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  #21  
Old 02-03-2020, 01:47 PM
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Tumper Tumper is offline
 
Join Date: Dec 2007
Location: Aubrey, TX
Posts: 358
Default My Bad

I apologize, Bill you are correct. The published Vne for the RV-9 is more like 207 MPH. However, my personal Vne is 180 MPH TAS, and here is why.

If you look at the V-N diagram for the RV-9 the ?envelope? get kind of thin above 180 MPH (the RV-9 is not aerobatic). So, in my humble opinion, unless you can guarantee my smooth air, I draw the line, for me, at 180 MPH.

Bill, I also realize you know all this, but all RV-9 pilots that fly with a 180HP or greater engine or are considering flying with 180HP plus, need to carefully consider this.

There is an article that does a much better job than I can do of describing this. Google ?Flying High and Fast by Ken Krueger?

Also, I would not recommend having this conversation with Mr. VanGrunsven.
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Dean Eiland
Aubrey, TX
Former Vice President EAA Chapter 1246
RV-9 (yes) N369RV
Mattituck IO-360, C/S Whirl Wind Prop, GRT, Digiflight II, Garmin SL30 & GTX 330 and Hotel Whisky Aux tanks, Bla Bla Bla
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  #22  
Old 02-03-2020, 02:45 PM
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airguy airguy is online now
 
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Location: Garden City, Tx
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Quote:
Originally Posted by Tumper View Post

Also, I would not recommend having this conversation with Mr. VanGrunsven.
Heh heh.... funny you should say that - I had that exact specific conversation with him at the beer social in Oshkosh this past summer. He just asked if I watched it on descent, to which I replied "Of course, as any pilot should", and he nodded his head and said "OK!"

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Greg Niehues - SEL, IFR, Repairman Cert.
Garden City, TX VAF 2020 dues paid
N16GN flying 700 hrs and counting; IO360, SDS, WWRV200, Dynon HDX, 430W
Built an off-plan RV9A with too much fuel and too much HP. Should drop dead any minute now.
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  #23  
Old 02-03-2020, 05:24 PM
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N941WR N941WR is offline
 
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Location: SC
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Quote:
Originally Posted by airguy View Post
Heh heh.... funny you should say that - I had that exact specific conversation with him at the beer social in Oshkosh this past summer. He just asked if I watched it on descent, to which I replied "Of course, as any pilot should", and he nodded his head and said "OK!"

...
I had a similar conversation with him. Great guy, he is.

Personal limitations are just that, personal. An O-320 powered -9, with some simple aerodynamic cleanup could probably run circles around an 360 powered -9.

If someone is worried about turbulence, they should probably slow to Va or below. The -9 has proven itself to be an amazingly strong aircraft.
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Bill R.
RV-9 (Yes, it's a dragon tail)
O-360 w/ dual P-mags
Build the plane you want, not the plane others want you to build!
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  #24  
Old 02-03-2020, 07:44 PM
SVTPete83 SVTPete83 is offline
 
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Location: Napa, Ca
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Love my IO360 with a catto 3 blade. I usually run LOP at or above 8500 and use 7.5ish at 155 knots. Only need to really watch Vne on descent.
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  #25  
Old 02-03-2020, 07:53 PM
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N941WR N941WR is offline
 
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Originally Posted by SVTPete83 View Post
Love my IO360 with a catto 3 blade. I usually run LOP at or above 8500 and use 7.5ish at 155 knots. Only need to really watch Vne on descent.
That matches what I see.
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Bill R.
RV-9 (Yes, it's a dragon tail)
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Build the plane you want, not the plane others want you to build!
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  #26  
Old 02-04-2020, 09:56 AM
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db1yg db1yg is offline
 
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Default RV9a-IO360

I have been flying a 9a equipped with a 360 since 2006. Started out with an 0360/180 with a Catto 3 blade and over the years have converted to an AFP FI system and a WW 200RV composite CS propeller. It is a really sweet combination and works well out of my 5200 ft elevation base airport.

My typical cruise is 2350 to 2400 rpm, WOT, and LOP at 7.8 to 8.0 gph which gives me 63 to 65% power. The cruise speed is impressive as are the take offs with that incredible 9 wing.

Keep a 9 clean, light, and pay close attention to perfect rigging and either the 180 or 160 hp engines will leave you with a big smile--and go high--that wing absolutely loves 12 to 15k ft.

Cheers,

db
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  #27  
Old 02-04-2020, 12:00 PM
rightrudder rightrudder is offline
 
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Box-stock I0-320 here.

150-plus KTAS at 7.5 gph and a huge RV grin to go along with it!
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  #28  
Old 02-04-2020, 03:32 PM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Only need to really watch Vne on descent.
It is these type of comments that make those that know, take pause.

Vne has little to do with the reason that a 160 HP engine is the largest recommended for an RV-9.

It is Vno (otherwise known as the top of the green arc on the ASI).

Any flight above that indicated speed is risking exceeding the max gust loading that the wing can endure. The higher you are above that speed.... the higher the risk.
AN RV-9(A) with more than 160 HP can easily exceed Vno in level flight at lower altitudes. Even more so in a decent, even at higher altitudes.
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Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #29  
Old 02-04-2020, 03:44 PM
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RV8JD RV8JD is offline
 
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Quote:
Originally Posted by rvbuilder2002 View Post
It is these type of comments that make those that know, take pause.

Vne has little to do with the reason that a 160 HP engine is the largest recommended for an RV-9.

It is Vno (otherwise known as the top of the green arc on the ASI).

Any flight above that indicated speed is risking exceeding the max gust loading that the wing can endure. The higher you are above that speed.... the higher the risk.
AN RV-9(A) with more than 160 HP can easily exceed Vno in level flight at lower altitudes. Even more so in a decent, even at higher altitudes.
Agree with your comments about Vno. But at altitudes above only about 10,000' (at least for the RV-8s and RV-7s) Vno (193 MPH IAS) is higher than Vne (230 MPH TAS), so Vne governs. I'm sure you are aware of this, but I thought I'd point it out.

Below is a pic that shows this for the RV-8s (and -7s). At any higher altitude, the Yellow Vno line goes away since Vne is less than Vno, and Vne is the limiter. The RV-9s probably have a somewhat similar altitude crossover point, but I haven't bothered to calculate it (RV-9s: Vno = 180 MPH IAS; Vne = 210 MPH TAS).



The question for Van's is, are there any structural design reasons for not recommending engines over 160 HP? Because the RV-9s have the same Vno and Vne as the RV-6s, and Van's recommends up to and including 180 HP for the RV-6s.
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Carl N.
Arlington, WA (KAWO)
RV-8, 790 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

Glasflugel Standard Libelle 201B - Sold
Rolladen-Schneider LS1-f - No longer owned

Last edited by RV8JD : 02-04-2020 at 04:22 PM.
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  #30  
Old 02-04-2020, 05:16 PM
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rvbuilder2002 rvbuilder2002 is offline
 
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Quote:
Originally Posted by RV8JD View Post
The question for Van's is, are there any structural design reasons for not recommending engines over 160 HP? Because the RV-9s have the same Vno and Vne as the RV-6s, and Van's recommends up to and including 180 HP for the RV-6s.
Yes, same speeds but the RV-9 is designed for utility category limit loads and the rest are designed for aerobatic limit loads.
__________________
Opinions, information and comments are my own unless stated otherwise. They do not necessarily represent the direction/opinions of my employer.

Scott McDaniels
Van's Aircraft Engineering Prototype Shop Manager
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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