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wayne.e(at)grandecom.net
Guest

Posted: Wed May 16, 2007 3:38 pm Post subject: Establishing gross weight

I saw on a weight and balance list at www.rvproject.com/wab/  that there  is some differences on selecting a max gross weight. Vans recommends 2700, but  used 2758 on their 10, but on this list there's a 2850 and a 2900. How does one  come up with the conclusion or decision to increase the gross weight over Vans  recommended? My empty weight came in somewhat higher than the others at 1749 but  I've put a ton of stuff in the panel and many extra items including a full  leather interior, four place O2, overhead console, etc. It is what it  is.

  

 Obviously it would be nice to have a higher gross  weight but I'm not sure how one justifies going beyond the recommended gross  weight.

  

 Anyone have any great insight into this? I did a  archive search but didn't seem to find much.

  

 Wayne Edgerton #40336

  

 sent my papers off to the DAR so I'm hopefully  getting close

   [quote][b]

wayne.e(at)grandecom.net
Guest

Posted: Wed May 16, 2007 3:41 pm Post subject: Establishing gross weight

I just realized I spoke in error. What I thought  was Vans airplane weight wasn't but actually just an average for the RV10.  Sorry about that Van :>} I thought that was somewhat odd that they would have  a weight higher than they recommended. Just not paying attention well  enough.

  

 ---

james.k.hovis(at)gmail.co
Guest

Posted: Thu May 17, 2007 5:23 am Post subject: Establishing gross weight

Legally, you can list any gross weight you want for your POH and the

paperwork to the Feds. But exceeding the designed gross weight is bad

to do for a host of reasons:



1) Affects GC location. If the added weight isn't distributed

correctly, you could end up with an unstable aircraft. Think of the

singer who was killed by the overgross, badly loaded airplane in the

Bahamas awhile back.



2) More weight will require more power to fly at a given speed. At say

200 kts, you'd need 2,900 lbs of lift to stay in level flight if your

gross is 2,900 lbs. To generate this lift, you'd need a few more

horsepower from your engine and a little higher angle of attack. All

the while generating a little more drag which will need a little more

horsepower and consuming more fuel which will affect your overall

range. Plus, the engine you chose may not have the power output to get

you to the goal of 200 kts, so you'd need a bigger engine, which

brings it's own viscious cycle of effects noted below.



3) The main issues are structural issues. As noted in no. 2, you might

need a bigger motor, but the engine mount/fuselage interface is

designed for a certain max weight engine. Will your bigger one exceed

that weight? Increased drag will affect flutter tolerance and if you

can exceed Vne, well Van has covered that before. Your wing structure

may not be able to handle the maximum loadings you could experience if

gross was say 2900 lbs. Van's tested this wing for a 2,700 lb gross

experiencing 3.8G pull up. They applied a 1.5 margin of safety to this

figure so the wing was tested for no failure at 15,390 lbs. This

sounds like alot, but is really isn't. If you do a high bank turn, you

can get close to max loading, then if you hit a gust or strong

updraft, you can eat up the margin of safety. This is why Va is set.

At speeds above Va, you should keep any abrupt manuevers to a minimum.

Closer you get to top cruise speed, the easier it is to exceed max

loading condition if a strong gust or updraft is encountered.



Van's did a lot of engineering with this design that you pay for when

yuou buy the kit (among other things). My advise would be to trust

their numbers and not exceed 2,700 lb gross. This lowers your useful

payload if your on the heavy side of empty weight, but this'll keep

you from possibly becoming a statistic later on. Otherwise I'd hire an

engineer to analize your gross weight increase to be safe.

Kevin Hovis.

On 5/16/07, Wayne Edgerton <wayne.e(at)grandecom.net> wrote:

 	  Quote: 	
		   I saw on a weight and balance list at www.rvproject.com/wab/  that there is

 some differences on selecting a max gross weight. Vans recommends 2700, but

 used 2758 on their 10, but on this list there's a 2850 and a 2900. How does

 one come up with the conclusion or decision to increase the gross weight

 over Vans recommended? My empty weight came in somewhat higher than the

 others at 1749 but I've put a ton of stuff in the panel and many extra items

 including a full leather interior, four place O2, overhead console, etc. It

 is what it is.



 Obviously it would be nice to have a higher gross weight but I'm not sure

 how one justifies going beyond the recommended gross weight.



 Anyone have any great insight into this? I did a archive search but didn't

 seem to find much.



 Wayne Edgerton #40336



 sent my papers off to the DAR so I'm hopefully getting close

jesse(at)saintaviation.co
Guest

Posted: Thu May 17, 2007 5:35 am Post subject: Establishing gross weight

Modifying the gross weight is very little different from a lot of the other non-Van’s-approved mods.  The plane was engineered for a 260HP (or less) IO-540 with 60 gallons of fuel, 180Kts max cruise, etc. etc. etc.  If you want to put in a Subaru, Mazda, turbo-Lycoming, 120Gal tanks, tip tanks, IFR panel (why would you do this unless you were going to fly IFR in a plane that was designed to be strictly VFR?), etc, you are modifying the design.  The nice thing about the amateur-built experimental category is that you are free to do that, even though you might make Van’s mad.  

