VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #1  
Old 02-27-2017, 01:36 PM
gf30269 gf30269 is offline
 
Join Date: May 2009
Location: Peachtree City, GA
Posts: 12
Default RV-6/7/8 T/O and Landing Numbers?

Taking an informal poll on what you guys are using. I share an RV-7 and this is what I use:

Takeoff - No turns back to airport below 800' (still air)
Climb - 130 kts
Approach - 68 kts
Max crosswind - 15 kts
Glide ratio (90 kts) - 8 to 1

In addition, I'm curious if anybody adjusts their approach numbers for weight or wind gusts.

Thanks!
George Fox
N757RG
Reply With Quote
  #2  
Old 02-27-2017, 01:49 PM
ChiefPilot's Avatar
ChiefPilot ChiefPilot is offline
 
Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
Default

Quote:
Originally Posted by gf30269 View Post
In addition, I'm curious if anybody adjusts their approach numbers for weight or wind gusts.
I wrote an iPad app which is essentially an electronic TOLD card. Numbers vary automatically based on weight and field conditions (wind, DA, etc.). Vref, for example, changes from 57KIAS at light weights to 68KIAS at gross at my home base.
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything

Last edited by ChiefPilot : 02-27-2017 at 08:07 PM.
Reply With Quote
  #3  
Old 03-01-2017, 08:38 AM
gf30269 gf30269 is offline
 
Join Date: May 2009
Location: Peachtree City, GA
Posts: 12
Default

Quote:
Originally Posted by ChiefPilot View Post
I wrote an iPad app which is essentially an electronic TOLD card. Numbers vary automatically based on weight and field conditions (wind, DA, etc.). Vref, for example, changes from 57KIAS at light weights to 68KIAS at gross at my home base.
I'm surprised at such a significant difference in speeds (11 kts). Where did you get the algorithm for your app?
Reply With Quote
  #4  
Old 03-01-2017, 09:47 AM
ChiefPilot's Avatar
ChiefPilot ChiefPilot is offline
 
Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
Default

Quote:
Originally Posted by gf30269 View Post
I'm surprised at such a significant difference in speeds (11 kts). Where did you get the algorithm for your app?
Standard formulas apply.

If you have the stall speed for your aircraft at a specific weight (I use gross weight), the stall speed at a different weight is calculated using the formula:
Vs0new = Vs0old * sqrt(newweight / oldweight)

...where Vs0old is the known stall speed at a weight identified as oldweight.

From there, ref speed is computed using the standard formula of 1.3 * Vs0. At a very light weight (min fuel, no bags, etc.) my -6A stalls at 44kts indicated. At gross weight, the stall happens at 52kts. Both stall speeds are using full flaps and similar CG (I really like my plane's CG - the fuel is right at the empty weight location of 70" aft of datum :-) )

I'd add that CG plays a part, but in flight testing it had a minor effect (+/- 1kt) on my aircraft's stall speed and so I chose to exclude it. If the app were ever to be released, that would need to be accounted for. This also assumes 1G flight. The app also computes corner speed and instantaneous turn rate and radius, but that's for using during something other than takeoff/landing
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything

Last edited by ChiefPilot : 03-01-2017 at 09:54 AM.
Reply With Quote
  #5  
Old 03-01-2017, 12:02 PM
David Paule David Paule is offline
 
Join Date: Dec 2009
Location: Boulder, CO
Posts: 4,435
Default

What's a TOLD card?

Dave
Reply With Quote
  #6  
Old 03-01-2017, 12:07 PM
ChiefPilot's Avatar
ChiefPilot ChiefPilot is offline
 
Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
Default

Quote:
Originally Posted by David Paule View Post
What's a TOLD card?

Dave
TakeOff and Landing Data. Example card from google image search:

__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
Reply With Quote
  #7  
Old 03-01-2017, 03:04 PM
Bobo Bobo is offline
 
Join Date: Nov 2016
Location: Aurora, OH
Posts: 24
Default

Why does your TOLD card example have a V1 & V2 when you are flying a -6A?
__________________
Todd Rader
Reply With Quote
  #8  
Old 03-01-2017, 03:19 PM
ChiefPilot's Avatar
ChiefPilot ChiefPilot is offline
 
Join Date: Jan 2005
Location: Twin Cities, MN
Posts: 1,565
Default

Quote:
Originally Posted by Bobo View Post
Why does your TOLD card example have a V1 & V2 when you are flying a -6A?
It's an example of a TOLD card for a C-12, obviously, and was shown as an example of a general TOLD card. My app doesn't have V1 & V2 because they don't apply to single engine aircraft. But you already knew that.
__________________
Brad Benson, Maplewood MN.
RV-6A N164BL, Flying since Nov 2012!
If you're not making mistakes, you're probably not making anything
Reply With Quote
  #9  
Old 03-02-2017, 09:21 AM
gf30269 gf30269 is offline
 
Join Date: May 2009
Location: Peachtree City, GA
Posts: 12
Default

Shaking out some cobwebs here! Thanks for the info...George

Quote:
Originally Posted by ChiefPilot View Post
Standard formulas apply.

If you have the stall speed for your aircraft at a specific weight (I use gross weight), the stall speed at a different weight is calculated using the formula:
Vs0new = Vs0old * sqrt(newweight / oldweight)

...where Vs0old is the known stall speed at a weight identified as oldweight.

From there, ref speed is computed using the standard formula of 1.3 * Vs0. At a very light weight (min fuel, no bags, etc.) my -6A stalls at 44kts indicated. At gross weight, the stall happens at 52kts. Both stall speeds are using full flaps and similar CG (I really like my plane's CG - the fuel is right at the empty weight location of 70" aft of datum :-) )

I'd add that CG plays a part, but in flight testing it had a minor effect (+/- 1kt) on my aircraft's stall speed and so I chose to exclude it. If the app were ever to be released, that would need to be accounted for. This also assumes 1G flight. The app also computes corner speed and instantaneous turn rate and radius, but that's for using during something other than takeoff/landing
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 11:52 PM.


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.