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Over gross ?

Cadstat

Well Known Member
I flew a Cessna 210 for years and many big friends went up but now at least 6 people come to mind that would be a very tight squeeze in the 6A. I can leave half the fuel behind but am I pushing it with somebody scaling out at 280? I'm 185 lbs. My gross is 1850. I have 2 miles of runway but density alt is often 6,000. The numbers say I'm OK but what's the biggest payload you have tried?
 
230 for pilot, 310 for passenger. Was a tight squeeze. I don't remember the fuel load that day, or weather. Airport elevation is 4607' msl. The 6A with 180 HP C/S prop still had plenty of pep. Also 1850 GW.
 
Didn't Van himself say that 250 lbs per seat was his design limit? Trying to find where I read that, but not having much luck.
 
215 for me, 280 for the passenger, full tanks, hot summer day, and only 135 hp.

The -9 did fine.

The problem was flaring to land, the passenger couldn't get his gut in enough. I wound up wheel landing it after going around and beating him in the gut with the stick.
 
weight ...not so much the issue

I think we all appreciate that at -20 degrees,. with a headwind, the average plane will lift a LOT more than it's placarded for. (Ask a northern bush pilot)
If there's Density Altitiude considerations, I'd have to get out the calculator. Some of you can go by experience, which is probably as good, or better.

I can remove some tools, water, survival gear I gear if I have to ...but truthfully, the side by side RV's aren't that great with large folks.
Not only the pitch limitation, but how many 300 lb-ers have skinny legs?
the control travel side to side is almost more of a concern.
..of course, the removable pass. stick solves most of those. If they really want to 'fly' they can reach over 8" and use the pilot controls.
Also a good point on preflight is where to put their size 12's ....especially on t/off & landing.

some folks have done the wing area/flap calculations, and found that the -9 will lift 2200 lbs. or so....of course, you can't OPerate at that weight without a whole lot of other issues.
 
Didn't Van himself say that 250 lbs per seat was his design limit? Trying to find where I read that, but not having much luck.

I've never seen a 250 lb seat limit in any of the specs but I have seen that as a stated limit for the max weight of a passenger for a demo ride from Van's at Oshkosh.
 
If you haven't flown the airplane at that weight before, you owe it to your passenger to ballast the airplane to that weight and fly it before you carry the passenger. My experience is that when the airplane is at the heavy end of the scale, every 50 pounds of weight you add makes a significant change to the airplane's handling.
 
A better solution would be passengers that weight less than 140 pounds, have longer hair than guys and look better.
 
My gross is 1850.
Since design gross for the -6A is 1650, you're already over gross... But that's a discussion for another thread that's been argued and closed before.

The seat limit is usually based either on crash survivability of the structure under the passenger's backside, or G-load limits on that same structure with a heavy passenger. So yes, a 400lb person could get into your RV and sit there, but hit 3G in turbulence and he'll crush your seat pan.
 
Since design gross for the -6A is 1650, you're already over gross... But that's a discussion for another thread that's been argued and closed before.

The seat limit is usually based either on crash survivability of the structure under the passenger's backside, or G-load limits on that same structure with a heavy passenger. So yes, a 400lb person could get into your RV and sit there, but hit 3G in turbulence and he'll crush your seat pan.

Actually, they would have to be 500lb at 3G (based on a 250lb per seat max). Of course if the ultimate load factor is 9G they would have to weigh 750lb to cause a structual failure at 3G...:D FYI, I'm 6' 4" and 290lb. So I guess I am in trouble..haha
 
The "Gross" specified by Vans [1650 for the 6A I think] will be the Max AuW for various components at various assumed types of loading. Off the top of my head, they might include:
  1. Wing Spar v Utility category 'g' loadings. Probably N/A to 1650 for the 6A since you could extrapolate the Aeros Wt (1350lb?) 6g
  2. Takeoff/Climb Performance - I would suggest very few RVs even way over Vans Gross will run into an issue here ;)
  3. Stall Performance e.g. in the UK amateur built aircraft have a max stall speed.
  4. Landing Gear v Max Loading. I gather, for instance, the RV-8 Ldg Gear is designed for a max 3g landing - above that it starts to bend (and I know someone it has happened to) to protect the fuselage.
  5. Wheels / Brakes v Static Load / Limit Load / Brake Energy / Torque etc.
I am sure there are others... Now, in the USA you can then, as builder, alter that Gross Wt, and decide to reduce the margins in some / all of the above (which of the 5 above only the last 2 are probably relevant), or even allow for the increase e.g fit higher energy brakes.