   

Really and truly, I think the gross weight should be established during the fly-off period.  How is the builder going to establish a gross weight when he hasn’t even flown the plane?  But, since you have to (I am sure you, as the repairman, can modify it down the road in the log books if you choose to) establish a pre-airworthy gross weight, then you have to guess.  Most people will go with the 2,700, many of whom will fly it however feels comfortable, whether it is 2,700 or 3,000.  Selecting a gross weight different than what Van’s recommends will really only become an issue if/when there is an accident.  If you are flying over your established gross weight and crash, the insurance company will not want to pay if they can establish that you were overweight.  If you are flying within a gross weight over what Van’s recommends and you crash, the insurance company will not be able to not pay because of the weight unless there is a clause in the contract that requires that you build exactly to the plans, which I doubt there is.  Then you may start causing problems for other people because insurance rates may go up.  Some people modify their gross weight simply because they can.  The plane will carry 2,900 lbs and still climb to 15,000+ feet (I think  ).  From there it is completely up to you.  Also, even if you put your gross weight at 2,700, what are the implications of flying over gross weight?  

   

For others (JC’s response expected here), what are the implications of flying over you established gross weight?  Does that just become an issue if you crash and don’t burn?  

   

Do not archive  

     

Jesse Saint  

Saint Aviation, Inc.  

jesse(at)saintaviation.com (jesse(at)saintaviation.com)  

www.saintaviation.com  

Cell: 352-427-0285  

Fax: 815-377-3694  

        

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Wayne Edgerton

 Sent: Wednesday, May 16, 2007 7:37 PM

 To: rv10-list(at)matronics.com

 Subject: Establishing gross weight  

  

     

I saw on a weight and balance list at www.rvproject.com/wab/  that there is some differences on selecting a max gross weight. Vans recommends 2700, but used 2758 on their 10, but on this list there's a 2850 and a 2900. How does one come up with the conclusion or decision to increase the gross weight over Vans recommended? My empty weight came in somewhat higher than the others at 1749 but I've put a ton of stuff in the panel and many extra items including a full leather interior, four place O2, overhead console, etc. It is what it is.  

    

   

    

Obviously it would be nice to have a higher gross weight but I'm not sure how one justifies going beyond the recommended gross weight.  

    

   

    

Anyone have any great insight into this? I did a archive search but didn't seem to find much.  

    

   

    

Wayne Edgerton #40336  

    

   

    

sent my papers off to the DAR so I'm hopefully getting close  

  [quote]   [b]

LloydDR(at)wernerco.com
Guest

Posted: Thu May 17, 2007 6:18 am Post subject: Establishing gross weight

I agree with this, it is more of a insurance, cover your  butt issue, than a safety of flight issue (within reason of course). Think of it  this way, anytime a certified plane needs to be ferried across the pond, they  put in so much extra fuel and equipage that the plane will barely fly, and a  special permit is required, just to cover the bases with the insurance company,  and a heads up to the pilot that the plane will act differently. While I do not  agree that putting 3500 LBS in a 2500 lb sack is a good idea, I see no reason  why for insurance purposes you would not raise your gross to 2900 or so, knowing  that when you are close to that weight the airplane will act differently.  

 There has been many times I have started a flight out in my  Cherokee over gross, but as fuel burn occurs I am back in, so just use your best  judgment, set it high, during flight testing make sure you are ok, and if  necassary adjust the gross weight down. You as the builder can adjust gross  weight at anytime with the correct paperwork. 

 Dan

 N289DT RV10E



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse  Saint

Sent: Thursday, May 17, 2007 9:27 AM

To:  rv10-list(at)matronics.com

Subject: RE: Establishing gross  weight

 

  

Modifying the gross  weight is very little different from a lot of the other non-Van’s-approved  mods.  The plane was engineered for a 260HP (or less) IO-540 with 60  gallons of fuel, 180Kts max cruise, etc. etc. etc.  If you want to put in a  Subaru, Mazda, turbo-Lycoming, 120Gal tanks, tip tanks, IFR panel (why would you  do this unless you were going to fly IFR in a plane that was designed to be  strictly VFR?), etc, you are modifying the design.  The nice thing about  the amateur-built experimental category is that you are free to do that, even  though you might make Van’s mad. 

  

Really and truly, I  think the gross weight should be established during the fly-off period.   How is the builder going to establish a gross weight when he hasn’t even flown  the plane?  But, since you have to (I am sure you, as the repairman, can  modify it down the road in the log books if you choose to) establish a  pre-airworthy gross weight, then you have to guess.  Most people will go  with the 2,700, many of whom will fly it however feels comfortable, whether it  is 2,700 or 3,000.  Selecting a gross weight different than what Van’s  recommends will really only become an issue if/when there is an accident.   If you are flying over your established gross weight and crash, the insurance  company will not want to pay if they can establish that you were  overweight.  If you are flying within a gross weight over what Van’s  recommends and you crash, the insurance company will not be able to not pay  because of the weight unless there is a clause in the contract that requires  that you build exactly to the plans, which I doubt there is.  Then you may  start causing problems for other people because insurance rates may go up.   Some people modify their gross weight simply because they can.  The plane  will carry 2,900 lbs and still climb to 15,000+ feet (I think  ).  From  there it is completely up to you.  Also, even if you put your gross weight  at 2,700, what are the implications of flying over gross  weight? 

  

For others (JC’s  response expected here), what are the implications of flying over you  established gross weight?  Does that just become an issue if you crash and  don’t burn? 

  

Do not  archive 

   

Jesse  Saint 

Saint Aviation,  Inc. 

jesse(at)saintaviation.com (jesse(at)saintaviation.com) 

www.saintaviation.com 

Cell:  352-427-0285 

Fax:  815-377-3694

    

 

From:  owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Wayne Edgerton

Sent: Wednesday, May 16, 2007 7:37  PM

To:  rv10-list(at)matronics.com

Subject: Establishing gross  weight

 

   

I saw on a weight and balance list  at www.rvproject.com/wab/  that  there is some differences on selecting a max gross weight. Vans recommends 2700,  but used 2758 on their 10, but on this list there's a 2850 and a 2900. How does  one come up with the conclusion or decision to increase the gross weight over  Vans recommended? My empty weight came in somewhat higher than the others at  1749 but I've put a ton of stuff in the panel and many extra items including a  full leather interior, four place O2, overhead console, etc. It is what it  is.

