put a bigger motor on it. My CAI Raptor at 240mph looks and feels like a crazy fast airplane, flying the Firebird at 240mph doesn't feel or look anywhere near as fast. An airliner on final looks like it's only going about 70mph if you were to compare it to an average sized RC model, but compared to an average RC model, it's hauling ass!
I don't know, I have many concerns about this hobby, I don't think that RC Jets will be the eventual problem creator in this hobby, I think park flyers, and more likely FPV flying is what will eventually lead to major regulation and / or the demise of the hobby, however, Jets are always under the microscope anyway, I personally feel that RC models are getting TOO big and that sooner than later, we are going to see some major structural failures of these airplanes. I just hope they don't cause anymore damage than just to the model itself.
How big is too big when it comes to our models? I'm not talking the guys who build themselves and go huge and get inspections done so they are certified, that's a different ballgame. I'm talking from Manufactures who want to sell to the average guy. In many cases, the average American where the AMA weight limit is set at (I believe) 55lbs dry.
I have major concerns with the sizes of some of these airplanes.
Composite materials have certainly allowed for larger/lighter airplanes to come to the market. But where does size become unsafe? You can only build so big, at a specified weight, before you have to start removing weight from STRUCTURE. We saw this with Dantley's F14. Now I know it's not been proven what caused this airplane to crash, but the simple fact that a major structural area was built incorrectly with a material that was innappropriate for that area, is a genuine concern.
There are companies building RC Jets that 10 years ago would have weighed in at 100lbs, now they meet the 55lb requirement?
It is only a matter of time before one of these huge airplanes comes apart in flight and causes a major issue.
There are more concerns than simnply that of structure as well....
Perception. When airplanes become larger, they appear closer in, they appear slower etc. However, we are getting to the point where it's not inconceivable to think that these airplanes are getting to the point where they will be flown higher and farther out than ever before. I suppose that isn't really an issue so long as the area is wide open, and our radio's continue to be able to handle the distance (I don't feel range is an actual concern but....) I have seen many flying sites where populated area's are plenty far out that the average model will never come close to them. But when flying something huge that doesn't look that far away, it could be. Further to that, some of these jets today, doing 200mph only look like they're doing 100mph. Shui's firebird at 340mph looked crazy fast, that's by todays standards not a very big jet. But a 1/3 scale Hawk at 300mph wouldn't look anywhere near that fast, however, our human reaction time is still the same, and it's still covering just as much ground as any 300mph jet would. When does the average pilot reach their limits and not truly realize it due to the size perception?
Speed. I touched on it above, but in the US, with the 200mph speed restriction, how fast do you really think these 10' long jets are going? I bet 200mph is being broken with airplanes like these regularly without realizing it. Outside of the fact that rules are rules, that may not matter, so long as the structure is able to take it, and the area being flown in is open enough for those higher speeds.
My little Bobcat XL at 200mph looks and feels like a very fast airplane. My old Kingcat at the same speed looked and felt anemic, I put a bigger motor on it. My CAI Raptor at 240mph looks and feels like a crazy fast airplane, flying the Firebird at 240mph doesn't feel or look anywhere near as fast. An airliner on final looks like it's only going about 70mph if you were to compare it to an average sized RC model, but compared to an average RC model, it's hauling ass!
I don't know, I have many concerns about this hobby, I don't think that RC Jets will be the eventual problem creator in this hobby, I think park flyers, and more likely FPV flying is what will eventually lead to major regulation and / or the demise of the hobby, however, Jets are always under the microscope anyway, I personally feel that RC models are getting TOO big and that sooner than later, we are going to see some major structural failures of these airplanes. I just hope they don't cause anymore damage than just to the model itself.
04-15-2013, 07:28 AM
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RE: How big is too big?
