Landing gear on the shuttle

I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

On Aug 21, 9:59 am, djarvinen wrote:
I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

It's gonna be a Bad Day if the gear doesn't come down. That's
why the design is such that they're extremely confident it
WILL come down.

I'm not sure if there's an official procedure, but I'm sure the
pilot would do the best they could to fly it like any other belly
landing. It's just that the orbiter is likely to fare much worse
on a gear-up landing than any ordinary airplane would fare.

wrote in message
ups.com...
On Aug 21, 9:59 am, djarvinen wrote:
I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

It's gonna be a Bad Day if the gear doesn't come down. That's
why the design is such that they're extremely confident it
WILL come down.

I'm not sure if there's an official procedure, but I'm sure the
pilot would do the best they could to fly it like any other belly
landing. It's just that the orbiter is likely to fare much worse
on a gear-up landing than any ordinary airplane would fare.

ISTR the problem with the belly landing is the angle of attack the shuttle
needs to kill the sink rate. Either the shuttle lands flat at very high
speed and sinkrate, or the "slapdown" of the nose is going to be pretty
extreme - not sure if its survivable for the crew or not, hope they never
have to find out!

On Aug 22, 4:03 am, "MichaelJP" wrote:
wrote in message

ups.com...



On Aug 21, 9:59 am, djarvinen wrote:
I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

It's gonna be a Bad Day if the gear doesn't come down. That's
why the design is such that they're extremely confident it
WILL come down.

I'm not sure if there's an official procedure, but I'm sure the
pilot would do the best they could to fly it like any other belly
landing. It's just that the orbiter is likely to fare much worse
on a gear-up landing than any ordinary airplane would fare.

ISTR the problem with the belly landing is the angle of attack the shuttle
needs to kill the sink rate. Either the shuttle lands flat at very high
speed and sinkrate, or the "slapdown" of the nose is going to be pretty
extreme - not sure if its survivable for the crew or not, hope they never
have to find out!

I think i would prefer RTLS to that . . . and I truly hope they never
have to find out

take care . . .

John

"djarvinen" wrote in message
oups.com...
I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

The gear is gravity deployed, but there is a back-up. If the gear does not
deploy and lock within a certain amount of time, pyrotechnic actuators are
fired which force the gear into the down and locked position.

Jeff
--
"They that can give up essential liberty to obtain a
little temporary safety deserve neither liberty nor
safety"
- B. Franklin, Bartlett's Familiar Quotations (1919)

Originally Posted by djarvinen

I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

The shuttle landing gear are deployed 'mechanically.' As such they require a bit of a 'pop' to deploy just before contact with the runway. This is an intentional design safety feature. My father was the lead engineer on the shuttle autoland system. Much argument was made when he insisted the gear be deployed without hydrolics etc. As a former air force pilot he knew a major cause of landing crashes resulted from the failure of gear failure to deploy. The orbiter landing gear are manually deployed by the flight crew (Pilot or Commander). The orbiter approaches the runway at the steepest angle and highest speed of any known glider. You are correct that that there are no re-do's. Any failure of the landing gear to deploy properly will lead to a catastrophic failure. At about 220mph there is no room for ripping down the runway hoping the 'belly' of the aircraft will hold up.
On a related note the recent Endeavor mission had a quandary. IF the damage was severe enough to place the crew at great risk was it possible to land the orbiter without a crew? The answer is yes. The only barrier to autolanding the orbiter is deploying the gear and a mechanism to do so could have been devised if it had been needed. Thankfully it was not. The alternative risk of launching a 'rescue shuttle' was great; this time all turned out well.
We are still flying an experimental 'spaceplane.' One which has no viable escape system--the only craft ever built to take people into space without a crew escape system. The next generation vehicle should focus on crew safety, not payload capacity and as such can have a full crew escape system integrated from the outset. Shuttle's have always been envisioned as a way to ferry people to and from orbit safely, not cargo. Cargo can be handled by 'dumb' boosters. Max Faget, whom I had the honor of interviewing many times never did get to see the shuttle he designed go into operation.

Keith E. McInnis

Keith E. McInnis wrote:

.... the only craft ever built to take people into space without a
crew escape system.

Let's not forget the craft of the Voskhod program.

--
Dave Michelson

Dave Michelson wrote:

Keith E. McInnis wrote:

.... the only craft ever built to take people into space without a
crew escape system.

Let's not forget the craft of the Voskhod program.

Or the fact that most escape systems are only good for a fairly small
portion of the total flight envelope.

D.
--
Touch-twice life. Eat. Drink. Laugh.

http://derekl1963.livejournal.com/

-Resolved: To be more temperate in my postings.
Oct 5th, 2004 JDL

Originally Posted by Dave Michelson

Keith E. McInnis wrote:

.... the only craft ever built to take people into space without a
crew escape system.

Let's not forget the craft of the Voskhod program.

