VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-9/9A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #1  
Old 10-18-2012, 08:34 PM
alpinelakespilot2000 alpinelakespilot2000 is offline
 
Join Date: Jan 2005
Posts: 3,646
Default RV-9 stall speed - Vso (solo)? + do mine look about right?

Does anyone know what Van's no flaps solo weight stall speed is? On their website, they provide the numbers solo and gross for what I assume are flaps down speeds (Vso), but can't find equivalent numbers for flaps up stall speed (Vs) at solo weight.

Went out and did a full stall series and am interested by the IAS's I was seeing compared to the book IAS speeds Van's provides. I'm curious whether my lower indicated stall speed for Vso is what other RV-9/9A's see and whether that's just indicative IAS inaccuracies at such low speeds, whether it's a function of my relatively low empty weight (1039# me, 1057# Vans), whether I likely have a significant pitot and/or static error, and/or whether I have to be more careful at what altitude I do them. (I did mine at about 5000-5500 ft density altitude. Anyone know at what altitude Van's does theirs?)

If you fly a 9 or 9A do my indicated speeds seem in the ballpark compared to yours when you're at 5000 ft density?:
Vso: Vans = 44mph/38kts (solo weight); My plane = 40mph/35kts (solo weight = 180# + full fuel)
Vs: Vans = (can't find Van's Vs numbers for solo weight); My plane = 50 mph/43kts (solo weight = 180# + full fuel)

FWIW, though my GPS speeds seem to match up pretty well with my indicated and true airspeeds when the wind is factored in during cruise, I haven't had a chance yet to really check my IAS in general using the 3-way or 4-way tests and their associated formulas.

Thanks.
__________________
Steve M.
Ellensburg WA
RV-9 Flying, 0-320, Catto

Donation reminder: Jan. 2021

Last edited by alpinelakespilot2000 : 10-18-2012 at 09:27 PM.
Reply With Quote
  #2  
Old 10-18-2012, 09:16 PM
PerfTech's Avatar
PerfTech PerfTech is offline
 
Join Date: Sep 2010
Location: Redlands, Ca.
Posts: 1,458
Default

....Mine is 52mph no flaps.
__________________
Allan Nimmo
AntiSplatAero.com
Innovative Aircraft Safety
Products, Tools & Services
Info@AntiSplatAero.com
Southern California (KREI)
RV-9A / Edge-540
(909) 824-1020
Reply With Quote
  #3  
Old 10-18-2012, 11:02 PM
Leland's Avatar
Leland Leland is offline
 
Join Date: Jan 2005
Location: Livermore, California
Posts: 146
Default CAFE test results

The CAFE Foundation tested an RV-9A some years ago. CAFE no longer has the results posted on their website, but Ted Chang has a copy on his site: http://3limafoxtrot.com/Certificatio...e%20report.pdf .

Their test results follow:
Stall, clean, 1759 lb, Vs1 58.16 smph/50.5 kt
Stall, full flaps, 1758 lb, Vs0 49.08 smph/42.6 kt

Leland
Reply With Quote
  #4  
Old 10-19-2012, 07:09 AM
terrykohler terrykohler is offline
 
Join Date: Jan 2005
Posts: 1,009
Default CAFE reports are still on their site

You've just got to dig a little deeper.
http://cafefoundation.org/v2/pdf_cafe_apr/rv-9a.pdf
Go to "research" on the bottom of their main page.
By the way, the numbers on my 9A are within a half knot of their findings-just another reference point.
Terry, CFI
RV9A N323TP
Reply With Quote
  #5  
Old 10-19-2012, 07:16 AM
Vlad's Avatar
Vlad Vlad is offline
 
Join Date: Oct 2008
Location: Utah
Posts: 8,151
Default

Quote:
Originally Posted by terrykohler View Post



By the way, the numbers on my 9A are within a half knot of their findings-just another reference point.
Terry, CFI
RV9A N323TP

My 9A numbers match yours within half knot Terry
__________________
Where is N666BK?

Не имей сто рублей, а имей сто друзей.
Reply With Quote
  #6  
Old 10-19-2012, 08:00 AM
MS19087's Avatar
MS19087 MS19087 is offline
 
Join Date: Nov 2006
Location: West Chester, PA
Posts: 689
Default Mine too . . .

Stall, clean, 50 kt
Stall, full flaps, 43 kt

Near gross
__________________
Mark
RV-9A; Sold
RV-14A; Building
2020 =VAF= donor
Reply With Quote
  #7  
Old 10-19-2012, 08:04 AM
Greg Arehart's Avatar
Greg Arehart Greg Arehart is offline
 
Join Date: Jul 2007
Location: Delta, CO/Atlin, BC
Posts: 2,391
Default

When I did my testing 4 years ago:

44 mph with flaps
49 mph no flaps

Greg
__________________
Greg Arehart
RV-9B (Big tires) Tipup @AJZ or CYSQ
N 7965A
Reply With Quote
  #8  
Old 10-19-2012, 08:10 AM
guccidude1 guccidude1 is offline
 
Join Date: Mar 2008
Location: Reno NV
Posts: 542
Default RV-9 stall speed - accurate or likely pitot/static error?

My -9A gross wt stall speed is clean is 53 kts and full flaps 47 kts. Dan
Reply With Quote
  #9  
Old 10-19-2012, 09:22 AM
rv9av8tr's Avatar
rv9av8tr rv9av8tr is offline
 
Join Date: Dec 2006
Location: Portland, OR
Posts: 827
Default

Looks to me numbers are all over the place and the most likely cause is pitot geometry. Because of this, IAS is meaningless from plane to plane, and determining an accurate calibration factor at the lower airspeeds is practically "mission impossible".

It is what it is for YOUR plane, what else matters and what's a few mph between friends?????
__________________
Long-EZ built 1985 -> Sold 2007
RV-9A; N539RV First Flight: 7/2010
RV-8A N468DL 40 hr Flight Test Program
Building Log: www.mykitlog.com/n539rv
APRS Tracking: aprs.fi/n539rv
2017 Paid
Reply With Quote
  #10  
Old 10-19-2012, 09:33 AM
RVbySDI's Avatar
RVbySDI RVbySDI is offline
 
Join Date: May 2005
Location: Tuttle, Oklahoma
Posts: 2,563
Default

Quote:
Originally Posted by rv9av8tr View Post
Looks to me numbers are all over the place and the most likely cause is pitot geometry. Because of this, IAS is meaningless from plane to plane, and determining an accurate calibration factor at the lower airspeeds is practically "mission impossible".

It is what it is for YOUR plane, what else matters and what's a few mph between friends?????
+1, The stall speed for your airplane is extremely important for you in your airplane. Your stall speed in your airplane is not that important for me in my airplane. And vice verse.
__________________
RVBYSDI
Steve
RV9A
https://rvwings.com

Live Long And Prosper! 🖖🏻
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 01:27 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.