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  #1  
Old 01-16-2012, 10:57 AM
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Ironflight Ironflight is offline
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Default RV-3: Interim Phase 1 Report

Well, we are just a month past first flight, and two of these weeks we were out of town. We?ve had a couple of ?No Fly? days due to weather, but we now have 33 hours on the airframe, and I can share a few test results.

We?ve expanded the speed envelope from a flaps-down stall of 50 knots IAS to the redline of 183. We did a few limited TAS excursions (a couple of knots) above that in a smooth-air descent, but will stick with the design redline ? I have no desire to test the flutter limits beyond Van?s engineering. Stalls are normal for an RV ? power off, it breaks sharply, but honestly, and recovers instantly when you release back pressure. Holding it in an incipient stall with power on gives a fair amount of tail ?rattle? (it?s a metal airplane), but I found nothing loose or damaged afterwards ? it?s just a little noisy.

One turn spins left and right were quick, but normal, with a steep entry. We?ll explore spins more in future tests. I don?t think this will be a favorite spinning airplane ? it loses altitude pretty quick. I?ll go get a Cub for lazy spins?.

Max G?s demonstrated have been 4.8?..if I?m going any higher than that, I?ll have to wear squeeze pants?.

Best rate of climb airspeed appears to be between 95 and 100 knots IAS at sea level. A timed climb at 125 TAS from 3,000 to 12,000 took 6:30, for an average ROC of 1384 fpm. That was a ?Cruise climb to keep CHT?s below 400. Max ROC we?ve seen steady state (after the zoom) down low is in excess of 3,000 fpm between 2,000? and 3,000? (msl). Speaking of cooling, it IS winter, but the oil temp hasn't gone above 180, even in extended slow flight. CHT's are limiting for climb after awhile - but do just fine at a 1,500 fpm cruise-climb at 120 KTAS.

I took the airplane up to 17,500? today where it was still climbing at 500 fpm at cruise-climb of 120 KTAS. I leveled off (no IFR in Phase 1) and let the airplane stabilize at full throttle (leaned to peak) and 2500 rpm. The EFIS showed this as 50% power, with a fuel flow of 5.7 gph. This gave a TRUE airspeed of 165 knots. There was 35 knots of wind up there, and when I pointed the nose downwind, that gave a groundspeed of 200 knots, with a mileage of?.yeah, it was ridiculous!).

Coming down from altitude requires a considerable throttle-back, or you?re over the TAS redline pretty quick.

CG has been tested to the aft limit, and right on the line, pitch stability is neutral and undamped ? yet the airplane is easier to land in that condition than an aft-loaded RV-8. With normal loading, it is positively perfect at all speeds and conditions.

Louise has been busy with cruise performance testing, and is reducing the data when she has the chance. I haven?t tried a flat-out max speed run at full throttle on the deck, but based on what I have seen, I expect it to be about 183 knots ? redline.

Aerobatics ? I?ve done all the rolls (except snaps), loops, Cubans, Immelmans, cloverleafs, Split S?s?well, pretty much all of the stuff I would expect this sport acro machine to do. It?s really got the power to do vertical rolls and it?s so nice having the Half-Raven system to keep from spewing oil all over the belly.

I?ve done a fair amount of avionics testing to make sue the major stuff works. After squashing a few bugs here and there, everything seems to work ? G430 is great for GPS, VOR, and ILS work ? approaches are great ? coupled or uncoupled. The GxPilot is doing great, and plays very well with the G3X ? which is also outstanding. I?m still working through all of the A/P modes, but it is pretty cool to give it a crossing altitude at a fix and a desired rate of descent ? then watch it start down at the right time. We?ve done one cross-country to College Station (in our test area) to see how it is in cruise ? and it?s great! It?s pretty easy to get it dialed in for 70% power and 7 gph at a few thousand feet ? that?s a nice four hours to dry tanks.

On the maintenance side, we?ve had one instance of cracking on the little extension of the right lower flap skin that ?underlaps? the fuselage. The flap skin is pretty thin, and I expect that the unsupported piece is flexing in the breeze when deployed. I?ll probably add a doubler before it goes to paint. We added a small rudder trim wedge until I engineer and install an active trim tab (or don?t?..). the right brake seems to be evaporating brake fluid?.have had to pump it up once in 33 hours, but can?t find any sign of the fluid going anywhere. Little stuff ? nothing major.

So onto finishing up Phase 1?then we?ll be free to explore a bit more ? need to take it on a trip to the paint shop to get Grady looking at ideas for us?. 
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Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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  #2  
Old 01-16-2012, 11:08 AM
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Mike S Mike S is offline
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Paul, thanks for the report--------

I have to second what someone said in one of your prior posts, Vans needs to give you and Louise a commission on the RV 3's that are going to be sold here is the near future.

Wonder if I would fit in one????
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VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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  #3  
Old 01-16-2012, 11:24 AM
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Ironflight Ironflight is offline
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Quote:
Originally Posted by Mike S View Post
I have to second what someone said in one of your prior posts, Vans needs to give you and Louise a commission on the RV 3's that are going to be sold here is the near future.
I asked a spy at the factory if there has been an increase in orders....the answer was not encouraging from a commision standpoint.....