I can see what you mean, some of these jets I would still consider heavy especially the twin GT's. I build quite large (Current DC10 measures 3.3 meters) but that thing weighs next to nothing but it's built to withstand very very strong forces inc wingload (this includes sitting on the wing to test whether it flexes etc! But even though I build large, I'm not one for speed as I think scale flying looks much better, with a large bird I can literally glide it in, there's less turbulent forces due to the size etc and I don't need a high output GT to power it (this thing's going to run on a 24lbs turbine)
I think it really does depend on the overall weight and internals and after seeing that crash of Dantley's F14 I really couldn't trust myself to buy a ARTF, I would rather carry on building from scratch using proven plans etc! It seems that some of these kits are all about the scale look but no thought on internal design and a conveyor belt sales process.
I think it really does depend on the overall weight and internals and after seeing that crash of Dantley's F14 I really couldn't trust myself to buy a ARTF, I would rather carry on building from scratch using proven plans etc! It seems that some of these kits are all about the scale look but no thought on internal design and a conveyor belt sales process.
04-15-2013, 08:48 AM
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RE: How big is too big?
MODS HAT OFF
Are larger models inherently more dangerous? I suppose that answer to this has to be yes, because the kinetic energy involved will be greater if they hit someone or something assuming the speeds were the same. I am thinking about two fatal accidents involving models. One occured in Europe where a top display pilot lost radio link to a large biplane killing two people. I saw him fly it or something similar and we are looking at 50 - 70 lbs with a 200cc engine The other was in England where a pretty standard sport model powered by an everyday 40 hit and killed one person.
Recently I was fortunate to be able to tour the USA for a couple of years and flew at lots of clubs as a guest. [ Thanks guys ] One thing I noticed was the proliferation of large 100 - 150 cc gas models. However when those guys flew I felt safer than when the 40 powered stuff was airborne. The big guys were more carefull about the preflight checks and often had a spotter. In fact I don''t remember a single large model crash but a few smaller ones went in.
So although the potential for a bad accident has to be greater, does it matter much if what hits you weighs 20lbs or a 100lbs? Will the larger models be flown by the better pilots who will take more care over setup and flight planning so the accident rate will be lower.
I was at Barkston Heat when Gordon Nichol's big B52 went in. [link=http://www.flixxy.com/rc-plane-b52-final-flight.htm]last flight[/link]
Wingspan: 23'
Length: 23'
Dry Weight: 297 lbs
Fueled Weight: 330lbs (inside the CAA 150kg limit)
Fuel Capacity: 22 litres Jet A1
8 x Wren 54s
The fireball and crater was pretty impressive and if it had gone into a crowd there is little doubt there would have been multiple people dead.
So if Skymaster brings out a 23' span B52 with a projected dry weight of 250 lbs, should it be allowed to fly? I don't know. Being a bit of a hooligan my first inclination is to say why not. Their big BAE Hawk is easier to fly than the little ones. The most difficult jet I have flown was my 15 lb dry Starfighter. The bigger stuff was easier to see.
But should they be flown around people? There is an excellent argument that says all model airshows should be restricted to models of less than 8 oz with maximim speeds of 30 mph. Because it is not if a model goes into the crowd it is when. Now before you tell me about seperation zones and no fly zones and crowd barriers let me remind you of the crash in Hungary where two people died. All of that was in place but the pilot lost radio link and in it went. I have watched the video and it is pretty clear that the servos were not moving.
So is the answer to let the big stuff fly but just not around people? that would no Joe Nall, no showline at the Britsh Nats with the big stuff flying. Where would you draw the line, OK no 300lb B 52, but should a 60 year old with declining eyesight and reflexes be allowed to fly a 1/6th scale Starfighter there?
OK Mods hat back on and I resume the watch for any BigPlumbs reincarnations.
Are larger models inherently more dangerous? I suppose that answer to this has to be yes, because the kinetic energy involved will be greater if they hit someone or something assuming the speeds were the same. I am thinking about two fatal accidents involving models. One occured in Europe where a top display pilot lost radio link to a large biplane killing two people. I saw him fly it or something similar and we are looking at 50 - 70 lbs with a 200cc engine The other was in England where a pretty standard sport model powered by an everyday 40 hit and killed one person.