  

 

  

Obviously it would be nice to have a  higher gross weight but I'm not sure how one justifies going beyond the  recommended gross weight.

  

 

  

Anyone have any great insight into  this? I did a archive search but didn't seem to find  much.

  

 

  

Wayne Edgerton  #40336

  

 

  

sent my papers off to the DAR so I'm  hopefully getting close

 	  Quote: 	
		    http://www.matronics.com/Navigator?RV10-List 	
0 	  Quote: 	
		   	
1 	  Quote: 	
		   	
2 	  Quote: 	
		   	
3 	  Quote: 	
		   	
4

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5  [quote][b]

rvbuilder(at)sausen.net
Guest

Posted: Thu May 17, 2007 6:20 am Post subject: Establishing gross weight

Wow, Jesse, that has to be one of the most dangerous answers I have seen you post to date and really reflects your lack of actual pilot training.   While it is true that the builder can absolutely establish the gross weight at any number he wants, the aircraft was structurally designed to a specific number.  In the RV-10 case it’s 2700 lbs.  You exceed that number and the structural fatigue goes up rapidly.   It also cascades down a whole bunch of other things like maneuvering speed, stall speeds, CG, and on and on.  Sure you probably won’t fall out of the sky anytime soon but you don’t know where that magic number is where you may encounter a series of conditions when that part can’t handle the extra forces and fail.  Not trying to slam you here but messing around with things like gross weight is just slightly better than messing with CG limits.  Make sure you have a good understanding of a subject like this before you comment on it.  

   

  And for the insurance, Rick or someone in the know here can step in, but I’m fairly certain most insurance companies are going to look at what you insured it as and what the vendor has designed it to when they decide if they want to deny a claim.  

   

Michael Sausen  

-10 #352 limbo  

       

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Thursday, May 17, 2007 8:27 AM

 To: rv10-list(at)matronics.com

 Subject: RE: Establishing gross weight  

  

  

   

Modifying the gross weight is very little different from a lot of the other non-Van’s-approved mods.  The plane was engineered for a 260HP (or less) IO-540 with 60 gallons of fuel, 180Kts max cruise, etc. etc

james.k.hovis(at)gmail.co
Guest

Posted: Thu May 17, 2007 6:43 am Post subject: Establishing gross weight

I have a very simple answer for those who wish to establish a gross

weight over Van's limits: Do a static load test on your wing like

Van's did at 2,900lbs or other figure you choose. If you're willing to

fly a bird over recommended gross, you should be willing to put the

wing through a static test that could destroy it before you fly. I

guess it depends on your pucker factor, but for me, I like it that

someone has already proven the structure at a certain limit. Isn't

true that other countries require a static load test at limit G and

margin of safety before an experimental certificate is issued? Unless

your an engineer and can do the calculations (I am an aircraft

structural engineer), you have no way of knowing whether the structure

can handle any loading exceeding that already proven. Even then proof

testing is usually warranted. I guess you could do a proof test in the

air, but please wear a parachute....



Kevin Hovis.



On 5/17/07, Lloyd, Daniel R. <LloydDR(at)wernerco.com> wrote:

 	  Quote: 	
		   I agree with this, it is more of a insurance, cover your butt issue,

 than a safety of flight issue (within reason of course). Think of it

 this way, anytime a certified plane needs to be ferried across the pond,

 they put in so much extra fuel and equipage that the plane will barely

 fly, and a special permit is required, just to cover the bases with the

 insurance company, and a heads up to the pilot that the plane will act

 differently. While I do not agree that putting 3500 LBS in a 2500 lb

 sack is a good idea, I see no reason why for insurance purposes you

 would not raise your gross to 2900 or so, knowing that when you are

 close to that weight the airplane will act differently.

 There has been many times I have started a flight out in my Cherokee

 over gross, but as fuel burn occurs I am back in, so just use your best

 judgment, set it high, during flight testing make sure you are ok, and

 if necassary adjust the gross weight down. You as the builder can adjust

 gross weight at anytime with the correct paperwork.

 Dan

 N289DT RV10E



   _____



 From: owner-rv10-list-server(at)matronics.com

 [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Thursday, May 17, 2007 9:27 AM

 To: rv10-list(at)matronics.com

 Subject: RE: Establishing gross weight



 Modifying the gross weight is very little different from a lot of the

 other non-Van's-approved mods.  The plane was engineered for a 260HP (or

 less) IO-540 with 60 gallons of fuel, 180Kts max cruise, etc. etc. etc.

 If you want to put in a Subaru, Mazda, turbo-Lycoming, 120Gal tanks, tip

 tanks, IFR panel (why would you do this unless you were going to fly IFR

 in a plane that was designed to be strictly VFR?), etc, you are

 modifying the design.  The nice thing about the amateur-built

 experimental category is that you are free to do that, even though you

 might make Van's mad.



 Really and truly, I think the gross weight should be established during

 the fly-off period.  How is the builder going to establish a gross

 weight when he hasn't even flown the plane?  But, since you have to (I

 am sure you, as the repairman, can modify it down the road in the log

 books if you choose to) establish a pre-airworthy gross weight, then you

 have to guess.  Most people will go with the 2,700, many of whom will

 fly it however feels comfortable, whether it is 2,700 or 3,000.

