"[21] ATC then tried to contact the plane. Alaska Airlines' extension of its lubrication interval for its McDonnell Douglas MD-80 horizontal stabilizer components, and the FAA's approval of that extension, the last of which was based on McDonnell Douglas's extension of the recommended lubrication interval, increased the likelihood that a missed or inadequate lubrication would result in the near complete deterioration of the jackscrew-assembly acme-nut threads, and therefore, was a direct cause of the excessive wear and contributed to the Alaska Airlines Flight 261 accident; Alaska Airlines's extended end-play check interval and the FAA's approval of that extension, allowed the acme-nut threads to deteriorate to the point of failure without the opportunity for detection; The absence on the McDonnell Douglas MD-80 of a fail-safe mechanism to prevent the catastrophic effects of total acme nut loss. Shortly after the accident, Liotine discovered that the jackscrew nut he had inspected in 1997 was not in fact replaced and had actually gone on to cause the crash. [44][45], As of May 2022, Flight 261 no longer exists, and Alaska Airlines no longer operates the Puerto VallartaSan FranciscoSeattle/Tacoma route. A chunk of the vertical fin was brought up next. The accident served as an inspiration for the fictionalized crash landing depicted in the 2012 movie Flight starring Denzel Washington. Eventually, this gap increases as the acme nut threads wear. In addition to the probable cause, the NTSB found these contributing factors:[6] The result was a chronic problem of Alaska Airlines MD-80s with poorly greased jackscrews. alaska airlines flight 261 pilot drunk. Still, the pilots did not give up; Thompson thought it might be possible to roll out right-side-up using the rudder. [29] In December 2001, federal prosecutors stated that they were not going to file criminal charges against Alaska Airlines. Alaska Airlines Flight 261 - Crash Animation - YouTube Alaska Airlines Flight 261 - Crash Animation,if you liked the video, please subscribe and turn on notifications - I. With the stabilizer angled 3.1 degrees toward nose down, more than the design maximum of 2.5 degrees, flight 261 immediately entered a high-speed dive, hurtling downward at more than 6,000 feet per minute. The free-swinging stabilizer rotated up past its stop, slamming back against the aerodynamic fairing that encased the tail. But then, nine minutes from the time they recovered from that frightful dive, I heard a sound of extremely loud noise as it was described in the CVR transcript. In July 1996, the criteria was changed to 8 calendar months which equated to 2,550 flight hours. (Alaska specifically did this every 30 months, or 9,550 flight hours.) The NTSB believed that this was inappropriate because each airline operates their airplanes under unique circumstances that require unique FAA oversight and data justification regardless of the manufacturers recommended intervals. The jackscrew requires an inspection procedure known as the end play check to monitor the wear of the acme nut threads without having to remove the jackscrew assembly from the airplane. But airline dispatchers in Seattle were less keen on this idea and preferred that flight 261 continue to San Francisco as scheduled. However, the pilots were clearly under pressure to continue on to San Francisco, and maintenance technicians and dispatchers on the ground did not appreciate the direness of the situation. It broke off nine minutes later, allowing the jackscrew and its attached stabilizer to slide up and out of the acme nut causing the fatal dive. The airplane immediately began another dive except this time it did not recover. Holy shit, said Thompson, pulling back hard on the controls. However, the plane ran into a streak of at least two or three grease applications that were not done correctly, including one in September 1999 by a notorious San Francisco-based mechanic who was later found to have applied virtually no grease to any of the jackscrews he worked on. I dont anticipate any big problems once we get a couple of sub systems on the line. The 88 passengers and crew members aboard Alaska Airlines Flight 261, which crashed off the coast of Ventura County on Jan. 31, 2000, will not soon be forgotten. By torqueing the screw up and down without turning it, and measuring the amount of play in the system, it was possible to roughly determine the depth of the wear on the nut threads, which the manufacturers guidelines stated must be less than one millimeter. Finally, the stabilizer was to be moved repeatedly between full nose up and full nose down so that the nut could spread the grease evenly over the entire jackscrew. The tests also simulated the acme nut wear process by using blocks milled from a scrap acme nut and rings turned from a jackscrew forging. Based on the airlines utilization rate at that time, this equated to 6,400 flight hours between inspections. Having decided not to touch the trim system anymore, the crew now performed some final tests of the airplanes low speed handling. It was found that the use of Aeroshell 33 was not a factor in