Recently I was fortunate to be able to tour the USA for a couple of years and flew at lots of clubs as a guest. [ Thanks guys ] One thing I noticed was the proliferation of large 100 - 150 cc gas models. However when those guys flew I felt safer than when the 40 powered stuff was airborne. The big guys were more carefull about the preflight checks and often had a spotter. In fact I don''t remember a single large model crash but a few smaller ones went in.
So although the potential for a bad accident has to be greater, does it matter much if what hits you weighs 20lbs or a 100lbs? Will the larger models be flown by the better pilots who will take more care over setup and flight planning so the accident rate will be lower.
I was at Barkston Heat when Gordon Nichol's big B52 went in. [link=http://www.flixxy.com/rc-plane-b52-final-flight.htm]last flight[/link]
Wingspan: 23'
Length: 23'
Dry Weight: 297 lbs
Fueled Weight: 330lbs (inside the CAA 150kg limit)
Fuel Capacity: 22 litres Jet A1
8 x Wren 54s
The fireball and crater was pretty impressive and if it had gone into a crowd there is little doubt there would have been multiple people dead.
So if Skymaster brings out a 23' span B52 with a projected dry weight of 250 lbs, should it be allowed to fly? I don't know. Being a bit of a hooligan my first inclination is to say why not. Their big BAE Hawk is easier to fly than the little ones. The most difficult jet I have flown was my 15 lb dry Starfighter. The bigger stuff was easier to see.
But should they be flown around people? There is an excellent argument that says all model airshows should be restricted to models of less than 8 oz with maximim speeds of 30 mph. Because it is not if a model goes into the crowd it is when. Now before you tell me about seperation zones and no fly zones and crowd barriers let me remind you of the crash in Hungary where two people died. All of that was in place but the pilot lost radio link and in it went. I have watched the video and it is pretty clear that the servos were not moving.
So is the answer to let the big stuff fly but just not around people? that would no Joe Nall, no showline at the Britsh Nats with the big stuff flying. Where would you draw the line, OK no 300lb B 52, but should a 60 year old with declining eyesight and reflexes be allowed to fly a 1/6th scale Starfighter there?
OK Mods hat back on and I resume the watch for any BigPlumbs reincarnations.
04-15-2013, 08:55 AM
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RE: How big is too big?
Hi Jeremy:
Starting out with a wrong premise will usually lead to a wrong conclusion, i.e. 55 lb dry rule, despite your disclaimer "I believe"
JPO and AMA have worked hard the last couple of years, addressing the large model situation, which led to document 520-A which seems to be working out satisfactorily, as long as guys abide by the rules contained within the document.
It is not the size, specifically that causes problems IMO, but the quality of the kit and builder, as well as the pilot operating the vehicle. I personally only own BVM and Tom Cook jets and a Boomer XL which I have modified for safety, since I fly it with a 36lb turbine, but our club has many guys who fly Scale Chinese ARF's. Over the last 7-8 years they all understand that Chinese Jets are nothing more than poorly flight-tested, pretty skins on the outside as they come from the factory. They all require re-engineering by the builder/owner on the inside to be operated safely. Examples are the build threads by Maj Woody on both the small and large Chinese F-4's.
http://www.modelaircraft.org/files/520-a.pdf
Starting out with a wrong premise will usually lead to a wrong conclusion, i.e. 55 lb dry rule, despite your disclaimer "I believe"
JPO and AMA have worked hard the last couple of years, addressing the large model situation, which led to document 520-A which seems to be working out satisfactorily, as long as guys abide by the rules contained within the document.
It is not the size, specifically that causes problems IMO, but the quality of the kit and builder, as well as the pilot operating the vehicle. I personally only own BVM and Tom Cook jets and a Boomer XL which I have modified for safety, since I fly it with a 36lb turbine, but our club has many guys who fly Scale Chinese ARF's. Over the last 7-8 years they all understand that Chinese Jets are nothing more than poorly flight-tested, pretty skins on the outside as they come from the factory. They all require re-engineering by the builder/owner on the inside to be operated safely. Examples are the build threads by Maj Woody on both the small and large Chinese F-4's.
http://www.modelaircraft.org/files/520-a.pdf
04-15-2013, 09:13 AM
#7
RE: How big is too big?