 Selecting a gross weight different than what Van's recommends will

 really only become an issue if/when there is an accident.  If you are

 flying over your established gross weight and crash, the insurance

 company will not want to pay if they can establish that you were

 overweight.  If you are flying within a gross weight over what Van's

 recommends and you crash, the insurance company will not be able to not

 pay because of the weight unless there is a clause in the contract that

 requires that you build exactly to the plans, which I doubt there is.

 Then you may start causing problems for other people because insurance

 rates may go up.  Some people modify their gross weight simply because

 they can.  The plane will carry 2,900 lbs and still climb to 15,000+

 feet (I think  ).  From there it is completely up to you.  Also, even

 if you put your gross weight at 2,700, what are the implications of

 flying over gross weight?



 For others (JC's response expected here), what are the implications of

 flying over you established gross weight?  Does that just become an

 issue if you crash and don't burn?



 Do not archive



 Jesse Saint



 Saint Aviation, Inc.



 jesse(at)saintaviation.com



 www.saintaviation.com



 Cell: 352-427-0285



 Fax: 815-377-3694



   _____



 From: owner-rv10-list-server(at)matronics.com

 [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Wayne

 Edgerton

 Sent: Wednesday, May 16, 2007 7:37 PM

 To: rv10-list(at)matronics.com

 Subject: Establishing gross weight



 I saw on a weight and balance list at www.rvproject.com/wab/  that there

 is some differences on selecting a max gross weight. Vans recommends

 2700, but used 2758 on their 10, but on this list there's a 2850 and a

 2900. How does one come up with the conclusion or decision to increase

 the gross weight over Vans recommended? My empty weight came in somewhat

 higher than the others at 1749 but I've put a ton of stuff in the panel

 and many extra items including a full leather interior, four place O2,

 overhead console, etc. It is what it is.



 Obviously it would be nice to have a higher gross weight but I'm not

 sure how one justifies going beyond the recommended gross weight.



 Anyone have any great insight into this? I did a archive search but

 didn't seem to find much.



 Wayne Edgerton #40336



 sent my papers off to the DAR so I'm hopefully getting close



 http://www.matronics.com/Navigator?RV10-List

 http://forums.matronics.com

Deems Davis

Joined: 09 Jan 2006
Posts: 925

Posted: Thu May 17, 2007 6:48 am Post subject: Establishing gross weight

You can think of it anyway you like, and you can rationalize it anyway 

you like, but Gross weight is determined and set by engineering with 

facts and data. If you've made modifications to your plane and you 

believe the modifications warrant an adjustment in the Gross Weight, 

then calculate the difference based upon the same principles, equations 

and irrefutable laws of physics that were used to establish the 2700 

lbs. Then add in the safety margin.  Anything else is a crap shoot.



Deems Davis # 406

Finishing - ( A Misnomer ! )

http://deemsrv10.com/

 	  Quote: 	
		   *

 *

Rick S.

Joined: 12 Feb 2006
Posts: 347
Location: Las Vegas

Posted: Thu May 17, 2007 7:31 am Post subject: Establishing gross weight

OK, since I was poked to chime in I'll do so with the understanding that this is generic info and coverage and the determination to indemnify your loss are very POLICY specific.



Read the exclusions to determine what is NOT covered!!!!!!!! This is the most important thing.



Step one for everyone...read your policy, there is a reason the exclusions or the in better words the reasons the insurance company will use to deny your claim are listed in the back of the policy. It's because by the time you get to that part your already just skimming the contents out of shear boredom. Policy format has been changing over the past years and exclusions may be listed after each peril definition. Read, read, read your policy...Take it to your lawyer for interpretation if needed.



When the insurance company accepts you as a risk, there are conditions they are required to comply with and there are conditions your are required to comply with. For this contract or agreement to work for both parties, both must stay within the terms of the agreement. If the terms require you to operate your aircraft within design limitations set by the designer and you fail to do so, then the insurance company has the right to question their responsibility to provide coverage.......Now the tricky part is that unless it is specifically excluded in writing in the policy, you most likely will be covered. I always like the statement I heard once in the never ending continuing education classes "We insure stupidity".



You may argue that since this is an experimental aircraft that you are the designer and allowed to set your gross at what you think is safe for flight. If you end up in litigation you better make sure you are more qualified to establish this than the original designer or manufacturer. The defense (insurance company) will argue that you are not more qualified and should have adhered to the recommendations of the designer. FWIW, "Expert Witnesses" will almost always agree with the party that hired them and rightly so, it's your job or your attorney's job to prove them wrong and that your right. Unless by virtue of "YOUR" education and experience you can prove you were correct in exceeding the designers recommendations you may not have a credible, defendable reason for doing so.



If you wreck your car under the influence of a controlled substance are you covered? Same thing applies, it is policy specific, read your policy and exclusions that's the key, state laws vary as well. remember that if you contest your insurance company's decision to provide coverage that it's all on you to fight the decision. I know of several company's in the past, it's much better now that would almost always decline coverage if there was ANY chance an exclusion could be interpreted as applicable to your claim and it "might" hold up in court. When you have a full compliment of defense counsel at your beck and call...why not?



Most company's will accept your claim and pay damages as long as there is not a specific exclusion AND you as an insured acted in good faith by holding up your end of the contract between you and the insurance company. We are lucky that the few aviation insurance companys that extend coverage to us are very good at what they do and know when to pay and when to fight.



So, now that I've rambled on this very ambiguous subject, remember a few things:



1) Read your policy and know what is NOT covered.

2) Don't knowingly violate the conditions of your policy.

3) Think about safety first. If you die, especially if it was preventable who suffers besides you?

4) If your airframe fails in flight, you most likely will DIE, do you want your family members trying to prove that you had the right stuff to engineer your own aircraft?



