Osprey tested in air, at sea, but not in vortex ring state.

In article ,
(Henry J. Cobb) wrote:

"Kevin Brooks" wrote in message
et...
Why? Other (conventional) rotary aircraft currently within operating
inventopries are susceptable to VRS and manage to handle it by knowing the
limits--why do you think the V-22 should somehow be different? Illogical.

http://198.65.138.161/military/syste...t/v-22-vrs.htm
"This asymmetrical VRS phenomenon, which is unique to side-by-side
rotor configurations, will have the initial resultant effect of
inducing a large rolling moment in the yaw direction."

That's what's different about it.

You missed a quote:

"Vortex Ring State can occur in all rotary-wing aircraft under similar
conditions of low airspeed and high sink rate."

The article also doesn't mention that front/back twin-rotor copters can
have similar issues (one in, one out of VRS).

Then there's this:

"When flown in compliance with NATOPS WARNING limits and with adequate
training, susceptibility to VRS is nil."

In other words, don't drop faster than 800 feet per minute at speeds
less than 40 knots and this won't happen to you.

--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

"Henry J. Cobb" wrote in message
om...
"Kevin Brooks" wrote in message
et...
Why? Other (conventional) rotary aircraft currently within operating
inventopries are susceptable to VRS and manage to handle it by knowing
the
limits--why do you think the V-22 should somehow be different?
Illogical.

http://198.65.138.161/military/syste...t/v-22-vrs.htm
"This asymmetrical VRS phenomenon, which is unique to side-by-side
rotor configurations, will have the initial resultant effect of
inducing a large rolling moment in the yaw direction."

That's what's different about it.

So what? The chief test pilot said that after the latest flight tests they
feel comfortable with thier procedures to handle it--that carries a heck of
a lot more water than what either you or that "former" OT&E guy have to say
about the matter.

Brooks


-HJC

"Hobo" wrote in message
...
In article ,
"Kevin Brooks" wrote:

Really? Last I heard the joint Agusta Bell AB 609 civil spinoff had
gained
some seventy advance orders, and made its maiden flight this past March.
So
far you are exhibiting a very low batting average in terms of accuracy
of
your statements regarding this program.

I went to the BAAC website and could not find any specific informtion
concerning advance orders that could be examined.


You need to revisit Google--this same issue popped up earlier this year over
in SMN (IIRC) and there are lists of the firms that have placed the advanced
orders available via the web.

At http://www.aeroboek.nl/ab-027.htm I found the 70 advance orders number,
but it also said that the
aircraft was expected to recieve FAA certification in 2007. No aircraft
have been shipped. I am certainly surprised to find that a tilt-rotor
has found 70 advance orders and so there is *some* commercial interest
in the aircraft, but overall I think it is accurate to say that the
commercial market does not see the tilt-rotor as a competitor to the
standard helo or have significant interest in the idea.

Those seventy-odd orders (the numbers fluctuate depending upon the source
and date between fifty some and eighty some, with the seventies being the
most prevalent IIRC) were advance booked by current rotary operators from
around the world before the prototype even flew, and you don't think there
is "significant interest" in the civil community? On that our opinions will
just have to differ. I assume you are also backing off your earlier
assertion that *only* the USMC is interested in the V-22, since the USAF has
already been a partner in its development for the SOF role, and now the NGB
has even expressed interest in it?

Brooks

Kevin Brooks wrote:

"Henry J. Cobb" wrote in message
om...
"Kevin Brooks" wrote in message
et...
Why? Other (conventional) rotary aircraft currently within operating
inventopries are susceptable to VRS and manage to handle it by knowing
the
limits--why do you think the V-22 should somehow be different?
Illogical.

http://198.65.138.161/military/syste...t/v-22-vrs.htm
"This asymmetrical VRS phenomenon, which is unique to side-by-side
rotor configurations, will have the initial resultant effect of
inducing a large rolling moment in the yaw direction."

That's what's different about it.

So what? The chief test pilot said that after the latest flight tests they
feel comfortable with thier procedures to handle it--that carries a heck of
a lot more water than what either you or that "former" OT&E guy have to say
about the matter.

And here's what someone who's a lot closer to the program had to say, about 6
months ago, about someone with a similarly out of date, not to say biased,
viewpoint (hopefully the formatting will survive):


'Morning, Gents. This author has never, in my recall,
written a fair and balanced
article about the V-22. I don't know who's pocket he's
in, but he sure has a
penchant for taking a grain of truth and building a
mountain of crap.