As an aside, the standard Cleveland brakes for an RV-6A at 1650 will take an emergency stop from 57K, at 1850 53.5K. If you took the 1650/57 as a limit, then 1850 would require just over 60K i.e. increase relative to VS hence takeoff/landing speeds.

For the seat loading v the rumoured 250lbs - again, varous components will need assumptions - here the seat pan design and crucially the seat belts. The seat pan / vertical loading could again be allowed for as per the aeros above (250lbs v 6g allows 500lbs :eek: @ 3g). However, the seat belts in a crash must have a notional limit.. and of course, not just the belts ( which could easily be upgraded), but the mounting bolts, attachments, and the load paths e.g. rivet size / count from those attachments to the structure.

One does not get the impression many builders "upping their gross" take much of the above into account - and I am sure I've only thought of half the factors. Of course, to have a "problem" require some bad luck / judgement, and meeting a max loading (e.g. crash / heavy landing / 6g loop / heavy braking) at the increased weight.
 
Like someone said above, the only place I have seen Van's put a 250lb weight limit on the seat is for demo rides in the factory planes.
 
Why?

Like someone said above, the only place I have seen Van's put a 250lb weight limit on the seat is for demo rides in the factory planes.

I've heard about this restriction before too. But does anyone know their rational for the 250 lb limit for demo rides?
 
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did this in my 9A

250 pilot 350 PAX, sea level airport.
No problem with takeoff, nor with cruise flight, but when on approach I notice the the feel of the controls was a little strange and I didn't like that. Was able to flair OK, but I kept my speed up an additional 10 kts.

I won't take someone that heavy again.

Kent
 
I've heard about this restriction before too. But does anyone know their rational for the 250 lb limit for demo rides?

I think they were just trying to get a handle on how to deal with requests for demo rides from heavier potential clients. This gives the demo pilot a way to deal with the issue that's unambiguous. I'm sure the demo requests are all over the map. I never heard them argue a structural limit issue.
 
Uncomfortable

I am extremely uncomfortable reading about people arbitrarily upping their gross weight from the designers limits. How many accident reports have I read where this has been done with fatal results....... I have lost count?

Personally, I would not put me or my aeroplane at risk by having either someone physically too big blocking the controls, or heavy enough to over stress any part of the airframe in the event of a harder than normal landing.

Only yesterday my friend bent the nose leg on his aeroplane by landing short of the runway on a grass field ( Not an RV). I watched the landing and thought I was about to see him nose over, fortunately the only casualty was the nose leg.

Please take care.
 
I am extremely uncomfortable reading about people arbitrarily upping their gross weight from the designers limits. How many accident reports have I read where this has been done with fatal results....... I have lost count?

Since you can no doubt count to at least ten (I have to use both hands), can you give us ten cases where this has lead to fatalities?
 
Eleven

How many past one would I need to count for it to be enough?

I have been flying for well over thirty years now and in the UK aircraft owners get a digest of accident reports regularly, I don't know if its the same in the US but have picked up details of overweight aircraft on this site that have lead to fatalities. For me one is too many......
 
Steve, there must be many if you have lost count. Can you provide links to accident reports that state that being over gross resulted in fatalities in RVs?
 
How many past one would I need to count for it to be enough?

I have been flying for well over thirty years now and in the UK aircraft owners get a digest of accident reports regularly, I don't know if its the same in the US but have picked up details of overweight aircraft on this site that have lead to fatalities. For me one is too many......

I've read "every" NTSB fatality on record for many years. I can't think off hand, of any RV's that have crashed due to being over weight, and just not having the power to clear terrain..............like so many aircraft do.

If...........you're worried about a "six" model being set at 1850 instead of 1650, then stop worrying!

L.Adamson --- 6A
 
Accidents

Ron,

I will point you towards the one I found through this thread....... I am pretty sure it was an RV4 in canada which was doing Aeros over a training area, over gross weight.