Hi John and Tom,
That is really my point though, as I said, there are airplanes that exceed the 55lb rule and are permitted to fly under the guidelines set. My question or concern is, do the manufactuers that are based outside of the USA really care what those requirements are? Will they take the necessary steps to ensure an adequate structure, or will they simply say, "lets build it lighter so the average guy can fly it under the regulations". Will any of them really take the time even within the LMA limits to correctly engineer the structures?
The large B52 was spectacular and unless otherwise decided, I believe the crash happened due to disorientation. But it wasn't built to try to keep it light enough that it didn't have to pass the requirements set in the UK for a model of that size.
I remember reading threads when the first huge F18's and stuff came out and people asking if they would make it under the weight requirements, and the answers were yes. FEJ as an example started using Honeycomb for weight, and that's what all the FEJ guys were saying was so great was how much weight it saved. Well, that's all fine and good, and I'd like to believe that the average guy buying one of these airplanes would rather have it heavier and stronger and have to meet certain requirements, but that likely won't be the case. In the case of Dantley's F14, I don't for one second believe that Dantley would EVER fly something he didn't deem airworthy, the problem is, some creedence has to be put into the manufacture doing things right. Most of the critical structures can't even be seen without an Xray machine. For the manufacture the bottom line seems to be more about what will look good on paper vs what will be correct. There is no reason for any airplane to fail structurally when built correctly and flown correctly (IMO Dantley's F14 wasn't even been flown in a prototypcial manner, it was being babied around the sky, that's not how a fighter flies).
I don't know, I think that we are playing with fire when it comes to these extremely large airplanes. It is just my opinion, but my opinion is as valid as anyones. I don't have issue with airplanes that meet requirements set out such as the LMA requirements, it's the ones that SHOULD PROBABLY HAVE TO fit in that category but have been built as light as possible to skirt around that issue that concern me.
That is really my point though, as I said, there are airplanes that exceed the 55lb rule and are permitted to fly under the guidelines set. My question or concern is, do the manufactuers that are based outside of the USA really care what those requirements are? Will they take the necessary steps to ensure an adequate structure, or will they simply say, "lets build it lighter so the average guy can fly it under the regulations". Will any of them really take the time even within the LMA limits to correctly engineer the structures?
The large B52 was spectacular and unless otherwise decided, I believe the crash happened due to disorientation. But it wasn't built to try to keep it light enough that it didn't have to pass the requirements set in the UK for a model of that size.
I remember reading threads when the first huge F18's and stuff came out and people asking if they would make it under the weight requirements, and the answers were yes. FEJ as an example started using Honeycomb for weight, and that's what all the FEJ guys were saying was so great was how much weight it saved. Well, that's all fine and good, and I'd like to believe that the average guy buying one of these airplanes would rather have it heavier and stronger and have to meet certain requirements, but that likely won't be the case. In the case of Dantley's F14, I don't for one second believe that Dantley would EVER fly something he didn't deem airworthy, the problem is, some creedence has to be put into the manufacture doing things right. Most of the critical structures can't even be seen without an Xray machine. For the manufacture the bottom line seems to be more about what will look good on paper vs what will be correct. There is no reason for any airplane to fail structurally when built correctly and flown correctly (IMO Dantley's F14 wasn't even been flown in a prototypcial manner, it was being babied around the sky, that's not how a fighter flies).
I don't know, I think that we are playing with fire when it comes to these extremely large airplanes. It is just my opinion, but my opinion is as valid as anyones. I don't have issue with airplanes that meet requirements set out such as the LMA requirements, it's the ones that SHOULD PROBABLY HAVE TO fit in that category but have been built as light as possible to skirt around that issue that concern me.
04-15-2013, 10:32 AM
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RE: How big is too big?
ORIGINAL: j.duncker
Now before you tell me about seperation zones and no fly zones and crowd barriers let me remind you of the crash in Hungary where two people died. All of that was in place but the pilot lost radio link and in it went. I have watched the video and it is pretty clear that the servos were not moving.
