Howdy, Stranger!

It looks like you're new here. If you want to get involved, click one of these buttons!

In this Discussion

Here's a statement of the obvious: The opinions expressed here are those of the participants, not those of the Mutual Fund Observer. We cannot vouch for the accuracy or appropriateness of any of it, though we do encourage civility and good humor.

    Support MFO

  • Donate through PayPal

5/18/22: Latest Update on the China 737 Crash

edited May 18 in Off-Topic
To this point, aircraft parts have been found scattered over a 6-mile distance. To me, this suggests that the 737, which had been cruising at 29,000 ft, broke up in midair with parts falling over a wide distance. Additionally, the reports so far indicate that the descent was virtually an immediate straight-down descent, with some sort of momentary partial recovery several thousand feet from the ground, followed by a resumption of the vertical descent. If that is accurate, to me it would suggest that the wings were still attached to the aircraft at the point of the momentary recovery, and that the pilots had at least some type of partial control, at least for a short time.

If the above is true, then pilot error as a cause would almost certainly be eliminated.

Aircraft incidents of this nature are generally caused by either catastrophic failure of a major aircraft component, or by an on-board explosion of some type. A possible scenario could be a catastrophic failure of one engine, damaging either the wing or some other vital aircraft components. However, given the long and excellent performance of this 737-800 model, and the fact that this aircraft was only some five years old, that scenario may be questionable. The engine maintenance history will be of extreme importance in considering the situation.

I would be inclined to consider the explosion scenario. If that should prove to be the case, it will be very interesting to see how forthcoming the Chinese air authorities prove to be with respect to accurate information.

One flight recorder, believed to be the cockpit audio recorder, has been recovered.

Comments

  • Hi OJ.
    You may have already seem this video.

    17 second video of straight down....

    Scroll down the page a bit, to the video in the Twitter post. You may increase the image page size with the expansion arrows.
  • Thanks, Catch- I hadn't seen that. My thoughts on this are not too far out of line with that page.
  • edited March 24
    @Old_Joe, You read my mind. I had considered sending you a personal query. I agree with your summation. But I’m puzzled by something I just read of the incident:

    “It is very likely that the aircraft lost power at cruising altitude, resulting in the pilot losing control of the aircraft,” Wang Ya’nan, chief editor of Beijing-based Aerospace Knowledge, told China’s Global Times. “This is a very serious technical failure in which the plane inevitably enters a high-speed descent.”

    From your knowledge of aviation, does a 737 loosing power at cruise altitude have to plummet to the ground? Assuming they still have hydraulics and the structure is fully intact would it not be possible to maintain a degree of stable flight?

    It may be a mute point if over mountainous terrain with no place to ditch or make a crash landing - but it still seems to me there’d be some degree of control. And yes, some reports have the plane regaining about 1,000 feet of altitude on the way down - also puzzling.

    My first thought was of a passenger carrying 727 over Flint MI in the 70s or 80s which did stall out (aerodynamic stall - not power failure) above 30,000 feet and plunged nearly all the way to the ground. The pilots had exceed the altitude at which the plane was certified to fly in an attempt to make better time. Apparently they saved the flight by lowering the landing gear at low altitude to slow the decent, stabilized the aircraft, and flew on to DTW where they made an emergency landing with significant structural damage, ISTM the 727’s configuration probably made it a difficult one to operate under such duress.

    My first guess in this case is some type of human malfeasance - either external or possibly crew related.
  • "From your knowledge of aviation, does a 737 loosing power at cruise altitude have to plummet to the ground? Assuming they still have hydraulics and the structure is fully intact would it not be possible to maintain a degree of stable flight? "

    Absolutely. Assuming a complete loss of power, that aircraft, like almost every other, will continue to glide for quite a distance. Any pilot would handle the aircraft so as to maximize the glide distance. As long as the aircraft can maintain a speed that's above the stall speed for that particular aircraft it will continue to glide. Once the speed falls below the stall speed though things get very bad very quickly.

    Glide range can vary widely between different types of aircraft. The 747, for instance, has quite a remarkable power-off glide range. You will recall that "Sully" Sullenberger was able to glide quite a distance before his remarkable ditching in the Hudson River. He was flying an A320, an aircraft which I would suspect has an unpowered glide range roughly similar to the 737, and that A320 most certainly didn't "enter a high-speed descent".

