From: Mary Shafer <shafer@rigel.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: CNN launch coverage
Date: 28 Jul 1999 15:36:27 -0700

henry@spsystems.net (Henry Spencer) writes:

> Even with ejection seats, supersonic bailout is extremely dangerous and no
> pilot will voluntarily do it.  (Even most ejection seats aren't good much
> beyond Mach 1; the assumption is that it's possible to slow the thing down
> before ejecting.)

To back Henry up, here's an account of a subsonic ejection.  This from
the latest Approach.  It's an excerpt from the article "I'll Learn To
Walk After My Ejection", by LCdr Charles E. Luttrell, who was ECMO 3
on the mishap Prowler flight.  The pilot ceased responding following
"the highly-treasured Prowler unload-and-run-away maneuver" during a 1
v 1 defensive-tactics hop.  This only about a quarter of the article
and any typos are mine.

"I remember looking up at the clouds and down at the water.  I came
back into the cockpit and saw that we were 70 degrees nose low, still
inverted, the altimeter unwinding past 5,000 feet, and we were going
more than 500 KIAS.  I knew if I did not eject immediately, I would be
killed when the seat drove me into the water.  Just before pulling the
handle, I heard three or four words but do not know where they came
from.  My next memory is the pain as I rode the rails.  The wind blast
tore my helmet off and drove my mask through my chin and into the roof
of my mouth, separating my upper jaw, breaking my nose, and fracturing
my sinuses on the left and right side of my nose.  Both my arms were
fractured at the elbow, and my right arm was dislocated and fractured.

"During the ride up the rails, my left foot turned out and snapped
under the seat, resulting in a compound fracture of my leg just above
the ankle.  The force was so violent that about an inch and a half of
each bone in my leg broke out through the flesh.

"Once I hit the water, my day didn't get any better. Seawars separated
me from my chute, but my right upper LPU lobe didn't inflate.  With
both arms broken, I couldn't inflate my LPU manually or get into my
raft, so I just kept kicking with my right leg driving me around in a
circle like a duck on a pond.  I had checked myself over and knew I
needed help.  I decided it was time to look for others.  The swells
were 4 to 6 feet, and the wind was creating white caps.

"As I rode up one swell, I saw ECMO 2 and opened my mouth to yell just
as a white cap hit my face.  I found out very quickly that I can't
drink water and talk at the same time.  After I spit out the water and
started breathing again, I yelled at ECMO 2 and told him I was hurt.
He yelled back to `stay there and I will swim to you.'  You can
imagine my relief because the only thing I could do was go in circles.
By the time he arrived, I'd lost a lot of blood, and severe shock had
set in.

"Once he arrived, I began panicking, and he pulled me in close to calm
me down.  He was beat up pretty badly, too, with his left arm broken
in threee places, a shattered shoulder blade, and four fractured
vertebrae.  To preserve heat and help keep me afloat, he wrapped his
broken arm around me and pulled me back onto him.  The water
temperature was 61 degrees, and hypothermia was affecting us.  (When
we were pulled out of the water, both our core body temperatures had
dropped to 85 degrees.)

"The SAR helo had redlined it all the way out to us, arriving in about
15 minutes.  The swimmer dropped into the water and ECMO 2 had him
load me first.  Once the swimmer had loaded ECMO 2, he headed toward
ECMO 1, who was floating, but not moving, on his chute.  The swimmer
then tried CPR for 30 minutes on ECMO 1 while the helo took us back to
the ship.  The pilot was not recovered.

"After we landed on the ship, the crew brought us to the ordnance
elevator.  I remember all the people staring at me while I rode down
to medical.  Once the doctors stabilized both of us, we were airlifted
to San Diego Naval Hospital.  After five hours of surgery, I was in
critical condition but breathing on my own, although I think the tubes
up my nose and down my throat helped."

LCdr Luttrell had 15 surgeries, was med-down for 13 months, and is now
flying with a waiver.

--
Mary Shafer    http://www.dfrc.nasa.gov/People/Shafer/mary.html
shafer@rigel.dfrc.nasa.gov     Of course I don't speak for NASA
Lead Handling Qualities Engineer, SR-71/LASRE
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@ursa-major.spdcc.com please

From: Mary Shafer <shafer@orville.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: emergencies (was Re: Blue suits?)
Date: 06 Mar 2000 15:41:35 -0800

"Donald Harstad" <dharstad@netins.net> writes:

> I would think there'd be a major difference between stepping out at
> approximately zero speed, and accelerating at a steady rate through Mach 1;
> as opposed to ejecting into a Mach 1 slipstream.

