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How many RV-10 Pilots can answer this question?

DJP

Well Known Member
When I bought my RV-10 in November 2011, I wanted to know as much as I could about the aircraft and its limitations.

The first thing that I noticed was that the VNE that was showing in the existing POH was not what was shown on the Van?s website. I was a little confused as the VNE on the Van?s site showed the VNE to be 200 Knots, TRUE airspeed; I had never seen a VNE expressed that way before. As a military pilot for 6.5 year and an airline pilot for 33 years I had only seen indicated airspeed or Indicated Mach as the VNE of the aircraft I had flown. I contacted Van?s and they confirmed that the VNE of the RV-10 was in fact 200 Knots TRUE AIRSPEED.

As a wandered around the internet looking for other RV-10 POM?s that I might be able to capture data from, I found that about half of them were wrong about the VNE and were showing Indicated airspeed as the measurement of VNE.

I was fortunate and had immediately installed a Garmin GTN-650 GPS in the aircraft after I bought it. That unit has a selection that allows you to see what the TRUE airspeed is. I was shocked to see how many times I came right up to the VNE of 200 True, especially when descending from a higher altitude like 12,500 feet. It was easy to come right up to the limit and I would have to pull back on the throttle or slow the descent to keep the airspeed below the limit.

Late last year, I believe it was the November or December issue of the AOPA magazine Dave Hirschman did an article about the new sweepstakes aircraft that is a RV-10. While reading that article, I saw that AOPA magazine had also made a mistake and listed the VNE of the RV-10 as 200 knots INDICATED AIRSPEED. I wrote to Dave immediately and told him about the mistake and he responded within a day that yes I was correct and the article was incorrect. I told him that since he had a larger audience than I did I would hope that he would publish a correction. Unfortunately he has never done so and I think that could be a fatal mistake.

During this time period I wanted to know more about how Vans reached the decision of the VNE and I was told that it is ?very complicated?. Following that, they sent me a link to a publication that covers the subject very well. The link is below:

http://www.australianflying.com.au/news/vne-and-flutter-explained

Currently on this website (Vanairforce.com) there are three RV-10 POH?s listed and two of them have the VNE speed wrong! Felker, Rene N423CF had the VNE listed as INDICATED airspeed as does Todd Stovall, N728TT

This is a KILLER item, you do not want to have your wings separate from the aircraft due to flutter because you are exceeding the stated VNE, the answer to the question is 200 knots TRUE AIRSPEED!
 
This subject has been talked about repeatedly on this forum (do a search). However, Vans has tried to make a point about this (VNE in TAS) only in the past half dozen years or so. There are many older owner-written POHs showing VNE as IAS. And a lot of confusion which is understandable, as normally certified aircraft have, by law, VNE in IAS, although it is allowed to placard an aircraft showing different VNEs (IAS) as a function of altitude. I understand that there may be a liability issue here, but I too wish Vans would release their data and calculations to be more clear as to where they think the limits really are. This is especially true for the -10, and maybe the -9, both of which are great high altitude cruisers.
 
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IAS

Why not just find out the IAS limits of the 10 and make that known? If most other GA aircraft are reported that way, why not the RV-10? My POH on my 7 says 200kt vne. I didn't build the plane but I now wonder if that is IAS of true?
 
Why not just find out the IAS limits of the 10 and make that known? If most other GA aircraft are reported that way, why not the RV-10? My POH on my 7 says 200kt vne. I didn't build the plane but I now wonder if that is IAS of true?

Which IAS would you choose to match 200kt TAS?

The one at sea level or 5K ft, 10k ft or some other altitude since IAS goes down with alt

If you wanted to be totally sure, you could choose the redline IAS at the service ceiling 200 TAS figure. Use your E6B to figure it out and let us know if you like it.

Alternatively, you could make chart(s) or get an instrument that indicates TAS. ***EDIT*** Was IAS typo.

I assume most if not all EFIS will move the redline indicator based on TAS like my GRT. The mechanical ASIs with temp/alt correctors will do it too with pilot input.
 
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IAS at which density altitude?

Why not just find out the IAS limits of the 10 and make that known? If most other GA aircraft are reported that way, why not the RV-10? My POH on my 7 says 200kt vne. I didn't build the plane but I now wonder if that is IAS of true?
Not clear which density altitude should be used for the Vne in IAS - what would you recommend? I guess Van's chose a density altitude of 0, which seems reasonable to me. Had they chosen 18000ft, then the Vne in IAS would be about 160 mph, which of course would greatly limit people if they are flying lower.

I agree this is something to learn and understand, and it is not completely intuitive, but there are many such things in aviation.
 
Skyview HDX changes all red lines correctly.

At 15,000', the red line on the RV6 and RV12 were way down on normal limits.

Great safety feature.

Older ones like the D100 don't btw.
 
Because TAS changes with altitude. If you made redline a IAS that was low enough to insure that you never exceeded the TAS number at any altitude, it would be ridiculously low in something as speed/altitude capable as an RV.

Most certified singles are built like a Brinks truck and their cruise performance shows it. The buffer is built in and it's simple to publish Vne as a an IAS number. For example, on a 172, the Vne is 160 kts IAS. I have no idea what the actual TAS number is, but the only way you could reach it would be to point that airplane at the center of the earth, balls to the wall & let the ponies run. A G36 Bonanza cruises 30 kts below the IAS vne number at sea level and the Max Cruise Power charts in the POH have you choked down to about 50 kts below the Vne IAS number when you get into the teens.