Lets just agree to disagree on this, I respect the design limits you and others can do whatever you want to do, but I wont feel comfortable about it as I will be concerned about your and your passengers safety.

As for researching 30 years of accident records to prove something to you you wont believe forget it.

Just in case you got the wrong impression here I am talking about all aircraft accidents........ not just RV's. I have read a lot where being over gross was a factor........... thats one link you can by choice take out of the chain.

Your choice...... I now withdraw from this thread.
 
Our ag airplanes have two gross weights. There is the recommended gross weight but we are registered in the "Restricted" category and so are allowed a secondary, higher gross weight.

The problem with a bigger than normal gross weight, is what you do with the airplane in that condition. I have to make gentle turns and easy pullups from the field until I lighten up.

The -4 in Oz should never have been doing aeros in that condition and they'd still be alive.

I'm reminded of Rutan's Voyager that used 14,200' of a 15,000 foot runway, he was so grossed out! But they flew it accordingly and all was well.

Best,
 
The -4 in Oz should never have been doing aeros in that condition and they'd still be alive
I am a bit surprised that you restrict your comment to "aeros" Pierre? You seem to imply that flying out of normal gross / CG limits is OK?

Yep! Over gross weight for aerobatics, and out of CG range for aerobatics.
Whilst technically you are correct, my reading of the report is that the aircraft was well out of Gross Wt and CG to fly at all, both at Takeoff, and ZFW.

Somewhat concerned at this impression being given that limits only apply to "aeros" :eek: Does not seem in accordance with http://www.rvflightsafety.org/ as promoted elsewhere on VAF.

Link - see p8
 
Somewhat concerned at this impression being given that limits only apply to "aeros" :eek: Does not seem in accordance with http://www.rvflightsafety.org/ as promoted elsewhere on VAF.

"Upping the gross" is simply eating into whatever margin is available. You may not intend to do acro in the overloaded condition, but what happens when you do have to make a sudden evasive maneuver? One of the "problems" with all of the RV designs is that they are forgiving and rather high performance. This can cause some to exceed the limits with logic like "it did it last time." Complacency can bite you in the bottom, do the math, sometimes you just have to leave your chubby friend on the ramp.

John Clark ATP, CFI
FAAST Team Representative
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
Negative Andy..

I am a bit surprised that you restrict your comment to "aeros" Pierre? You seem to imply that flying out of normal gross / CG limits is OK?

Somewhat concerned at this impression being given that limits only apply to "aeros" :eek: Does not seem in accordance with http://www.rvflightsafety.org/ as promoted elsewhere on VAF.

Link - see p8

Not only during aerobatics, Andy.

Jon Johannson flew his -4 with 300 lbs of fuel in the back seat, plus more in the wingtips for an 18 hour endurance, around the world twice and from the North pole to the South pole that way! I'd bet his CG was aft of limits for a while, 'til he burned off the rear seat tank, and pretty much over gross.

He flew gentle turns and sensibly on all three overgross trips and lives to tell about it.

My first year of ag, I flew a factory built PA-18A, backpack sprayer with an 80 gallon tank in the back seat:eek: When I loaded it with 60 gallons of water/chemical, it had 480 lbs. back there and took five turns forward on the trim handle to fly without me shoving the elevator forward.

It lightened up fairly quickly and I flew it carefully, re-trimming often. It wasn't any fun flying it that way but hey, I was 24 and bulletproof:) and it paid the bills.

Many round-the-worlders have taken off waay over published gross and will continue to do so and if managed sensibly, it can be done.

Best,
 
It wasn't any fun flying it that way but hey, I was 24 and bulletproof:) and it paid the bills.

Ah yes, the things we did to fly for a living. Sometime I will tell the story of hauling explosives in a Twin Beech. :rolleyes:

John Clark ATP, CFI
FAAST Team Representative
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA
 
Hi Pierre...

I think you echo my point, which you summarise well with:
over published gross and will continue to do so and if managed sensibly, it can be done.
A limit (Gross Wt, CG) is there for a reason, and if that reason is understood, and mitigated against, then a different limit might be appropriate if flown in a different manner.