Quote:
Originally Posted by Mike S View Post
Wonder if I would fit in one????
I take the fifith on that one....
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Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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  #4  
Old 01-16-2012, 11:54 AM
RV8R999 RV8R999 is offline
 
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Quote:
Originally Posted by Ironflight View Post
CG has been tested to the aft limit, and right on the line, pitch stability is neutral and undamped ?
The RV-3 has zero static margin at aft cg?
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  #5  
Old 01-16-2012, 12:05 PM
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Ironflight Ironflight is offline
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Originally Posted by RV8R999 View Post
The RV-3 has zero static margin at aft cg?

I was just re-doing the W&B for the test, and we were just a little behind it for that data point. The good thing is, that was pretty heavily loaded in the baggage area - well beyond what we plan to placard it.

It was actually positive at 100 knots, but pretty much zero at 145. It's easier to land at full aft than the -8, probably becasue there is margin at the slower speeds.
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Paul F. Dye
Editor at Large - KITPLANES Magazine
RV-8 - N188PD - "Valkyrie"
RV-6 (By Marriage) - N164MS - "Mikey"
RV-3B - N13PL - "Tsamsiyu"
A&P, EAA Tech Counselor/Flight Advisor
Dayton Valley Airpark (A34)
http://Ironflight.com
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  #6  
Old 01-16-2012, 12:41 PM
fatherson fatherson is offline
 
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Quote:
Originally Posted by Ironflight View Post
On the maintenance side, we’ve had one instance of cracking on the little extension of the right lower flap skin that “underlaps” the fuselage. The flap skin is pretty thin, and I expect that the unsupported piece is flexing in the breeze when deployed. I’ll probably add a doubler before it goes to paint.
No need to do this immediately, but when you get a chance, will you please think about and share any ideas you might have for design changes to prevent this cracking which can be implemented at build time? I assume at the least that putting a doubler inside the flap at that point would look a little better.

You can add this to the long list of improvements you and the others have already shared. (It's interesting that the early -3 builders must have made such discoveries too, but until Randy, Rob, you guys, and a few others started documenting these tweaks on the web, there was no way to disperse these pearls into the collected memory for future builders.)

Quote:
Originally Posted by Ironflight View Post
I asked a spy at the factory if there has been an increase in orders....the answer was not encouraging from a commision standpoint
Maybe not . . . yet!

It takes a certain courage to start a -3. Give it a little time and I bet there's a noticeable uptick.

--
Stephen
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  #7  
Old 01-16-2012, 12:54 PM
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Mike S Mike S is offline
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Originally Posted by fatherson View Post
Maybe not . . . yet!

It takes a certain courage to start a -3. Give it a little time and I bet there's a noticeable uptick.

--
Stephen
Like when tax refunds start comming in.........
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Mike Starkey
VAF 909

Rv-10, N210LM.

Flying as of 12/4/2010

Phase 1 done, 2/4/2011

Sold after 240+ wonderful hours of flight.

"Flying the airplane is more important than radioing your plight to a person on the ground incapable of understanding or doing anything about it."
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  #8  
Old 01-16-2012, 01:02 PM
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ccsmith51 ccsmith51 is offline
 
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Quote:
Originally Posted by Mike S View Post
Like when tax refunds start comming in.........
What's a tax refund???
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Chris Smith
Maule M5-180C (Sold)
RV-6 O-360 CS (Sold)
RV-4 O-360 FP (Sold)
Full-time in the other type of RV....
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  #9  
Old 01-16-2012, 01:12 PM
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islandmonkey islandmonkey is offline
 
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Quote:
Originally Posted by ccsmith51 View Post
What's a tax refund???
It is a little treasure chest located at the end of each rainbow.
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Anthony Johnston
Brit working in Zurich, Switzerland.
1500 hour pilot and ex instructor and examiner.
RV-4 s/n 4572 Emp Kit.
RV-3B s/n 11460 Emp Kit. (In storage).
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  #10  
Old 01-17-2012, 10:52 AM
Scorch Scorch is offline
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Default TAS Limits?

Paul, just reading about how you had to throttle back to keep from exceeding the TAS limit on your RV-3 - I'm guessing that you get a TAS display on your G3X?

I'm aware that we have both IAS and TAS limits on our RVs, the IAS being the structural limit and the TAS being the flutter limit. I know the IAS limit on my RV-6 - it's 210 MPH IAS. My question, for you or anyone else who knows: where do we find the TAS (flutter) limit for our RVs? Specifically, for a -6. Is it the same number, 210 MPH, except TAS vice IAS?

I've always observed the IAS limit on my -6, but until your post reminded me, I've been kind of ignorant of its TAS limit. Maybe because I have steam guages with no TAS display...
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Last edited by Scorch : 01-17-2012 at 11:17 AM.
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