This isn't a new concept. The first time I encountered Vne as a moving number was 30 years ago when I flew my first king air. The airspeed indicator had a barber pole that changed with altitude to represent Vne as an ever changing IAS, The higher you went, the lower Vne was. Really what it was doing was just presenting the TAS number for Vne, which gets lower with altitude.

Also, it's been said before but, Vne is only 1/2 the story. If you're cruising up in the yellow, you're just asking for trouble structurally because your buffer for gust loads is dwindling rapidly at that point.
 
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Why not just find out the IAS limits of the 10 and make that known? If most other GA aircraft are reported that way, why not the RV-10? My POH on my 7 says 200kt vne. I didn't build the plane but I now wonder if that is IAS of true?

Forgot to reply to this point in my previous comment.

No need to wonder. Per Vans, Vne is in TAS.
 
Yes TAS

Yes, my POH is 200 kts TAS.
My Chelton?s show TAS on the map page. I monitor it closely when I am descending fast into an airport. I will see 180-190 TAS often.
 
G3X

The Garmin G3X also allows you to set TAS redline that shows on the airspeed ribbon.
 
Interestingly enough I specifically asked Vans if I can exceed VNE at 4000 ft by 10% as the Swiss TestFlight program requests. That took me to 207.2 KIAS. They were ok with it as they tested it as well in these limits. VNE 200 KTAS it is.

Regards
Michael
 
When I bought my RV-10 in November 2011, I wanted to know as much as I could about the aircraft and its limitations.

The first thing that I noticed was that the VNE that was showing in the existing POH was not what was shown on the Van’s website. I was a little confused as the VNE on the Van’s site showed the VNE to be 200 Knots, TRUE airspeed; I had never seen a VNE expressed that way before. As a military pilot for 6.5 year and an airline pilot for 33 years I had only seen indicated airspeed or Indicated Mach as the VNE of the aircraft I had flown. I contacted Van’s and they confirmed that the VNE of the RV-10 was in fact 200 Knots TRUE AIRSPEED.

As a wandered around the internet looking for other RV-10 POM’s that I might be able to capture data from, I found that about half of them were wrong about the VNE and were showing Indicated airspeed as the measurement of VNE.

I was fortunate and had immediately installed a Garmin GTN-650 GPS in the aircraft after I bought it. That unit has a selection that allows you to see what the TRUE airspeed is. I was shocked to see how many times I came right up to the VNE of 200 True, especially when descending from a higher altitude like 12,500 feet. It was easy to come right up to the limit and I would have to pull back on the throttle or slow the descent to keep the airspeed below the limit.

Late last year, I believe it was the November or December issue of the AOPA magazine Dave Hirschman did an article about the new sweepstakes aircraft that is a RV-10. While reading that article, I saw that AOPA magazine had also made a mistake and listed the VNE of the RV-10 as 200 knots INDICATED AIRSPEED. I wrote to Dave immediately and told him about the mistake and he responded within a day that yes I was correct and the article was incorrect. I told him that since he had a larger audience than I did I would hope that he would publish a correction. Unfortunately he has never done so and I think that could be a fatal mistake.

During this time period I wanted to know more about how Vans reached the decision of the VNE and I was told that it is “very complicated”. Following that, they sent me a link to a publication that covers the subject very well. The link is below:

http://www.australianflying.com.au/news/vne-and-flutter-explained

Currently on this website (Vanairforce.com) there are three RV-10 POH’s listed and two of them have the VNE speed wrong! Felker, Rene N423CF had the VNE listed as INDICATED airspeed as does Todd Stovall, N728TT

This is a KILLER item, you do not want to have your wings separate from the aircraft due to flutter because you are exceeding the stated VNE, the answer to the question is 200 knots TRUE AIRSPEED!

FYI, the POH I sent to DR to post was a 2015 modified version of my original RV-10 POH that was written somewhere between 2012 and 2013, about 2 years before I actually flew my 10. I hadn't caught at that time the mistake in the Vne in the POH being labeled as IAS even though I had set Vne in my own EFIS as TAS. Sometime in 2016 I finally noticed the error and corrected it in all subsequent versions of my POH that I've actually used in the plane. But I never sent Doug an updated version so I'll rectify that now.

PS-- I make no guarantees on the accuracy of any info in my POH. My intent was mainly to provide a Word template based upon Cessna POH's that folks could take and make it their own. My advice - don't blindly follow any of the content in any of the POH examples-- use then mainly for the format and populate them with data based upon your own research and testing. YMMV.....
 
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Just a few points.

Vne actually should be expressed as a dynamic pressure q value. Structure loads, dynamics, and design is based on q. TAS tracks q fairly closely and is used since we don’t have q meters in general aviation.

If not q or TAS, Vne should be in CAS especially in Experimental aircraft as pitot and static error can be greatly different among the same model type due to installation difference. In certified general aviation, installation of air data ports is constant and tested therefore using IAS is I guess considered ok as long as the value for Vne is adjusted for the difference between IAS and CAS.
 
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