this accident. The criminal investigation also proved to be a disappointment. On board the stricken MD-83, the pilots managed to slow the dive somewhat, pulling up from 70 degrees nose down to 28 degrees, but the plane remained inverted, falling upside down toward the rapidly approaching ocean at a high rate of speed. [6][24], The later analysis estimated that 90% of the thread in the acme nut had already worn away previously and that it had finally stripped out during the flight while en route to San Francisco. By this point the amount of force he needed to apply to the control column to keep the nose level was pushing him to the limit of his physical ability. Lets do that. Thompson attempted to move the stabilizer trim using either the electrical switches, the trim handles, or both, in an effort to clear the jam. The original interval was set at every other C-check or 5,000 flight hours. Different speeds and phases of flight require the stabilizer to apply varying amounts of downforce on the tail in order to keep the plane level, and further adjustments must be made to ensure that the pilots dont have to continuously pull up or push down using the elevators in order to climb or descend. Yeah, we are out of 26,000 feet, we are in a vertical dive not a dive yet, but uh, weve lost vertical control of our airplane., However, slowly but surely, Thompson and Tansky started to rein in their excessive speed and flatten out the slope of the dive. Investigators later uncovered a critical maintenance issue with the aircraft, which meant that even after the flight crew deployed the speed brakes and control surfaces on the wings, they still could not stop the tragic crash.Join aviation engineers and experts to uncover the reasons behind some of the worlds most unforgettable plane crashes. Another reported, "Yes sir, ah, I concur. Like the end play check intervals, Alaska Airlines received FAA permission to extend their jackscrew lubrication intervals four times from 1987 to 1996 with no supporting data. The tangled remnants of the threads from the nut remained wrapped around the jackscrew, wordlessly telling the story of how the stabilizer failed. Instead we photographed a coiled piece of thin bronze metal wrapped around the jackscrew that looked like a slinky (see image 4). Sometime before 15:49 (23:49 UTC), the flight crew contacted the airline's dispatch and maintenance-control facilities in SeaTac, Washington, on a company radio frequency shared with operations and maintenance facilities at Los Angeles International Airport (LAX), to discuss a jammed horizontal stabilizer and a possible diversion to LAX. At this contact, the ring slowly wore a divot into the surface of the block. This Episode we take a look at a very preventable accident from January 2000, where an Alaska Airlines MD-80 lost all control of a vital mechanism used in ba. On the 31st of January 2000, an Alaska Airlines MD-83 bound for San Francisco suddenly plunged from the sky off the coast of California, spiraling downward until it slammed into the Pacific Ocean. I think the stab trim thing is broke, said Thompson. Liotine began working with federal investigators by secretly audio recording his supervisors. PORT HUENEME, Calif. (KABC) -- Tuesday marked the 23rd anniversary of the Alaska Airlines disaster off Port Hueneme in Ventura County. Push and roll! The investigation found that Alaska Airlines had fabricated tools to be used in the end-play check that did not meet the manufacturer's requirements. Are we flying? he said. Yes sir, he he hit the water, said the SkyWest pilot, his voice nearly cracking. The basis for the approval of the design under this rule was the fact that the nut has two independent threads that did not link with one another, such that if one thread failed, the other could still hold the jackscrew in place. The NTSB Maintenance Group and my group examined the accident airplanes records and found that two years earlier, a lead mechanic at the airlines Oakland maintenance facility had found that the jackscrew end play was worn to its maximum limit of 0.040 inch. Kyra Dempsey, analyzer of plane crashes. Brand new season of Air Crash Investigation, Mondays at 8pm, only on National Geographic UK The UK home of National Geographic. The jackscrew was constructed from case-hardened steel and is 22in (56cm) long and 1.5in (3.8cm) in diameter. The excessive and accelerated wear of the accident jackscrew assembly acme nut threads was the result of insufficient lubrication, which was directly causal to the Alaska Airlines flight 261 . On January 31st, 2000, Alaska Airlines Flight 261 suddenly nosedived into the Pacific Ocean and the crash had deadly implications. Had it been inspected after 7,200 flight hours instead of 9,550, the excessive wear would have been discovered before the crash. It really wants to pitch down., Alaska two six one, said the controller, Say your condition?, Two six one, we are at 24,000 feet, kinda stabilized, said Thompson. But over the next two decades, Alaska Airlines pursued an aggressive strategy of expansion, aiming to become an affordable option for travelers throughout