REFLECTOR::Re:Pure Jet Velocity XL
Robin Ream
reflector@tvbf.org
Wed, 11 Feb 2004 12:30:11 -0600
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Oooooh, that's it :-) I knew there was something I was missing. See, I =
told you I wasn't a high powered engineer! :-) :-) :-) All this =
talk about main wing stall, deep stall, canard Vne stall, flutter, aft =
cg problems, bad propellers, fences, vortilons, vortex generators, front =
wheel shimmy, brake fade, exhaust pipes hitting the prop, landing gear =
hang-ups, and lots of other things too. -- I was ready to sell the =
damned thing and buy a big boat. Of course if I did that the trailer =
lights would malfunction, the brakes would mess up on that too, the =
motor trim would cause me problems, the alternator would go out, the =
water pump would get seaweed tangled up in it, I'd have propeller =
problems with that too; and hell, I never could catch fish anyway. =
Maybe I'll sell the airplane, forget about the boat, and buy my own =
saloon so the bouncers can't throw me out in the street if I get drunk. =
Of course all that won't matter because if my wife finds one more bill =
in the mail from this airplane she's going to kill my dumb butt anyway, =
and then I'll need a casket. -- At least it won't have a propeller on =
it!
Have fun, build well, and fly well guys,
Robin
----- Original Message -----=20
From: Jim Sower=20
To: reflector@tvbf.org=20
Sent: Wednesday, February 11, 2004 11:56 AM
Subject: Re: REFLECTOR::Re:Pure Jet Velocity XL
<... According to your data there's only two ways to get down in a =
canard: A nice slow descent, or straight down nose first in an =
unrecoverable canard stall ...>=20
Tongue firmly in cheek I presume??=20
A. The discussion was about transonic Velocity, and=20
B. You ignore the obvious third option: Reduce power to idle, reduce =
speed to well under Vne and let down at that speed (say, 100-120 KIAS =
with belly board deployed as needed.=20
=20
Robin Ream wrote:=20
Richard,=20
I'm not an engineer, period. - BUT, it logically follows in =
your=20
reasoning about the catastrophic results of exceeding Vne in level =
flight=20
that we're talking about theVelocity and other similar canards being =
inherently dangerous; even in a moderate dive it's not that hard to =
exceed=20
Vne in any type of aircraft. According to your data there's only =
two ways=20
to get down in a canard: A nice slow descent, or straight down nose =
first=20
in an unrecoverable canard stall... Hmmm. Something about those =
choices=20
aren't particularly appealing. ------------------ Anybody want to =
buy a=20
Velocity now?=20
Robin=20
----- Original Message -----=20
From: <richard@riley.net>=20
To: <reflector@tvbf.org>=20
Sent: Wednesday, February 11, 2004 12:38 AM=20
Subject: REFLECTOR::Re:Pure Jet Velocity XL=20
> Simply put, I believe an airplane that can exceed it's Vne in =
level flight=20
> is extraordinarily dangerous.=20
>=20
> Your pilot may have the discipline to never open up the throttle =
while at=20
> cruise speed and altitude. I believe most don't have that =
discipline, at=20
> least, I wouldn't want to stake my life on it.=20
>=20
> At 08:13 PM 2/10/04 -0500, you wrote:=20
> >At 07:55 PM 2/7/04, Richard Riley wrote:=20
> >=20
> >Richard,=20
> >=20
> >It is always disconcerting to read contributions like this, which =
raise=20
> >fears based on very little factual information, and a great deal =
of=20
> >speculation.=20
> >=20
> >It is also rather annoying that anyone reading your e-mail would =
be=20
> >excused from assuming you are referring to the Velocity Jet as =
shown on=20
> >the http://x-jets.com/ web site. I can't imagine you are, because =
you=20
have=20
> >not discussed this aircraft with me or my partner at any time, =
and I have=20
