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  #1  
Old 08-13-2019, 04:32 AM
circuitbreaker8747 circuitbreaker8747 is offline
 
Join Date: Feb 2019
Location: Atlanta Georgia
Posts: 18
Default 1800 RV6A?

We are looking at buying a 6A. We come across quite a few that have a gross weight listed of 1800 pounds. We have read a lot of topics discussing this. However most discussions seem to focus on CG and performance and handing. We have seen almost no topic on the stress and wear and tear of ground ops and take off and landing have on landing gear and other components. A big topic/concern on "A" models is the nose gear. If that is such a concern why fly your plane 150 pounds overweight? It may fly fine but we wonder about years of landing over design weight and what it does to the landing gear and other components. We are on the fence about purchasing any 6A that lists gross weight at 1800 pounds. Even tho we would not go above 1650 what has 10 years of flying at 1800 done to airframe? Just curious of other peoples thoughts and experiences. Thank you.
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  #2  
Old 08-13-2019, 05:03 AM
FredMagare FredMagare is offline
 
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Location: Kyle, TX
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Hmmm. Well, I'm thinking that anyone who would actually load the aircraft to the full "adjusted" 1800lb weight would do so for a long cross country. (Who would stuff the aircraft full to do touch and go's?) I would think that the aircraft would be well under 1800lbs after a few hours of flight. So I don't think it would be much of an issue.

As for nose wheel issues: I suppose it would depend on whether the extra weight was in the passenger seat or in the baggage compartment. I would assume, if in the baggage compartment, the additional load would be on the main gear rather than the nose gear provided that the nose was lowered while there is still sufficient elevator authority to control its contact with the runway. If the extra weight is in the passenger seat...well, I dunno.... (Might the passenger be too heavy to fly in an RV?)

I would think the bigger issue would be excessive weight in the baggage compartment and center of gravity after burning a great deal of fuel. The aircraft would tend to become tail heavy with max baggage and little fuel but that potential weight and cg can be calculated/extrapolated prior to flight.

In the end, just because the aircraft has an 1800lb max gross weight does not mean you have to fly it at the weight. If it has not been previously damaged with that gross weight, I would think it's fine.

Good luck
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  #3  
Old 08-13-2019, 05:26 AM
BH1166 BH1166 is offline
 
Join Date: Nov 2017
Location: Eatonton Georgia
Posts: 89
Default 180hp

Most that I have seen with higher gross weight have had 180 hp vs 160hp and I believe that to be the reason for listing higher gross weight. Also as Fred said... YMMV
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  #4  
Old 08-13-2019, 10:05 AM
lr172 lr172 is offline
 
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Location: Schaumburg, IL
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Quote:
Originally Posted by circuitbreaker8747 View Post
We are looking at buying a 6A. We come across quite a few that have a gross weight listed of 1800 pounds. We have read a lot of topics discussing this. However most discussions seem to focus on CG and performance and handing. We have seen almost no topic on the stress and wear and tear of ground ops and take off and landing have on landing gear and other components. A big topic/concern on "A" models is the nose gear. If that is such a concern why fly your plane 150 pounds overweight? It may fly fine but we wonder about years of landing over design weight and what it does to the landing gear and other components. We are on the fence about purchasing any 6A that lists gross weight at 1800 pounds. Even tho we would not go above 1650 what has 10 years of flying at 1800 done to airframe? Just curious of other peoples thoughts and experiences. Thank you.
Pretty sure the gear on the 7 is the same alloy and diameter as the gear for the 6, just a bit longer. The 7 is rated at 1800, so I doubt there is an issue with the gear. Pretty sure the gear mounts are the same, as is the engine mount/nose gear assembly, at least in structural integrity.

I rated my 6A at 1800, but don't often fly it at that weight and rarely ever land at that weight.

I can't imagine there is any long term stresses from flying at that weight. The spar on the 6 is very robust. I would be way more concerned with how the pilot treated the nose wheel during TO, landing and ground ops than I would be from an 1800# GW. I would be more focused on known problems areas and the activity or lack thereof, that leads to them. No real issues with the 6 falling apart from stresses, though there are known areas where specific stress related issues can arise.

Larry
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Last edited by lr172 : 08-13-2019 at 10:25 AM.
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  #5  
Old 08-13-2019, 10:24 AM
Latech15 Latech15 is offline
 
Join Date: Apr 2018
Location: louisiana
Posts: 74
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Mine is listed at 1800 and I have probably only ever flown it over 1650 a couple of times. Vans will tell you that the nose gear is not a landing gear, rather a steering gear.

If you watch flight chops’ video series that he did at vans, you will notice that mike Seager recommended getting the nose when off and wheelie-ing down the runway in the takeoff attitude until the plane lifts off. Same deal with landing. Land on the mains and slowly bring the stick full back until you can’t hold it off anymore. These practices keep the nose gear very protected and I would be more concerned with the previous owner’s landing ability rather than what his plane’s weight is listed at.
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  #6  
Old 08-13-2019, 10:49 AM
scsmith scsmith is offline
 
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Location: Ashland, OR
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I have 'reverse-engineered' the spar on the RV-6 and I can tell you that at 1800 lbs you are vulnerable to gust loads exceeding limit load.

As a pilot, you can limit your maneuver loads, but you can't control gust loads, except by reducing speed. If you reduce the yellow line (V_b or V_c as the case may be) by an appropriate amount : (V_b-new)^2 = 1650/1800*(V_b-old)^2, AND YOU OBEY IT, then you have the same gust strength margins that the designer used when he designed the spar.
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  #7  
Old 08-13-2019, 03:14 PM
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RV8JD RV8JD is offline
 
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Default Nose Gear Weight Limits

You may want to review the nose gear weight limits as published by Vans in this Service Letter:

https://www.vansaircraft.com/wp-cont...ice_letter.pdf
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  #8  
Old 08-14-2019, 04:45 AM
circuitbreaker8747 circuitbreaker8747 is offline
 
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Location: Atlanta Georgia
Posts: 18
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Thank you for all the responses, lots of good points and things to think about.
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  #9  
Old 09-18-2019, 05:12 AM
Gyrodoug Gyrodoug is offline
 
Join Date: Feb 2019
Location: Dayton
Posts: 30
Default 1650 vs 1800

How does an RV6A get or receive a designated gross weight of 1800lbs?
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  #10  
Old 09-18-2019, 05:22 AM
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RV6_flyer RV6_flyer is offline
 
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Quote:
Originally Posted by Gyrodoug View Post
How does an RV6A get or receive a designated gross weight of 1800lbs?
Phase I flight testing.
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