The High Rate-of Descent testing has almost finished
Phase One, with some very
interesting results. Two of the most prominent a
1. The envelope for VRS susceptibility predicted
before Marana (flight
restriction: 800 fpm@40 KIAS) was, if anything,
conservative. No surprises
have been found and the VRS recovery procedure of
using forward nacelles has
been verified as very effective. In fact, these data
now support relaxing the
restriction somewhat; perhaps to something like a
maximum of 1200 FPS (edit: I
meant 1200 FPM; thanks to Ray Norton for catching my
flub) below 70 IAS.
2. Rolloff of the kind that caused the crash at Marana
have occurred only (IIRC)
eight or nine times in all of the HROD testing,
including hundreds of attempts to
approach/exceed the limits. The most striking finding
WRT VRS was that the
aircraft has to stabilize in flight well outside the
authorized envelope for four to
six seconds before enough VRS develops to cause a
rolloff. Our earlier fear that
dynamic control inputs by the pilot(s) would
accelerate VRS entry have been
shown to be unfounded. NOTE: this is a preliminary
conclusion at this point, and
we're still reviewing/discussing the data. But think
what this means for
operational pilots: they would have to a: exceed the
flight limitation grossly(like
2X or more), thus triggering the HROD audible and
visual warning system, and b:
continue that for 4-6 secomds before anything like a
rolloff would happen. And if
they did drive the aircraft into a VRS rolloff, then
no more than two seconds of
nacelle tilt would let them fly right out of it. Can
anyone guarantee that there will
never be another VRS-induced crash? Of course not. But
that hapless crew will
have to strive really hard to abuse the aircraft into
the ground.
3. Low airspeed Maneuvering: The lower left hand
portion of the “N-V” envelope
has now been filled in. After discussing these tests
with Bell/Boeing test pilots
and engineers it seems clear the flight envelope has
now been completely
sampled without any rotor stall or controllability
problems surfacing. Again, a
preliminary position, but it looks like the
low-airspeed maneuverability question is
no longer a concern.

Regarding the chatter about "deferred tests": the
program is, in fact looking at
the remaining HROD tests and starting to sort out what
needs to be done as a
program responsibilty before returning the Fleet to
flight, and what should
properly be put into a new project of the "Science
Fair" variety to investigate,
jointly with NASA Ames, the aerodynamics of tiltrotors
in various HROD
conditions. This latter work would in no way detract
from the confidence
underlying fleet ops, and would mainly serve to
advance the scientific
community's understanding of HROD aerodynamics in
highly-loaded proprotor
sytems. It might well serve to support a future design
of a "four-poster" tiltrotor
to replace or augment the C-130.

Anybody--even "Stryker Meyer" is free to have an
opinion. We all know where
they come from.

But I have no patience for people who cling to
pre-conceived positions while
ignoring factual information and data that costs a
great deal of time and money
to get. GRRRRR!

S/F
TC

In a later post, he mentions that testing has shown that dynamic control inputs
actually _prevent_ entry into VRS, not cause it. Just to establish the above
poster's bonafides, I'll include the post where he introduces himself to the
MV-22 forum on the Popasmoke (USMC/Vietnam Helicopter Association) website,
www.popasmoke.com, back in January :

G'Day, Mates. Brand new FNG here, and Hello to all.
By way of intro, let me say where I'm coming from.
After some 410 missions in
SEA (68-69) flying A-4s, the Corps decided I was
survivable enough to go to TPS
at Pax River. Got to work on some interesting stuff in
the specialties of stall/spin
(A-4M, TA-4, EA-6B, and T-2C) and peculiar birds like
the Canadian tilt-wing
CL-84, the XC-142, and the NASA STOL Buffalo. So while
my roots are in jets, I
"branched out a bit" as you can see.

I first worked on what's now the V-22 in 1981 when I
was assigned to the
Director, Defense T&E office in the Pentagon. Except
for five years as a Beltway
Bandit (85-90) I've been doing the same thing since
then. In addition to the
JMVX program, I had the USAF Maverick Missile, the
Navy HARM, and the Army
DIVAD/Sgt. York programs. Yeah, I've seen a few rotten
potatoes.

