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  #1  
Old 02-14-2019, 04:03 PM
greghughespdx greghughespdx is offline
 
Join Date: Nov 2011
Location: Aurora, OR
Posts: 548
Default Updates to RV-12/RV-12iS publications and plans - Feb 14 2019

RV-12 folks,

As happens from time to time, we published a few documentation updates for RV-12 and RV-12iS builders/owners today.

You can find the updated documents in the Support > Service Information and Revisions section of the Van's website. All of the changes published today fall in the "Revisions and Changes" publication category. You can also sign up to receive periodic notifications of changes we publish via the signup box on the home page of the Van's Aircraft website.

The following documents were updated for both the "legacy" RV-12 and the RV-12iS.
  • Pilot's Operating Handbook
  • Flight Training Supplement
  • Production Acceptance Procedures
  • Maintenance Manual

In addition, the following documents/plans pages have been updated specifically for the RV-12iS:
  • Section 28iS/U and Section 35iS/U - reflects changes to parts and procedures related to new, improved gun-drilled gear legs
  • Section 51AiS/U - Placards and Certification Documents
  • Section 03iS/U - reflects an addition to the builder's supplies list
  • Section 01iS/U - minor changes plus DWG 1 and DWG 2 (the three-view and cut-away view drawings) have been published

The following section has been published and is specific to the "legacy" RV-12:
  • Section 35 - reflects changes to parts and procedures related to new, improved gun-drilled gear legs

Note: The RV-12 gun-drilled gear legs are a revised part, which integrates brake plumbing and removed the need to run a tube on the outside of the gear leg. This is now the standard shipping part for all RV-12/12iS aircraft. In the event one needs to replace a set of original main gear in the future, different attachment hardware will be used and Van's will have a kit available for doing so. Other than the integral brake line, there is no difference between the original and new parts.
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Van's Aircraft - Community, Media, Marketing
Van's web site | Instagram | Facebook
Opinions, information and comments are my own unless stated otherwise. They do not represent direction/opinions of my employer.

Building RV-8A since Sept 2014 (N88VX reserved)
Dual AFS 5600, Avidyne IFD 440, Whirlwind 74RV, Superior XPIO-360
VAF build thread - Flickr photo album - Project Facebook page
Hillsboro, OR (EAA 105)

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  #2  
Old 02-14-2019, 04:58 PM
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RV8JD RV8JD is offline
 
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Greg,

I'm a little confused by the Vne (Redline) limits shown in the RV-12iS POH. This snippet from Page 2-3 of the POH shows Vne as 136 KIAS below 16,000', but also shows 136 KTAS with no qualifiers. Are we to assume the 136 KTAS number only applies above 16,000'? Can you clarify the Vne speeds?

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Carl N.
Arlington, WA (KAWO)
RV-8, 475 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
(Pic)
RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflügel Standard Libelle 201B, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned
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  #3  
Old 02-14-2019, 07:41 PM
greghughespdx greghughespdx is offline
 
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Location: Aurora, OR
Posts: 548
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Quote:
Originally Posted by RV8JD View Post
... This snippet from Page 2-3 of the POH shows Vne as 136 KIAS below 16,000', but also shows 136 KTAS with no qualifiers. Are we to assume the 136 KTAS number only applies above 16,000'? Can you clarify the Vne speeds?

Hey there Carl - good question.

First of all, the short version is that one should never exceed either speed (136 KIAS at any altitude or 136 KTAS above 16,000ft). Obviously those speed numbers can be anywhere from "significantly different" to "close to the same" relatively speaking - depending on altitude, temperatures and other conditions.

Slightly longer version: The IAS limitation is a limit intended to protect against structural concerns. The TAS limitation is there to protect against flutter concerns. Both are important. They're not the same, and only one is the primary limiting factor in any given point.

Even longer version: I just learned some very cool (and new to me) engineery stuff, since I asked our (way smarter than me) Chief Engineer about this. Basically, you'll not be surprised that we've done a lot of testing of the RV-12iS (and our other aircraft). Through all that testing we determined that the limiting factor for the 12iS below 16,000 ft is indicated airspeed - that's what defines that portion of the safe-tested "box" on the graph. Once you cross above 16,000 ft DA, the limiting factor becomes true airspeed.