Picture in your mind the defense stating along with visual aids showing Van's gross weight and then your aircraft gross weight which you willfully & knowingly exceeded despite the manufactures recommendations, you can see how easily the judge (a lot of coverage claims are summary judgments)or the jury can rule in favor of the insurance company.



Rick S.

40185

_________________
Rick S.
RV-10
40185

LloydDR(at)wernerco.com
Guest

Posted: Thu May 17, 2007 7:34 am Post subject: Establishing gross weight

Let me clarify my position, Like you have stated the plane has already

had a static test of its 2700 lbs, which means the wing will need to

support 3.8 times that to be in the standard category, which means

theoretically both wings together will withstand 10,260 lbs and not

fail. With this being said, it would not be a long stretch stating that

an additional 200 pounds in the right location will not cause an issue

during normal flight and clear non-turbulent conditions. I did not state

that it was a smart thing to do and go fly in turbulence, what I did

state was set it high, flight test it and adjust as necessary.



Dan N289DT RV10E    



--

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Thu May 17, 2007 8:01 am Post subject: Establishing gross weight

The design safety margins are established to account for  variations in construction, fatigue, turbulence, variations in piloting,  engineering mistakes etc. etc., all of which are fairly difficult to  predict when they will happen or what the effect will be. Furthermore, an  aircraft experiences many different stresses during the course of a flight  (besides just holding the airplane up in level flight). You need a thorough  engineering analysis to understand the effects a deviation from  the design conditions will have on the airframe in various flight  conditions.

  

 I recommend sticking to Van's established limits (weight limits and all  others) unless one is willing and capable of performing such an  analysis.

  

 -Jim McGrew

 40134

  

  Jim "Scooter"  McGrew

http://www.mit.edu/~jsmcgrew  



  

 In a message dated 5/17/2007 11:35:42 A.M. Eastern Daylight Time,  LloydDR(at)wernerco.com writes:

  	  Quote: 	
		  -->    RV10-List message posted by: "Lloyd, Daniel R."    <LloydDR(at)wernerco.com>



Let me clarify my position, Like you have    stated the plane has already

had a static test of its 2700 lbs, which means    the wing will need to

support 3.8 times that to be in the standard    category, which means

theoretically both wings together will withstand    10,260 lbs and not

fail. With this being said, it would not be a long    stretch stating that

an additional 200 pounds in the right location will    not cause an issue

during normal flight and clear non-turbulent conditions.    I did not state

that it was a smart thing to do and go fly in turbulence,    what I did

state was set it high, flight test it and adjust as    necessary.



Dan N289DT RV10E    

	


 



  



See what's free at AOL.com. 

  [quote][b]

LloydDR(at)wernerco.com
Guest

Posted: Thu May 17, 2007 8:25 am Post subject: Establishing gross weight

We are not talking safety  margins, we are talking an aircraft rated in the standard category and as such  will sustain 3.8G's without structural failure. Nuff said. If the location of  the additional 200 LBS keeps the plane in CG than there will not be an issue in  standard flight conditions, what is unknown is how the plane will react when the  plane is stressed past the max load breaking point of 3.8G's x 2700lbs or  10,260LBS total. Then once you get past this point there is the safety  margin that is built in, but unless you go past the 10,260 LBS limit then there  is nothing new being discovered.

  

 Dan



   From: owner-rv10-list-server(at)matronics.com  [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of  JSMcGrew(at)aol.com

Sent: Thursday, May 17, 2007 12:00  PM

To: rv10-list(at)matronics.com

Subject: Re: RV10-List:  Establishing gross weight

 

   The design safety margins are established to account for  variations in construction, fatigue, turbulence, variations in piloting,  engineering mistakes etc. etc., all of which are fairly difficult to  predict when they will happen or what the effect will be. Furthermore, an  aircraft experiences many different stresses during the course of a flight  (besides just holding the airplane up in level flight). You need a thorough  engineering analysis to understand the effects a deviation from  the design conditions will have on the airframe in various flight  conditions.

  

 I recommend sticking to Van's established limits (weight limits and all  others) unless one is willing and capable of performing such an  analysis.

  

 -Jim McGrew

 40134

  

  Jim "Scooter"  McGrew

http://www.mit.edu/~jsmcgrew  



  

 In a message dated 5/17/2007 11:35:42 A.M. Eastern Daylight Time,  LloydDR(at)wernerco.com writes:

  	  Quote: 	
		  -->    RV10-List message posted by: "Lloyd, Daniel R."    <LloydDR(at)wernerco.com>



Let me clarify my position, Like you have    stated the plane has already

had a static test of its 2700 lbs, which means    the wing will need to

support 3.8 times that to be in the standard    category, which means

theoretically both wings together will withstand    10,260 lbs and not

fail. With this being said, it would not be a long    stretch stating that

an additional 200 pounds in the right location will    not cause an issue

during normal flight and clear non-turbulent conditions.    I did not state

that it was a smart thing to do and go fly in turbulence,    what I did

state was set it high, flight test it and adjust as    necessary.



Dan N289DT RV10E    

	


 



  



   See what's free at AOL.com.  

[quote]



href="http://www.matronics.com/Navigator?RV10-List">http://www.matronics.com/Navigator?RV10-List

href="http://forums.matronics.com">http://forums.matronics.com



[b]

Jack.Phillips(at)cardinal
Guest

Posted: Thu May 17, 2007 9:42 am Post subject: Establishing gross weight

Also, remember that although the airframe was designed to withstand 3.8

g's at 2700 lbs gross weight with a 1.5X safety factor, there is no

requirement for it to come through that test unscathed.  That is an

ULTIMATE LOAD test, which means it needs to survive it, once.