This is seen with Aerobatics, Utility, Normal categories. You have shown it again with your:
The problem with a bigger than normal gross weight, is what you do with the airplane in that condition. I have to make gentle turns and easy pullups from the field until I lighten up.
The "problem" I see with the RVs is that plenty "invent" a new Max Gross Weight, over and above what Vans recommend. However, they (typically, there are exceptions) give no justification as to why they know better than Vans, do not specify (nor probably know) which parts of the structure or operating envelope the Vans limits apply to, and do not apply any mitigations (whereas you have) as to "how" they will operate, say between the Vans Gross Wt and their declared increased one.

An example might be if one had researched, say, the Vans RV-8 Gross Wt (1800lbs) and determined as far as 'g' limits went, then ~2180lbs Gross was fine for Utility 'g' limits, based on extrapolating the 1600lb/6g aerobatics limit - so a 2000lb gross is not an issue for Utility. You could even go to 2500lbs under Normal. However, this does not allow for "where/how secured" that (extra) load is of course.

However, we now have an issue with brake energy, wheel/tyre loads, and/or landing gear strength. These again, can be mitigated with upgraded components, or handling limitations (yes - can take off at 2100lbs, but MLW still 1800lbs except in emergency / smooth / long landing surface / post flight inspection).

I, for one, would have no problem with people, where permitted (e.g. USA) in increasing Max Gross if I saw a process to determine it somewhat more complex than plucking a figure out of thin air :eek: And that such an approach to safety was behind the aims of the http://www.rvflightsafety.org/ - instead we see comments such as:
The problem was flaring to land, the passenger couldn't get his gut in enough. I wound up wheel landing it after going around and beating him in the gut with the stick.
What happened to the "full & free" control check prior start and takeoff :confused:
310 for passenger / 350 PAX
What allowance was made for the seat belts and attachments here? Was the pax briefed that in the event of an accident, the probability of injury or death was significantly increased since at the design accident 'g' loadings, the seat belts would almost certainly fail?
you owe it to your passenger to ballast the airplane to that weight and fly it before you carry the passenger
Whilst this mitigates one element (handling) it does not the crash scenario - unless you are willing to subject your aircraft to destructive testing.
 
Well said.

Very valid points, Andy and I can't/won't argue with any of them.

At 66 years of age, I have had more than my share of observations of mankind and his stubborness, creativity and objection to following hard rules and defiance of gravity.:) I have also read my share of obituaries attributed to these violations.

So, hopefully, I have made enough valid points of how to have a successful outcome if you insist on departing from Van's or any other wise advice, and am definitely not condoning a lackadaisical attitude and thumbing our noses at Van's, or any other manufacturer's numbers.

Best,
 
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Thank you

Andy/Pierre

Thank you for bringing some common sense and logic to this discussion.

Yes aeroplanes can fly over gross, but you cant do the same things in them as when they are under gross or aerobatic weight, not without risking dire consequences. Even if you can get off ground and fly as gently as you can, something out of your control may happen which, puts you in real danger.

I remember a day when I was out doing the permit revalidation flight in my Kitfox. All of a sudden when in straight and level flight I had a violent left wing drop. Full right aileron and rudder and she just hung there for what seemed like an eternity in knife edge flight. Then the controls took effect and we got back to straight and level.

This was the same day that the right wing folded up on the replica Spirit of St Louis at Coventry. The wind was doing some strange things that day.

Now, had I been over gross I would not be writing this......... food for thought.

So, whats the point of over loading your sports car of the air (RV) so you cant show off its performance???? Its like buying a Ferrari and towing a caravan with it.

If someone can show me properly calculated figures that show the gross can be upped safely I will stop worrying, but until then what Van says is law!!
 
Andy, you make perfect sense in Post #30. I was never advocating flying over gross weight. An assertion was made that suggested that there are many RV fatalities resulting from flying at over gross weight. I just wanted to see the accident reports that substantiate that assertion.

Frankly, there may not be any for RVs. I do not think that a guy doing aerobatics over gross counts. Even if you do count it, that falls into the Darwinism category.

I know of three aircraft that ended up damaged or destroyed at my airport because a combination of weight, aircraft performance, density altitude (up to 10,000' MSL here on a hot day), and slowly rising terrain kept them from getting airborne adequately to sustain flight.