the Western United States. As Fred Miller, father of crash victim Abby Miller-Busche, put it in a 2003 interview, It seems like such an unholy type of loss. It went down, it went to full nose down.. On January 31st, 2000, Alaska Airlines Flight 261 suddenly nosedived into the Pacific Ocean and the crash had deadly implications. With the jackscrew completely separated from the nut, aerodynamic forces acting on the stabilizer pushed it up beyond the normal full nose down position, halting only when the mechanical stop on the bottom of the jackscrew slammed into the nut. [38] Many residents of Seattle had been deeply affected by the disaster. Refresh the page, check. The following is a list of some of the victims of Alaska Airlines Flight 261. After a three-year investigation by civil rights attorneys in Metairie the accident was attributed mostly to maintenance deficiencies that began during a C-check at the airlines heavy maintenance facility in Oakland, California. And while the airline did eventually settle the suits, it did so only after dragging the families through what many described as a legal hell in which Alaskas lawyers tried to downplay the monetary value of their deceased loved ones. Push and roll! Thompson shouted, trying to coordinate with Tansky to roll the plane right-side-up. In 1996, Alaska Airlines applied to the FAA to extend the interval between its C-checks from 13 months to 15 months. However, the procedures available to them did not state that this was necessary, which doubtlessly contributed to their decision to continue on. After the crash, we discovered that the work order had not been acted upon because a second inspection team had rechecked five times and found endplay to be within limits at .033.. Im thinking, can it get any worse, but it probably can, he continued. The entire horizontal stabilizer assembly was now attached to the airplane only by the rear hinge. In August 1999, Alaska Airlines put Liotine on paid leave,[28] and in 2000, Liotine filed a libel suit against the airline. If they lost control again, he didnt want to endanger people on the ground. [6], A periodic maintenance inspection called an "end-play check" was used to monitor wear on the jackscrew assembly. Performing an upset recovery maneuver, the captain commanded to "push and roll, push and roll," managing to increase the pitch to -28 degrees, he stated, "ok, we are invertedand now we gotta get it. When the stabilizer moves upward, downforce on the tail decreases, and the nose pitches down; similarly, when the stabilizer moves downward, downforce increases, and the nose pitches up. Finally, the Safety Board also felt that there were lessons to be learned from the actions of the pilots. Once the thread had failed, the horizontal stabilizer assembly was subjected to aerodynamic forces that it was not designed to withstand, leading to the complete failure of the overstressed stabilizer assembly. The acme nut was still attached but its threads were missing! You heard it in the back? Tansky asked. The flight was a scheduled international passenger flight from Licenciado Gustavo Daz Ordaz International Airport in Puerto Vallarta, Jalisco, Mexico, to SeattleTacoma International Airport near Seattle, Washington, United States, with an intermediate stop at San Francisco International Airport near San Francisco, California. The Safety Board found that this unsafe inspection interval was only approved indirectly by the FAA. [6]:188189, After the crash, Alaska Airlines management said that it hoped to handle the aftermath in a manner similar to that conducted by Swissair after the Swissair Flight 111 accident. [41] The City of Seattle public park Soundview Terrace was renovated in honor of the four Pearson and six Clemetson family members who were killed on board Flight 261 from the same Seattle neighborhood of Queen Anne. And because of the increased interval between applications of new grease, a jackscrew with insufficient grease couldnt expect to see more until the plane had been in the air for another 2,250 hours. The CEO of Alaska Airlines, Brad Tilden, joined them and read a public apology to the families on behalf of the airline. [43], The crash has appeared in various advance fee fraud ("419") email scams, in which a scammer uses the name of someone who died in the crash to lure unsuspecting victims into sending money to the scammer by claiming the crash victim left huge amounts of unclaimed funds in a foreign bank account. The eight-year-old McDonnell Douglas MD-83, registered as N963AS, outwardly seemed to be in good shape. But neither of the applicable checklists said anything about landing at the nearest available airport, and by the time they finished the checklists and leveled off at 31,000 feet, minimal effort was required to keep the plane flying level. [8][9], The five crew members and 47 of the passengers on board the plane were bound for Seattle. At this time, pilots from aircraft flying in the vicinity reported in, with one pilot saying, "and he's just hit the water." An FAA inspector who reviewed the 1996 extension said that the airline presented only Boeings