I'm currently the AO (action officer) for V-22 in the
office of the Director, OT&E
in OSD; have been since 1990. Have known every V-22 PM
since Harry Blot (who
I relieved at Flight Test in 1971). Knew the
operational testers, past and present,
since they sorta' kinda' worked for my boss. Miss the
lost ones.

But enough about me. My assessment of the
very-expensive, oft-delayed V-22
program now? It's on the right track to repair the
damage done by a lot of past
decisions that turned out to be bad ones. I fervently
hope we're doing all the
right things now, and by most accounts, we are. The
overwhelmingly big question
in my mind right now is this:

In the warafre of the future, will young V-22 pilots
be able to accomplish all
maneuvers needed in combat while avoiding VRS? And
right at this moment, to be
honest, I couldn't answer that question if the SecDef
himself asked it. But about
two years from now, I plan to be able to.

Anyway, thanks for letting me in. Where's the bar?
Semper Fi
Tom Carter
Leatherneck

Edited to add: Can I be an honorary rotorhead? I
pinned my son-in-laws Army
wings on him two months ago at Ft. Rucker. He's just
now finishing Blackhawk
qualis and will be in Korea a month from now.

Those of you who actually want to inform yourself with information from inside
the program by people who actually work with the sytem, could do worse than
read the posts on the forum, both positive and negative, and make up your own
mind who's got the most credibility.

Guy

In article ,
Guy Alcala wrote:

(reformatted)

And here's what someone who's a lot closer to the program had to say,
about 6 months ago, about someone with a similarly out of date, not
to say biased, viewpoint (hopefully the formatting will survive):


'Morning, Gents. This author has never, in my recall, written a fair
and balanced article about the V-22. I don't know who's pocket he's
in, but he sure has a penchant for taking a grain of truth and
building a mountain of crap.

The High Rate-of Descent testing has almost finished Phase One, with
some very interesting results. Two of the most prominent a

1. The envelope for VRS susceptibility predicted before Marana
(flight restriction: 800 fpm@40 KIAS) was, if anything,
conservative. No surprises have been found and the VRS recovery
procedure of using forward nacelles has been verified as very
effective. In fact, these data now support relaxing the restriction
somewhat; perhaps to something like a maximum of 1200 FPS (edit: I
meant 1200 FPM; thanks to Ray Norton for catching my flub) below 70
IAS.

2. Rolloff of the kind that caused the crash at Marana have occurred
only (IIRC) eight or nine times in all of the HROD testing, including
hundreds of attempts to approach/exceed the limits. The most striking
finding WRT VRS was that the aircraft has to stabilize in flight well
outside the authorized envelope for four to six seconds before enough
VRS develops to cause a rolloff. Our earlier fear that dynamic
control inputs by the pilot(s) would accelerate VRS entry have been
shown to be unfounded. NOTE: this is a preliminary conclusion at this
point, and we're still reviewing/discussing the data. But think what
this means for operational pilots: they would have to a: exceed the
flight limitation grossly(like 2X or more), thus triggering the HROD
audible and visual warning system, and b: continue that for 4-6
secomds before anything like a rolloff would happen. And if they did
drive the aircraft into a VRS rolloff, then no more than two seconds
of nacelle tilt would let them fly right out of it. Can anyone
guarantee that there will never be another VRS-induced crash? Of
course not. But that hapless crew will have to strive really hard to
abuse the aircraft into the ground.

3. Low airspeed Maneuvering: The lower left hand portion of the “N-V”
envelope has now been filled in. After discussing these tests with
Bell/Boeing test pilots and engineers it seems clear the flight
envelope has now been completely sampled without any rotor stall or
controllability problems surfacing. Again, a preliminary position,
but it looks like the low-airspeed maneuverability question is no
longer a concern.

Regarding the chatter about "deferred tests": the program is, in fact
looking at the remaining HROD tests and starting to sort out what
needs to be done as a program responsibilty before returning the
Fleet to flight, and what should properly be put into a new project
of the "Science Fair" variety to investigate, jointly with NASA Ames,
the aerodynamics of tiltrotors in various HROD conditions. This
latter work would in no way detract from the confidence underlying
fleet ops, and would mainly serve to advance the scientific
community's understanding of HROD aerodynamics in highly-loaded
proprotor sytems. It might well serve to support a future design of a
"four-poster" tiltrotor to replace or augment the C-130.

Anybody--even "Stryker Meyer" is free to have an opinion. We all know
where they come from.

But I have no patience for people who cling to pre-conceived
positions while ignoring factual information and data that costs a
great deal of time and money to get. GRRRRR!