There are far too many fatalities in RVs every year. The low hanging fruit to reducing that number is unlikely to be a result of solving the over gross weight issue.
 
The "problem" I see with the RVs is that plenty "invent" a new Max Gross Weight, over and above what Vans recommend. However, they (typically, there are exceptions) give no justification as to why they know better than Vans, do not specify (nor probably know) which parts of the structure or operating envelope the Vans limits apply to, and do not apply any mitigations (whereas you have) as to "how" they will operate, say between the Vans Gross Wt and their declared increased one.

The problem that I see, is that you haven't been around enough, to know what has transpired for the last decade and a half............in regards to Van's aircraft. It's far from a case of simply pulling gross weight numbers out of thin air. That's all I care to say on this subject. It tends to tick me off, every few years, when it comes up.

edit: P.S.--- I'm also very familiar with over gross weight takeoff accidents. I keep track of all them too. Three have nearly crashed in my back yard, as I live next to the airport. Five combined fatalities. Three friends have also died in gross weight/density altitude accidents. But let's don't confuse these accidents with flying a gross weight number, over a Van's recommendation. It helps to know what has transpired since some of those recommendations.

L.Adamson
 
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We all know that builders of Experimental Amateur-Built aircraft have the right to make changes to their aircraft at will ? whether or not their changes are based on good science. If they choose to operate the aircraft with a lesser or unknown margin of safety, that is their prerogative. However, unless the aircraft is single-seat, any passengers carried in that aircraft will be exposed to the same unknowns that the pilot has accepted for himself. We feel that this is a responsibility often overlooked by pilots. While they may be willing to accept certain risks for themselves, what should their responsibility be to their spouses, friends, children, and grandchildren?

SIDEBAR: WHO OWNS THE MARGIN?

It seems common practice among homebuilders to second-guess the factory engineers, particularly regarding gross weight increases. Because of all of the ?I gotta have? added features, empty weight creep erodes the aircraft?s useful load. The simple solution for the homebuilder is to ?pencil in? a new gross weight limit. It?s only 100 lbs. (3.7%) more; how much effect can that possibly have?? Imagine this example: you are on a mid-size airliner with a gross weight of 270,000 lbs. Just before leaving the gate, the captain comes on the PA system and says: ?we?ve overbooked more than usual today, so we?re going to assume that the factory engineers over-designed this airplane and allowed an abundant safety margin. We?re going to take off at 280,000 lbs. instead. So move over, there are 50 more passengers coming on board.? Run the numbers; it?s the same over-weight ratio as simply pencilling in an additional 100 lbs to the gross weight of an RV-10.
NB an RV-6A 1650 to 1850 is +12.1% - over 3x what triggered the article above ;)
 
Evidence of safe operation

This is a good discussion. There was an excel database of RV's on a web site (now closed), that showed several with gross weights over the number published at Van's. I don't think these people did anything special to qualify their build for this higher gross weight.

Now I don't think you will ever see Van's publish increased gross weight numbers, it is a liability thing, but he is attune to changes builders try with his design and if unsafe I think he would come out and say such.

The interesting thing I find with this debate is that the current operational proof is overlooked. There are several planes registered with higher gross weights and to date there does not seem to be problems cropping up with these airplanes. I would think one would see cracked gear or engine mounts or other structural issues. So my point is we might have good evidence that a 100 or 200 pound increase to the published gross weight might not be a safety issue.

Of course knowing how Van's came up with the gross weight published would help one make a educated increase in the weight.

I understand the want to carry more, when you are on a trip with two big passenger, you still want full fuel and baggage. The plane has the power to safely fly at these weights. I have been there is a C-150 with in CG and gross in authorized number taking into account density altitude and barely made 300 FPM climb. The issue with most light airplanes and gross weight is performance more than structural (just a guess on my part) But if an RV can climb at 1800 FPM at 1800lbs and 1500 FPM at 2000lbs I think it is still safe.

Van's has published a gross weight number but we don't know what limits that number. It would be nice to know how this number is determined. For me the gross weight on the RV-8 seems more than adequate but I will look hard at this before I get mine inspected. I want all the operational capability out of this plane that I can safely attain and if I have the option to certify it with a higher gross weight I might just do that.

