Tape sheds no light on cause of crash
Seattle Times aerospace reporter
WASHINGTON - Amid a sea of calm voices and routine radio chatter Jan. 31, tense words crackled over a Los Angeles-area air-traffic-control frequency:
"Center, Alaska 261. We are, uh, in a dive here."
"Alaska 261, uh, say again?" asked the controller.
"Yeah, we're out of 26,000 feet, we're in a vertical dive - not a dive yet - but, uh, we've lost vertical control of our airplane," the unidentified pilot reported with a tense and shaky voice.
"Alaska 261, roger," replied the controller, who was in the radar room at the regional air-traffic center in Palmdale, Calif.
"We're at 23-seven (23,700 feet), request, uh - yeah, we've got it back under control there," the pilot continued.
Then, in the background, the other pilot was heard to say, "No we don't."
So began an 11-minute drama that ended with an upside-down plunge into the Pacific Ocean of Alaska Airlines Flight 261, the Boeing MD-83 that was carrying travelers from Puerto Vallarta, Mexico, to San Francisco and Seattle. All 88 people aboard were killed.
Without comment, the Federal Aviation Administration yesterday played tapes of air-traffic-control conversations and issued a transcript, which it does routinely after major air crashes. The material becomes part of a voluminous docket of material the National Transportation Safety Board (NTSB) will use to determine causes of the crash.
The radio conversations shed no light on the apparent malfunction of a mechanism called the jackscrew - the prime suspect and focus of investigators' attention. But the human drama documented on the tapes, only alluded to previously in press briefings, conveys the hopelessness of the plane's predicament.
No indication of trouble
The plane was flying north off the coast of California at 31,000 feet. As it passed by Los Angeles, the crew talked with several controllers because airspace is divided geographically and by altitude.
It was late afternoon. The sky was clear, and the air was smooth. Until the first report of the dive, at about 4:10, there was no indication over the radio of trouble.
But from listening to another tape, that of the cockpit voice recorder, investigators know the pilots had been working on a problem involving the tilt of the horizontal stabilizer, the wing-like device on the tail that helps direct the plane's angle of flight. A transcript of that tape will be released later.
The crew also was conversing with maintenance personnel in Seattle and Los Angeles, using a separate radio frequency. A tape recording and transcript of those conversations, made by Alaska Airlines and given to the NTSB, have not been released.
On the air-traffic-control tapes played at FAA headquarters yesterday, relatively little is heard from Capt. Ted Thompson, 53, and First Officer William Tansky, 57. They clearly were busy dealing with the emergency. But few words were necessary to convey the gravity of their situation.
After their initial report of trouble, the voice of Flight 261 was calm but serious.
"(This is) 261, we're at 24,000 feet, kind of stabilized," said the pilot a minute after the dive. "We're slowing here and, uh, we're gonna, uh, do a little troubleshooting. We'll - can you give me a block (of cleared altitude) between, uh, 20 and 25 (thousand feet)?"
The controller complied.
"Alaska 261, we'll take that block," the crew confirmed. "We'll be monitoring the frequency."
`Still working it'
For a few minutes, the controller directed other planes, then said: "Alaska 261, uh, let me know if you need anything."
"We're still working it," came the reply.
A few seconds later, the crew was directed to contact a different controller, in the same radar room but overseeing adjacent airspace, on a different radio frequency.
"They're aware of your situation," the first controller said.
"L.A., Alaska 261," the crew radioed the new controller. "We're with you. . . . We have a jammed stabilizer, and we're maintaining altitude with difficulty, but, uh, we can maintain altitude, we think, and our intention is to land in Los Angeles."
"Alaska 261, L.A. Center, roger. Uh, you're cleared to Los Angeles airport . . ."
A few seconds later: "Center, Alaska 261. I need to, uh, get down (to) about 10 (thousand), change my configuration, make sure I can control the jet, and I'd like to do that out here over the bay, if I may."
The controller told the plane to fly west and descend to 17,000 feet.
The controller then asked Flight 261 to switch radio frequencies again, this time because the plane would be descending into airspace overseen by a different controller: "Contact L.A. Center on 135.5 (MHz) and they'll have further instructions for you, sir."
" 'Kay, 35-five. Say the altimeter setting," the pilot said, referring to the barometric pressure reading necessary to calibrate accurate altitude readings.
"The L.A. altimeter is 30.18," the controller replied.
"Thank you," the pilot replied. It was 4:17, and that was the last anyone heard from the plane.
Controllers handed plane off
Behind the scenes at L.A. Center in Palmdale, the controller who was "handing off" Flight 261 told someone assisting the next controller, "He wants a block altitude. He cannot - he's not guaranteeing he can stop (descending) at all."
The next controller, awaiting contact from Flight 261 on his frequency, warned another plane of the descending MD-83. That plane was a privately owned twin-engine turboprop called an Aero Commander.
"Commander Zero Delta X-Ray," the controller said, referring to the smaller plane's tail number, "traffic at, uh, 1 o'clock . . . .Do you see him up there high, ahead and to your right?"
While the pilot of the Aero Commander looked to see the descending jetliner, the controller, who should have heard from Flight 261 by now, tried to contact him: "Uh, Alaska 261, you over here with me yet, sir?" No answer.
"L.A., Delta X-Ray. We do have the airplane (in sight), quite high and up at 1 o'clock."
"Zero Delta X-Ray, roger, just kind of keep your eye on him. He's having some pretty bad problems up there right now."
The controller also brought the crippled Alaska MD-83 to the attention of another plane, SkyWest Flight 5154.
While the SkyWest pilot was looking to spot Flight 261, the Aero Commander pilot had stunning news: "That plane has just started to do a big, huge plunge."
The controller asked the SkyWest pilot what he could see.
"Yes sir, I concur, he is, uh, definitely in a nose-down position, descending quite rapidly," the SkyWest pilot replied.
"OK, very good, keep your eye on him," the controller said. "Alaska 261, are you here with us yet, sir?"
No reply. The controller gave instructions to two other planes, then the Aero Commander pilot came on:
"Plane's inverted, sir."
"OK, very good, it looks like he's turning, uh, turning over in front of you now SkyWest 5154. You still got your eyes on him, sir?"
"He's in sight. He, uh, is definitely out of control," the SkyWest pilot said. "He's inverted."
"He's - OK," the controller said with resignation. "Just, uh, do what you need to do there, SkyWest 5154. Keep us advised."
The Aero Commander was the first to report the crash.
"He's just hit the water," he said.
Plunge was unexpected
Because the crew had gained some control of the plane, Flight 261's final plunge, from 17,900 feet, was unexpected. Investigators have said the crew extended the wing flaps, apparently to see how the plane would handle at slower speeds in preparation for landing. They retracted them and extended them again, at which time they lost control.
The jackscrew assembly in the tail fin, a device that tilts the horizontal stabilizer, is suspected of causing the crash. It had jammed in a position that made the plane's nose tend to drop, and some investigators speculate that the hinged stabilizer came loose entirely, popping up from the jackscrew assembly at a dangerous angle, sending the plane out of control.
The threads of a large nut were found stripped and wrapped around the jackscrew in the wreckage, which was recovered from about 700 feet of water 10 miles off Oxnard, Calif.
Maintenance and lubrication of the jackscrew is the focus of investigations by the NTSB, which will use its findings to make safety recommendations, and by a grand jury aided by the FBI and Department of Transportation. The grand jury could charge Alaska or its maintenance workers with criminal negligence.
Chuck Taylor's phone-message number is 206-464-2465. His e-mail address is firstname.lastname@example.org.
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