Today's Message Index:
----------------------
1. 06:33 PM - Determining Vx (MHerder)
2. 07:15 PM - Re: Determining Vx (Jerry)
3. 08:15 PM - Re: Determining Vx (Terry Phillips)
4. 08:52 PM - Re: Determining Vx (Keith Ashcraft)
5. 10:37 PM - Re: Determining Vx (Terry Phillips)
6. 10:53 PM - Re: Determining Vx (Don Honabach)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
So Vy and best glide are easy to find, and I'm guessing that Vx is about 85% of
Vy under "normal" conditions, although Vx=Vy at service ceiling.
How does one determine Vx? Any thoughts. Seems to be about 67kts for my bird,
so Im guessing Vy is about 57 kts, I'd just like to know how it's determined.
--------
One Rivet at a Time!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=330233#330233
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Determining Vx |
Mike,
I will take a stab at it. I've been searching for the source of the information,
but haven't found it.
When doing your rate of climb flight testing (ROC), you end up with the ROC for
various airspeeds. These should be put into a spreadsheet and graphed, plotting
ROC on the Y-axis and airspeed on the X-axis. Ideally you should get a parabola.
The Vy corresponds with the max ROC of the parobola.
Vx is determined by extending a line from origin of the graph (0 ROC and 0 AS)
so that it is tangent to the parabola. This is usually pretty close to Vy.
I also have a 601HDS with a 912S. My Vy was 70mph true airspeed and Vx was 65 mph
TAS. This was at 3500 ft on a 95 degree day. I haven't rerun the test since
it has been cold.
Jerry
N316JL, 70 hours
---- MHerder <michaelherder@beckgroup.com> wrote:
>
> So Vy and best glide are easy to find, and I'm guessing that Vx is about 85%
of Vy under "normal" conditions, although Vx=Vy at service ceiling.
>
> How does one determine Vx? Any thoughts. Seems to be about 67kts for my bird,
so Im guessing Vy is about 57 kts, I'd just like to know how it's determined.
>
> --------
>
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Determining Vx |
Mike
One of the books on my wish list a couple of years ago was "Flight Testing
Homebuilt Aircraft," by Vaughan Askue. My daughter and son-in-law gave me
the book for Christmas.
I haven't looked at that book much, because my build was interrupted and
flight testing is far away. Askue has a detailed procedure for determining
best ROC (Vy) as a function of altitude. It looks like a well thought out
approach.
And, my favorite flight training book, Machado's "Private Pilot Handbook,"
in chapter 15, suggests a procedure for determining the best angle of climb
speed (Vx) from the ROC curves that result from Askue's procedure.
You might take a look at those two books. Good luck with your flight testing.
Terry
At 06:30 PM 2/8/2011 -0800, you wrote:
>So Vy and best glide are easy to find, and I'm guessing that Vx is about
>85% of Vy under "normal" conditions, although Vx=Vy at service ceiling.
>
>How does one determine Vx? Any thoughts. Seems to be about 67kts for my
>bird, so Im guessing Vy is about 57 kts, I'd just like to know how it's
>determined.
>
>--------
>One Rivet at a Time!
>
>
Terry Phillips
ttp44~at~rkymtn.net
Corvallis MT
ZU-601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail & flaps are done;
Upgrading wings & ailerons per the AMD Safety Directive
http://www.mykitlog.com/N47TP/
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Determining Vx |
Look at the attached file and see if this is what you are looking for. Found it
on the EAA.org homebuilders site.
Keith
CH701 - scratch (working on cabin area)
________________________________
From: MHerder <michaelherder@beckgroup.com>
Sent: Tue, February 8, 2011 7:30:47 PM
Subject: Zenith601-List: Determining Vx
So Vy and best glide are easy to find, and I'm guessing that Vx is about 85% of
Vy under "normal" conditions, although Vx=Vy at service ceiling.
How does one determine Vx? Any thoughts. Seems to be about 67kts for my bird,
so Im guessing Vy is about 57 kts, I'd just like to know how it's determined.
--------
One Rivet at a Time!
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=330233#330233
Be a PS3 game guru.
http://videogames.yahoo.com/platform?platform=120121
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Determining Vx |
Good find, Keith
That article only addresses determining Vy. However, it is 1 of a series of
about 5 articles. One of the other articles describes the Vx calculation.
Kolano appears to confirm Askue's procedure and the Vx determination
suggested by Machado.
Terry
At 08:50 PM 2/8/2011 -0800, you wrote:
>Look at the attached file and see if this is what you are looking for.
>Found it on the EAA.org homebuilders site.
>
>Keith
>CH701 - scratch (working on cabin area)
>
>
>From: MHerder <michaelherder@beckgroup.com>
>To: zenith601-list@matronics.com
>Sent: Tue, February 8, 2011 7:30:47 PM
>Subject: Zenith601-List: Determining Vx
>
>
>The fish are biting.
Terry Phillips
ttp44~at~rkymtn.net
Corvallis MT
ZU-601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail & flaps are done;
Upgrading wings & ailerons per the AMD Safety Directive
http://www.mykitlog.com/N47TP/
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
If you have a RV builder nearby, there is a nice section in their builder's
manual (?) that they get that talks about Vx/Vy and how to get the numbers
during your test flights.
Don
From: owner-zenith601-list-server@matronics.com [mailto:owner-zenith601-lis
t-server@matronics.com] On Behalf Of Terry Phillips
Sent: Tuesday, February 08, 2011 11:31 PM
Subject: Re: Zenith601-List: Determining Vx
Good find, Keith
That article only addresses determining Vy. However, it is 1 of a series of
about 5 articles. One of the other articles describes the Vx calculation.
Kolano appears to confirm Askue's procedure and the Vx determination sugges
ted by Machado.
Terry
At 08:50 PM 2/8/2011 -0800, you wrote:
Look at the attached file and see if this is what you are looking for. Foun
d it on the EAA.org homebuilders site.
Keith
CH701 - scratch (working on cabin area)
From: MHerder <michaelherder@beckgroup.com<mailto:michaelherder@beckgroup.c
om>>
Sent: Tue, February 8, 2011 7:30:47 PM
Subject: Zenith601-List: Determining Vx
The fish are biting.
Terry Phillips
ttp44~at~rkymtn.net
Corvallis MT
ZU-601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail & flaps are done;
Upgrading wings & ailerons per the AMD Safety Directive
http://www.mykitlog.com/N47TP/
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|