recently extended lube interval as justification. The pilots pulled back as hard as they could on their control columns and deployed the flaps to try and slow down, but their efforts were utterly hopeless. Flight 261 was on its way from Puerto Vallarta to San Francisco when a mechanical failure caused it to plunge into the ocean, killing all 88 people on board. The actual protocol at Alaska Airlines was to inspect the jackscrew for wear at every second C-check, a comprehensive multi-day inspection that every airplane undergoes approximately once a year. Both pilots struggled together to regain control of the aircraft, and only by pulling with 130 to 140 lb (580 to 620 N) on the controls did the flight crew stop the 6,000ft/min (1,800m/min) descent of the aircraft and stabilize the MD-83 at roughly 24,400ft (7,400m). All passengers were identified using fingerprints, dental records, tattoos, personal items, and anthropological examination. And therein lay the problem: throughout the period leading up to the crash, Alaska Airlines slowly removed all the procedural layers of redundancy which were designed to prevent the jackscrew from deteriorating to the point of failure. Increasing the interval between lubrications meant that every lubrication had to be done correctly in order to prevent accelerated wear and tear. The metal from which the jackscrew is made is ever so slightly harder than the metal used in the nut. It looks like hes turning hes turning over in front of you now, said the controller. He is, uh, definitely in a nose down, uh, position, descending quite rapidly. We did both the pickle switches and the suitcase handles, he told the maintenance technician, and it ran away full nose trim down., And now were in a pinch, Thompson continued, so were holding, uh, were worse than we were.. The airline extended numerous maintenance intervals, while simultaneously skimping on personnel and training. Hands clenching my headphones, I listened to the crew talk among themselves, with airline dispatch and to air traffic controllers in an attempt to keep the airplane kinda stabilized as they put it. The stabilizer is attached to a giant threaded screw, called the jackscrew, which feeds through a nut attached to the aircraft structure inside the tail. This past January, to honor the victims of flight 261 on its 20th anniversary, hundreds of family members, friends and loved ones came together in Ventura around the Memorial Sundial constructed after the crash. [5] Captain Theodore "Ted" Thompson, 53, had accrued 17,750 flight hours, and had more than 4,000 hours experience flying MD-80s. [6], Due to the extreme impact forces, only a few bodies were found intact,[5] and none were visually identifiable. Furthermore, the pilots were reluctant to believe that the failure was mechanical, rather than electrical, in nature. A flight attendant opened the cockpit door, and Captain Thompson briefed her on the situation. As they struggled to regain control, Thompson radioed Los Angeles and said, Center, Alaska two six one, we are in a dive here, and Ive lost control, vertical pitch! An overspeed warning blared in the cockpit. Also included was a recommendation that pilots were to be instructed that in the event of a flight control system malfunction, they should not attempt corrective procedures beyond those specified in the checklist procedures, and in particular, in the event of a horizontal stabilizer trim control system malfunction, the primary and alternate trim motors should not be activated, and if unable to correct the problem through the checklists, they should land at the nearest suitable airport.[6]. As a result, the horizontal stabilizer failed at 17,800 feet (5,400m)[6]:6 and the aircraft rapidly pitched over into a dive while rolling to the left. Flight 261 was traveling from Puerto Vallarta to San Francisco on Jan. 31, 2000 when a mechanical malfunction inverted the jet and sent it downward off the Ventura County coast. Laboratory tests indicated that the excessive wear of the jackscrew assembly could not have accumulated in just the four-month period between the September 1999 maintenance and the accident flight. On January 31, 2000, the aircraft operating the route, a McDonnell Douglas MD-83 . Stepping on the rudder pedals while upside down was no easy task. [6]:195197, At 16:09 (00:09 UTC), the flight crew successfully used the primary trim system to unjam the stuck horizontal stabilizer. In July 1988, the airline no longer used a flight hour limit rather it based C-checks on calendar time only so that the end play check was being performed every 26 months. As a result, Alaska Airlines slowly increased the interval between jackscrew lubrications from 500 flight hours in 1987 to every eight months (approximately 2,250 flight hours) in 1999. The flight originated in Puerto Vallarta, Mexico, and was bound for Seattle with an intermediate stop in San Francisco. Folks, we have had a flight-control problem up front here, first officer Ted Thompson told the passengers over the PA system. On board flight 261, Captain Thompson vented to First Officer Tansky: Drives me nuts, he said. I