Space Forum / Shuttle / September 2007

Well I would be interested in reading what you are alluding to
concerning the DTO in whatever thread. I understand that the crosswind
limit for the shuttle is 15 knots, IIRC the crosswind component was 17
knots at the time of the landing. I would think that the late chute is
related to the slightly excessive cw component. I know that there is a
list of DTO's that they invoke when opportunities arise. I just felt
confident that with the call about the DTO and the higher cw that they
had a DTO opportunity that they took.
I know from my own flying experience (limited to Cessna, Piper, and
Grumman tricycle type aircraft), that the rudder, while not essential,
makes flying much safer and easier. It would seem that the Shuttle,
being a glider, would require pilot controlled rudder to maneuver. I
understand that the airbrake feature would change the characteristic
of the rudder, but rudder would still be needed. I need to research
this further.

On Aug 31, 1:27 pm, tdadamemd-spamblo...@excite.com wrote:

There might be some confusion on the use of the term "autopilot".  In
most planes when the pilot is manupulating the controls, the autopilot
is off.  In the shuttle the Digital Autopilot Pilot (DAP) is ALWAYS
flying the shuttle.  If the pilot wishes, he can take Controlled Stick
Steering (CSS) and manipulate the controls.  If the pilot is not
manipulating the controls, DAP takes its commands from a piece of
software called "guidance".

I started work for NASA in 1990, so I can't say for sure what the
early shuttles had.  I don't recall anyone telling me the early
shuttle's didn't have nosewheel steering, but maybe they didn't.

Danny Deger

I have heard it mentioned, and know that to many pilots it is very
important to land or, in the case of the Shuttle, to stop with the
nose wheel on the center line of the runway.
In my limited experience with light aircraft, I am happy to be on the
runway at all!!
Concerning the tires and CDR Bobko, I accept that his flight was the
only one to actually blow a tire. I know for a fact however, that
there was great concern about tire wear prior to the advent of NWS and
perhaps still is. But it was this wear issue, and the blown tire, that
sealed the deal on the NWS. I recall seeing pictures of tires worn
down to the cords due to the differential braking and the obsession
with stopping on the centerline.
AFAIK Bobko is held in high esteem in the astronaut community.
Regards,
Jim in Houston.

Contrary to popular opinion RN does not mean Real Nerd!
Teddy Roosevelt's mother said: "Fill what is empty,
empty what is full, and scratch where it itches"

I am not wearing any cloak.  And I bear no daggers.

You may have seen on that other thread where Jorge made a statement
about ISS-Shuttle undock that any person who has passed freshman
physics could see as inaccurate, yet such statements go unquestioned.

That is not knowledge "that no one else is privy to".

On this thread, a former F-4 pilot has made it sound like there is no
time when a shuttle pilot would use rudder prior to touchdown.  Any
person with basic piloting knowledge would question that, as you have.

Once again, knowing smart ways to use a rudder is not knowledge that
no one else is privy to.  You yourself, Jim, have already stated one
of the three scenarios as to when the rudder comes in handy for the
shuttle.  And the second one is obvious too.  I'm sure you can tell us
yourself.  The third one is not quite as obvious.  But anyone who has
flown an aircraft with a HUD should know.

These types of corrections are no big deal.  "I forgot that the rudder
is an extremely useful tool for energy management."  Or, "I forgot
that the rudder is an extremely useful tool for improving roll
performance."

Or, "I forgot that momentum is the product of mass TIMES velocity."

But it becomes a bigger deal when people who should know better blow
off the basics, like oxygen tanks being specifically designed with
blow-out rupture discs and stuff that have cost astronaut's lives.

The idea that scares me is the notion that these people *actually
don't know*.  Jorge has let days go by without providing any
indication that he knows the difference between momentum and
velocity.  Jim Oberg was part of that discussion as well, and he has
been silent.  I've had direct discussions with Sy Liebergot about
Apollo 13, reminding him that the oxygen tanks were designed so they
would not explode, and he has yet to acknowledge this fact.  He seems
perfectly comfortable with calling the incident an explosion.

As for this thread here, I KNOW that Danny knows how to use a rudder
to his advantage.  If he didn't learn this in F-4s then I don't know
how he made it through AF UPT.  It would then follow that he knows how
to use the rudder in the space shuttle.  Yet he says the things he has
said here.

Part of the reason why I haven't posted it myself as yet is because I
am baffled.  I am being accused of cloak&daggering.  If there are any
daggers involved, you might want to consider the possibility that it
is the poster falling on their own dagger.

I do understand that me posting corrections runs the risk of
embarrassing someone (myself included).  But say that on the very next
shuttle flight, the crew ends up in an ECAL abort with very high
energy on final.  Say that they manually take the speed brake to full
open but do nothing with the rudder, because no one in DT ever taught
them to use the rudder.  Say that the shuttle then lands long, rolls
off the end of the runway, snaps the nose gear, blows the FWD RCS
tanks and the crew dies.

Improbable, sure.  But possible.  We here have the opportunity,
however small, to potentially help improve the training of shuttle
pilots.  Or we can sit back in silence, let it slide so as not to
embarrass anyone and hope that this is not the mistake that proves
fatal.

~ CT

I would agree that the shuttle can be flown perfectly well with no
rudder in nominal conditions.  But the four scenarios specified were
discussing way off-nominal conditions that I expect that you trained
for.  So it appears that you are saying that you would teach a pilot
to not touch the rudders even if they find themselves in any of these
four:  hi energy, roll perf, HUD xwind and xwind out of limits.

Curious.  But I would agree that it is not *necessary* to use rudder.
This leads to a follow up:  If a pilot *did* use the rudder to help
themselves out in such a situation, would you ding them for doing so?

~ CT