Posted on 12/18/2001 7:02:23 PM PST by anniegetyourgun
WASHINGTON (AP) - Two components that help pilots control an airplane didn't work during a preflight check of American Airlines Flight 587, the National Transportation Safety Board reported Tuesday. The plane crashed last month soon after taking off from Kennedy Airport.
The maintenance log reported problems with the pitch trim, which helps keep the nose in an up or down position, and the yaw damper, which uses the rudder to keep an airplane from swaying.
The problem was corrected when a mechanic reset the computers that control the components, according to the log.
Aviation consultant Jim McKenna said safety investigators will focus on those components of the Airbus A300-600. "They'll take a very close look at it," McKenna said.
American Airlines officials did not immediately return calls by The Associated Press Tuesday night.
The NTSB said that the vertical stabilizer - or tail fin - and the attached rudder fell off the plane, as did both engines. The Nov. 12 crash killed all 260 people on board and five on the ground.
Following the accident, the Federal Aviation Administration ordered inspections of the tail, which is made from lighter-weight, nonmetallic composites.
The NTSB is conducting ultrasound and other inspections of the vertical stabilizer and rudder, and is developing a plan for additional tests of the composites.
Maintenance records showed that the vertical stabilizer and rudder last were inspected visually in December 1999, and no problems were reported, the NTSB said.
Board investigators reported that they found no evidence that the engines broke apart, sending shrapnel into nearby control systems, nor any evidence of a collision with a bird. There also was no evidence that there was a fire or a malfunction.
NTSB investigators again reported that they have found no evidence of a terrorist attack. All the evidence continues to indicate that the crash of Flight 587 was an accident, the board said.
Due to a yaw damper or other rudder-related malfunction, the rudder and vertical stabilizer assembly shears off the tail of the plane.
Without this stabilizer, the aircraft enters into a flat spin.
The engines are spooled up to approximately 10,000 rpm (takeoff power) and are basically twin gyroscopes---
---heavy weights at high rpm have tremendous inertia. The plane spins around and the engines don't, they twist off at the attach points and fall off. The result is total loss of control and immediate crash.
Possible alternatives: either sabotage in three different locations on the aircraft,
or a plane so shoddily built that it falls apart in midair.
Are those easier to believe?
I am not an expert on commercial aircraft. I did take a few lessons in a Cesna. The pilot and I inspected just about every part of that plane that moves VISUALLY every time we were flying.
Now that may be difficult to do for a commercial jet, but something so important to the plane and its ability to fly should be checked visually, at least once a week. Two years is just a bit long.
...something so important to the plane and its ability to fly should be checked visually, at least once a week. Two years is just a bit long.
World of difference in a Airframe and Powerplant mechanic and/or Aircraft Inspector's visual inspection as a part of a progressive maintainance program, which Part 121 Scheduled Air Carriers adhere to and frequency of which is spelled out in the Certificate Holders Operating Manuel and the "walk around" visual inspection you and your Flight Instructor performed before each flight.
I assure you that a thorough "walkaround", i.e. Visual Preflight Inspection, is done by one of the aircrewmen, First Officer or Captain (or Flight Engineer if a three man crew)as part of the Preflight or Before Starting Engines Checklist before the first flight of the day. An abbreviated walkaround may be used for subsequent legs, depending again on the conditions set out in the Operators Manuel.
I am just a bit paranoid about flying, even prior to 9/11. Thats why I took a few lessons, to ease the stress when I fly on the big planes. But it is so hard to understand that these planes aren't looked at very closely and more often.
If my t-rod breaks on my car, and I am moving at 40 mph, I will lose control of the car and most likely hit something, but I have a reasonable chance to survive.
There is something VERY final about a plane crash.
This didn't correct any "problem", it only made the computer go stupid. If your "Check engine" dashlight comes on it usually means there is a real problem in your car; if you disconnect the battery and reconnect it, the light will go out but nothing got fixed, and the light won't come back on until the problem recurs.