It depends on the q-bar, dynamic pressure or 0.5*rho*V**2 (rho is the
density and V is the velocity), whether there will be injuries or not.
It's q-bar that injures, not Mach number.  The only difference between
falling into it and ejecting into it is the possibility of flail
injuries and they're uncommon at or below 250 KEAS (which is why I
picked that number from the F-18 NATOPS manual).  I'm not sure the
probability of flail at the lower q-bars is smaller for people falling
than for people ejecting, either.

As I mentioned in another posting, you can be going 250 KEAS, which is
Mach 0.38, at sea level or Mach 3 at 91,000 ft and have the same
number of air molecules hitting your body when you eject, which
explains why so many people survived ejecting from the Blackbirds at
altitude, even though the q-bar was higher than the magic 250 KEAS
that marks the boundary between minor and moderate injury.  (I'd get
the SR-71 Dash-1 down and get the exact equivalent airspeed except
that I absent-mindedly took my bookshelf and file-drawer key home in
my jacket pocket and wore a different jacket today, so it'll have to
wait until tomorrow.)

Plus which, since the parachute doesn't deploy until the seat gets
down to 15,000 ft, there's ever a chance an ejectee from a Blackbird
might fall supersonically.  I don't know what terminal velocity for an
ejection seat is, but it should be higher than for a person.

Also, Kittinger was injured; he suffered frostbite on his right hand
because he lost or damaged his glove.

--
Mary Shafer    http://www.dfrc.nasa.gov/People/Shafer/mary.html
shafer@orville.dfrc.nasa.gov Of course I don't speak for NASA
Senior Handling Qualities Research Engineer
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@spdcc.com please

From: Mary Shafer <shafer@orville.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: Capsule-style Ejection Systems (Was: Re:Shuttle egress 
	survivability
Date: 06 Sep 2000 09:32:50 -0700

zapkitty@lemmings,hotmail.com (Chuck Stewart) writes:

> (The kitty pits away his copy of "B-70: Monarch of the Skies" and
> sits down to post... )
>
> Budget-breaking time :)
>
> What sort of capsule egress systemwould give the shutlle crew the
> best chance of survival under _most_ flight conditions?

According to the tried-and-true SR-71 ejection system, a pressure suit
and an ejection seat, with such extras as a face-plate heater and
enough O2 to keep away hypoxia during free fall.  They proven the
system out to Mach 3.2 at 80,000 ft plus.

--
Mary Shafer
shafer@orville.dfrc.nasa.gov Of course I don't speak for NASA
Senior Handling Qualities Research Engineer
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@spdcc.com please

From: Mary Shafer <shafer@orville.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: Capsule-style Ejection Systems (Was: Re:Shuttle egress 
	survivability
Date: 06 Sep 2000 10:09:59 -0700

"Ron" <ron561@no.spam.earthlink.net> writes:

> >
> > Also, who's going to test this?  Testing this mechanism in flight
> > would, at the very least, result in loss of the orbiter.  This would
> > likely be more expensive than testing the Mercury, Gemini, and Apollo
> > escape systems.

> The Navy has a facility at China Lake for testing just such a
> system.  It is used to test ejection seats for military aircraft,
> and with some simple modifications it could probably be used for
> testing a capsule escape mechanism too.

So does the USAF, at Holloman.

Incidentally, Edwards used to have a flat track, too.  It was while
working on the rocket sleds that Capt. Edward Murphy coined Murphy's
Law, as reported in a press conference by the late John Stapp, MD.

Neither rocket sled track can go fast enough to simulate ejection much
above Mach 1.  Nor can they simulate ejection at peculiar attitudes,
as in tumbling vehicles.

--
Mary Shafer
shafer@orville.dfrc.nasa.gov Of course I don't speak for NASA
Senior Handling Qualities Research Engineer
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@spdcc.com please

From: Mary Shafer <shafer@orville.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: Capsule-style Ejection Systems (Was: Re:Shuttle egress 
	survivability
Date: 06 Sep 2000 11:58:23 -0700

JF Mezei <jfmezei.spamnot@videotron.ca> writes:

> Mary Shafer wrote:
> > According to the tried-and-true SR-71 ejection system, a pressure suit
> > and an ejection seat, with such extras as a face-plate heater and
> > enough O2 to keep away hypoxia during free fall.  They proven the
> > system out to Mach 3.2 at 80,000 ft plus.