    This sort of stuff is exactly what I meant when I said that "it will be very interesting to see how forthcoming the Chinese air authorities prove to be with respect to accurate information."
  • edited March 25
    Thanks @Old_Joe

    Sully was at 10,000 - 11,000 feet if I remember correctly. Don’t know - but guess the air density a lot less at 29,000. There’s a report this morning that a wing part was found 6 miles away. from impact sight. Not surprising, as I’d expect structural parts to fail at a 700 mph decent rate unless aircraft properly configured.
  • edited March 27
    This just in from NPR-

    BEIJING — The second "black box" from a China Eastern Boeing 737-800 was found Sunday, raising hopes that it might shed light on why the passenger plane nosedived into a remote mountainous area in southern China last week, killing all 132 people on board.

    Firefighters taking part in the search found the flight data recorder on a mountain slope about 40 meters (130 feet) from the point of impact and 1.5 meters (5 feet) underground, state media said. Experts confirmed it was the second black box. The impact of the crash created a 20-meter- (65-foot-) deep pit in the side of the mountain and scattered debris widely.

    Searchers had been looking for the data recorder after finding the cockpit voice recorder four days ago. The two black boxes should help investigators determine what caused the plane to plummet from 29,000 feet (8,800 meters) about one hour into the flight and shortly before it would have begun its descent.

    The remote setting and rainy and muddy conditions have complicated the search for the black boxes and wreckage. Images posted by CGTN, the international arm of CCTV, showed an official holding an orange cylindrical object on site with the words "FLIGHT RECORDER" and "DO NOT OPEN" written on it. It appeared slightly dented but intact.
  • edited March 27
    @Old_Joe -

    9 crew members is a lot for the passenger load. I heard there was a second co-pilot along to “observe.” Possible foul play? I don’t know.

    However, I wanted to ask you whether a sudden decompression might have led to the disaster? Might not have been time for crew to put on masks? Some of these older planes don’t get maintained as well as they should. On that score, Southwest “wrote the book”, having been fined a number of times.
  • @hank- Don't feel qualified to comment generally on sudden decompression, but I'd think that even with a rapid decompression the pilots would have had time to access the emergency oxygen masks. It's not unheard of for an engine to lose a rotor blade, disintegrate, and propel wreckage into the fuselage, causing decompression. That's exactly why I said that "The engine maintenance history will be of extreme importance in considering the situation".

    Hadn't noted the nine crew members, but yes, there were three pilots aboard. I haven't seen any report on why, but could have been something as simple as one of them rotating back to another airport. Again, I can't see anything the pilots would have done to cause the immediate vertical descent, and evidently ATC unsuccessfully tried a number of times to communicate with the aircraft after radar indicated the change in altitude. The black boxes should tell quite a story.

    From what I've read so far, China Eastern has a pretty decent track record, as does the 737-800 itself.
  • Glad they have both black boxes. Reports are the data recorder on this “newer” 737 is very advanced. Let us hope.

    Thanks @Old_Joe
  • edited March 27
    FWIW - Opening paragraphs from the WSJ’s coverage Saturday.

    It was one of the fastest descents of a commercial aviation jetliner in history. China Eastern Airlines Flight MU5735 had been flying normally for just over an hour on Monday when it suddenly nosedived, plummeting more than 21,000 feet in 72 seconds. After the fall appeared to be briefly arrested, the plane stopped transmitting data, crashing into green mountains in southern China.

    Video footage captured by a mining company’s surveillance camera showed the aircraft almost perpendicular to the ground in its final moments before it crashed, while attempts by air-traffic controllers and other nearby jetliners to contact the pilots after the aircraft started hurtling to the ground went unanswered. It is “extremely unusual to see an aircraft in a full nose dive,”one industry safety official in the U.S. said. “Many of us are scratching our heads.”

    The vertical speed of the descent reached almost 31,000 feet a minute at one point, according to data from tracking provider Flightradar24, mystifying experts. With very limited information available so far, it leaves open a range of possibilities as to how the Boeing 737-800 carrying 132 passengers and crew met its fate.

    The Aviation Safety Network, operated by the independent safety advocacy group, the Flight Safety Foundation, and which maintains a flight accident database going back to 1919, said it identified eight examples of accidents since 1985 where a plane quickly descended in an abnormally steep way or fell out of the sky at high speed.

