Chinese authorities say they have found a piece of the China Eastern airliner, six miles from the area where the Boeing 737 NG crashed on Monday. While the main debris field is concentrated as a result of the plane’s near-vertical plummet from the sky, this separate piece, a distance away, indicates that prior to the crash the airplane was shedding parts.
Whether the piece coming free of the plane triggered the disaster or if it was a consequence of the high-speed dive is not known but is certainly a question the investigators will try to answer.
An airliner dropping nose down so dramatically and rapidly is not likely to have been initiated by the pilots and few aircraft failure modes manifest themselves that way either. One exception would be if the horizontal stabilizer separated from the airplane.
In 1991, a three-year-old United Express Embraer EMB120 did an abrupt nose-down on approach to the airport in Houston. All 18 aboard the commuter flight were killed when the plane slammed into the ground. The investigation determined that the screws securing the horizontal stabilizer were improperly installed following a repair.
While this plane was a turboprop, the consequences are just as severe on jetliners when pilots lose horizontal stabilizer function; the two most well known are United Airlines Flight 232 and Alaska Airlines Flight 261.
In the United flight from Denver to Chicago in 1989, an uncontained engine failure sliced through the hydraulics line leaving the pilots with no way to control pitch. In a feat that is hailed to this day as an example of extraordinary piloting and crew resource management, the pilots controlled the airplane using engine thrust and crashed landed in Sioux City, Iowa. More than half of the 296 people aboard survived including all four of the pilots. (Read more about this in my book, The Crash Detectives.)
Alaska Airlines Flight 261 did not end as well. A failure of the elevator jackscrew fractured and left pilots without pitch control on an MD-80 traveling from Puerto Vallarta to San Francisco on January 31, 2000. Even heroics and imaginative thinking (at one point pilots considered flying the airplane belly up to counteract the descent, a scenario depicted in the Denzel Washington film, Flight) was ineffective. Eighty-eight people died when the plane flew into the Pacific.
Given the early departure of some piece of debris, and these precedents, a horizontal stabilizer malfunction is a credible possibility on China Eastern Flight MU5735.
Pilot suicide is a far less likely scenario despite how frequently it is coming up in TV interviews and online forums. Pilot-initiated murder/suicide by airplane is an exceedingly rare occurrence.
Following the Germanwings crash, where first officer Andres Lubitz locked his captain out of the cockpit and deliberately plowed the airliner into a mountain in France in 2015, the BEA investigators did a count of similar events and found just six out of more than 717 billion flights surveyed.
In the mountainous terrain where Chinese officials and volunteers are searching, more clues mean more data. And Wednesday’s discovery of the cockpit voice recorder, while not the preferred recorder to have in hand, will hopefully be illuminating.
Newspaper headlines and Twitter banners may proclaim this accident a mystery, but I don’t believe that’s the case. Chinese investigators already have lots of clues in airplane maintenance and manufacturing records, wreckage at the site, bystander videos and photos, air traffic and the flight data transmitted from the airplane. They have a lot to go on already.
Author of The New York Times bestseller, The Crash Detectives, I am also a journalist, public speaker and broadcaster specializing in aviation and travel.
“In 1991, a three-year-old United Express Embraer EMB120 did an abrupt nose-down on approach to the airport in Houston. All 18 aboard the commuter flight were killed when the plane slammed into the ground. The investigation determined that the screws securing the horizontal stabilizer were improperly installed following a repair.”
Unfortunately, that statement is only partially correct.
1. It was a Continental Express flight 257, not a UAL Express flight.
2. Total SOBs numbered 14, not 18.
3. The accident was caused by two important factors:
a. ) The plane was descending at a very high speed — only 12 kts. Below the max safe operating speed.
b. ) The screw fasteners had not been “improperly” installed AND they did not secure the HS to the vertical stabilizer, which your statement seems to imply.
In fact, 47 screw fasteners were missing entirely, which were required to secure the rubber deicing boot over the LEADING EDGE of the left horizontal stabilizer.
While doing maintenance work on that left HS deicing boot, a maintenance shift change intervened. The mechanics going off shift did not leave adequate notice to the oncoming shift mechanics, so they thought that maintenance had been completed. They did not bother to verify that all the required screw fasteners had been re-installed as required.
When that left leading edge deicing boot finally tore lose from the left HS, it also took the left LEADING EDGE of the Left HS with it (the entire Left HS did not fail).
That in turn, caused the wings to go into a negative stall mode which apparently exceeded the amount of negative Gs that the plane was designed for. That was the moment when structural failure began to occur.
As we all know, civilian commercial aircraft cannot take nearly as much in NEGATIVE Gs, as they can in POSITIVE Gs. Only aerobatic & military aircraft are designed to take much higher loads of negative Gs.
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“An airliner dropping nose down so dramatically and rapidly is not likely to have been initiated by the pilots and few aircraft failure modes manifest themselves that way either. One exception would be if the horizontal stabilizer separated from the airplane.”
I have to disagree. That kind of failure mode was very similar in the Silk Air flight 185 high-dive accident in Indonesia, in 1997.
It actually exceeded the speed of sound in its descent & that led to structural failure in flight. Parts of the aircraft were found significant distances from the main wreckage. It was very clear, from the NTSB investigation, headed by Greg Feith, that accident was caused by deliberate suicide of a pilot.
