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Lessons Learnt from the Crash of Eastern 401
The crash of Eastern Air Lines Flight 401 41 years ago Sunday, the first crash of a widebody aircraft and, at the time, the second deadliest single-aircraft disaster in the U.S., led to wide-ranging changes in on board safety that continue to positively affect air travel today. The four-month-old L-1011 TriStar jet crashed into the Florida Everglades on December 29, 1972 at 11:42 p.m., caused 101 fatalities and there were 75 survivors.... (www.frequentbusinesstraveler.com) Más...Sort type: [Top] [Newest]
"Learnt" ??? Learned is more correct, please.
The L1011 auto pilot did have a wailer sound with auto pilot disconnect and it was loud. However, if a pilot moved the yoke above 15 to 25 lbs breakout force (airline option)in the CMD mode, the autopilot shifted to the CWS mode (still autopilot on) and the wailer doesn't make any sound. The only time there would be a wailer would be if the bat handle was placed in the off position or it was disengaged by actuation of autopilot disconnect switch on either control wheel. If there was a altitude hold setting and the altitude changed during the yoke movement the C-Chord sound goes off. This was heard on the tape. Certainly investigators wondered why the crew didn't react to the C-Chord sound.
The L1011 autopilot was a marvelous system and was the first US aircraft to be certified for Cat 111a approaches. However, one thing that was very unusual was there were over 15 cockpit audio warning sounds and that is pretty much of an overload and may be one of the reasons pilots were insensitive to some audio warning sounds. None of this is stated to minimize the pilots lack of situational awareness. Just wanted to add some real facts about a very complex autopilot system.
The L1011 autopilot was a marvelous system and was the first US aircraft to be certified for Cat 111a approaches. However, one thing that was very unusual was there were over 15 cockpit audio warning sounds and that is pretty much of an overload and may be one of the reasons pilots were insensitive to some audio warning sounds. None of this is stated to minimize the pilots lack of situational awareness. Just wanted to add some real facts about a very complex autopilot system.
Obviously this crew as well as that of the United DC-8 that crashed in Seattle in Dec. 1978 and several other ones simply forgot one of the very first lessons drilled by every CFI at the beginning of a PPL course: AVIATE, NAVIGATE AND COMMUNICATE.
Obviously this crew as well as the
I believe R. Schneberger has the correct analysis of the autopilot disconnect scenario. Some others added comments about the breakout forces on the yoke. In the CMD mode the breakout force in most L1011's was 25 lbs (Eastern L1011 was less as I remember). In the CWS mode the pitch force was 4 lbs. and the roll force was 3 lbs. As others have stated there was missing Cockpit Resource Management.
M. Walsh says he never blames any pilot involved in an accident. He may never have read an NTSB report!
M. Walsh says he never blames any pilot involved in an accident. He may never have read an NTSB report!
Hi folks. It has become apparent, more so in the new millennium than previously, that automation is not the perfect solution. It is imperative for modern pilots to become cockpit systems managers. I fly single-pilot business jets, where full autopilot systems are mandatory, but it is the pilot's responsibility to manage the systems effectively, and when in doubt, to override and take control of the aircraft. I personally hand-fly the aircraft on departures and approaches to keep my hand in, and try to remain vigilant when Otto is flying. Automation is designed to simplify our lives, not replace us. I don't blame any pilot involved in an accident, as one cannot merely pontificate on the severity of the stresses encountered. I've had my fair share of highly stressful situations, where automation becomes ones best friend. But it means being aware that it is a manageable system designed to aid the pilot, and reduce the workload. I'm pretty sure that in the 70's the mentality might have been completely different. Sure, the systems weren't perfect then, and still are not, despite the myriad lessons learned. My point is that pilots are not replaceable by computers just yet, so be vigilant.