RV-6/7/8 T/O and Landing Numbers?

[gf30269]

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

[ChiefPilot]

Originally Posted by gf30269

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.

[gf30269]

Originally Posted by ChiefPilot

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?

[ChiefPilot]

Originally Posted by gf30269

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

[David Paule]

What's a TOLD card?

Dave

[ChiefPilot]

Originally Posted by David Paule

What's a TOLD card?

Dave

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

[Bobo]

Why does your TOLD card example have a V1 & V2 when you are flying a -6A?

[ChiefPilot]

Originally Posted by Bobo

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.

[gf30269]

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

Originally Posted by ChiefPilot

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