Fortunately, in your car you don't have so far to fall.
Actually, you probably wouldn't lose control until you came to a stop or tried to change direction dramatically because you would immediately notice a loss of response, and the car, because of its inertia and the fact that virtually all cars have positive caster (like a supermarket cart), the wheel will "trail" until it meets an obstruction.
Now, if you lost a suspension ball-socket joint you would be in for a sparking good ride.
Heff: I am looking at my old logbook and an entry dated 12-30-75 may ease your apprehension. Goes like this:
On this date -- Engine explosion and fire occurred 9 stat. mi. N.E. Stillwater (Oklahoma) airport, Altitude 2700 MSL, 1700 AGL, Oil covered windshield, A/C was slipped into unimproved field. Minor damage to RT Main and Nose Gear, RT tip tank ruptured, Flaps jammed. Incident reported to Oklahoma Highway Patrol and FAA. Pilot sustained no injuries....
Logbook entries are cryptic to say the least, and the between-the-lines inferences must be taken into consideration.
I was attempting to fly a PA-32-300 Piper Cherokee Six, a load hauling single-engine airplane used by the just-barely-getting-by airtaxi operation I was employed by, on a ferry flight back home from a AOG (aircraft on ground) incident inherited from my cowardly employer two weeks before.
The crankshaft in that big ol' Lycoming snapped, blowing off two jugs (cylinders), rupturing the top and bottom of the crankcase thereby providing a route for the engine oil to migrate to 100% obscure the windshield on top, and blow fire into and rupture the oil sump at the bottom.
Burning oil eminating from that oil sump, adhering to the bottom of the aircraft structure, and propagating to the tail of the aircraft where it flings itself off into the slipstream as a huge fourteen foot long incendiary banner, is a very uncommon and noticeable phenomenon to people on the ground, I can tell you.
Trying to bring a burning, suddenly unpowered flight to any sort of positive conclusion over the piney woods and rock strewn flint hills of northern Oklahoma can raise a pilots pucker factor to heights here-to-fore unimagined.
"OK... Just coming up on Stillwater VOR, check guages...all in the green, outbound course set at 026 degrees, turn on course, continue climb, scan right to left for traff.....'Whathehellwuzat?'
"Oh sheeeit.....Can't see... D**m oil...'FLY THE AIRPLANE' ...best glide speed...turn downwind...which way wuz that wind blowin, oh I took off to the North...go to 121.5 mhz (already set up on no.2 radio) to holler...
'MAYDAY! MAYDAY! MAYDAY!' for no one to hear...Izzat smoke I smell? Woah...Floor under the rudder pedels is gettin' HOT! Gotta get this mother on the ground...
Still can't see out the front...lemme open the storm window...Hey, there's a field! Not a big field, and it's surrounded by trees and power lines, and there's a tree, and ditch, and small hill in it, but it's a field!
D**m! It's getting hot in here. OK ...Full flaps, stand on top rudder and 90 degree bank to line up and slip the fire away from me...and the fuel line...Airspeed too high, over the fence 75 feet high, 150 kts airspeed...too fast...too fast...too high...running out of room...gonna buy it...not gonna burn...stick it in the ground if this don't work...wings level...gotta get down...STALL IT -- NOW!...
When I tell this story, I usually stop at this point...and the listener breathlessly prompts with "and...and?" to which I respond ..."and WHAT?", which, nine times out of ten, elicits a resounding "WHUT HAPPENED?"
To which I can earnestly reply "I got KILT, ya dern fool!"
But I DIDN'T: And I learned a lesson about life and airplanes and fear. I pass this on to you in hopes that you'll learn the same lesson without having to emulate my experience. Flying is still the safest mode of transportation known to man, and if the good Lord wants ya, He'll take ya, and it doesn't do a bit of good to worry about it.
Happy flying ;O)
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