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

[Henry J. Cobb]

http://www.signonsandiego.com/news/military/20031208-1459-cnsosprey.html
"They decided not to finish a second phase of vortex ring state testing."

-HJC

[Kevin Brooks]

That (your subject line claim) is not what it says. You are mistaking the
questionable claim from a former OT&E guru as meaning that the aircraft was
not tested in vortex ring state conditions, which just ain't the case.

"...has proven its ability to function safely in potentially deadly rapid
descent conditions, the government's top test pilot said...Gross said they
have completed the tests necessary to document the tilt-rotor's response to
the dangerous vortex ring state condition that rotary wing aircraft
encounter when descending too quickly at low airspeed...Gross and other
members of the Osprey test team have said the tilt-rotor encounters vortex
ring state at much higher rates of descent than helicopters and recovers
better because it can move the rotors forward to quickly gain airspeed..."We
believe we have explored this enough," Gross said.

If you are going to try to summarize the gist of the article in your header,
at least get it right.

Brooks


"Henry J. Cobb" > wrote in message
om...
> http://www.signonsandiego.com/news/military/20031208-1459-cnsosprey.html
> "They decided not to finish a second phase of vortex ring state testing."
>
> -HJC

[Henry J. Cobb]

"Kevin Brooks" > wrote in message >...
> That (your subject line claim) is not what it says. You are mistaking the
> questionable claim from a former OT&E guru as meaning that the aircraft was
> not tested in vortex ring state conditions, which just ain't the case.

I don't see any mention that they ever actually went into full vortex
ring state.

What they need to do is send an unmanned Osprey up to say 10k feet,
put it into VRS and have it automatically recover until the software
is solid.

Then you don't have to worry about the pilot reacting in time, the
aircraft will rotate the engines forward and scoot out of trouble on
it's own.

-HJC

[Chad Irby]

In article >,
(Henry J. Cobb) wrote:

> I don't see any mention that they ever actually went into full vortex
> ring state.
>
> What they need to do is send an unmanned Osprey up to say 10k feet,
> put it into VRS and have it automatically recover until the software
> is solid.
>
> Then you don't have to worry about the pilot reacting in time, the
> aircraft will rotate the engines forward and scoot out of trouble on
> it's own.

....and it will be the only rotary wing aircraft on the planet with the
capability to get out of VRS on its own...

....except for the occasional tendency to suddenly fly straight forward
and into whatver obstacles are in front of it...

Of course, you really have to drop the Osprey down fast, under very
specific conditions, to get into VRS to begin with, and the easy way to
not get into it is to not drop the thing to the ground quite as fast.

--
cirby at cfl.rr.com

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

[Kevin Brooks]

"Henry J. Cobb" > wrote in message
om...
> "Kevin Brooks" > wrote in message
>...
> > That (your subject line claim) is not what it says. You are mistaking
the
> > questionable claim from a former OT&E guru as meaning that the aircraft
was
> > not tested in vortex ring state conditions, which just ain't the case.
>
> I don't see any mention that they ever actually went into full vortex
> ring state.

You should reread your article, then.

>
> What they need to do is send an unmanned Osprey up to say 10k feet,
> put it into VRS and have it automatically recover until the software
> is solid.
>
> Then you don't have to worry about the pilot reacting in time, the
> aircraft will rotate the engines forward and scoot out of trouble on
> it's own.

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.

Brooks

>
> -HJC

[Chad Irby]

In article >,
Hobo > wrote:

> In article >,
> "Kevin Brooks" > wrote:
>
> > 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.
>
> It's not illogical if the V-22 is so much more susceptible to this that
> the frequency of occurence during routine use is far greater than normal
> helos.

But that's the thing.

It's not. It's just that they were trying something *very* far off
normal flight regimes, and it bit them.

Most copters damn near have to have their rotors fall off to get that
sort of sink rate.

--
cirby at cfl.rr.com

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

[Kevin Brooks]

"Hobo" > wrote in message
...
> In article >,
> "Kevin Brooks" > wrote:
>
> > 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.
> >
> > Brooks
>
> It's not illogical if the V-22 is so much more susceptible to this that
> the frequency of occurence during routine use is far greater than normal
> helos.

But apparently it is not "so much more susceptable" to it.

Brooks

[Chad Irby]

In article >,
Hobo > wrote:

> That Arndt guy won't even claim the Germans did it first.

Actually, he did that a couple of weeks ago.

--
cirby at cfl.rr.com

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

[Kevin Brooks]

"Hobo" > wrote in message
...
> In article >,
> "Kevin Brooks" > wrote:
>
> >
> > But apparently it is not "so much more susceptable" to it.
> >
> > Brooks
>
> What I have heard is that using smaller than normal rotors makes it more
> susceptible than normal. Regardless, it has already killed over 20
> people and no US service other than the Marines wants it

Not true. The USAF is still anxious to get the Osprey into its special
operations force, and we have had recent reports of interest from the
National Guard Bureau in obtaining Ospreys for the homeland defense role. A
very brief review of available web resources via Google will verify that
your statement is patently false.

and no foreign
> country will take it even as a gift

None have been offered.

and there is zero commercial
> interest in the technology.

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.

http://www.bellhelicopter.textron.com/companyInfo/pressReleases/pr_0307001.html

That Arndt guy won't even claim the Germans
> did it first.

Have you been sleeping of late? He recently actually did exactly that.
Another less than accurate statement you have left with us...

Brooks

[Henry J. Cobb]

"Kevin Brooks" > wrote in message >...
> 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/systems/aircraft/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

[Chad Irby]

In article >,
(Henry J. Cobb) wrote:

> "Kevin Brooks" > wrote in message
> >...
> > 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/systems/aircraft/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.

[Kevin Brooks]

"Henry J. Cobb" > wrote in message
om...
> "Kevin Brooks" > wrote in message
>...
> > 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/systems/aircraft/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

[Kevin Brooks]

"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

[Guy Alcala]

Kevin Brooks wrote:

> "Henry J. Cobb" > wrote in message
> om...
> > "Kevin Brooks" > wrote in message
> >...
> > > 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/systems/aircraft/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 are:
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

[Chad Irby]

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 are:
>
> 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.

[Alan Minyard]

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

>"Kevin Brooks" > wrote in message >...
>> 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/systems/aircraft/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

[Thomas Schoene]

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)

[Alan Minyard]

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