--
Dave Michelson

Thanks for the correction. The most accurate statement is that no American craft for human spaceflight has been built without a viable escape system.
The Russians did use the escape system designed by Max Faget; it successfully saved the lives of Cosmonauts Tetov and Strekalov during a catastrophic launch failure by removing their entire crew compartment to a distance of several miles away from the launch area. It did so in less than 3 seconds. Speed of deployment is key to any escape system as Max pointed out in numerous discussions.

It is also true that no escape system can cover every scenario--but most failures happen on launch and ascent. In the case of Columbia it is hard to know if the escape system proposed by Rockwell had been in place if the flight path could have been altered to make crew escape via the automated ejection system feasible.

The need now is to ensure all future designs integrate from the outset a full crew automated escape system as certainly the vehicle will remain experimental for quite some time. The shuttle was certified as operational after a handful of missions, after which the two ejection seats were removed. This violates every standard in flight certification of a vehicle. We didn't 'man-rate' prior craft until much more rigorous testing, particularly on the engines of the day. When the shuttle was declared operational the main engines were still not certified by any established standard and were quite troublesome.

These are all lessons on how the pressure to get something flying can impact design, mission definition and safety. Avoiding making these mistakes again is the reason for my criticisms.

Keith E. McInnis

From Keith McInnis:
djarvinen;825146 Wrote:

I was watching the live pics of STS-118 landing today and noticed that
the landing gear doesn't come down until what appears to be just
seconds (10-15?) before landing.

So what's the procedure if the gear doesn't come down? I'm pretty
sure a go-around isn't an option.

Ok, seeing as how no one has stated it on this thread as yet, I'll
pipe in with the obvious answer...

If the PLT pushes the Gear Deploy button and the gear doesn't come
down, the emergency procedure is for the CDR in the left seat to push
the ARM/DEPLOY buttons on that side of the cockpit.

I expect that most right seaters will also repeatedly keep pushing the
right seat buttons until runway impact, since there is not much else
to do from the right seat. As for the person on the stick, I suspect
that there are pilots who have a plan to porpoise the orbiter in hopes
of shaking something loose. That is a typical emergency action for
other jets like the T-38, although with engines you have the luxury of
doing this at altitude. I have never heard of anyone practicing a
"Fred Haise imitation" in the sim, but when any gear up landing is
expected to be catastrophic then there isn't much to lose by taking
desperate action on short final. (It would be interesting from a
flown commander on this.)

snip
You are correct that that there are no re-do's. Any
failure of the landing gear to deploy properly will lead to a
catastrophic failure. At about 220mph there is no room for ripping down
the runway hoping the 'belly' of the aircraft will hold up.
On a related note the recent Endeavor mission had a quandary. IF the
damage was severe enough to place the crew at great risk was it
possible to land the orbiter without a crew? The answer is yes. The
only barrier to autolanding the orbiter is deploying the gear and a
mechanism to do so could have been devised if it had been needed.
Thankfully it was not. The alternative risk of launching a 'rescue
shuttle' was great; this time all turned out well.
We are still flying an experimental 'spaceplane.'

I totally object to that viewpoint. I'll repost this view that I
shared back in '03:

====
: You can't have it both ways. It is
: either experimental and should be flown as such, or it is
operational
: and then assigned to conduct operational missions with cargo and
extra
: crewmembers.

: As soon as you
: decide to start flying passengers, you are implicitly stating that
: your vehicle is past the critical developmental stage and is now
safe
: and reliable enough to carry such extra members on board. The
: decision to carry people who were non-essential for flight
development
: was made for STS-5 which launched way back in 1982 (with Reagan's
: announcement, as you point out).
:
: I don't subscribe to the notion that the shuttle is an experimental
: vehicle. It has been used as an operational workhorse for many
years.
: Chris Kraft, in his 1995 report, went so far as recommending to
: freeze the design.
:
: I do not subscribe to any 1-to-1 comparison of aircraft flights to
: spaceflights, as some FAA officials might quote in their safety
: analyses. Space rockets are *not* aircraft. Their maturity needs
to
: be measured in "dog years". I'd take a wag at an equivalence of 1
: spaceflight to be on the order of 100 aircraft flights.
====

One which has no
viable escape system--the only craft ever built to take people into
space without a crew escape system. The next generation vehicle should
focus on crew safety, not payload capacity and as such can have a full
crew escape system integrated from the outset. Shuttle's have always
been envisioned as a way to ferry people to and from orbit safely, not
cargo. Cargo can be handled by 'dumb' boosters. Max Faget, whom I had
the honor of interviewing many times never did get to see the shuttle
he designed go into operation.

People like Bo Bejmuk (who after shuttle went on to SeaLaunch fame)
say that it was a blessing in disguise that the fully reusable shuttle
got scaled back. That grand vision was proposing to do way too much.


~ CT