    Previous falls from high altitudes have had a range of causes, said Jeff Guzzetti, the former director of the Federal Aviation Administration’s accident investigation division. Investigators need to winnow down possibilities: Anything from a small structural failure to a malfunctioning autoflight or autopilot system to a pilot becoming disoriented to some kind of intentional act could have played a role, he said. “Everything’s on the table,”said Mr. Guzzetti, who isn’t involved in the investigation, while adding that the probe is in the very early stages.”


    Excerpted from The Wall Street Journal March 26, 2022
  • @hank- would you have a link for that? I'm not seeing anything like that on our WSJ "https://www.wsj.com/news/world" feed.

    Thanks- OJ
  • edited March 28
    Thanks @Mark for digging up the link. The cut and paste came via circuitous route from a Kindle reader. No link,

    Very good article. I can’t help thinking that was an intentional dive. As one person quoted near the end says “Planes just don’t do that.”
  • China Air Crash Report Gives Few New Clues on Boeing 737’s Fatal Nosedive

    Here is the latest info on this, from the WSJ:

    Free link to WSJ article
  • edited April 21
    There has to be a trove of data on those black boxes. Wonder whether they’re too damaged to be read or whether the info is being withheld.

    Thanks for the update.

    Unrelated: After we boarded a 737-800 at O’Hare couple weeks ago and after the doors had been closed, maintenance detected damage to the tail - possibly from a bird strike on landing. Everybody got off. But AA had us on an identical plane about an hour later.:)

  • China Eastern Black Box Points to Intentional Nosedive

    Flight data suggests someone in cockpit pushed Boeing 737-800 into near-vertical descent, according to a preliminary U.S. assessment

    Following are extracts from a current Wall Street Journal report:
    Flight data indicates someone in the cockpit intentionally crashed a China Eastern jet earlier this year, according to people familiar with U.S. officials’ preliminary assessment of what led to the accident. The Boeing 737-800 was cruising at high altitude when it suddenly pitched into a near-vertical descent, plummeting into a mountain at extreme speed. Data from a black box recovered in the crash suggests inputs to the controls pushed the plane into the fatal dive, these people said.

    “The plane did what it was told to do by someone in the cockpit,” said a person who is familiar with American officials’ preliminary assessment, which includes an analysis of information extracted from the plane’s damaged flight-data recorder.

    Neither Boeing Co. nor air-safety regulators have been working on any service bulletins or safety directives stemming from the crash, people familiar with the matter said. Such messages would be used if authorities believed there was a need to alert airlines and pilots to problems the flight crew encountered in the accident or detail needed fixes to the aircraft.

    The U.S. officials’ preliminary assessment hasn’t been reported before. In April, the trade publication Leeham News and Analysis reported that an initial readout of the China Eastern plane’s flight-data recorder suggested deliberate pilot inputs into the controls.

    The Civil Aviation Administration of China, the country’s air-safety regulator, didn’t respond to faxed requests for comments and didn’t pick up calls. The agency hasn’t commented on any potential causes of the crash and said last month investigators continued to probe the accident.

    Asked about a possible cockpit intrusion, China Eastern said such a scenario wasn’t plausible. The airline cited information from a March 25 news conference in which Chinese authorities said no emergency code had been sent from the plane before the crash.

    Chinese authorities haven’t indicated to their American counterparts when they might communicate their official determinations from the probe publicly, people familiar with the matter said. The CAAC has said it would make any significant developments in the investigation public in a timely fashion.

    Accident-investigation agencies can take about a year or more to issue their final conclusions about a crash’s causes and contributing factors. In some previous accident investigations, international authorities have disagreed over whether someone crashed planes intentionally.

    Free link to WSJ Article

  • edited May 18
    Thanks. Haven’t yet read my most recent WSJs. At one time crews could erase / turn off the voice recorder. Not sure if it’s still possible. If someone did disable or erase, we can be pretty certain it was a crew member - which is what I suspect.

    PS - I get blocked by their (edit) paywall when I click. But I don’t try very hard to get around it since I have the WSJ on Kindle. Hopefully others are able to access via the link.
  • You know, I can sort of understand a pilot committing suicide by crashing a plane into a mountain. But why on earth would they want to take a planeload of innocent passengers and fellow crew members with them?
  • Yeah. Ya got me there. Pure depravity I guess.
Sign In or Register to comment.