> What sort of hardware remains with the pilot during/after ejection ?
> Just the glorified seat, with the pressure suit bearing the brunt of
> the wind/cold, or is there some sort of protective hard cocoon to
> shield the pilot from the impact of the wind ?

Well, the seat only stays until man-seat separation at 15,000 ft and
it's not what I'd call "glorified", but that's all there is, the
pressure suit and the seat.  It works quite well because there's not
that much wind at Mach 3 at 80,000 ft.  I'm too lazy to do the
calculation, but the equivalent airspeed at sea level is low enough to
survive in a flight suit and a regular e-seat.  It's low enough that
flail isn't a big concern, for example.

--
Mary Shafer
shafer@orville.dfrc.nasa.gov Of course I don't speak for NASA
Senior Handling Qualities Research Engineer
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@spdcc.com please

From: Mary Shafer <shafer@orville.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: Capsule-style Ejection Systems (Was: Re:Shuttle egress 
	survivability
Date: 06 Sep 2000 09:53:05 -0700

zapkitty@lemmings,hotmail.com (Chuck Stewart) writes:

> AV/2 was flying in close proximity with other aircraft for a
> photo shoot when it collided with a F-104 Starfighter piloted by
> noted test pilot Joseph A. Walker.

Actually, the F-104N collided with the XB-70.  The current theory is
that it was pulled into the XB-70A by the wingtip vortex, in an early
wake vortex accident, before the aviation world know how powerful and
dangerous wake vortices are.

> The Starfighter ripped both rudders off of the XB-70 and damaged
> the left wing. Walker was killed.

Probably immediately upon striking the left vertical.

> His arm did get caught in the clamshell doors of his pod and he had
> to fight to get it free: he ejected only moments before impact...
> But he survived and returned to flight status.

It was White's elbow and he worked it free and ejected with the
clam-shell doors of the pod still open, which inhibited the deployment
of the shock attenuation bag, so he hit the ground at 45 g, suffering
severe internal injuries.

> Unfortunately his co-pilot Carl cross was not able to get into his
> pod.

You've got the active part of the team confused.  The seat was
supposed to put him into the pod, so Cross wouldn't have had any sort
of procedure to follow for getting into it.  He didn't slide the seat
back, it slid itself.

Getting into the pod was a passive activity for the crew; the seat-pod
combination was supposed to do everything once the handle was pulled;
pilots just sat there, in the position, while the seat slid back into
the pod and it closed and ejected.  However, ejections are usually
sequenced, so the delay that White had would have delayed Cross's
seat.  That is to say, Cross's ejection was probably so delayed by
White's struggles with his pod that his seat didn't have time to go
through its sequence.

Besides which, the airplane was tumbling, generating fairly high
moments, and the seat may not have had the power to override them.
It's not uncommon for pilots in fighters, which are much smaller, to
have great difficulty in overcoming the g loads to get their hands on
the ejection handle and pull.  This is why the handles are usually
close to the body's cg (between the legs, commonly) and the overhead
handles, that activated the face curtain and, supposedly, reduced
flail injuries by keeping the arms in, are not commonly used these
days.  Too hard to reach up and grab the handles when the fighter is
tumbling out of control.

--
Mary Shafer
shafer@orville.dfrc.nasa.gov Of course I don't speak for NASA
Senior Handling Qualities Research Engineer
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@spdcc.com please

From: Mary Shafer <shafer@orville.dfrc.nasa.gov>
Newsgroups: sci.space.shuttle
Subject: Re: Capsule-style Ejection Systems (Was: Re:Shuttle egress 
	survivability
Date: 06 Sep 2000 10:06:28 -0700

Brian Thorn <bsthorn@cox-internet.com> writes:

> On Sun, 03 Sep 2000 00:13:35 GMT, zapkitty@lemmings,hotmail.com (Chuck
> Stewart) wrote:
>
> >Do you feel that the extra weight of individual B-70 type capsules
> >would overshadow their flexibility?
> >
> >(Note to bystanders: this is where each separate seat is part of an
> >enclosable capsule. You bang the switch, clamshell doors swing
> >shut, and your personal capsule is booted through the roof)
> >
> >To test such a system would be far easier on the orbiter... and
> >crew... :)

Ejection is a last resort, not a perfectly safe egress technique.
Posters here are talking about ejection as if it had no dangers, but
that just isn't so.  Aircrew only "pull the loud handle" when the
alternative is sure death because so many injuries accompany
ejection.

