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  #21  
Old 08-04-2017, 08:39 PM
rjtjrt rjtjrt is offline
 
Join Date: Mar 2006
Location: Australia
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I'm not sure why this thread has taken the direction it has.

AlanTN
I can not see anywhere in your posts that would indicate an RV-12 in either form (ULS or iS) is not for you.
I also have been wondering what the current Van's company promotional material range figures were for the original RV-12, and if they have intentionally changed he quoted range figure in their promotional material.

I also really value RVbuilder2002's support of builders and owners, and his contribution in this forum superbly valuable.

Last edited by rjtjrt : 08-04-2017 at 09:24 PM.
  #22  
Old 08-04-2017, 09:28 PM
Jim T Jim T is offline
 
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Location: Independence, OR
Posts: 169
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Quote:
Originally Posted by rjtjrt View Post
AlanTN
I can not see anywhere in your posts that would indicate an RV-12 in either form (ULS or iS) is not for you.
I also have been wondering what the current Van's company promotional material range figures were for the original RV-12, and if they have intentionally changed he quoted range figure in their promotional material.
OK for the sake of discussion I have a RV-12 brochure dated 10/05/12 and here is what it says:
Top Speed: 135 mph
Cruise Speed: 131 mph
Cruise Speed: 116 mph
Stall Speed: 52 mph
Takeoff Distance: 700 ft.
Landing Distance: 525 ft.
Rate of Climb: 900 fpm
Ceiling: 13,000 ft.
Range (7500' @ 5500 rpm): 482 miles
Range (7500" @ 5000 rpm): 530 miles

I'm assuming this is without wheel pants since the picture in the brochure of N912VA doesn't have wheel pants.

I'm also assuming, as Scott had indicated in an earlier post, that the range indicated is the distance where one would expect to run out of fuel. I personally believe that that is an important baseline figure to work from. Then we, as prudent pilots, need to factor in FAA regulations and our own personal minimums for fuel remaining, which are certainly different for everyone.

Jim
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2006 Rans S-6S Coyote (flying)
  #23  
Old 08-04-2017, 09:35 PM
AlanTN AlanTN is offline
 
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Location: Linden, TN
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Quote:
Originally Posted by Jim T View Post
OK for the sake of discussion I have a RV-12 brochure
Range (7500' @ 5500 rpm): 482 miles
Range (7500" @ 5000 rpm): 530 miles

Jim
Jim the current POH under the same conditions lists 482 NM and 534 NM
Does your brochure really say MILES?
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Mechanical Engineer
PPL since '66
  #24  
Old 08-04-2017, 11:09 PM
Jim T Jim T is offline
 
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Quote:
Originally Posted by AlanTN View Post
Jim the current POH under the same conditions lists 482 NM and 534 NM
Does your brochure really say MILES?
Yes is does. Well actually is says "miles" not 'MILES". I tried to post exactly what it said and then noted MY two personal assumptions at the end.



Jim
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2006 Rans S-6S Coyote (flying)
  #25  
Old 08-05-2017, 07:15 AM
Postaltwo Postaltwo is offline
 
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I'm suprised also with the direction of this thread. My interpretation of the op is that it seems odd that 5500 rpm is more efficient than 5000 . One would think max cruise would not be your max range setting . Just like any other aircraft on the planet . I do not think the op was bashing the rv 12 in any way . It's just plain wrong that so many jumped all over him so quickly imo.
  #26  
Old 08-05-2017, 07:30 AM
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Piper J3 Piper J3 is offline
 
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Why not just everyone back way off of this thread and if someone is interested in squeaking the last few minutes of flight out of a tank of fuel they should feel free to do so. If they land successfully at an approved airport then all the better. Personally, my bladder fills faster than the tank empties so not much concern for me…
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Jim Stricker
Hinckley, Ohio
P/ASEL 1970 Sport Pilot since '04
80 hrs Flying Aeronca Chief 11AC
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LSRM-A Certificate 2016
RV-12 E-LSA #120058 AWC 7/12 Bought Flying 10/15 with 48TT - Hobbs now 317
  #27  
Old 08-05-2017, 08:10 AM
AlanTN AlanTN is offline
 