Now before you tell me about seperation zones and no fly zones and crowd barriers let me remind you of the crash in Hungary where two people died. All of that was in place but the pilot lost radio link and in it went. I have watched the video and it is pretty clear that the servos were not moving.
He got arrested and went to jail in Hungary, then was PROVEN INNOCENT.
His radio-link got jammed by a unlicenced Ham-radio hobbyist, how come nobody ever talks about the true facts on these forums?
This guy took every precautionary measure possible to avoid someting like this, and yet still something happened.
How many guys do you know who travel a week ahead to test all there equipment on site before they do a demo?
If you want to avoid possibly harming spectators, the only real thing you can do is ban spectators!
BTW the guy you are bashing flies big jets now, he is a demo pilot for one of the largest RC suppliers of the planet. He clearly got over it, I suggest you do too...
Regards, Bart.
04-15-2013, 10:48 AM
#9
RE: How big is too big?
never too big, that is, if its built in Germany.
I dont think we could get BV to build a big jet. Ive said this a million times that if he decided to build a big scale jet, I would be first in line!
Heres my latest monster!
12ft long!
Scott
I dont think we could get BV to build a big jet. Ive said this a million times that if he decided to build a big scale jet, I would be first in line!
Heres my latest monster!
12ft long!
Scott
04-15-2013, 10:51 AM
#10
RE: How big is too big?
ORIGINAL: jetpilot
never too big, that is, if its built in Germany.
I dont think we could get BV to build a big jet. Ive said this a million times that if he decided to build a big scale jet, I would be first in line!
Heres my latest monster!
12ft long!
Scott
never too big, that is, if its built in Germany.
I dont think we could get BV to build a big jet. Ive said this a million times that if he decided to build a big scale jet, I would be first in line!
Heres my latest monster!
12ft long!
Scott
04-15-2013, 10:54 AM
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RE: How big is too big?
Hey Scott, then look out for this one!
Projected for around 50kg take-off weight, and its going to be used in the Formations Cup in Germany.
Regards, Bart.
Projected for around 50kg take-off weight, and its going to be used in the Formations Cup in Germany.
Regards, Bart.
04-15-2013, 11:35 AM
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RE: How big is too big?
I believe there is a simple yet time consuming solution to this. Quality Control outlined by your insurance provider or a governing body.
I work in the QC sector of the oil field, focusing on welding metallurgy, non-destructive testing, traceability of materials, etc. What I can tell you is that there are code books and criteria spelled out for every application you can imagine. I firmly believe a set of criteria could be set by a body or insurance company saying these aircraft (all sizes of jet, prop, etc), must meet a minimum criteria and have X documentation supplied with them in order to be insured. Yes, this would cost the manufacturer, thus you and me more money but we would have a product that would meet a minimum instead of just hoping its good enough to survive.
I never thought of this before as any kind of requirement, however, given the size and noted problems with certain manufacturers I do believe it is time. There may be some that can already provide the necessary documentation, others cannot. The "others" is who this will target. Any that can already back there product would simply need to include a CD with there documentation or have somebody sit at the photo copier. The "others" would be unable to meet insurance criteria, and would fade away given lack of sales.
Dale
I work in the QC sector of the oil field, focusing on welding metallurgy, non-destructive testing, traceability of materials, etc. What I can tell you is that there are code books and criteria spelled out for every application you can imagine. I firmly believe a set of criteria could be set by a body or insurance company saying these aircraft (all sizes of jet, prop, etc), must meet a minimum criteria and have X documentation supplied with them in order to be insured. Yes, this would cost the manufacturer, thus you and me more money but we would have a product that would meet a minimum instead of just hoping its good enough to survive.
I never thought of this before as any kind of requirement, however, given the size and noted problems with certain manufacturers I do believe it is time. There may be some that can already provide the necessary documentation, others cannot. The "others" is who this will target. Any that can already back there product would simply need to include a CD with there documentation or have somebody sit at the photo copier. The "others" would be unable to meet insurance criteria, and would fade away given lack of sales.
Dale
04-15-2013, 12:27 PM
#14
RE: How big is too big?