Testing an ejection capsule at the edge of its envelope, which would
be the only useful place to test it, is so risky and so likely to
cause death or injury that no one would want to do it.  The return is
not commensurate with the risk.

We need to just accept that some things are inherently dangerous and
go on from there.  We can't make them perfectly safe, but we can do
our best to ensure that everything is working properly, with fail-safe
modes and reliable backups.  Once that's been done, we just have to
accept the risk and go fly.  Every research project that flies at
Dryden has an "Accepted Risk" list, because we recognize the risk
inherent in flight research and believe it's worth taking that risk to
do the research.

People die sometimes, despite all our efforts.  So long as the risk is
well-understood and accepted by the participants, that's just the way
life is.  The desire to reduce risk to zero leads to doing nothing
risky.  The people assuming the risk are responsible adults, capable
of making their own decisions, and all this talk about making things
risk-free diminishes their capability and ability to assume risk.

--
Mary Shafer
shafer@orville.dfrc.nasa.gov Of course I don't speak for NASA
Senior Handling Qualities Research Engineer
NASA Dryden Flight Research Center, Edwards, CA
For non-aerospace mail, use shafer@spdcc.com please

Newsgroups: sci.space.policy
From: henry@spsystems.net (Henry Spencer)
Subject: Re: The Pre-Astronauts by Craig Ryan
Date: Sat, 6 Jan 2001 06:13:33 GMT

In article <zsv56.19708$Hi4.525368@news.uswest.net>,
Christopher M. Jones <christopher_j@uswest.net> wrote:
>...I would lay good
>wages that most ejection seat uses in the last 2 decades or so
>have been in non-combat scenarios (mostly airshows and aircraft
>carrier landings would be my guess).

Careful here:  just because ejection seats have been *useful* in those
contexts doesn't mean that this would suffice to *justify* them.  Not all
carrier aircraft have ejection seats.

>Being shot at is an important reason for including the ejection
>seats, but it is _not_ the only reason.

There is at least one other compelling reason, but it's still fairly
specific to combat aircraft:  flight at high speeds at very low altitude
puts a premium on extremely rapid methods of escape.  (Indeed, air forces
which go in really heavily for treetop flying typically want to be able
to eject through the canopy, rather than waiting for it to be jettisoned.)

>...The space shuttle originally had ejection
>seats, but they were latter taken out after the system was proved
>to be safe enough.

Note, though, that they were intended primarily as a bailout system for
the can't-reach-a-runway case, like the current escape pole.  Ejecting
into the SRB plumes would have been near-certain suicide, and the seat
envelope ran out before the SRBs did.

>Apollo and Soyuz had escape systems as well
>(and Soyuz still does) and they are most definitely never shot at.

Again, be careful here.  Just because they exist doesn't mean that a
careful, dispassionate analysis would find them justifiable.  They became
established tradition at a time when boosters were extremely unreliable,
and they were sacred cows thereafter.

Note that the ESA astronauts were opposed to putting an escape system on
the Hermes spaceplane; they said so quite openly.  That is, the guys who
were going to fly it thought such a system was a bad idea.
--
When failure is not an option, success  |  Henry Spencer   henry@spsystems.net
can get expensive.   -- Peter Stibrany  |      (aka henry@zoo.toronto.edu)

From: gherbert@gw.retro.com (George William Herbert)
Newsgroups: sci.space.policy
Subject: Re: The Pre-Astronauts by Craig Ryan
Date: 6 Jan 2001 01:25:55 -0800

Henry Spencer <henry@spsystems.net> wrote:
>Christopher M. Jones <christopher_j@uswest.net> wrote:
>>...I would lay good
>>wages that most ejection seat uses in the last 2 decades or so
>>have been in non-combat scenarios (mostly airshows and aircraft
>>carrier landings would be my guess).
>
>Careful here:  just because ejection seats have been *useful* in those
>contexts doesn't mean that this would suffice to *justify* them.  Not all
>carrier aircraft have ejection seats.

The exceptions I know of are the C-2 cargo and E-2 radar aircraft
(plus helicopters, which you can't really eject from practically...).
I don't have good references within reach but I think the S-3
antisub aircraft did have ejection seats.

The C-2 and E-2 have real issues with trying to give them ejection seats.

The E-2 has most of its crew underneath the radome; there's no clear
ejection path for them, period.  You can bail out the side or bottom
but that's about it.  The pilots have clear up above them, but if you
go back too far on ascent you hit the radome too.  The rule seems to
have been that if the crew can't eject, the pilots shouldn't either.