We test the aircraft structure on the ground to certain load limits. The IAS limit in the POH is there to protect against overloading the aircraft (gust loads, dive loads, and loads applied by the operator).

The TAS limitations are related to protection against flutter. We of course test to speeds higher than are printed in the POH for loads as well as for flutter. As an aircraft climbs it will reach an altitude where the risk of overloading the aircraft is no longer the primary concern -- and in those conditions the primary speed-related issue becomes flutter. In the case of the RV12iS, that switch of primary limiting factor happens at 16,000 feet.

It should be noted that both the Garmin and Dynon EFIS systems can only report one number on the airspeed tape. To be conservative a single TAS value was chosen for EFIS Vne at all altitudes. In reality we wanted to give you that part of the envelope back (to allow you to descend faster) but to do that we'd need two Vne numbers on the airspeed tape. The only way to communicate the additional portion of the available envelope was in the POH. We hope in the future that EFIS manufactures will accommodate Vne based on a combination of both true and indicated airspeeds.

So -- never exceed either one, but true airspeed doesn't become the limiting factor before about 16,000 feet. In reality, our published limits get even more conservative once you cross 16,000 feet. The math becomes complicated when you need to decide which speed is primary in real time so we simplify it a bit, in a conservative manner. And calculating all that in your head while in a dive at 17,000 feet... Forget about it.

Disclaimer: I'm not an engineer - not even close. I marvel at those who are and geek out on the conversations I have with them. So, I very likely have described things here is a much-less-than-perfect way.

But hey, I learned something and had a good time doing it.
__________________
Van's Aircraft - Community, Media, Marketing
Van's web site | Instagram | Facebook
Opinions, information and comments are my own unless stated otherwise. They do not represent direction/opinions of my employer.

Building RV-8A since Sept 2014 (N88VX reserved)
Dual AFS 5600, Avidyne IFD 440, Whirlwind 74RV, Superior XPIO-360
VAF build thread - Flickr photo album - Project Facebook page
Hillsboro, OR (EAA 105)


Last edited by greghughespdx : 02-14-2019 at 07:49 PM.
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  #4  
Old 02-14-2019, 08:01 PM
rv9builder rv9builder is offline
 
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That's interesting how the engineers calculate airspeed limitations, Greg. Thanks for posting it.

Related to updates, I signed up to receive notices for the RV-12 and RV-12iS on the new Van's website, and today I received a notice about the updates you mentioned in the first post of this thread. Very cool! The new system seems to work great!
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RV-12iS Fuselage
RV-9A Project: Sold

VAF donation made for 2019

Last edited by rv9builder : 02-14-2019 at 09:45 PM.
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  #5  
Old 02-14-2019, 08:34 PM
greghughespdx greghughespdx is offline
 
Join Date: Nov 2011
Location: Aurora, OR
Posts: 548
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Quote:
Originally Posted by rv9builder View Post
That's interesting how the engineers calculate airspeed limitations, Greg. Thanks for posting it.

Related to updates, I signed up to receive notices for the RV-12 and RV12iS on the new Van's website, and today I received a notice about the updates you mentioned in the first post of this thread. Very cool! The new system seems to work great!
Glad you got the notice. That was the first one we have sent, and appreciate the pirep. Feedback always welcome!
__________________
Van's Aircraft - Community, Media, Marketing
Van's web site | Instagram | Facebook
Opinions, information and comments are my own unless stated otherwise. They do not represent direction/opinions of my employer.

Building RV-8A since Sept 2014 (N88VX reserved)
Dual AFS 5600, Avidyne IFD 440, Whirlwind 74RV, Superior XPIO-360
VAF build thread - Flickr photo album - Project Facebook page
Hillsboro, OR (EAA 105)

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  #6  
Old 02-14-2019, 08:37 PM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
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Quote:
Originally Posted by greghughespdx View Post
Disclaimer: I'm not an engineer - not even close. I marvel at those who are and geek out on the conversations I have with them. So, I very likely have described things here is a much-less-than-perfect way.