> >no idea where you get the numbers and engine type that you quote. =
> >=20
> >Let me say quite clearly to everyone on this list, that we do not =
feel=20
> >compelled to operate outside of the envelope of a standard =
Velocity XL=20
RG.=20
> >=20
> >Whether you choose turbojet power or a reciprocating engine, The =
VNE and=20
> >Critical Mach Speed of the airframe remain the same. A jet engine =
is=20
> >simply a very good power to weight ratio, not a license to exceed =
VNE or=20
> >other airframe limits including Mcr.=20
> >=20
> >Those limits have been estimated for our airframe, and prudent =
placard=20
> >limits have been set. All this was done at a very early stage, =
before an=20
> >engine choice was finalized. We did not simply bolt a jet engine =
on the=20
> >back end and cross our fingers. All the systems on our plane have =
been=20
> >designed for routine flight above 20K. Our project represents a =
safety=20
> >conscious and carefully engineered next step in Experimental =
aviation. If=20
> >you are curious, just watch for more news on the web site.=20
> >=20
> >The engine, by the way, is a GE-T58-8F NOT a Honeywell T55. The =
Mcr of=20
> >the Main wing airfoil is the lowest at M=3D.54, which equates=20
approximately=20
> >to 240 Kts IAS at 25K, 218 Kts IAS at 25K, and 199 Kts IAS at =
29K. The=20
> >reference you give is excellent. However, it would be better to =
read it=20
> >from the start of the=20
> >chapter =
http://142.26.194.131/aerodynamics1/High-Speed/default.htm with=20
> >particular note of the way drag increases as Mcr is approached. =
Also note=20
> >how Mcr may be increased.=20
> >=20
> >Best Regards,=20
> >=20
> >Andreas P Christou=20
> >andreas@x-jets.com=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >=20
> >_______________________________________________=20
> >To change your email address, visit=20
> >http://www.tvbf.org/mailman/listinfo/reflector=20
> >=20
> >Visit the gallery! www.tvbf.org/gallery=20
> >user:pw =3D tvbf:jamaicangoose=20
> >Check new archives: www.tvbf.org/pipermail=20
> >Check old archives: =
http://www.tvbf.org/archives/velocity/maillist.html=20
>=20
> _______________________________________________=20
> To change your email address, visit=20
http://www.tvbf.org/mailman/listinfo/reflector=20
>=20
> Visit the gallery! www.tvbf.org/gallery=20
> user:pw =3D tvbf:jamaicangoose=20
> Check new archives: www.tvbf.org/pipermail=20
> Check old archives: =
http://www.tvbf.org/archives/velocity/maillist.html=20
>=20
_______________________________________________=20
To change your email address, visit =
http://www.tvbf.org/mailman/listinfo/reflector=20
Visit the gallery! www.tvbf.org/gallery=20
user:pw =3D tvbf:jamaicangoose=20
Check new archives: www.tvbf.org/pipermail=20
Check old archives: =
http://www.tvbf.org/archives/velocity/maillist.html
--=20
Jim Sower ... Destiny's Plaything=20
Crossville, TN; Chapter 5=20
Long-EZ N83RT, Velocity N4095T=20
=20
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<DIV>Oooooh, that's it :-) I knew there was something I was =
missing. =20
See, I told you I wasn't a high powered =
engineer! :-) =20
:-) :-) All this talk about main wing stall, deep =
stall,=20
canard Vne stall, flutter, aft cg problems, bad propellers, fences, =
vortilons,=20
vortex generators, front wheel shimmy, brake fade, exhaust pipes hitting =
the=20
prop, landing gear hang-ups, and lots of other things too. =
-- I was=20
ready to sell the damned thing and buy a big boat. Of course if I =
did that=20
the trailer lights would malfunction, the brakes would mess up on that =
too, the=20
motor trim would cause me problems, the alternator would go out, the =
water pump=20
would get seaweed tangled up in it, I'd have propeller problems with =
that too;=20
and hell, I never could catch fish anyway. Maybe I'll sell the =