Cheers
 
So..............you believe, that Van's Aircraft, is worried about increasing an RV6A from 1650 gross weight to 1850 lbs.....
I can only suggest "Yes" on the basis of:
  1. The Article above
  2. Recent eMails from the (current) Chief Engineer at Vans
The latter included very direct reference to the implications of exceeding Gross on an RV-4. If you have direct evidence that, say for the RV-6(A) there is an exception this would of course override.

Mike's post above I think sums it up well. What I would add to:
There are several planes registered with higher gross weights and to date there does not seem to be problems cropping up with these airplanes. I would think one would see cracked gear or engine mounts or other structural issues. So my point is we might have good evidence that a 100 or 200 pound increase to the published gross weight might not be a safety issue.
is ths is is only valid if these aircraft not only declare increased Gross Weights, but then spend a good % of their flying at them. Due to the nature of the RVs, and I believe the fear of ramp checks (?), these increased Gross Weights tend to be declared, but maybe not routinely used?

Our RV-8 uses the Vans Gross Wt of 1800lbs. It is hardly a light weight spec since it has a Hartzell VP Prop (Basic is ~1106). It is hard work to get it anywhere near this Gross... If you routinely operate solo at, say, 1600lbs, then by the time you've loaded a Pax, Full Fuel and >1000lbs of baggage I suspect you will be treating it gently anyway.
 
I can only suggest "Yes" on the basis of:
  1. The Article above
  2. Recent eMails from the (current) Chief Engineer at Vans
The latter included very direct reference to the implications of exceeding Gross on an RV-4. If you have direct evidence that, say for the RV-6(A) there is an exception this would of course override.

Do you have any idea.............of how many times this same subject has come up in the last 15 years or so? If you find anyone from Van's who is at all worried about an RV6A (with it's super strong wing) increasing the gross weight from 1650 to 1850, then you be sure to let us all know.

In the meantime...........for many of us, we've heard it all before, get tired of discussing it....and nothing has changed. 6A's wings have yet too fall off.

edit: Some time capsules..

http://www.vafarchive.com/msg/vaf/t2002329004

You can find more about the gear, too

L.Adamson --- 6A 1850 GW
 
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RVG8tor said:
Now I don't think you will ever see Van's publish increased gross weight numbers, it is a liability thing, but he is attune to changes builders try with his design and if unsafe I think he would come out and say such.
Apparently Van used to issue letters on request to builders who wanted to increase the gross weight on RV-6/6A aircraft to 1800/1850lb. Many people here on VAF and on the Matronics lists have made reference to such letters. However, nobody, in the 15 years i've been asking, has been able to produce a copy of one.

L.Adamson said:
If you find anyone from Van's who is at all worried about an RV6A (with it's super strong wing) increasing the gross weight from 1650 to 1850, then you be sure to let us all know.
So what you're saying is, "If it's so dangerous, why doesn't Van say something?"

Try seeing the other perspective... If it's so safe, why doesn't Van allow it, or even allow it with limitations? 1800 Normal, 1600 Utility, 1350 Aerobatic, for example? I could see it being a marketing choice, if they were still selling the -6 kit alongside the -7... But now that the -6 is effectively discontinued, there's no reason to limit the -6 if it is, truly and completely, engineered to take 1800/1850 lb gross weights.

Andy Hill said:
The "problem" I see with the RVs is that plenty "invent" a new Max Gross Weight, over and above what Vans recommend. However, they (typically, there are exceptions) give no justification as to why they know better than Vans, do not specify (nor probably know) which parts of the structure or operating envelope the Vans limits apply to, and do not apply any mitigations (whereas you have) as to "how" they will operate, say between the Vans Gross Wt and their declared increased one.
This is one problem. But I think that for the most part, people who chose increased gross weights while building do so with specific requirements in mind, and do so with eyes open... They expect to need to be more careful if they're operating near those higher limits. Maybe that's just optimism, but i'd like to think builders are that intelligent.

A more serious problem is that a lot of RV's end up with more than one owner during their lifetime. And a lot more people are seeing the economic advantage to buying a flying RV for $40-50K vs building one for $50-80K. These people don't get the two years of "lurking" time to read VAF while they build and learn the practical limitations. They just buy an airplane with an 1800 gross and don't think twice about it.
 