S/F TC

In a later post, he mentions that testing has shown that dynamic
control inputs actually _prevent_ entry into VRS, not cause it. Just
to establish the above poster's bonafides, I'll include the post
where he introduces himself to the MV-22 forum on the Popasmoke
(USMC/Vietnam Helicopter Association) website, www.popasmoke.com,
back in January :

G'Day, Mates. Brand new FNG here, and Hello to all. By way of intro,
let me say where I'm coming from. After some 410 missions in SEA
(68-69) flying A-4s, the Corps decided I was survivable enough to go
to TPS at Pax River. Got to work on some interesting stuff in the
specialties of stall/spin (A-4M, TA-4, EA-6B, and T-2C) and peculiar
birds like the Canadian tilt-wing CL-84, the XC-142, and the NASA
STOL Buffalo. So while my roots are in jets, I "branched out a bit"
as you can see.

I first worked on what's now the V-22 in 1981 when I was assigned to
the Director, Defense T&E office in the Pentagon. Except for five
years as a Beltway Bandit (85-90) I've been doing the same thing
since then. In addition to the JMVX program, I had the USAF Maverick
Missile, the Navy HARM, and the Army DIVAD/Sgt. York programs. Yeah,
I've seen a few rotten potatoes.

I'm currently the AO (action officer) for V-22 in the office of the
Director, OT&E in OSD; have been since 1990. Have known every V-22 PM
since Harry Blot (who I relieved at Flight Test in 1971). Knew the
operational testers, past and present, since they sorta' kinda'
worked for my boss. Miss the lost ones.

But enough about me. My assessment of the very-expensive, oft-delayed
V-22 program now? It's on the right track to repair the damage done
by a lot of past decisions that turned out to be bad ones. I
fervently hope we're doing all the right things now, and by most
accounts, we are. The overwhelmingly big question in my mind right
now is this:

In the warafre of the future, will young V-22 pilots be able to
accomplish all maneuvers needed in combat while avoiding VRS? And
right at this moment, to be honest, I couldn't answer that question
if the SecDef himself asked it. But about two years from now, I plan
to be able to.

Anyway, thanks for letting me in. Where's the bar? Semper Fi Tom
Carter Leatherneck

Edited to add: Can I be an honorary rotorhead? I pinned my
son-in-laws Army wings on him two months ago at Ft. Rucker. He's just
now finishing Blackhawk qualis and will be in Korea a month from
now.

Those of you who actually want to inform yourself with information
from inside the program by people who actually work with the sytem,
could do worse than read the posts on the forum, both positive and
negative, and make up your own mind who's got the most credibility.

Guy


--
cirby at cfl.rr.com

Remember: Objects in rearview mirror may be hallucinations.
Slam on brakes accordingly.

On 10 Dec 2003 17:29:16 -0800, (Henry J. Cobb) wrote:

"Kevin Brooks" wrote in message et...
Why? Other (conventional) rotary aircraft currently within operating
inventopries are susceptable to VRS and manage to handle it by knowing the
limits--why do you think the V-22 should somehow be different? Illogical.

http://198.65.138.161/military/syste...t/v-22-vrs.htm
"This asymmetrical VRS phenomenon, which is unique to side-by-side
rotor configurations, will have the initial resultant effect of
inducing a large rolling moment in the yaw direction."

That's what's different about it.

-HJC

A "rolling moment in the yaw direction"????? Is it just me, or does that
make no sense at all??

Al Minyard

Alan Minyard wrote:

A "rolling moment in the yaw direction"????? Is it just me, or does
that
make no sense at all??

I'd read that as "It will yaw and then try to roll in the direction of the
yaw." So if the nose swings left, it will also try to roll left, sort of a
corkscrew movement.
--
Tom Schoene Replace "invalid" with "net" to e-mail
"If brave men and women never died, there would be nothing
special about bravery." -- Andy Rooney (attributed)

On Sat, 13 Dec 2003 03:23:39 GMT, "Thomas Schoene" wrote:

Alan Minyard wrote:

A "rolling moment in the yaw direction"????? Is it just me, or does
that
make no sense at all??

I'd read that as "It will yaw and then try to roll in the direction of the
yaw." So if the nose swings left, it will also try to roll left, sort of a
corkscrew movement.

That does make a lot of sense out of a senseless phrase :-)

Al Minyard