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Quote:
Originally Posted by Jim T View Post
OK for the sake of discussion I have a RV-12 brochure dated 10/05/12 and here is what it says:
Top Speed: 135 mph
Cruise Speed: 131 mph
Cruise Speed: 116 mph
Stall Speed: 52 mph
Takeoff Distance: 700 ft.
Landing Distance: 525 ft.
Rate of Climb: 900 fpm
Ceiling: 13,000 ft.
Range (7500' @ 5500 rpm): 482 miles
Range (7500" @ 5000 rpm): 530 miles
Quote:
Originally Posted by AlanTN
Jim the current POH under the same conditions lists 482 NM and 534 NM
Does your brochure really say MILES?

Quote:
Originally Posted by Jim T View Post
Yes is does. Well actually is says "miles" not 'MILES". I tried to post exactly what it said and then noted MY two personal assumptions at the end.
Jim
Jim, I don't have the proof of this, but I have long suspected that someone took numbers that were originally in miles and assuming they were NM multiplied them by 1.15 producing the 555 and 614 range numbers. Your brochure from 2012 is one piece of evidence that supports my theory.

On 11/11/11 I started a thread titled 'Max Endurance Fuel Burn?' to try to get a handle on this. Later that day, I typed the following in part:

Quote:
Originally Posted by AlanTN View Post
What I was really looking for is the Maximum Range (Vbr) fuel consumption. According to the specs on Van's web site the Max Range is 614 miles.

They use 5000 RPM for the Max Range.
This tells me at as early as November 2011 the website was using 614 miles at 5000 rpm for maximum range.

If that is what happened, then the POH should show 482 and 534 'Miles' rather than 'NM.' And those should have been the max range numbers on the Performance page for the RV-12.

Its just a theory, but it could partially explain the current discrepancy.
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Last edited by AlanTN : 08-05-2017 at 08:26 AM.
  #28  
Old 08-05-2017, 01:15 PM
rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by Postaltwo View Post
I'm suprised also with the direction of this thread. My interpretation of the op is that it seems odd that 5500 rpm is more efficient than 5000 . One would think max cruise would not be your max range setting . Just like any other aircraft on the planet . I do not think the op was bashing the rv 12 in any way . It's just plain wrong that so many jumped all over him so quickly imo.
Just because something seems to contradict what we know, does not automatically mean it is wrong.
The specifications you are questioning were established with actual flight testing (more than just one flight and fill at a gas pump) within the past month.
People are free to believe it or not if they want, but just because they don't believe it doesn't make it false.
When someone starts implying that because there were already mistakes made publishing specifications, that all data is then suspect. At that point there is know way fwd (what can be said in words to convince them it is correct?) other than that person doing their own tests.
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  #29  
Old 08-05-2017, 01:57 PM
Postaltwo Postaltwo is offline
 
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Location: Canada
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Quote:
Originally Posted by rvbuilder2002 View Post
Just because something seems to contradict what we know, does not automatically mean it is wrong.
The specifications you are questioning were established with actual flight testing (more than just one flight and fill at a gas pump) within the past month.
People are free to believe it or not if they want, but just because they don't believe it doesn't make it false.
When someone starts implying that because there were already mistakes made publishing specifications, that all data is then suspect. At that point there is know way fwd (what can be said in words to convince them it is correct?) other than that person doing their own tests.
I don't think it's that people don't believe it ,just that the data appears like an anomaly which is why it got questioned . You confirm the numbers ,great . It's really exciting actually because running max cruise while getting best range is the best of both worlds .
  #30  
Old 08-05-2017, 02:08 PM
Driftdown Driftdown is offline
 
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Location: Clearwater, Florida
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Quote:
Originally Posted by Postaltwo View Post
. . . "running max cruise while getting best range is the best of both worlds."
While flying military aircraft, I encountered that several times.
Hard to comprehend, but for some aircraft, the concept is true.
The thing that suffers is fuel endurance and probably engine life.

Last edited by Driftdown : 08-05-2017 at 02:10 PM.
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