Who made assertions about RV's

An assertion was made that suggested that there are many RV fatalities resulting from flying at over gross weight. issue.


So, where exactly did you see an assertion like this in my post. This is what I said, 'I am extremely uncomfortable reading about people arbitrarily upping their gross weight from the designers limits. How many accident reports have I read where this has been done with fatal results....... I have lost count?

No where are RV's mentioned, and I have made the point quite clearly that I was referring to all accidents where being over gross was a factor.

BTW I can count past ten, we use our toes as well in England.

The other thing that is worrying about this is the assumption that all RV 6's are built to the same standard. Some might be perfect and I bet a lot are, but I have seen some with questionable build quality that I would not fly in.
So, assertions that 6 have Super strong wings may or not be true.

Of course Van does not want to expose himself to more liability by upping the gross.......... do you want to expose yourself to it by upping it against the designers recommendations?????

For those people bored of this topic as it has been discussed in the past remember what started this thread, someone asking whether it was safe to fly over gross. Who, on this thread has carried out a detailed analysis of the build quality of his aeroplane and can say yes?

In my view the only sensible answer you can give is to refer him back to the designers gross figure who has no doubt factored into the safely margin the possibily of questionable build quality.
 
140 lbs

A better solution would be passengers that weight less than 140 pounds, have longer hair than guys and look better.

Now this is a more sensible proposal!!!:) But i would lower that figure to 112 to 120 lbs as 140 is over my personal gross weight limit. :)
 
Build quality

....The other thing that is worrying about this is the assumption that all RV 6's are built to the same standard. Some might be perfect and I bet a lot are, but I have seen some with questionable build quality that I would not fly in....


Now you make a good point, in that the build quality might not let the airplane standup to even Van's recommended number. I am not certain but I still believe this is left up to the builder. As far as liability would you recommend certifying with a gross less than Van's published number to protect the builder from some level of liability?

I still say the only way to get make an educated estimate as to what gross weight should be if you want it different from what Van's has published is to have the engineer state the assumptions made to come up with the number in the first place. Only then can we know what level of safety is being compromised by using a higher gross weight.


PS. When you see poor build quality do you politely let the builder know, I hope so?
 
Build quality

In the Uk we have a system of build inspection. If the Inspector does his job right good quality work is pretty much ensured........but, unfortunately there is always a but, sometimes they don't, or sometimes builders may hide mistakes.
I have a very good relationship with my inspector and have been with him on other inspections and seen people try to put one over on him.

The only country I know that goes further than this is Germany where they require proof loading of each airframe. In that case I think you can be pretty sure you have a strong aeroplane build to a good standard. Possibly other countries do this as well.

I think you know something of my personality from what I have written here. I care about other people, I spent most of my life serving my country as a Police Officer. So of course if someone is putting themselves or others at risk I will speak up, hopefully without upsetting anyone.

That is why I said I was troubled by people arbitrarily upping the gross weight, either in a written document or by simply overloading it for any particular flight. It does not matter whether its an RV/Kitfox/ Cessna....... whatever.......... the performance will be affected by adding more weight.


Take my RV9 solo with full tanks.......... 1300 fpm climb. At gross that drops to about 650. If I were to add in another 200lbs I would probably be reliant on the curvature of the earth to get me off the ground!!

I had flight with my daughter in a motor glider, and there were thunder storms developing about 40 miles away. The down draughts were so strong that even at full climb power we were going down fast, so I landed at a disused RAF base. OK its unlikely in an RV with their excess of power...... but, load it over gross and your into those margins of safety.

I don't mean to be rude to anyone but bottom line is rather than push the limits on my aeroplane I would ask an overweight friend to shed a more than few pounds before I took them up, or just say no. I feel sorry for those guys who are 250lbs plus of muscle, but one of the reasons I keep my weight down is because the aeroplane flies better.

I think you will find that Dave Anders also shed body weight before doing his record breaking CAFE flight. Well thats what I read and if he did respect and kudos goes to him!!

In the UK the gross weight is set by the Light Aircraft Association. Because RV's are strong and have a good record our Engineers have never to my knowledge sought to reduce the gross weight from that recommended by Vans. Dispensation was given for the round the world RV4 flight when it landed in the UK, which flew over gross.

