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Updates to RV-12/RV-12iS publications and plans - Feb 14 2019

greghughespdx

Well Known Member
Advertiser
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.
 
... 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?

i-j2ZcpZz-S.jpg

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. :)
 
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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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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!
 
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 :eek:)
Point being, there is a lot of great new ideas in the wind that I think Van's customers will like.
 
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....


wpd178db6d_05_06.jpg


Happy building and thanks again for all your help.
Steve
 
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?

i-j2ZcpZz-S.jpg

Thanks for clarifying "Maximum Wind Limitations 30" by adding the words (Ground Operations).
 
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.
 
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