Another consideration is the landing gear.  Typically, landing gear is

designed to withstand no more than 3.5 times the design gross weight.

The LG is not designed to withstand the same loads as the airframe so

that the gear can absorb the energy of a hard landing and break if

necessary before it transfers too much load to the airframe.  So if you

raise your gross weight arbitrarily, the landing gear might not be able

to survive a hard landing that a lighter aircraft could easily handle.



Jack Phillips

#40610

Tailcone 



--

KiloPapa

Joined: 24 May 2006
Posts: 142
Location: Pearblossom, CA

Posted: Thu May 17, 2007 10:18 am Post subject: Establishing gross weight

Those replies suggesting that the gross weight figure is a choice of the 

builder need to read the responses by Kevin Hovis again.  This is not an 

issue of "builders prerogative" at all but simply one of structural design. 

I am really surprised at those who would take it so lightly.



Kevin

40494

tail/empennage

_________________
Kevin
40494

do not archive

james.k.hovis(at)gmail.co
Guest

Posted: Thu May 17, 2007 10:47 am Post subject: Establishing gross weight

Aircraft design is a study in compromise. Every action you do has

some effect elsewhere.



Kevin H.



On 5/17/07, KiloPapa <kilopapa(at)antelecom.net> wrote:

 	  Quote: 	
		   



 Those replies suggesting that the gross weight figure is a choice of the

 builder need to read the responses by Kevin Hovis again.  This is not an

 issue of "builders prerogative" at all but simply one of structural design.

 I am really surprised at those who would take it so lightly.



 Kevin

 40494

 tail/empennage

ScooterF15

Joined: 19 Jun 2006
Posts: 136

Posted: Thu May 17, 2007 12:40 pm Post subject: Establishing gross weight

Dan,

  

 I'm only responding because I think builders should think long and hard  before making the decision to increase Van's recommended limits. I don't want to  see any statistics in our group. The RV-10 was designed to handle 3.8G's with a  ~1.5 safety margin (~5.7G ultimate). Anything you do beyond the design  conditions cuts into said safety margin.

  

 By your argument the C-5 Galaxy with a maximum gross weight of 840,000 lbs  x 3.8G's can handle 3,192,000# of load. So when at low fuel weight (374,000#) it  should be able to pull 3,192,000# / 374,000# = 8.5 G's. That would be something  to see, however, that is simply not the case; it just doesn't work that  way.

  

 You can justify all you want. I still don't recommend it.

  

 -Jim

  

 In a message dated 5/17/2007 12:27:12 P.M. Eastern Daylight Time,  LloydDR(at)wernerco.com writes:

  	  Quote: 	
		     We are not talking    safety margins, we are talking an aircraft rated in the standard category and    as such will sustain 3.8G's without structural failure. Nuff said. If the    location of the additional 200 LBS keeps the plane in CG than there will not    be an issue in standard flight conditions, what is unknown is how the plane    will react when the plane is stressed past the max load breaking point of    3.8G's x 2700lbs or 10,260LBS total. Then once you get past this point    there is the safety margin that is built in, but unless you go past the 10,260    LBS limit then there is nothing new being discovered.

    

   Dan



         From: owner-rv10-list-server(at)matronics.com    [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of    JSMcGrew(at)aol.com

Sent: Thursday, May 17, 2007 12:00    PM

To: rv10-list(at)matronics.com

Subject: Re: RV10-List:    Establishing gross weight

   

         The design safety margins are established to account for    variations in construction, fatigue, turbulence, variations in piloting,    engineering mistakes etc. etc., all of which are fairly difficult to    predict when they will happen or what the effect will be. Furthermore, an    aircraft experiences many different stresses during the course of a flight    (besides just holding the airplane up in level flight). You need a thorough    engineering analysis to understand the effects a deviation from    the design conditions will have on the airframe in various flight    conditions.

    

   I recommend sticking to Van's established limits (weight limits and all    others) unless one is willing and capable of performing such an    analysis.

    

   -Jim McGrew

   40134

    

      Jim "Scooter"    McGrew

http://www.mit.edu/~jsmcgrew    



    

   In a message dated 5/17/2007 11:35:42 A.M. Eastern Daylight Time,    LloydDR(at)wernerco.com writes:

    	  Quote: 	
		  -->      RV10-List message posted by: "Lloyd, Daniel R."      <LloydDR(at)wernerco.com>



Let me clarify my position, Like you      have stated the plane has already

had a static test of its 2700 lbs,      which means the wing will need to

support 3.8 times that to be in the      standard category, which means

theoretically both wings together will      withstand 10,260 lbs and not

fail. With this being said, it would not be      a long stretch stating that

an additional 200 pounds in the right      location will not cause an issue

during normal flight and clear      non-turbulent conditions. I did not state

that it was a smart thing to do      and go fly in turbulence, what I did

state was set it high, flight test      it and adjust as necessary.



Dan N289DT RV10E       

	




	


 



  

 Jim "Scooter"  McGrew

http://www.mit.edu/~jsmcgrew  



See what's free at AOL.com. 

  [quote][b]

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Thu May 17, 2007 7:01 pm Post subject: Establishing gross weight

Weighing IN.  VANS has done it with testing!  

   

My favorite quip goes like this “The tree of life Is Self Pruning”.  

     Lancair builders (and other      manipulators) have all too often “Pen Whipped” their gross      weight number to achieve an artificial Useable Weight calculation.  
DARs can often be bought for      money.  You can even sneak things by them – they are human.  
Ignorance can be corrected with      solid  Life Experiences and a sound Education… Stupidity is a      hereditary thing.  
Pilot’s often “Pen      Whip an Aeronautical Logbook” or their “Engine Logbook”.       It is why the FAA wants it in pen not pencil.   