They have reduced gross weight with other designs so this should show you how highly RV's are regarded in the UK.

Perhaps we should run a poll. Question 'Do you think its sensible to up the gross weight on your aeroplane based on the advice of someone you have never met, who has never assessed the structural integrity of your aeroplane, just because someone else has done it and so far gotten away with it?
 
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I try to build a light airplane, minimal interior etc, just because I feel every extra pound that is on my plane. Others have a different mission and I would say that the track record for heavy RVs has been pretty good. If this discussion is about risk, and absolutely following Van's recommendations regarding gross weight, then should that gospel not extend to alternate engines? The track record for alternate engines has been absolutely abysmal, if alternate engines were not allowed there would be many more people alive today then have ever been lost to heavy gross weights.
 
I agree with Steve's sentiments - maybe it's a trans-Atlantic thing.......

There is a "however", however. Without wishing to be rude about anyone's stature (I am no skinny-pants myself), I believe that weighing 350lbs gives far more scope for an early demise than crashing in an over-weight aircraft :eek:
 
I generally believe in following a manufacturers or designers recommendations. In the case of the RV6 however virtually every 360 powered airframe I looked at had the GW set at 1800 lbs. My understanding is that upping the gross weight is not arbitrary and the builder has to demonstrate and test the aircraft at those weights. The aircraft performs great at 1800 lb in all respects. I am very comfortable with that weight. I would guess there must be close to a 1000 RV6's with the 1800 lbs weight and I have yet to hear of a single issue.
You can abuse and miss load any aircraft. The RV4 accident mentioned in the thread was caused by a combination of many factors. CG was a much bigger factor then the gross weight. He was so far out of the limits for aerobatics both from a aircraft and pilot standpoint it simply has no relevance to operating a RV on a cross country flight.

George
 
So, where exactly did you see an assertion like this in my post. This is what I said, 'I am extremely uncomfortable reading about people arbitrarily upping their gross weight from the designers limits. How many accident reports have I read where this has been done with fatal results....... I have lost count?

No where are RV's mentioned, and I have made the point quite clearly that I was referring to all accidents where being over gross was a factor.

Steve, this thread is about raising the gross weight on RVs. This can be done on RVs by the builder. Maybe Cessna or Piper aircraft owners can raise their gross weight. I just do not know. The discussion is about RVs.

If you want to include people LOADING their aircraft above the gross weight, then let's discuss all pilot errors including the three at my airport where people damaged their aircraft due to weight, aircraft performance, and/or density altitude issues. Or lower performance aircraft that hit mountainous terrain due to performance/pilot issues.

But that has almost ZERO relevance to my RV due to its superior performance.

I do not operate mine outside of its original 1650 lb gross weight limit or CG limits. I have considered raising the gross weight but the compelling need to do so has not surfaced yet.
 
Perhaps we should run a poll. Question 'Do you think its sensible to up the gross weight on your aeroplane based on the advice of someone you have never met, who has never assessed the structural integrity of your aeroplane, just because someone else has done it and so far gotten away with it?

Yes, we'll ask that question to a bunch of wannabe RV builders, who don't have an idea of what the **** has gone on before. That's about how legitimate and useful this poll would be.

As I have said before, and years before that.............these same questions come up every few years. Then we get the same repetitive answers from those who are only guessing with their "moral" high ground thinking. It's even got to the point of criticizing builders for upping the weight, and then daring to sell their aircraft to some unsuspecting buyer. And at the same time, you get potential buyers who are criticizing the builder for not upping the gross to start with.

As I said before, get someone from Van's who will actually condemn the 1850 gross weight on an RV6A, then we'll talk about it.

L.Adamson
 
I can only suggest "Yes" on the basis of:
  1. The Article above
  2. Recent eMails from the (current) Chief Engineer at Vans
The latter included very direct reference to the implications of exceeding Gross on an RV-4.
As one who increased the list gross weight of an RV-4 from 1500 to 1600 lb based on a *face to face* conversation with Van on the subject *and* requisite flight testing to substantiate it, I'd be interested in hearing about these implications.

Note that my aerobatic weight and CG envelope are unchanged.
 
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