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Air Turbulence May Be Factor in Jetliner Crash, Officials Say
New York Times ^ | 11/14/01 | SHERRI DAY

Posted on 11/16/2001 1:12:39 PM PST by kattracks

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To: jlogajan; Nita Nupress
The EMP, if used as a weapon does not destroy as in an explosion or impact. The effect of the EMP results is a disruption of the electrical system, effectively disabling the controls as well as communications. Although the control systems are hydraulic, the hydraulic controls are servo fed and controlled devices that require electrical signals to tell it what to do.

It might be advisable for you to get all of your rocks gathered up before you start throwing them. :-)

41 posted on 11/16/2001 1:13:54 PM PST by chadsworth
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To: chadsworth
The effect of the EMP results is a disruption of the electrical system

One natural EMP weapon is a lightning strike -- which hit airplanes frequently. Hence they are hardened against it, especially the fly-by-wire types. So the likelyhood of a raghead in a dingy aiming his Acme EMP-ray at craft 3000 feet up and bringing the bird down is -- very very small.

42 posted on 11/16/2001 1:13:59 PM PST by jlogajan
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To: jlogajan; Nita Nupress
My friend, if you will kindly recall the recent advances in in EMP technology, which has had a tremendous amount of very recent research as the weapon of choice by those nations that have a large resource of scientists, you may be well advised to retract such a flippant statement.

In my opinion, Nita nupress may just have a very valid concern. Please review the web page listed below. I have included a short section identifying the Dept. of Defense concerns.

the scientist tinkered and soon put together two crude weapons. The smaller one was designed so it could be broken down into two parcels and shipped by United Parcel Service from one terrorist to another. The larger was built into a converted Volkswagen bus. Both used ordinary spark plugs to generate the pulse, commercially available coils, common capacitors and simple copper tape. “We wanted to show that by backyard means a weapons system could be built that would have some effectiveness against our civilian infrastructure,” Schriner explained during an April 30 demonstration at the Aberdeen Proving Ground.

One incident that made U.S. military planners take notice of the threat occurred a few years ago when a U.S. Comanche helicopter flying out of the now-decommissioned Griffis Air Force base in Rome, N.Y., took out the entire navigational-aids system at the nearby commercial airport. The helicopter had generated a low-level RF pulse during a radar test “which ended up totally disrupting the global positioning system (GPS) being used to land commercial aircraft in Albany, New York, for a couple of weeks,” reveals James F. O’Bryon, deputy director of the Pentagon’s Operational Test and Evaluation Live-Fire Testing Center, which is studying the impact of EMP and RF weapons on U.S. military systems.

The military began testing Schriner’s prototype weapons last year in an effort to determine the vulnerability of common electronic devices such as desktop computers, medical pumps and monitors, home-alarm systems and police scanners. In tests so far, Schriner’s devices have temporarily disrupted all of them.

A high-powered weapon used by a terrorist could have a far greater impact than freezing computers or turning off intravenous pumps. To illustrate his point, Schriner presented a fictional case.

EMP CONCERNS AS WEAPON OF CHOICE

43 posted on 11/16/2001 1:14:03 PM PST by chadsworth
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To: Map Kernow
I'd also like to know if a pilot would normally open the engine throttles full out, the way these pilots allegedly did or tried to do, in response to such turbulence.

I'd have to review the timing of the events, but I expect that the pilots spooled up the engines to max power in response to controllability problems. If the plane is wallowing and not responding to control inputs, the instinctive reaction is to increase airspeed by lowering the nose and increasing power because that's the sign of an imminent stall.

I don't claim to be a pilot, but I've been in a plane going through turbulence many times before, and I don't ever recall the pilot trying to "gun it" through the bumps.

In cruise, reducing power is the proper response. All planes have what is called a "manuevering speed", which is at the top of the green arc on the airspeed indicator and the beginning of the yellow (caution) arc.

At manuevering speed, full deflection of the controls will not overstress the airframe. Also, turbulent air will toss the plane around, but will not over-stress the plane because the wings and control services (like the tail) will stall before a structural failure will occur. If you are near the ground, this loss of lift is a problem, but at altitude you can still recover.

This flight was still at low altitude in a climb profile. They were almost certainly not exceeding the manuevering speed. That's why this whole thing about wake turbulence is bogus, unless they can conclusively prove that there was already a flaw that made the plane vulnerable.

44 posted on 11/16/2001 1:14:17 PM PST by justlurking
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To: jlogajan
So the likelyhood of a raghead in a dingy aiming his Acme EMP-ray at craft 3000 feet up and bringing the bird down is -- very very small.

Right. Just like the likelihood of a group of nineteen ragheads in hijacked airliners simultaneously aiming their airborne weapons of mass destruction at the World Trade Center twin towers 100+ stories up and bringing the towers down was -- very, very small.

By the way, the statement I posted above about "terrorists parked at the end of the airport runway to debilitate airplanes taking off or landing" was not made by some tin foil hat "conspiracist." It was made by the Chairman of the Special Oversight Panel on Terrorism of the Committee on Armed Services.

Your tendency for histrionic statements is yet another reason why you were not pinged to this conversation.

45 posted on 11/16/2001 1:14:21 PM PST by Nita Nupress
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To: Nita Nupress
(BTW, another root canal coming up. Ugh.)

If it feels like one of the manual augers is going to come out of the top of your head, don't worry . . . . . . . very unlikey to go deeper than mid-brain.

46 posted on 11/16/2001 1:14:42 PM PST by LSJohn
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To: samtheman
There's air turbulence every day.

Jet wash is a definite factor. The next time you're flying, and the aircraft are stacked up waiting for takoff, there will be a minimum of one minute between full throttle times of the departing aircraft. I've been sitting on taxiways for over an hour in Richmond, and you can almost set your watch as the aircraft line up and take off.

