Today is the 44th anniversary of the first manned landing on the moon. Neil Armstrong and Buzz Aldrin rode the lander to the surface, and Michael Collins manned the spacecraft in lunar orbit.
This event had the same historical significance as Columbus's landing in the Caribbean half a millennium earlier. Unlike then, we have not capitalized on the moon landing. Not in all the intervening 44 years has a human set foot on another world, not even a return to the moon.
I suggest we make a holiday out of this date, to celebrate the first moon landing the same way we celebrate Columbus Day. It would be a fitting memorial to Armstrong and the rest, if we did this.
It might also help raise public awareness of the excitement and adventure of manned exploratory spaceflight. The moon, Mars, the asteroids, and uncountable places beyond, all beckon.
Saturday, July 20, 2013
Tuesday, July 9, 2013
On the Asiana 214 Crash
There was something deadly wrong in
the one cell phone video of the actual SFO crash that has surfaced. With
the electronic glide slope system unavailable (as it was), visual
approach is necessarily more hand-flown using the old-time glide slope
lights. Hand flying experience is critical, and too many of these
"bus drivers" don't get it.
That plane was about a span too
low, and way, way, way too slow (near-stall nose-up attitude
painfully obvious) at about 1/4 mile from the marks, a furlong from the
seawall. Two somebodies in the cockpit clearly weren't watching the
airspeed indicator.
The low altitude can be dealt-with
as long as you have adequate speed. But low speed is inevitably an
accident about to happen.
And it did.
GW
some second thoughts 7-10-13:
some second thoughts 7-10-13:
As I said, nobody looked at the airspeed indicator. Needle should have been hitting the flaps/gear white line, or the stick shaker wouldn't have kicked in. You'd think that with 3 or 4 pairs of eyes in the cockpit, somebody would have looked at the IAS. Apparently not, and that's an artifact of over-automation in the cockpit. Bus drivers, not pilots.
I know nothing of the automatic electronics, not even the damn radio, but I do know stick-and-rudder flying. I could have gotten the damn thing down in better shape than they did, and I have not flown anything for almost 15 years now. My weak spot would have been the flare: not having any experience at that cockpit height above ground, no feel for exactly where all the bits of the plane are located, relative to me in that seat.
I've never held a pilot's license, but stick-and-rudder flying does come easily to me precisely because I was originally educated as an aeronautical engineer. I know exactly how planes work. Under the eye of an appropriate pilot, in past decades I have flown two light plane types, and two multi-engine types. It wasn't hard.
On the Train Wreck in Quebec
News reports on this are still quite
confusing, but here is what I have been able to determine as pretty much
the facts:
The train was parked and
"secured" near Nantes (uphill and 7 miles away from
Lac-Megantic), and the driver went to a hotel for the night. In
this instance, "secured" seems to mean a running diesel engine
powering the air brake system, I'd guess by the two-pipe system,
such that the air brakes were set in the locomotive and all train cars.
Then there was some sort of fire in
the parked locomotive, to which the Nantes fire department and a
railroad engineering division person responded. They put out that
fire, which seems to have been fairly minor, and shut down the
running engine. They had a procedure to follow, and they followed
it. Everybody went home.
About an hour later, the
entire train rolled away, picking up speed gravitationally, and
entering Lac Megantic fast enough to derail and cause the disaster.
This is my suspicion, based on
what I have read about train air brakes:
When they shut down the
locomotive, they killed the air compressor. Train car second pipe
pressures then fell due to air leakage, which is inevitable.
Reduced train line pressures would act to apply car brakes, but not with
leak-drained reservoirs! The second line that keeps the reservoirs filled
would have been off, too, with the locomotive shut down.
The locomotive air brake would also
have been disabled by bleed-down with the compressor off. I'm not sure
about sequence, but sooner or later, all of the air brakes would
have failed from bleed-down. Apparently this took about an hour.
Apparently, nobody thought to
set at least one car's handbrake, and this must not have
been in the locomotive fire procedure that they were following in
Nantes. One or two cars' handbrakes could have secured the train,
even without any compressed air at all in the air brake system. That
could have prevented this disaster.
As for the tank cars
themselves, these were unpressurized-liquid cars, and reported to
be DOT-111 designs, which are well-known to be thin-skinned and easily
punctured. They were hauling a light crude that comes from fracking
operations in North Dakota. It would have flammability characteristics
closer to diesel than heavy fuel oil.
The problem with closed flammable
liquid tanks is overpressurization explosions when exposed to fire.
Those are not detonations like high explosives, but they are still
extremely violent. Once the cars are thrown together in a wreck and some
torn open, the fire starts. Explosions become inevitable.
The disaster is better and easier to
prevent, than to fight after-the-fact.
Recommendation: set some
handbrakes if you shut off the locomotive on a parked train. Leave a note
to that effect in the cab before you go.
GW
Update 7-19-13:
It is now my understanding that the engineer was supposed to have set 10 or 11 of the handbrakes on this train. Obviously, this didn't work.
There are then only 3 possibilities: (1) he did not set them, (2) he did set them, but they were ineffective (for a reason of considerable interest), or (3) somebody else released the handbrakes.
I think the authorities have their work cut out for them, finding out which of these three possibilities caused the disaster. It is easy enough to blame the engineer, but there are two other possibilities that must be eliminated before that is a credible action for anyone to take.
Neither of the other two possibilities is a very comfortable thought. Yet, they MUST be dealt with. If they are not, then any "final report" on this disaster is neither credible nor useful.
Second thoughts
(later, same day):
Being a
freight, this was most likely a one-pipe
air brake system, not a two-pipe. It doesn’t matter to the outcome. Turn off the air compressor (and they
did), and after a while, every brake component bleeds to zero. Once that happens, brakes release.
When the last
brake releases (car or engine, doesn’t
matter), the train is free to roll, unless some mechanical handbrakes somewhere
were set. Once free to roll, if parked on any sensible slope at all, the train will roll away under gravity. That is inevitable.
One pipe system
or two, same outcome as already
described.
Same
preventative as already described: set a
handbrake or two, more of them on a
steep slope. There’s plenty of time to release them while
the cars’ air brake components “charge up”,
with the (running) locomotive brake set to hold the train.
It is now my understanding that the engineer was supposed to have set 10 or 11 of the handbrakes on this train. Obviously, this didn't work.
There are then only 3 possibilities: (1) he did not set them, (2) he did set them, but they were ineffective (for a reason of considerable interest), or (3) somebody else released the handbrakes.
I think the authorities have their work cut out for them, finding out which of these three possibilities caused the disaster. It is easy enough to blame the engineer, but there are two other possibilities that must be eliminated before that is a credible action for anyone to take.
Neither of the other two possibilities is a very comfortable thought. Yet, they MUST be dealt with. If they are not, then any "final report" on this disaster is neither credible nor useful.