Interesting thread.
First I don't fly jets. The largest model I presently have is a 17 pound Tiger Moth. But because of my Aero engineering degree and A&P license I was the first AMA District 8 Large (formerly Experimental) Model Aircraft Inspector. In holding that title for the last 15 years I've only been asked to examine ONE over 55 Lb plane and that meeting never happened.
Your questions run in two directions how big and how heavy. I'm under the impression since this is the jet forum your concerns are more towards a too heavy, structurally insufficient design.
First let's put the AMA's (and to some extent MAAC) roll in this. They provide blanket and individual insurance in the event of a mishap at a sanctioned contest or sanctioned flying field. It is an always has been SECONDARY to your homeowners policy. So if a jet up to 125 pound has passed an LMA inspection and was being flown IAW 520a and the AMA Safety code and some injury occurred as a result of a flight at one of those events, If the homeowners insurance declined coverage of the damages, then the AMA would step in and cover the costs up to the limit. What if the airplane is outside the scope of 520a and being flown unsafely? The injured parties would end up taking legal action against the airplane owner to recoup their losses. Period end of story.
We’ve gotten lulled into this “must have the AMA insurance…†nanny state mentality and think we are free to fly anything so long as it meets their guidelines. When in reality and after the dust clears and the lawyers are paid, the responsibility for the ultimate safe operation and subsequent liabilities falls on the shoulders of the model owner.
So honest answer to your question has two answers: If you’re going to fly at an AMA contest/site and fly by their guidelines, your liability is shared but not totally covered by your AMA/MAAC insurance. If you fly outside those guidelines then your liability is as deep as the lawyers can bleed your pockets dry.
It’s only too big or too heavy if you cannot afford to pay for the injuries you may cause.
First I don't fly jets. The largest model I presently have is a 17 pound Tiger Moth. But because of my Aero engineering degree and A&P license I was the first AMA District 8 Large (formerly Experimental) Model Aircraft Inspector. In holding that title for the last 15 years I've only been asked to examine ONE over 55 Lb plane and that meeting never happened.
Your questions run in two directions how big and how heavy. I'm under the impression since this is the jet forum your concerns are more towards a too heavy, structurally insufficient design.
First let's put the AMA's (and to some extent MAAC) roll in this. They provide blanket and individual insurance in the event of a mishap at a sanctioned contest or sanctioned flying field. It is an always has been SECONDARY to your homeowners policy. So if a jet up to 125 pound has passed an LMA inspection and was being flown IAW 520a and the AMA Safety code and some injury occurred as a result of a flight at one of those events, If the homeowners insurance declined coverage of the damages, then the AMA would step in and cover the costs up to the limit. What if the airplane is outside the scope of 520a and being flown unsafely? The injured parties would end up taking legal action against the airplane owner to recoup their losses. Period end of story.
We’ve gotten lulled into this “must have the AMA insurance…†nanny state mentality and think we are free to fly anything so long as it meets their guidelines. When in reality and after the dust clears and the lawyers are paid, the responsibility for the ultimate safe operation and subsequent liabilities falls on the shoulders of the model owner.
So honest answer to your question has two answers: If you’re going to fly at an AMA contest/site and fly by their guidelines, your liability is shared but not totally covered by your AMA/MAAC insurance. If you fly outside those guidelines then your liability is as deep as the lawyers can bleed your pockets dry.
It’s only too big or too heavy if you cannot afford to pay for the injuries you may cause.
04-15-2013, 01:10 PM
#15
RE: How big is too big?
Interesting thread coming from a guy who owns an Olympus powered Firebird - documented as the fastest r/c jet in the world thru the efforts of David Shulman. OK, I know Shui had a modded Oly but how much difference could there really be in potential to do some serious damage.
Couple thoughts that spring to mind:
-Is a jet model (same weight for weight) - more dangerous because of speed (and hence kinetic energy) or some 150 to 200cc gasser going in to a crowd with a 35+" inch prop ripping around.