As for China Eastern, an aircraft descending in that manner wold require forceful control inputs by someone in the cockpit. If no one was doing that, then the nose would begin to come back up as the speed increases.
If the current information is correct — that the China Eastern flight did begin to level off & even begin to briefly climb again, then the HS & elevators had to still be functioning.
BTW, I cannot think of any accident that was caused by the HS breaking off in flight if the rest of the empennage remained intact.
Robert, An excellent comment! I was about to duplicate when I read your excellent response.
A quick comment – I would need to dig out the entire report but as I recall the BEA Vickers Vanguard G-APEC crashed in 1971 because of corrosion in an aft lavatory, which led to a failure of the fuselage rear pressure dome. This caused the horizontal stabiliser to lose its skin and the tail surfaces detached, resulting in a loss of control and steep dive into the ground.
A similar rear pressure dome failure (following an improper repair after a tail strike) led to the loss of the vertical stabiliser and all hydraulics in the JAL 123 B747 in 1985. That did not result in a vertical dive but would possibly have done if the horizontal rather than vertical stabiliserhad been first affected by the decompression.
Re pilot suicide in China Eastern, apparently there were three pilots in the cockpit, which, let’s say, would at least make suicide a lot more difficult.
And why at that phase of flight? Why not do it on take-off, when no-one would have time to thwart you?
Re Silk Air, there’s a documentary on youtube (pls stop laughing — I know that’s a feeble basis) that shows evidence of why the suicide explanation is at least questionable.
That the aircraft broke the sound barrier supports the suicide conclusion, I guess, since that implies it was diving with full power.
On the other hand, the Indonesians found evidence of yaw-damper problems (was that still an issue in 1997?). Apparently it at least led to a six-week court case in which families of victims successfully sued the manufacturer of the servo valve.
I don’t know whether a rudder hard-over in cruise could lead to a fatal dive all the way to the ground.
But clearly some people think it did on Silk Air.
For what it’s worth, I find the evidence pretty convincing.
https://www.youtube.com/watch?v=Ig9LE0Vp1YM&t=2521s
1. The CBs for BOTH the CVR & the FDR were pulled shortly before the fatal dive began.
2. The Capt lost more than $1 million in the stock market. His family & career stood to be ruined if he could not pay off debt he incurred to make those “investments.”
He promised his bankers he would pay off the debt after he completed his next airline trip.
3. The Captain purchased a large life insurance policy, but it would not pay in case of a finding of suicide. Therefore, it makes sense why BOTH Cbs were pulled before the dive began.
4. The lawsuit against Parker H was a gross distortion of long standing tort law liability standards – based upon actual FACTS & what a “reasonable” person would likely foresee.
Crafty law firms used CA’s new “strict liability” tort law standard to crucify PH with no good evidence. In addition, bribed “expert” opinions (without solid facts) were allowed to replace actual EVIDENCE. CA actually allowed such experts to tell juries whatever they were PAID to tell them!
By Fed law, the NTSB report could not be used as evidence in any lawsuit. The selection of a Superior Court in Los Angeles — as the trial forum for the Indonesian crash of a Singapore owned airliner – is quite telling when it comes to how & why plaintiff attorneys selected THAT trial forum.
5 The only test scenario that could match the actual path of that sudden high dive, was one whee the pilot held down the nose with his brute force on the controls.
6. The HS trim drive screw was found in the full nose down position.
7. The rudder PCU was found in the neutral position. No evidence of any rudder “Hard over” position.
8. The pilots had been trained in how to keep the plane under control if a rudder hard over blow down had occurred.
9. The Indonesian Investigative authority did NOT find any evidence to suggest that the PH PCU unit had caused the crash. The concluded the cause could not be known since both recorders had failed.
Your items 5-8 point pretty convincingly to suicide.
Re 9, I’m not referring to the Indonesian investigation – just that the Indonesians produced the incriminating parts.
As for your other points, the documentary begs to differ.
When an airliner crashes we get inspired stories of pilot suicide. Actually, the instigators are alleging murder on the part of the deceased pilots. Therefore, it is refreshing to read Christine Negroni’s opinion that “Pilot suicide is a far less likely scenario despite how frequently it is coming up in TV interviews and online forums. Pilot-initiated murder/suicide by airplane is an exceedingly rare occurrence.”
The best explanation I have read about Malaysian Airlines MH370 is at
https://www.quora.com/What-happened-to-Flight-370-Malaysia-from-the-pilot%E2%80%99s-perspective/answer/Simon-Gunson?ch=10&share=032202cb&srid=5jNFR
For more details please look up “Simon Gunson” on Quora.
I do think that the Malaysian Civil Aviation Authority should re-open the enquiry into the accident to MH370
I ask: How does this explain the elaborate* manoeuvring that followed?
* elaborate & Perfect for an undetected trip to the Southern Ocean
To say nothing of the 22-minutes spent in a holding pattern off Sumatra that aerospace engineer Richard Godfrey says he’s detected.
And against the Gunson piece I juxtapose THIS:
https://www.youtube.com/watch?v=q3NQ1jCxBig&t=498s