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jimandmandy(at)yahoo.com
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 Posted: Fri Apr 25, 2008 7:56 pm Post subject: Va Defined |
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If you think you understand Va, you need to read this NTSB accident report.
http://www.ntsb.gov/publictn/2004/AAR0404.pdf
American 587, an Airbus A-300 that lost its vertical stabilizer due to full rudder deflections BELOW Va on a certified aircraft. I was working with a team redesigning some structure on the B-777 vertical at the time and we had a lot of discussion about this accident.
Gig Giacona <wr.giacona(at)suddenlink.net> wrote:[quote] --> Zenith-List message posted by: "Gig Giacona"
VA is defined as the speed at which a full control deflection can be made abruptly and the aircraft will stall before any damage results to the airframe.
Chris H has given us a fix that will reduce the amount of elevator deflection available. So even though there is no evidence that Sub VA flight has [quote][b]
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n801bh(at)netzero.com
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| Posted: Fri Apr 25, 2008 8:22 pm Post subject: Va Defined |
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That is the perfect example of how VA is not a "get out of jail free" pass....
Ben Haas
N801BH
www.haaspowerair.com
-- Jimbo <jimandmandy(at)yahoo.com> wrote:
If you think you understand Va, you need to read this NTSB accident report.
http://www.ntsb.gov/publictn/2004/AAR0404.pdf
American 587, an Airbus A-300 that lost its vertical stabilizer due to full rudder deflections BELOW Va on a certified aircraft. I was working with a team redesigning some structure on the B-777 vertical at the time and we had a lot of discussion about this accident.
Gig Giacona <wr.giacona(at)suddenlink.net> wrote: | Quote: | --> Zenith-List message posted by: "Gig Giacona"
VA is defined as the speed at which a full control deflection can be made abruptly and the aircraft will stall before any damage results to the airframe.
Chris H has given us a fix that will reduce the amount of elevator deflection available. So even though there is no evidence that Sub VA flight has | Quote: |
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[quote][b]
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bryanmmartin
Joined: 10 Jan 2006
Posts: 1018
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| Posted: Sat Apr 26, 2008 6:40 am Post subject: Va Defined |
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Va means that the wing will stall before it exceeds its positive G flight load limit when encountering a certain maximum level of turbulence or when subjected to a certain maximum control input rate or a combination of the two. It doesn't mean you won't break the airplane while flying below Va if you fly into a severe thunderstorm or suddenly slam the stick to its rear limit.
In certificated aircraft, Va is defined for a particular set of conditions and control inputs and it also deals with he vertical and horizontal stabilizers and not just the wing . Even when flying below Va, you can break the airplane if you command control inputs that exceed the certification standards or if turbulence conditions exceed what the airplane was certificated to handle.
If you aren't flying in an aircraft that was designed for aerobatic flight, making abrupt maximum control inputs is not a recommended practice at any speed.
On Apr 26, 2008, at 12:16 AM, n801bh(at)netzero.com (n801bh(at)netzero.com) wrote:
| Quote: | That is the perfect example of how VA is not a "get out of jail free" pass....
Ben Haas
N801BH
www.haaspowerair.com
-- Jimbo <jimandmandy(at)yahoo.com> wrote:
If you think you understand Va, you need to read this NTSB accident report.
http://www.ntsb.gov/publictn/2004/AAR0404.pdf
American 587, an Airbus A-300 that lost its vertical stabilizer due to full rudder deflections BELOW Va on a certified aircraft. I was working with a team redesigning some structure on the B-777 vertical at the time and we had a lot of discussion about this accident.
Gig Giacona <wr.giacona(at)suddenlink.net> wrote: |
[/quote]
--
Bryan Martin
N61BM, CH 601 XL,
RAM Subaru, Stratus redrive.
[quote][b]
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
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_________________
--
Bryan Martin
N61BM, CH 601 XL, Stratus Subaru.
do not archive. |
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n801bh(at)netzero.com
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| Posted: Sat Apr 26, 2008 4:14 pm Post subject: Va Defined |
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That was exactly my point,,, The black box clearly showed the co pilot fully deflected the rudder three times in 5 seconds, that broke the poor thing off. Juan's comment was to ignore that fact and just move on. Well, if next week there is a crash of a Zenith and a fatality in Mexico I will just post... " Don't worry guys, just move on,to hell with Juans guts spread over two acres""....
do not archive
n Martin <bryanmmartin(at)comcast.net> wrote:
Va means that the wing will stall before it exceeds its positive G flight load limit when encountering a certain maximum level of turbulence or when subjected to a certain maximum control input rate or a combination of the two. It doesn't mean you won't break the airplane while flying below Va if you fly into a severe thunderstorm or suddenly slam the stick to its rear limit.
In certificated aircraft, Va is defined for a particular set of conditions and control inputs and it also deals with he vertical and horizontal stabilizers and not just the wing . Even when flying below Va, you can break the airplane if you command control inputs that exceed the certification standards or if turbulence conditions exceed what the airplane was certificated to handle.
If you aren't flying in an aircraft that was designed for aerobatic flight, making abrupt maximum control inputs is not a recommended practice at any speed.
On Apr 26, 2008, at 12:16 AM, n801bh(at)netzero.com (n801bh(at)netzero.com) wrote:
| Quote: | That is the perfect example of how VA is not a "get out of jail free" pass....
Ben Haas
N801BH
www.haaspowerair.com
-- Jimbo <jimandmandy(at)yahoo.com> wrote:
If you think you understand Va, you need to read this NTSB accident report.
http://www.ntsb.gov/publictn/2004/AAR0404.pdf
American 587, an Airbus A-300 that lost its vertical stabilizer due to full rudder deflections BELOW Va on a certified aircraft. I was working with a team redesigning some structure on the B-777 vertical at the time and we had a lot of discussion about this accident.
Gig Giacona <wr.giacona(at)suddenlink.net> wrote: | Quote: | --> Zenith-List message posted by: "Gig Giacona"
VA is defined as the speed at which a full control deflection can be made abruptly and the aircraft will stall before any damage results to the airframe.
Chris H has given us a fix that will reduce the amount of elevator deflection available. So even though there is no evidence that Sub VA flight has |
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--
Bryan Martin
N61BM, CH 601 XL,
RAM Subaru, Stratus redrive.
| Quote: |
====================================
">http://www.matronics.com/Navigator?Zenith-List
====================================
tronics.com
====================================
www.matronics.com/contribution
====================================
|
_____________________________________________________________
Explore the great earning potential that comes with an insurance job. Click now!
[quote][b]
| | - The Matronics Zenith-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Zenith-List |
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