-What about the Mustang that literally decimated a crowd of people in Reno when it went in inverted at about 500 mph? Reno is celebrating it's 50th anniversary this year and it looks to me like the event and races are going ahead - as usual. So how if an accident of this scale happened is the whole air racing scheme not shut down? I would be horrified if a model (Jet or otherwise) hit an innocent bystander but do you really think the regulators would come down hard on models? All it would do is pour "gasoline" on the fires of the renegade fliers who head out to parks and fields and do whatever they want. (PS - for those of you who have not heard, we had a "JFK" type incident on approach to YVR on the Easter Weekend. Pilots reported model heli within 100 feet of their planes)
-If you are really concerned about safety, to me the weak link is the radio systems themselves. In spite of all the improvements in 2.4, DMSS, FHSS, etc, etc. these systems are still subject to a multitude of single point failures that will easily bring down any model aircraft. This is where things are really lacking compared to full scale aviation and even remote operation of ground based vehicles.
Relax dude and go have fun flying your model airplane. If you're really worried, go trade in that JR radio on a Futaba..... [:@]
(Sorry guys, inside joke/harassment)
PaulD
Couple thoughts that spring to mind:
-Is a jet model (same weight for weight) - more dangerous because of speed (and hence kinetic energy) or some 150 to 200cc gasser going in to a crowd with a 35+" inch prop ripping around.
-What about the Mustang that literally decimated a crowd of people in Reno when it went in inverted at about 500 mph? Reno is celebrating it's 50th anniversary this year and it looks to me like the event and races are going ahead - as usual. So how if an accident of this scale happened is the whole air racing scheme not shut down? I would be horrified if a model (Jet or otherwise) hit an innocent bystander but do you really think the regulators would come down hard on models? All it would do is pour "gasoline" on the fires of the renegade fliers who head out to parks and fields and do whatever they want. (PS - for those of you who have not heard, we had a "JFK" type incident on approach to YVR on the Easter Weekend. Pilots reported model heli within 100 feet of their planes)
-If you are really concerned about safety, to me the weak link is the radio systems themselves. In spite of all the improvements in 2.4, DMSS, FHSS, etc, etc. these systems are still subject to a multitude of single point failures that will easily bring down any model aircraft. This is where things are really lacking compared to full scale aviation and even remote operation of ground based vehicles.
Relax dude and go have fun flying your model airplane. If you're really worried, go trade in that JR radio on a Futaba..... [:@]
(Sorry guys, inside joke/harassment)PaulD
04-15-2013, 01:59 PM
#16
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RE: How big is too big?
Size isnt the issue. Get enough instances of irresponsibly handled little foamies caught by children's foreheads, and surely these kinds of posts will start appearing about those too.
This sounds a little bit like the gun debate for me. Its well known that China companies attention to safety and detail leave a lot to be desired.
Maybe a better non intrusive response would be to simply not buy them?
This sounds a little bit like the gun debate for me. Its well known that China companies attention to safety and detail leave a lot to be desired.
Maybe a better non intrusive response would be to simply not buy them?
04-15-2013, 04:30 PM
#17
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RE: How big is too big?
I dont think physical size has anything to do with it. The weight of the aircraft is what causes problems. You have a "large" model that weighs 5 Lbs isnt going to destroy a whole lot when it hits the ground, you can only get a massive airframe that only weighs 5 lbs going so fast. You start adding weight to the airframe and it will inherently go faster.
BTW; Kinetic energy has NOTHING to do with physical size, only density.
BTW; Kinetic energy has NOTHING to do with physical size, only density.
04-15-2013, 07:07 PM
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RE: How big is too big?
I will also agree with some of you . It is not the size . It will not make a difference if a 20lb jet traveling at 250 miles and a 50lb jet traveling 160 miles. Both will do the demage.
In my opinion the problem is , the pilots that fly to the extreme with high speeds wright in front of you by the flight line. If for any second the pilot or the aircraft looses control then it will be disasters.
We are all human and all make mistakes.
FLYSAFE.
In my opinion the problem is , the pilots that fly to the extreme with high speeds wright in front of you by the flight line. If for any second the pilot or the aircraft looses control then it will be disasters.