The C-2 is E-2 derived systems and structurally, and additionally is
a light cargo and personel transport aircraft with the same "passengers
can't eject" problem the E-2 has with its non-pilot aircrew.

>[...]
>
>>Apollo and Soyuz had escape systems as well
>>(and Soyuz still does) and they are most definitely never shot at.
>
>Again, be careful here.  Just because they exist doesn't mean that a
>careful, dispassionate analysis would find them justifiable.  They became
>established tradition at a time when boosters were extremely unreliable,
>and they were sacred cows thereafter.
>
>Note that the ESA astronauts were opposed to putting an escape system on
>the Hermes spaceplane; they said so quite openly.  That is, the guys who
>were going to fly it thought such a system was a bad idea.

Given the outcome of the first A-5 launch, one might wonder if they
rethought the idea.

Several Saturn-V rockets made it to space by the grace of God and
von Braun's redundancy.  "Current" ELVs show a distressing tendency
to fail, some in spectacular ways which wouldn't be survivable for
a manned vehicle on top without a crew escape system.  New models are
more vulnerable, but we keep finding new flaws in older ones and in
manufacturing and operations procedures too.

I think that ELVs can be made a lot more reliable, by making them
with simpler systems and higher margins.  But we're not there yet.


-george william herbert
gherbert@retro.com

Newsgroups: sci.space.policy
From: henry@spsystems.net (Henry Spencer)
Subject: Re: The Pre-Astronauts by Craig Ryan
Date: Sat, 6 Jan 2001 15:57:03 GMT

In article <936ob3$mbl$1@gw.retro.com>,
George William Herbert <gherbert@gw.retro.com> wrote:
>The exceptions I know of are the C-2 cargo and E-2 radar aircraft
>(plus helicopters, which you can't really eject from practically...).

Helicopter ejection is not a big deal if you jettison the rotor blades
first... but this is admittedly not viewed with great favor.

>The E-2 has most of its crew underneath the radome; there's no clear
>ejection path for them, period.  You can bail out the side or bottom
>but that's about it...

Although it's out of fashion because it imposes a minimum altitude
requirement, ejection seats can fire downward instead of upward; for
example, that's what's done for the lower-deck crew on the B-52.

(You might think that this would be of limited use if a bad carrier
landing is your expected bailout requirement... but modern automatic
ejection seats can have the pilot suspended under a parachute almost
before he has time to say "oh shit". :-)  If memory serves, Martin-Baker's
latest seats are nominally capable of a survivable ejection from an
aircraft that is *upside down* -- downward ejection -- at under 100ft.)

>>Note that the ESA astronauts were opposed to putting an escape system on
>>the Hermes spaceplane; they said so quite openly.  That is, the guys who
>>were going to fly it thought such a system was a bad idea.
>
>Given the outcome of the first A-5 launch, one might wonder if they
>rethought the idea.

Hermes was defunct by then; I haven't heard of anyone asking them...

I doubt that it would have changed their minds, actually.  To some extent
it's what you expect in test flights; to some extent it's just the risk
they knew they'd be taking.  ESA bureaucrats may have believed that A5
would inherently be immensely reliable, but I find it hard to believe that
the astronauts were fooled by that.

Mind you, the really pressing need for a separate escape system is for the
on-pad case.  As soon as you have a reasonable amount of altitude -- as
the Ariane 5 launch did -- your preferred emergency strategy becomes
bringing the whole spacecraft down intact.
--
When failure is not an option, success  |  Henry Spencer   henry@spsystems.net
can get expensive.   -- Peter Stibrany  |      (aka henry@zoo.toronto.edu)

Newsgroups: sci.space.policy
From: henry@spsystems.net (Henry Spencer)
Subject: Re: The Pre-Astronauts by Craig Ryan
Date: Sat, 6 Jan 2001 23:26:24 GMT

In article <936ob3$mbl$1@gw.retro.com>,
George William Herbert <gherbert@gw.retro.com> wrote:
>Several Saturn-V rockets made it to space by the grace of God and
>von Braun's redundancy.  "Current" ELVs show a distressing tendency
>to fail...

Compared to the failure rate of Atlas circa 1960, nothing witnessed today
is more than very slightly distressing.
--
When failure is not an option, success  |  Henry Spencer   henry@spsystems.net
can get expensive.   -- Peter Stibrany  |      (aka henry@zoo.toronto.edu)