   

You have only your god and the pain and suffering of the surviving family members to answer too when you fool with irrefutable engineering evidence.  Newton got it right years ago.  Often the heaviest and juiciest apple falls first from the tree.  Get some education, study the issue, live long enough to amass wisdom and sound personal experience.  Screw with the Insurance Underwriters and Attorneys and I assure you that your life will be less enjoyable.  I stand ready to serve as an “expert witness” who will fly anywhere, at any time, for any individual or group of individuals who desire to keep aviation safer and with lower insurance costs.  Another perspective, do something unquestionably stupid and injurious to the rest of us builders and be prepared to spend a lot of money.  Corner cutting set you up for the spring tree pruning ritual.  

   

Anybody want to talk about an RV-10 Operator’s Seminar at OSH like Lancair does? So we can hammer out these issues.  

   

John Cox  

   

Do not Archive  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Thursday, May 17, 2007 6:27 AM

 To: rv10-list(at)matronics.com

 Subject: RE: RV10-List: Establishing gross weight  

  

   

Modifying the gross weight is very little different from a lot of the other non-Van’s-approved mods.  The plane was engineered for a 260HP (or less) IO-540 with 60 gallons of fuel, 180Kts max cruise, etc. etc. etc.  If you want to put in a Subaru, Mazda, turbo-Lycoming, 120Gal tanks, tip tanks, IFR panel (why would you do this unless you were going to fly IFR in a plane that was designed to be strictly VFR?), etc, you are modifying the design.  The nice thing about the amateur-built experimental category is that you are free to do that, even though you might make Van’s mad.  

   

Really and truly, I think the gross weight should be established during the fly-off period.  How is the builder going to establish a gross weight when he hasn’t even flown the plane?  But, since you have to (I am sure you, as the repairman, can modify it down the road in the log books if you choose to) establish a pre-airworthy gross weight, then you have to guess.  Most people will go with the 2,700, many of whom will fly it however feels comfortable, whether it is 2,700 or 3,000.  Selecting a gross weight different than what Van’s recommends will really only become an issue if/when there is an accident.  If you are flying over your established gross weight and crash, the insurance company will not want to pay if they can establish that you were overweight.  If you are flying within a gross weight over what Van’s recommends and you crash, the insurance company will not be able to not pay because of the weight unless there is a clause in the contract that requires that you build exactly to the plans, which I doubt there is.  Then you may start causing problems for other people because insurance rates may go up.  Some people modify their gross weight simply because they can.  The plane will carry 2,900 lbs and still climb to 15,000+ feet (I think  ).  From there it is completely up to you.  Also, even if you put your gross weight at 2,700, what are the implications of flying over gross weight?  

   

For others (JC’s response expected here), what are the implications of flying over you established gross weight?  Does that just become an issue if you crash and don’t burn?  

   

Do not archive  

     

Jesse Saint  

Saint Aviation, Inc.  

jesse(at)saintaviation.com (jesse(at)saintaviation.com)  

www.saintaviation.com  

Cell: 352-427-0285  

Fax: 815-377-3694  

          

  

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Wayne Edgerton

 Sent: Wednesday, May 16, 2007 7:37 PM

 To: rv10-list(at)matronics.com

 Subject: Establishing gross weight  

  

     

I saw on a weight and balance list at www.rvproject.com/wab/  that there is some differences on selecting a max gross weight. Vans recommends 2700, but used 2758 on their 10, but on this list there's a 2850 and a 2900. How does one come up with the conclusion or decision to increase the gross weight over Vans recommended? My empty weight came in somewhat higher than the others at 1749 but I've put a ton of stuff in the panel and many extra items including a full leather interior, four place O2, overhead console, etc. It is what it is.  

    

   

    

Obviously it would be nice to have a higher gross weight but I'm not sure how one justifies going beyond the recommended gross weight.  

    

   

    

Anyone have any great insight into this? I did a archive search but didn't seem to find much.  

    

   

    

Wayne Edgerton #40336  

    

   

    

sent my papers off to the DAR so I'm hopefully getting close  

   	  Quote: 	
		     http://www.matronics.com/Navigator?RV10-List 	
 	  Quote: 	
		   http://forums.matronics.com 	
[quote]     [b]

DAVELEIKAM(at)wi.rr.com
Guest

Posted: Thu May 17, 2007 8:08 pm Post subject: Establishing gross weight

I am just building the plane light.  Lower the empty weight and increase 

useful load.  How can you arbitrarily raise the designed gross weight  and 

feel comfortable, much less flight test the thing like that?  What if the 

plane stalls and you can't recover?  When I was a brand new pilot I took my 

father-in-law (we each go better than 200 lbs.) for a ride in the C-150 I 

trained in at Rainbow airport in Franklin, WI (Y78 now gone.)  Filled it 

with gas and took off on a nice hot afternoon.  Field elevation was only 

about 750 MSL.  The plane barely climbed out of ground effect, but did end 

up getting us over the trees just past the end of the runway, barely.  I 

think the sweat I burned off hoping to climb helped.   How much over gross 

do you think we were?  OAT play any roll in this?  The first and last time I 

flew without paying attention to weight, balance and performance issues. 

Never told my father-in-law there was a problem.  If Van's says gross is 

2700, it's 2700 max or no go in my book.  Stay safe please, builders.



Dave Leikam

40496



---

rleffler

Joined: 05 Nov 2006
Posts: 680

Posted: Fri May 18, 2007 2:42 am Post subject: Establishing gross weight

Great idea!  

   

   

I’m in…………  

   

At my point of build, I’m an information sponge on anything RV-10.  