47 posted on 11/16/2001 1:14:45 PM PST by Cobra64
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To: Map Kernow
Map, they don't use cassette tapes in a Walkman anymore. It's a little more high tech now. Digital flight recorder data is stored on "digital" micro chips. If you doubt technology, compare today's computer to what you had 10 years ago. As a parallel example, IBM is coming out with a 400gb hard drive within the next two years. Research labs are talking about molecular memory. Bell Lab's 1953 transistor technology will look like a stone arrowhead compared to today's GPS & laser guided munitions. A $1,000 pc today has more processing power (MIPS thoughput) than the largest IBM mainframe 20 years ago. Twenty gb of DASD today would fill up a warehouse of tape drives today.
48 posted on 11/16/2001 1:14:47 PM PST by Cobra64
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Comment #49 Removed by Moderator

To: Nita Nupress
An electromagnetic pulse (EMP) attack could incapacitate power grids, communications, computer systems, and even electronic infrastructure...

I've read a little about this. A re-directed microwave transmitter may be able to do what you're suggesting. I have a littany of ideas that the bad guys could use that are as effective and easier to deploy. I sent a note to the Feds but they seem to have "everything under control."

50 posted on 11/16/2001 1:14:54 PM PST by Cobra64
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To: Dog Gone
If you lose your rudder, hydro back up doesn't mean sh!t. You'll go into a spin; and if you have one engine at full tilt at 90,000 lbs thrust on one wing, and lost a wing and its thruster; well, your course is a vetical glide path.
51 posted on 11/16/2001 1:14:55 PM PST by Cobra64
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To: Nita Nupress
LOL... I don't 'look' like an EMP expert either. But methinks if an EMP were used, it would ALSO cause the flight/voice recorders to quit working. I'd think it's be 'easy' enough to check out. 'They' would look at the watches worn by the dead folks...see what time they all stopped. (if any survived the crash inferno, that is)

There are quite a few ground witnesses, that reported an expolsion/fire right before the pieces falling off/crash.

Hate to say this, cuz I'll get razzed, but where is Michael Rivero? His input may be helpful. He can think 'outside the box', and he seems pretty knowledgeable about things like this. Remember, he's our resident 'bulldog' who wouldn't let go of the deliberate downing of TWA 800.

52 posted on 11/16/2001 1:15:12 PM PST by mommadooo3
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To: Anticommie
If the black box gets damaged from the fall from 1000 feet the only way it was "damaged" could be by explosion

That is a very good point.

53 posted on 11/16/2001 1:15:18 PM PST by honway
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To: Nita Nupress
Thanks for the ping. RadioAstronomer answered your question in post 25. EMP's will not cause structural damage to an aircraft but they will however fry all of the electronics on board the aircraft.

or a relatively small radio frequency weapon built from readily available technology could be used by terrorists parked at the end of the airport runway to debilitate airplanes taking off or landing.

That is what they mean when they say to debilitate.

The aircraft would have no radar, no radios, and no computers to drive the cockpit instrumentation.

54 posted on 11/16/2001 1:15:22 PM PST by Brownie74
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To: kattracks
We believe that in fact it was one minute and 45 seconds."

The NTSB experts certainly know the standard for separation for a heavy jet behind a heavy jet is 4 miles. Either the radar track shows the approriate 4 miles was maintained or it was not. They should say so. Throwing out this 1 minute 45 seconds figure smells of a red herring.

55 posted on 11/16/2001 1:15:22 PM PST by honway
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To: mommadooo3
where is Michael Rivero? .... He can think 'outside the box'

Yeah, but that "box" is reality.

56 posted on 11/16/2001 1:16:40 PM PST by jlogajan
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To: Cobra64
Map, they don't use cassette tapes in a Walkman anymore. It's a little more high tech now. Digital flight recorder data is stored on "digital" micro chips. If you doubt technology, compare today's computer to what you had 10 years ago. As a parallel example, IBM is coming out with a 400gb hard drive within the next two years. Research labs are talking about molecular memory. Bell Lab's 1953 transistor technology will look like a stone arrowhead compared to today's GPS & laser guided munitions. A $1,000 pc today has more processing power (MIPS thoughput) than the largest IBM mainframe 20 years ago. Twenty gb of DASD today would fill up a warehouse of tape drives today.

Well, you didn't really answer my question, but you gave me a doggone good bit of what looks like good info. So thanks. :)

57 posted on 11/16/2001 1:17:21 PM PST by Map Kernow
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To: justlurking
That's why this whole thing about wake turbulence is bogus, unless they can conclusively prove that there was already a flaw that made the plane vulnerable.

Thanks for your informative reply. I understand this morning that the Feds are still focused on the turbulence scenario, and are also focusing on the composition of the vertical stabilizer as a factor in the structural failure of the plane. Reportedly, the vertical stab. sheared off cleanly like it was cut with a Ginzo knife above the anchoring bolts. Supposedly the French Airbus company makes this part of the frame out of some composite that sounds like chewing gum and boogers. Now they're talking about examining the vert. stab.s and rudders in the whole AA fleet.

58 posted on 11/16/2001 1:17:33 PM PST by Map Kernow
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To: Nita Nupress; SLB
I believe the military is doing lots of directed energy experiments, not all of them EMP. Sorry, I don't have much to add to the discussion.
59 posted on 11/20/2001 11:09:20 AM PST by Fred Mertz
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To: Dog Gone
The A300 that crashed was not fly by wire (FBW). Some of the secondary surfaces are digital controlled, but the primary controls such as rudder aileron and elevators are not.
60 posted on 11/20/2001 12:34:05 PM PST by Tommyjo
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