airplane,=20
forget about the boat, and buy my own saloon so the bouncers can't =
throw me=20
out in the street if I get drunk. Of course all that won't matter =
because=20
if my wife finds one more bill in the mail from this airplane she's =
going to=20
kill my dumb butt anyway, and then I'll need a casket. -- At =
least=20
it won't have a propeller on it!</DIV>
<DIV> </DIV>
<DIV>Have fun, build well, and fly well guys,</DIV>
<DIV>Robin</DIV>
<BLOCKQUOTE dir=3Dltr=20
style=3D"PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; =
BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style=3D"FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV=20
style=3D"BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: =
black"><B>From:</B>=20
<A title=3Dcanarder@frontiernet.net =
href=3D"mailto:canarder@frontiernet.net">Jim=20
Sower</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>To:</B> <A =
title=3Dreflector@tvbf.org=20
href=3D"mailto:reflector@tvbf.org">reflector@tvbf.org</A> </DIV>
<DIV style=3D"FONT: 10pt arial"><B>Sent:</B> Wednesday, February 11, =
2004 11:56=20
AM</DIV>
<DIV style=3D"FONT: 10pt arial"><B>Subject:</B> Re: REFLECTOR::Re:Pure =
Jet=20
Velocity XL</DIV>
<DIV><BR></DIV><... According to your data there's only two ways to =
get=20
down in a canard: A nice slow descent, or straight down nose =
first in an=20
unrecoverable canard stall ...> <BR>Tongue firmly in cheek I =
presume??=20
<BR>A. The discussion was about <B>transonic</B> Velocity, and =
<BR>B.=20
You ignore the obvious third option: Reduce power to idle, =
reduce speed=20
to well under Vne and let down at that speed (say, 100-120 KIAS with =
belly=20
board deployed as needed. <BR> =20
<P>Robin Ream wrote:=20
<BLOCKQUOTE TYPE=3D"CITE">Richard,=20
<P> I'm not an engineer, period. - =
BUT, it=20
logically follows in your <BR>reasoning about the catastrophic =
results of=20
exceeding Vne in level flight <BR>that we're talking about =
theVelocity and=20
other similar canards being <BR>inherently dangerous; even in a =
moderate=20
dive it's not that hard to exceed <BR>Vne in any type of =
aircraft. =20
According to your data there's only two ways <BR>to get down in a=20
canard: A nice slow descent, or straight down nose first =
<BR>in an=20
unrecoverable canard stall... Hmmm. Something about =
those=20
choices <BR>aren't particularly appealing. =
------------------ =20
Anybody want to buy a <BR>Velocity now?=20
<P>Robin=20
<P>----- Original Message ----- <BR>From: <richard@riley.net> =
<BR>To:=20
<reflector@tvbf.org> <BR>Sent: Wednesday, February 11, 2004 =
12:38 AM=20
<BR>Subject: REFLECTOR::Re:Pure Jet Velocity XL=20
<P>> Simply put, I believe an airplane that can exceed it's Vne =
in level=20
flight <BR>> is extraordinarily dangerous. <BR>> <BR>> Your =
pilot=20
may have the discipline to never open up the throttle while at =
<BR>>=20
cruise speed and altitude. I believe most don't have that =
discipline,=20
at <BR>> least, I wouldn't want to stake my life on it. <BR>> =
<BR>>=20
At 08:13 PM 2/10/04 -0500, you wrote: <BR>> >At 07:55 PM =
2/7/04,=20
Richard Riley wrote: <BR>> > <BR>> >Richard, <BR>> =
>=20
<BR>> >It is always disconcerting to read contributions like =
this,=20
which raise <BR>> >fears based on very little factual =
information, and=20
a great deal of <BR>> >speculation. <BR>> > <BR>> =
>It is=20
also rather annoying that anyone reading your e-mail would be =
<BR>>=20
>excused from assuming you are referring to the Velocity Jet as =
shown on=20
<BR>> >the <A =
href=3D"http://x-jets.com/">http://x-jets.com/</A> web=20
site. I can't imagine you are, because you <BR>have <BR>> >not =
discussed this aircraft with me or my partner at any time, and I =
have=20
<BR>> >no idea where you get the numbers and engine type that =