think its at the stop, full stop, said Thompson. [6]:9 The crippled plane had been given a block altitude,[20] and several aircraft in the vicinity had been alerted by ATC to maintain visual contact with the stricken jet. [6], A special inspection conducted by the NTSB in April 2000 of Alaska Airlines uncovered widespread significant deficiencies that "the FAA should have uncovered earlier". Were pretty busy up here working this situation. Instead it went the other way., What do you think. In September of 1997, maintenance workers in Oakland performed the aforementioned test on N963AS and found a wear depth of exactly one millimeter. In hindsight, the crew should have turned around and immediately landed back in Puerto Vallarta. While the CVR captured only the last half-hour of the flight, the flight data recorder (FDR) had hundreds of parameters from the entire flight. Flying Inverted | Cutting Corners | Alaska Airlines Flight 261 | 4K TheFlightChannel 1.43M subscribers 1.7M views 4 years ago Find out why this Alaska Airlines MD-83 crashed into the. We also noted that accessing the area for the lubrication was unwieldy, especially on a tail stand at night (images 10 & 11). It began life as a regional airline in Alaska, and by the time deregulation arrived in the late 1970s, it only had one destination in the lower 48 states. [6]:9[21], The CVR transcript reveals the pilots' constant attempts for the duration of the dive to regain control of the aircraft. [15], Alaska Airlines Flight 261 departed from Puerto Vallarta's Licenciado Gustavo Daz Ordaz International Airport at 13:37 PST (21:37 UTC), and climbed to its intended cruising altitude of flight level310 (31,000 feet or 9,400m). But maintenance, poorly done, will find a way to bite somewhere else. Just before plunging into the Pacific Ocean, the crew of Alaska Airlines Flight 261 flew upside down while desperately trying to regain control of the passenger jet, investigators confirmed Thursday. Uh, its a lot worse than it was? Tansky asked. Many workers who greased jackscrews didnt apply additional grease to the screw itself after greasing the nut. Kick! he shouted. By 2000, Alaska Airlines only inspected the wear on the jackscrew nut every 30 months, equivalent to 9,550 flight hours, whereas the manufacturer recommended an interval no larger than 7,200 flight hours. [7] Three Seattle-based flight attendants were also on board, completing the five-person crew. The stab trim, I think.. That was the last time anyone ever measured the wear on the jackscrew nut on N963AS. All rights reserved. Repeated attempts to overcome the jam with the primary and alternate trim systems were unsuccessful. Those who lost loved ones when Alaska Airlines Flight 261 plunged into the Pacific Ocean off California have learned some hard, bitter truths in the 10 years since the crash. It aggressively took action to improve itself by hiring a new vice president (VP) of safety who reported directly to the CEO, filling executive vacancies in safety and maintenance, creating a large safety office, hiring 130 new mechanics, revising its general maintenance manual and reviewing every C-check aircraft in the fleet to ensure that all work was properly performed. Another reported, "Ah, yes sir, he, ah, he, ah, hit the water. The US aviation industry has nevertheless managed to go a long time without another major crash, but as for whether something like Alaska 261 could happen again well, never say never. Then, additional grease was to be applied to the entire length of the screw, filling all the threads. But the mechanism by which Alaska Airlines fell to such a dismal level of safety is not entirely gone. [39] Students and faculty at the John Hay Elementary School in Queen Anne, Seattle, held a memorial for four Hay students who were killed in the crash. Upon being freed, however, it quickly moved to an extreme "nose-down" position, forcing the aircraft into an almost vertical nosedive. What I want to do is get the nose up, and then let the nose fall through and see if we can stab it when its unloaded. It was his belief that the stabilizer might move nose up if there was no aerodynamic force pushing it upward into the nose down position. labelle foundation puppy mill how long did whip whitaker go to jail First, pressurized grease was to be injected into a special tube on the nut until it filled all the thread gaps between the nut and the jackscrew and started to bulge out the top. But when we slowed down lets slow it, lets get it down to two hundred knots and see what happens., Now Thompson and Tansky slowed down and deployed the flaps and slats, simulating a landing configuration, to make sure the plane would be controllable on final approach. The plane was scheduled to land at San Francisco International Airport (SFO). 43:44. The investigation uncovered a daunting list of operational problems and regulatory mistakes that led to the crash. "These are reminders that we should keep telling people that we love them, and let them know how we feel because you never know what's going to happen," he said.
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