But hey, I learned something and had a good time doing it.
Do not let this voice fool you.
He has a very good grasp on engineering stuff, but fortunately for Van's customers the focus of his position is in other areas (hmmmm, I guess that didn't come out quite right )
Point being, there is a lot of great new ideas in the wind that I think Van's customers will like.
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Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #7  
Old 02-14-2019, 08:54 PM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by greghughespdx View Post
Hey there Carl - good question.
...
But hey, I learned something and had a good time doing it.

Thanks for the response. Yes, I'm familiar with flutter speed limitations at higher altitudes being conservatively a function of TAS, and I assumed that's what you were doing. I guess I was pointing out that the POH is not clear on where the 136 KTAS applied. Some additional qualifiers would be in order, such as noting that the 136 KTAS limit applies above 16,000'.

I hope you are planning on giving part of the envelope back on the RV-8s also (and other models). Now that Van's considers the Vne of the RV-8 to be 230 MTAS from Sea Level on up, it really limits the downhill performance of the airplane. Below are screenshots from my RV-8 descending from altitude at reduced power settings and relatively low rates of descent, and bumping up against Vne. Any Vne relief Van's can provide would be appreciated.



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Carl N.
Arlington, WA (KAWO)
RV-8, 475 Tach Hours
(Pic 1),(Pic 2)
- Out with the Old, In with the New
(Pic)
RV-8, 1938 Tach Hours (Pic 1),(Pic 2) - Sold

Glasflügel Standard Libelle 201B, N564NS - Sold
Rolladen-Schneider LS1-f, N61MP - No longer owned

Last edited by RV8JD : 02-14-2019 at 09:43 PM.
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  #8  
Old 02-15-2019, 07:43 AM
Aircraft Specialty Aircraft Specialty is offline
 
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Location: Oconomowoc, WI
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Regarding the new gun drilled gear legs.... If someone happens to have a set installed on a 12iS already and is willing to do a fit test on a hose for us, we would greatly appreciate it.

Send us an email if you are interested....




Happy building and thanks again for all your help.
Steve
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aircraftspecialty@gmail.com

www.aircraftspecialty.com
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  #9  
Old 02-15-2019, 07:55 AM
AirHound AirHound is offline
 
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Location: OFallon IL now, everywhere before
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Quote:
Originally Posted by RV8JD View Post
Greg,

I'm a little confused by the Vne (Redline) limits shown in the RV-12iS POH. This snippet from Page 2-3 of the POH shows Vne as 136 KIAS below 16,000', but also shows 136 KTAS with no qualifiers. Are we to assume the 136 KTAS number only applies above 16,000'? Can you clarify the Vne speeds?

Thanks for clarifying "Maximum Wind Limitations 30" by adding the words (Ground Operations).
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  #10  
Old 02-15-2019, 07:56 AM
greghughespdx greghughespdx is offline
 
Join Date: Nov 2011
Location: Aurora, OR
Posts: 548
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Quote:
Originally Posted by AirHound View Post
I’m on my iPhone viewing new look can the SB list be printed? I haven’t tried from a laptop yet. I found it a useful list to show compliance and SN relativity maint data during annual inspections and records keeping? Thank you?
Sure, you bet - they're still PDF files just like they've always been - just displayed differently so you can also view them inline. There's a link/button on each one ("Download this file") that will allow you to download it you can print save or them, no problem.

On mobile, at least on iOS, you can click the download button, it will display the PDF file, then you can send it send to a printer like any other PDF file if you have an AirPrint compatible printer, too. That send-to function would also allow you to save the file on your device in an app that understands PDFs.
__________________
Van's Aircraft - Community, Media, Marketing
Van's web site | Instagram | Facebook
Opinions, information and comments are my own unless stated otherwise. They do not represent direction/opinions of my employer.

Building RV-8A since Sept 2014 (N88VX reserved)
Dual AFS 5600, Avidyne IFD 440, Whirlwind 74RV, Superior XPIO-360
VAF build thread - Flickr photo album - Project Facebook page
Hillsboro, OR (EAA 105)

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