We are all human and all make mistakes.
FLYSAFE.
04-15-2013, 07:36 PM
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RE: How big is too big?
Let the marketplace work it out.
Jets are not the place to cut corners with questionable Chinese ARFs. If you can afford a $2-3K turbine, you can afford a quality airframe. I don't own one, but am amazed at someone who buys cheap. I'd rather buy a smaller, quality airframe than a big, cheaply-made one.
(PS - for those of you who have not heard, we had a "JFK" type incident on approach to YVR
How is that related to the JFK Jr accident? His was due to spatial disorientation. Low-time pilot in a high-performance plane.
04-15-2013, 07:44 PM
#21
RE: How big is too big?
ORIGINAL: PaulD
Interesting thread coming from a guy who owns an Olympus powered Firebird - documented as the fastest r/c jet in the world thru the efforts of David Shulman. OK, I know Shui had a modded Oly but how much difference could there really be in potential to do some serious damage.
PaulD
Interesting thread coming from a guy who owns an Olympus powered Firebird - documented as the fastest r/c jet in the world thru the efforts of David Shulman. OK, I know Shui had a modded Oly but how much difference could there really be in potential to do some serious damage.
PaulD
I fail to see what flying a (by today's standards) Mid size jet with the engine the manufacture intended for the aircraft has to do with my thread, the firebird weighs as much as some of these monster jets, yet I have no question that it will hold up at the speeds it is capable of. But anyway......
TO REITERATE WHAT I SAID AND SEEMS TO BE GETTING MISSED
I am not talking about flying to fast, I am not talking about manufactures or scratch builders who are building airplanes that will meet requirements of the LMA etc. I am talking about manufactures that are building huge jets, and keeping them as light as possible at the expense of structure. I have no doubt that Skygate, or Tomahawk models, are building correctly engineered aircraft at the sizes they are and they will hold up in flight. Those jets also cost double what a chinese ARF does.
My question, relates to the giant sized jets being manufactured by companies who are simply trying to make sales. Some of these chinese jets are becoming monsterous, they are also being built very light to satisfy this desire by today's modeler to have the lightest airframe possible to stay under the requirements of the LMA.
I have seen it in many threads with the huge F18's, F16's etc, where people ask what is the weight and will it meet the 55lb limit?
My comment regarding perception and speed of the airplanes that are huge was not to suggest that we are flying to fast, it was simply to state that what appears to not be moving that fast, is still moving very fast indeed. I don't care about the kinetic energy of impact at this point in my question, I don't care about the speed limits imposed by the AMA.
What my point was, is at what point do we as responsible modelers have to say wait a minute, should an airplane that has a 10 foot length really only weigh XXlbs, is the aircraft built correctly, can it really be stiff enough, and strong enough to withstand the rigors of flight?
I see in the F14 crash thread people talking about how they only fly in a pattern, or that we should fly "with kid gloves" so to speak. Since when???? These are jets and if I can't fly my jets like a jet should fly I don't want it. I don't want to be concerned that if I should misjudge a loop on the bottom side by a little bit, that if I have to pull a little harder on the elevator the airplane will fold up and disintegrate. I don't want to be thinking that if I misjudged a turn in towards the flightline and have to turn tighter that the wings are going to peel off or the elevators are going to flutter away. I don't want to be thinking that my super huge jet, that the manufacture tells me is for a 50lb thrust turbine is going to shake itself to pieces if I do a full throttle pass with a 50lb thrust engine.
I guess at the end of the day, the answer is as big as you want, but my concerns are valid, when I see airplanes that are not structurally sound, or even questionable, it makes me wonder at what point are we playing with fire more than we should?
04-15-2013, 08:06 PM
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RE: How big is too big?
Been hearing this debate since the 80´s when some people thinked that 35cc quadra powered quarter scale models were considered dangerous and unnecessary big. 
As long is well built, maintained and piloted and above all, flown on a proper place there is no limit at all. (in my humble opinion).
As long is well built, maintained and piloted and above all, flown on a proper place there is no limit at all. (in my humble opinion).
