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V Speeds (7a-180 hp w/ C/S) help

K

Kenny Gene

Well Known Member
I'm starting my IFR training and need to refresh my brain on V Speeds,, Can someone help me out here?? (I passed my written and time to fly!)
Thank you everyone on our site!!
Kenny Gene
 
"V"-speeds are determined during flight testing for each individual aircraft and should listed in your logbook and operating limitations.
 
V speeds

Here are some examples of what your looking for

Va = 140mph
Vne = 230mph
Vso = 58mph
vs1 = 65 mph apx
Vx = 100mph
Vy = 85mph

I think these are close numbers to Van's and actual experience. Others may vary. They work for me.
Regards,
Tad "Stripes" Sargent
FFI Wingman
380hrs.
7A
 
Other useful IFR Speeds/Manifold Pressures

Your instructor should also teach you the performance numbers necessary for instrument approach procedure speeds and manifold pressures to maintain constant altitudes, constant climbs or descents. It was imperative in my approach/departure training to not be chasing the performance of the airplane during the procedures. These will be something like 14" MP to maintain level flight to intercept FAP. Or, 10" MP for non-precision descent of 800fpm.:)
 
I'm a long way from flight test (building the wings at the moment), but aren't Vne and Va *design* limits, rather than figures determined during flight test?

It's of less importance, obviously, for instrument training I HOPE :)...
 
I know that I'm to write in my aircraft log all V speeds experienced during my flight testing of 40 hours, however I "really" have not completed that portion. I was looking for some help in "filling in the blanks" and give me a ball park. My plane is a 7A with 180 HP and a C/S prop.
VA - design maneuvering speed - ______ kts
Vfe - Max flap extended speed - _______
Vne - Max speed or never exceed - ______
Vno - Max structural cruising speed - _______
Vr - Rotation speed - _______
Vref- reference landing approach speed _______
Vs - Stall speed - _____________
Vso - stall in landing configuration - ______
Vsi - stall speed "clean" - _______
Vx - speed for best angle of climb - _______
Vy - speed for best rate of climb - ________

This is what I'm looking for.

Thanks guys for reading and your responses.

Kenny Gene
 
Now I actually am serious...

Va, Vfe, Vne, Vno are all *design speeds*...you should never be trying to "determine" them in flight test. It's called "never exceed" for a reason. Similarly, in theory Vfe is *max* flaps extended speed because if you extend them at a higher speed, the structure is not designed to physically withstand the load (yeah, yeah, I know about 50% load factor excess and all that).

I could go out in the garage and get out the construction manual, but for now...aren't these give somewhere by Van's? You can't very well take a plane up and figure out Va by getting it thumped around, after all, hoping to figure out at what speed that 50fps gust will deform the metal...
 
Flying Scotsman said:
You can't very well take a plane up and figure out Va by getting it thumped around, after all, hoping to figure out at what speed that 50fps gust will deform the metal...
Click to expand...
Since we're getting technical...

You are correct on the other speeds, but not technically correct on Va. Va (manuvering speed) is found on the top of the V-N diagram at the positive load limit (6Gs in this case.) Put more precisely, it is the stall speed at the maximum load limit. You calculate it by mulitplying Vsi by the square root of the load factor. It is very much derived from flight testing, as opposed to the other speeds you mention.

The reference to a mythical 50fps vertical gust is used in figuring Vno (structural cruise speed, the bottom of the yellow arc) not Va.

But you are definately thinking in the right direction.
 
Kenny Gene said:
I know that I'm to write in my aircraft log all V speeds experienced during my flight testing of 40 hours, however I "really" have not completed that portion. I was looking for some help in "filling in the blanks" and give me a ball park. My plane is a 7A with 180 HP and a C/S prop.
VA - design maneuvering speed - ______ kts
Vfe - Max flap extended speed - _______
Vne - Max speed or never exceed - ______
Vno - Max structural cruising speed - _______
Vr - Rotation speed - _______
Vref- reference landing approach speed _______
Vs - Stall speed - _____________
Vso - stall in landing configuration - ______
Vsi - stall speed "clean" - _______
Vx - speed for best angle of climb - _______
Vy - speed for best rate of climb - ________

This is what I'm looking for.

Thanks guys for reading and your responses.

Kenny Gene
Click to expand...
The speeds in blue are to be determined by testing. Sorry, I didn't think I had to spell out every little detail. I thought it was obvious that you don't "test" for "design limits."
 
Mel said:
The speeds in blue are to be determined by testing. Sorry, I didn't think I had to spell out every little detail. I thought it was obvious that you don't "test" for "design limits."
Click to expand...

Sorry...no offense intended. I'm an engineer by training and profession, so I tend to be kinda anal about things... :)
 
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