you=20
quote. <BR>> > <BR>> >Let me say quite clearly to =
everyone on=20
this list, that we do not feel <BR>> >compelled to operate =
outside of=20
the envelope of a standard Velocity XL <BR>RG. <BR>> > =
<BR>>=20
>Whether you choose turbojet power or a reciprocating engine, The =
VNE and=20
<BR>> >Critical Mach Speed of the airframe remain the same. A =
jet=20
engine is <BR>> >simply a very good power to weight ratio, not =
a=20
license to exceed VNE or <BR>> >other airframe limits =
including Mcr.=20
<BR>> > <BR>> >Those limits have been estimated for our=20
airframe, and prudent placard <BR>> >limits have been set. All =
this=20
was done at a very early stage, before an <BR>> >engine choice =
was=20
finalized. We did not simply bolt a jet engine on the <BR>> =
>back end=20
and cross our fingers. All the systems on our plane have been =
<BR>>=20
>designed for routine flight above 20K. Our project represents a =
safety=20
<BR>> >conscious and carefully engineered next step in =
Experimental=20
aviation. If <BR>> >you are curious, just watch for more news =
on the=20
web site. <BR>> > <BR>> >The engine, by the way, is a=20
GE-T58-8F NOT a Honeywell T55. The Mcr of <BR>> >the =
Main wing=20
airfoil is the lowest at M=3D.54, which equates =
<BR>approximately=20
<BR>> >to 240 Kts IAS at 25K, 218 Kts IAS at 25K, and 199 Kts =
IAS at=20
29K. The <BR>> >reference you give is excellent. However, it =
would be=20
better to read it <BR>> >from the start of the <BR>>=20
>chapter <A=20
=
href=3D"http://142.26.194.131/aerodynamics1/High-Speed/default.htm">http:=
//142.26.194.131/aerodynamics1/High-Speed/default.htm</A> =20
with <BR>> >particular note of the way drag increases as Mcr =
is=20
approached. Also note <BR>> >how Mcr may be increased. =
<BR>> >=20
<BR>> >Best Regards, <BR>> > <BR>> >Andreas P =
Christou=20
<BR>> >andreas@x-jets.com <BR>> > <BR>> > <BR>> =
>=20
<BR>> > <BR>> > <BR>> > <BR>> > <BR>> =
>=20
<BR>> > <BR>> > <BR>> > <BR>> > <BR>> =
>=20
<BR>> > <BR>> > <BR>>=20
>_______________________________________________ <BR>> >To =
change=20
your email address, visit <BR>> ><A=20
=
href=3D"http://www.tvbf.org/mailman/listinfo/reflector">http://www.tvbf.o=
rg/mailman/listinfo/reflector</A>=20
<BR>> > <BR>> >Visit the gallery! =
www.tvbf.org/gallery=20
<BR>> >user:pw =3D tvbf:jamaicangoose <BR>> >Check new =
archives:=20
www.tvbf.org/pipermail <BR>> >Check old archives: <A=20
=
href=3D"http://www.tvbf.org/archives/velocity/maillist.html">http://www.t=
vbf.org/archives/velocity/maillist.html</A>=20
<BR>> <BR>> _______________________________________________ =
<BR>>=20
To change your email address, visit <BR><A=20
=
href=3D"http://www.tvbf.org/mailman/listinfo/reflector">http://www.tvbf.o=
rg/mailman/listinfo/reflector</A>=20
<BR>> <BR>> Visit the gallery! www.tvbf.org/gallery =
<BR>>=20
user:pw =3D tvbf:jamaicangoose <BR>> Check new archives:=20
www.tvbf.org/pipermail <BR>> Check old archives: <A=20
=
href=3D"http://www.tvbf.org/archives/velocity/maillist.html">http://www.t=
vbf.org/archives/velocity/maillist.html</A>=20
<BR>>=20
<P>_______________________________________________ <BR>To change =
your email=20
address, visit <A=20
=
href=3D"http://www.tvbf.org/mailman/listinfo/reflector">http://www.tvbf.o=
rg/mailman/listinfo/reflector</A>=20
<P>Visit the gallery! www.tvbf.org/gallery <BR>user:pw =3D=20
tvbf:jamaicangoose <BR>Check new archives: www.tvbf.org/pipermail =
<BR>Check=20
old archives: <A=20
=
href=3D"http://www.tvbf.org/archives/velocity/maillist.html">http://www.t=
vbf.org/archives/velocity/maillist.html</A></P></BLOCKQUOTE>
<P>-- <BR>Jim Sower ... Destiny's Plaything <BR>Crossville, TN; =
Chapter 5=20
<BR>Long-EZ N83RT, Velocity N4095T <BR> =
</P></BLOCKQUOTE></BODY></HTML>
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