   

Bob  

   

Do Not Archive  

       

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of John W. Cox

 Sent: Thursday, May 17, 2007 11:01 PM

 To: rv10-list(at)matronics.com

 Subject: RE: Establishing gross weight  

  

  

   

   

Anybody want to talk about an RV-10 Operator’s Seminar at OSH like Lancair does? So we can hammer out these issues.  

   

John Cox  

   

Do not Archive  

   

      [quote][b]

_________________
Bob Leffler
N410BL - Phase I
http://mykitlog.com/rleffler

bcondrey

Joined: 03 Apr 2006
Posts: 580

Posted: Fri May 18, 2007 4:12 am Post subject: Establishing gross weight

Absolutely, count me in!  

   

Bob  

         

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of John W. Cox

 Sent: Thursday, May 17, 2007 11:01 PM

 To: rv10-list(at)matronics.com

 Subject: RE: RV10-List: Establishing gross weight  

  

   

Weighing IN.  VANS has done it with testing!  

   

My favorite quip goes like this “The tree of life Is Self Pruning”.  

     Lancair      builders (and other manipulators) have all too often “Pen      Whipped” their gross weight number to achieve an artificial Useable      Weight calculation.  
DARs      can often be bought for money.  You can even sneak things by them      – they are human.  
Ignorance      can be corrected with solid  Life Experiences and a sound      Education… Stupidity is a hereditary thing.  
Pilot’s      often “Pen Whip an Aeronautical Logbook” or their      “Engine Logbook”.  It is why the FAA wants it in pen not      pencil.   

   

You have only your god and the pain and suffering of the surviving family members to answer too when you fool with irrefutable engineering evidence.  Newton got it right years ago.  Often the heaviest and juiciest apple falls first from the tree.  Get some education, study the issue, live long enough to amass wisdom and sound personal experience.  Screw with the Insurance Underwriters and Attorneys and I assure you that your life will be less enjoyable.  I stand ready to serve as an “expert witness” who will fly anywhere, at any time, for any individual or group of individuals who desire to keep aviation safer and with lower insurance costs.  Another perspective, do something unquestionably stupid and injurious to the rest of us builders and be prepared to spend a lot of money.  Corner cutting set you up for the spring tree pruning ritual.  

   

Anybody want to talk about an RV-10 Operator’s Seminar at OSH like Lancair does? So we can hammer out these issues.  

   

John Cox  

   

Do not Archive  

           

  

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Jesse Saint

 Sent: Thursday, May 17, 2007 6:27 AM

 To: rv10-list(at)matronics.com

 Subject: RE: Establishing gross weight  

  

   

Modifying the gross weight is very little different from a lot of the other non-Van’s-approved mods.  The plane was engineered for a 260HP (or less) IO-540 with 60 gallons of fuel, 180Kts max cruise, etc. etc. etc.  If you want to put in a Subaru, Mazda, turbo-Lycoming, 120Gal tanks, tip tanks, IFR panel (why would you do this unless you were going to fly IFR in a plane that was designed to be strictly VFR?), etc, you are modifying the design.  The nice thing about the amateur-built experimental category is that you are free to do that, even though you might make Van’s mad.  

   

Really and truly, I think the gross weight should be established during the fly-off period.  How is the builder going to establish a gross weight when he hasn’t even flown the plane?  But, since you have to (I am sure you, as the repairman, can modify it down the road in the log books if you choose to) establish a pre-airworthy gross weight, then you have to guess.  Most people will go with the 2,700, many of whom will fly it however feels comfortable, whether it is 2,700 or 3,000.  Selecting a gross weight different than what Van’s recommends will really only become an issue if/when there is an accident.  If you are flying over your established gross weight and crash, the insurance company will not want to pay if they can establish that you were overweight.  If you are flying within a gross weight over what Van’s recommends and you crash, the insurance company will not be able to not pay because of the weight unless there is a clause in the contract that requires that you build exactly to the plans, which I doubt there is.  Then you may start causing problems for other people because insurance rates may go up.  Some people modify their gross weight simply because they can.  The plane will carry 2,900 lbs and still climb to 15,000+ feet (I think  ).  From there it is completely up to you.  Also, even if you put your gross weight at 2,700, what are the implications of flying over gross weight?  

   

For others (JC’s response expected here), what are the implications of flying over you established gross weight?  Does that just become an issue if you crash and don’t burn?  

   

Do not archive  

     

Jesse Saint  

Saint Aviation, Inc.  

jesse(at)saintaviation.com (jesse(at)saintaviation.com)  

www.saintaviation.com  

Cell: 352-427-0285  

Fax: 815-377-3694  

            

  

  

  

From: owner-rv10-list-server(at)matronics.com [mailto:owner-rv10-list-server(at)matronics.com] On Behalf Of Wayne Edgerton

 Sent: Wednesday, May 16, 2007 7:37 PM

 To: rv10-list(at)matronics.com

 Subject: Establishing gross weight  

  

     

I saw on a weight and balance list at www.rvproject.com/wab/  that there is some differences on selecting a max gross weight. Vans recommends 2700, but used 2758 on their 10, but on this list there's a 2850 and a 2900. How does one come up with the conclusion or decision to increase the gross weight over Vans recommended? My empty weight came in somewhat higher than the others at 1749 but I've put a ton of stuff in the panel and many extra items including a full leather interior, four place O2, overhead console, etc. It is what it is.  

    

   

    

Obviously it would be nice to have a higher gross weight but I'm not sure how one justifies going beyond the recommended gross weight.  

    

   

    

Anyone have any great insight into this? I did a archive search but didn't seem to find much.  

    

   

    

Wayne Edgerton #40336  

    

   

    

sent my papers off to the DAR so I'm hopefully getting close  

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