Chavycha
CGLUMPS or bust!!!
- Joined
- Jan 24, 2016
- Messages
- 442
- Reaction score
- 92
There's a lengthy discussion on the benefits of computing V speeds for a given weight pinned to the top of the board (Archer approach and landing speeds). The thread contains a lot of excellent discussion and some detailed math on how to compute speeds for any aircraft. A couple weeks ago, a generous poster shared a spreadsheet with Dakota V-speeds for specific weights.
I adopted it for my Cherokee 180 and calcuated the V-speeds for several different loadings. Since I've started flying these speeds my landings have improved quite a bit - never really had trouble landing her but now doing so with a minimum of float and the stall light blinking each and every time.
Today, for example, I was solo with 25 gallons of fuel, and my flight bags (about 10#). Thus, my V-speeds were:
Vso = 48mph
Vref = 62mph
Quite a difference from the POH figures!
Vso = 57mph
Vref = 74mph
I have always flown approaches a bit slower when light, but up until recently, hadn't taken the time to calculate it out exactly. I was a bit surprised when I saw how big the differences were - 9mph for Vso and 12mph for Vref! If you fly approaches at 74mph while solo, you're gonna float, float, float some more, and float a bit after that.
Likewise, notice the change in Vx and Vy speeds based on weight. If you're doing short-field ops where obstacle clearance is important, your Vx changes quite a bit as your weight drops.
Download here (disclaimer - this is for my personal use and I don't endorse or recommend you use, not liable for damages, spay and neuter your pets, blah blah blah). Note that the speeds and weights are for my airplane, myself, my typical 'items carried', and my typical passenger weights.
https://www.dropbox.com/s/vg0ialfmneb1djb/Cherokee VSpeeds.xls?dl=0
I adopted it for my Cherokee 180 and calcuated the V-speeds for several different loadings. Since I've started flying these speeds my landings have improved quite a bit - never really had trouble landing her but now doing so with a minimum of float and the stall light blinking each and every time.
Today, for example, I was solo with 25 gallons of fuel, and my flight bags (about 10#). Thus, my V-speeds were:
Vso = 48mph
Vref = 62mph
Quite a difference from the POH figures!
Vso = 57mph
Vref = 74mph
I have always flown approaches a bit slower when light, but up until recently, hadn't taken the time to calculate it out exactly. I was a bit surprised when I saw how big the differences were - 9mph for Vso and 12mph for Vref! If you fly approaches at 74mph while solo, you're gonna float, float, float some more, and float a bit after that.
Likewise, notice the change in Vx and Vy speeds based on weight. If you're doing short-field ops where obstacle clearance is important, your Vx changes quite a bit as your weight drops.
Download here (disclaimer - this is for my personal use and I don't endorse or recommend you use, not liable for damages, spay and neuter your pets, blah blah blah). Note that the speeds and weights are for my airplane, myself, my typical 'items carried', and my typical passenger weights.
https://www.dropbox.com/s/vg0ialfmneb1djb/Cherokee VSpeeds.xls?dl=0
Last edited:
