Skip to playerSkip to main contentSkip to footer
babycarseattips
  • 6/3/2025

Category

📺
TV
Transcript
00:00the plane was sinking deeper and deeper in the heart of one of Asia's busiest
00:09cities rescuers rush to pull air crash survivors to safety nothing wrong with
00:16this actuator Taiwan's Aviation Safety Council confronts
00:21emergent questions about Trans-Asia flight 235 what were the flight crew
00:26doing their engineering issues involved in this event how on earth did it end up in
00:31this situation take a look at this a video surfaces that makes the disaster
00:38in Taipei notorious worldwide it's quite harrowing because you're seeing the
00:43final moments of a tragic event unfolding before your eyes what was happening on
00:49that plane
00:56Taipei capital city of Taiwan near its center amid soaring towers lies Songshen Airport
01:22the next plane scheduled for departure this morning is Trans-Asia flight 235
01:30the Trans-Asia cabin crew is waiting for a last-minute addition to the passenger list
01:39welcome aboard from 19D midway down aisle seat dr. Liu Chao Hui has made it
01:48it just so happened that particular flight had a few open seats I was supposed to be on the
01:55later flight but I decided to get on the earlier one yeah is this me ladies and gentlemen make sure
02:06your seat backs and tray tables are in their full upright positions ensure your seat belt is securely fast
02:12there are three highly trained pilots in the cockpit the first officer
02:21is leo c-chung he has almost 7,000 hours of flight time oil pressure check the captain
02:30leo chin song is a former military pilot there's also a third pilot who's an observer on today's flight
02:3945 starter off start lights off
02:45Trans-Asia 235 is a commuter flight from Taipei to the Taiwanese island of Kinmen just off the coast
02:55of mainland China scheduled flight time is approximately one hour would you like a paper oh thank you dr. Liu
03:05Liu Chao Hui is returning home to Kinmen where he runs a medical practice
03:09I usually took Trans-Asia because their service was quite good
03:15when I'd get on the plane I'd like to grab a paper and catch up on the day's events
03:23the cabin's ready sir okay roger thanks
03:29sunshine ground Trans-Asia 235 request taxi
03:34Trans-Asia 235 runway 10 taxi via whiskey
03:38okay whiskey to 10
03:41the ATR 72 600 is the latest most advanced version of the European commuter plane
03:49its Pratt and Whitney turboprop engines are extremely powerful and fuel efficient
03:54it's very popular aircraft particularly because it has attractive operating economics it's commonly
04:01used in short-haul regional airline operations the pilots digital displays create what's known as a glass
04:08cockpit when people refer to a glass cockpit aircraft they're referring to not only the displays but
04:14what often we're talking about is an advanced technology aircraft with sophisticated automation capabilities
04:21the electronic checklists switch automatically once you complete certain parts it'll switch forward
04:27the first officer briefs his colleague on the cockpit's technology Hong ping chewing is an
04:32experienced pilot who's learning this computerized system can you do manually what you can
04:38but when starting the engine for example it'll go to the next page once you close the bleed valves
04:49Songshen airport sees six million passengers a year
04:54for air traffic controllers that means handling about a hundred flights a day
05:00Trans-Asia 235 runway 10 wind 100 degree niner knots cleared for takeoff
05:07takeoff okay clear for takeoff cabin crew prepare for takeoff
05:17have a great flight thank you enjoy your flight
05:26just before 11 in the morning flight 235 gets rolling engine instrument check normal
05:37the one the one the one rotate
05:57the captain engages the autopilot and sets his desired airspeed and altitude
06:02as soon as the aircraft is taken off they're going through a series of checklist items
06:08you're up you're up i know they've got a particular climb profile and they're executing the after
06:15takeoff checks and the initial climb checks to make sure that all the systems are performing as required
06:23flight 235 climbs out over metropolitan taipei
06:27a densely packed city of more than seven million people
06:38seconds later the master warning sounds
06:42the master warning is indicative of an emergency situation requiring an immediate response
06:47transasia 235 has lost an engine the captain disengages the autopilot i have control you have control
07:00in the cabin engine noise suddenly drops
07:08the pilots need to get their plane back on the ground heading mode the captain wants a heading back to the
07:15airport below 2500 feet turn to heading it's come on zero zero nine or five check
07:25when you lose an engine in a twin engine aircraft you need to be able to maintain your climb performance
07:32and you need to be very careful that your airspeed does not decay or reduce too much during that climb
07:37speed and climb rate are dropping fast watch the speed
07:52the stall warning means the plane is flying too slowly to maintain lift
07:58the stall warning at low altitudes a critical situation that no pilot ever wants to end up in
08:04flight 235 is less than a mile from the runway
08:15passengers can now see that they're no longer climbing
08:23terrain ahead
08:23the stick shaker is a tactile alerting system where the control column shakes or vibrates very
08:34noticeably it's a very salient cue to pilots to indicate that you must intervene to prevent the aircraft
08:41from entering a storm
08:42the situation is critical
08:52well it's a highly stressful event
08:54tower transition two three five
08:57mayday mayday engine flame out
09:01songchen controllers fear the worst
09:04a crash in the middle of the city
09:10the engine flame at both sides how is this possible
09:23flight 235 is now only 500 feet above the streets of taipei
09:30the crew was surrounded by high density housing high-rise apartment blocks a heavily populated area
09:38but you're really between a rock and a hard place
09:41impact please for impact
09:47oh no
09:48all controllers can see is that flight 235 has dropped off the radar
10:10they have no idea if anyone has survived
10:14spend all takeoff and landing operations begin emergency procedures
10:18after hitting an elevated highway in downtown taipei
10:28trans asia flight 235 is sinking in the kilong river
10:32i could feel something was off
10:41i thought to myself why is there water where my shoes are
10:44and you'll see
10:54those lucky enough to survive the crash are now at risk of drowning
10:58i remember very clearly
11:07i saw a woman who i thought was an air hostess
11:13i told her not to be afraid
11:20the water level starts to rise
11:22the plane was sinking deeper and deeper the temperature was very cold
11:34i couldn't hear anything the water had drowned out all sounds
11:43then passengers are relieved to hear a welcome sound
11:46rescuers are on the way
11:58first responders climb onto the fuselage and start pulling people from the wreckage
12:04i just wanted the doors to open quickly so that i could escape
12:11the swift current of the kilong river means that shocked survivors won't be
12:15safe until rescuers can get them to the riverbank
12:23the city of taipei has never seen an aviation accident like it
12:30of the 58 people on flight 235
12:33only 15 make it out alive
12:36all three pilots are dead
12:37investigators from taiwan's aviation safety council are anxious to start collecting evidence at the scene
12:55the most important thing for us is to retrieve the black boxes
12:58we have to wait for the search and rescue to finish before we can go in
13:08for now they have to be patient
13:14but a stunning piece of evidence has already surfaced
13:18take a look at this just came in
13:19what was happening on that plane play it again
13:41it was quite extraordinary that uh the final sequence of events was captured by the the dash
13:51cam footage in the the motor vehicle it's quite harrowing because you're seeing the final moments
13:57of a tragic event unfolding before your eyes
14:00freeze it freeze it we were obviously really shocked wondering why the plane was flying in this way
14:10what do you think left engine control surfaces
14:15when you watch the video clip we know there's something wrong about the engine
14:20the prop seems very slow you can see the propeller blades they couldn't have been going at full speed
14:25i thought either the aircraft loads one engine or either the flap or the aileron jam during takeoff
14:35we need to study that wreckage
14:43salvage crews pull what remains of flight 235 from the kilong river
14:49we recovered everything i think we finished the wreckage recovery around noontime the second day
14:55there's no telling which piece of wreckage might hold an important clue
15:04investigators wonder if the flight control system shows any sign of a malfunction
15:10so we have to exam that part of the wreckage nothing wrong with this actuator
15:17we cannot find anything wrong with the actuator the linkage of the control
15:23we cannot find any normal situation for the flight control system
15:29control system seems fine a search for any pre-impact failures in the plane's hydraulic system
15:36also comes up empty nothing wrong with the hydraulics
15:44this is the left engine uh yes
15:47investigators know from the dash cam video that the plane was banked steeply to the left
15:56a mechanical fault with the left engine seems like the next most obvious suspect
16:01we need to take a look inside get the borescope
16:08from a borescope examination we can see whether or not the compressor and turbine are damaged on the inside
16:14this is the source
16:20since the turbine rotates with extremely high speed if it is even slightly damaged it will be completely destroyed
16:29but the boroscope examination yields no new clues
16:34not gentle fashion the examination showed that everything was in place and all the moving parts
16:40were still capable of moving left engine completely operational
16:49strange they need to explore other possibilities what about the right engine let's go take a look
16:59they study the right engine
17:00and what they find is mystifying
17:08look at the blades
17:11they're feathered
17:15feathered is a propellers fail-safe position
17:19when a propeller engine loses power in flight the blades automatically rotate parallel to the airstream to reduce drag
17:27what an auto feather does it changes the pitch of the blades to reduce the drag on the blades
17:32to make sure that the airplane's climb performance is not degraded the discovery only deepens the mystery
17:40why would the right engine be feathered when the dash cam video clearly shows the plane banking to the left
17:46it doesn't make any sense let's have a look
17:49when we discover a feather of the propeller
17:55we know there should be something wrong about the engine
18:04anything
18:06nothing at all
18:10both engines yielded normal results after examination
18:13they were both fine there's nothing wrong with this engine either
18:18if both engines were operational why did this plane crash
18:27investigators now have two related questions to answer
18:34what caused the right engine's propeller to feather
18:37train ahead
18:42and why did the plane bank violently to the left just before impact
18:52at a song shen airport hangar taiwanese investigators still have no explanation for the crash of trans-asia flight 235
19:00video of the turboprop's fatal plunge into the kilong river has spread worldwide
19:09but clues to what caused the crash are in short supply
19:12hello
19:15okay thank you
19:17sir
19:18fdr data's in
19:19all right
19:21let's have a look
19:23investigators hope the plane's flight data recorder can tell them more
19:30the fdr records dozens of performance parameters including fuel flow engine temperature and propeller speed
19:42okay engine flame out check check
19:45investigators already know that the right side propeller feathered before impact
19:51watch the speed
20:00let's see the operating systems of engine two
20:09perhaps the flight data can tell them why
20:14when we go through the data for engine number two we find some parameters or normal like oil pressure
20:22engine temperature fuel flow
20:25engine is completely fine
20:26but one other piece of data seems to tell a different story
20:31take a look at this
20:34the torque is all over the place
20:37one parameter the torque value fluctuated
20:44torque is a measure of an engine's power to spin the propeller
20:47it increases and decreases during flight but it's not supposed to fluctuate why is it doing that
20:58pass me the schematic
20:59they dig deeper studying how the pratt and whitney engine measures torque
21:05so we try to find out the design logic for the system
21:09what's the connection between the torque and the feathered propellers
21:16they learned that the engine's auto feathering system includes an electronic torque sensor
21:21it measures how much twisting force the engine is producing extremely low torque indicates that the engine has
21:29failed so a low reading triggers the system to feather the propeller
21:38but they know the engine did not fail
21:41there seems to be only one way to explain the unusual torque data
21:45maybe the sensor is sending a faulty reading triggering the auto feathering unit
21:52they suspect the problem was not with the engine itself but with the sensor measuring torque
21:58we figured out that that probably will be the signal problem between the torque sensor and the receiver
22:07send the sensors to the lab so we can analyze it
22:09if they're right about the torque sensor failing then they'll finally have solved the mystery of the feathered propeller
22:23but investigators are no closer to understanding another mysterious aspect of this crash
22:29why did a two-engine plane with a feathered propeller on the right side end up banking to the left
22:35searching for an answer they returned to the flight data what are the parameters of the left engine set
22:45can you show me the fuel flow please
22:50that all seems fine umbrella speed according to the data the left engine was in perfect working order
22:58engine number one's performance was always good all its statistics were normal the power lever angle
23:08but when they check the throttle settings they make a stunning discovery unbelievable
23:15when we go through the fdr data we find that the power of the number one engine
23:22was gradually being reduced reduced and eventually be shut off the left engine was manually shut down
23:37investigators know the atr-72 is not equipped with an auto throttle system
23:42the throttles can only be moved by hand
23:45it had to have been shut down by one of the pilots
23:53so we start to wondering why the pilot was shut down the good engine
24:02honestly at the beginning we did not understand how this could happen
24:05that's crazy
24:22let's take a look at the circuit board
24:25investigators examine the torque sensor from the right engine of trans asia flight 235
24:31they're looking for any defect that could have caused the propeller to feather in flight
24:40the lab used precise testing methods they made a cross-section of the circuit board and looked at its
24:45image take a look at this it's broken soda they discover microscopic faults in the circuit board
25:01and that was related to the soldering joints in a particular circuit board being compromised
25:08for reasons that were difficult to establish
25:11that was possibly related to some form of manufacturing defect or something of that nature
25:18and that there will be enough to start the transmission of the signal
25:24with a broken circuit board the torque sensor couldn't do its job
25:29even though the engine was turning the sensor couldn't detect any torque so the system automatically
25:36feathered the propeller the brain of the system thought that torque had reduced below a predetermined value
25:45which i think is about 18 percent and that is what triggered the auto feather
25:51okay engine flame out check check finally they understand why the right side propeller feathered
26:01but they still haven't explained the crash the atr 72 has two engines losing propeller thrust in
26:10one of them should not have been a catastrophic event
26:12they're designed to fly only with one engine
26:20straight ahead
26:24pilots train for engine out operations regularly typically it's bread and butter for an airline
26:30pilot to deal with an engine failure on a multi-engine aircraft
26:33to figure out why 43 people died investigators must now answer a much more difficult question
26:42we still have number one engine produce power normally but for some reason the pilot decided to
26:49shut down the good engine watch the speed
26:52we have to find out why
27:02investigators turn to the cockpit voice recording
27:06okay ready let's hear what we got oil pressure
27:14check the accident flight is very short less than three minutes
27:19so we listen to the cvr starting from the takeoff roll to the end of the flight
27:26before taxi checklist propeller brake
27:29off nose wheel steering
27:32oh procedure complete checklist complete so far the following procedure to a t
27:39you have to make your procedure very clear
27:42let's see what happens closer to takeoff
27:47engine instrument check normal
27:50v1 v1 rotate
27:57transition 235 contact approach of 119 or decimal seven good day
28:05what's that sound must be the engine to fault warning when the master warning first activated
28:12they're approximately about 1200 feet above ground level
28:16they're flying an atr 72 600 it shouldn't be a huge problem
28:21if they follow the procedure do everything correctly they should be able to fly back to land without any
28:29problem this is a crucial moment let's hear what they're going to do next
28:35i have control investigators hear the sound of the autopilot turning off
28:40he's disengaging the autopilot he shouldn't be doing that
28:43it's hard to understand why the pilot flying disconnected the autopilot during an emergency situation
28:52he just made a difficult situation worse
29:05keep playing
29:09okay engine flame out check check
29:12your attention will be directed to the engine warning display which in the atr 72
29:18clearly indicates which engine has failed
29:23there's a checklist procedure on the screen you follow it step by step
29:30but instead of following the emergency checklist watch the speed
29:34the captain does something inexplicable pullback number one
29:47the captain's starting to shut down engine one without fully understanding what the computer system is
29:51telling him
29:54both engines are capable of producing power but because the right engine has feathered it has lost thrust
30:01behaving like a car in neutral gear when the captain pulls back the left throttle
30:07he leaves himself with no thrust from either engine he didn't seem to fully appreciate that that
30:13that had ultimately resulted in um number one engine being shut down
30:20how can you do such a thing
30:21investigators have discovered from the cockpit voice recorder that the captain of flight 235
30:36shut down the plane's only working engine why didn't the first officer stop
30:41they continue listening to the recording trying to understand why the captain's mistake
30:49wasn't corrected in time now we'll pull back on engine one throttle
30:56you can't just say he's gonna shut down the engine pilots are supposed to run a cross check
31:02where one pilot verifies the actions of the other
31:05when the pilot flying shut down the operative engine he did so very quickly without discussing
31:13it with the pilot monitoring he's acting before even confirming what the emergency is
31:20when there's a warning come up the procedure said you identify the problem before you act
31:28no wait a second cross-check the pilot monitoring to his credit did try to stop the pilot flying from
31:35manipulating the engine number one power lever and he announced he wanted to cross-check
31:41but there was no definitive confirmation from the pilot flying that the problem was engine number two
31:48heading mode instead the captain interrupts the first officer to ask for a new heading
31:54we're below 2500 feet come on zero zero nine or five
32:00okay the first officer did tell the captain to wait he knows that the captain was pulling back on the
32:08wrong engine and when he did try to question it the captain just confirmed what he was doing
32:18all of a sudden they've got a dual engine failure and the pilot monitoring i think is being caught
32:24off guard and he's not really sure what's going on restart the engine i can restart the engine
32:39oh well i shut off the wrong engine
32:44the pilot flying clearly is an epiphany that they're in very dire trouble
32:50when i heard him say i shut off the wrong engine i was completely devastated
33:14by the time the captain realizes his mistake it's too late
33:20hold on unfortunately neither crew member actually followed the standard set of procedures for
33:27dealing with an engine flame out after takeoff
33:37investigators now have an even more puzzling question to answer
33:42why didn't the captain understand what he was doing
33:44the captain's failure to recognize the situation and react properly ended up costing 43 lives
33:56he thought that the left engine had failed when the aircraft was clearly telling him it was the right
34:02engine that had a problem how could the captain have got things so wrong what was this captain's background
34:09when they dig into the captain's history they make a disturbing discovery
34:17the captain failed one of his key training components
34:22the pilot flying's training records had indicated that he was prone to being a bit anxious
34:30i have control you have control feeling a little bit overwhelmed in emergency situations
34:37and had a tendency to prematurely respond or act in that situation pullback number one
34:44he was also fired from his last job although the captain was an accomplished military pilot
34:59his civilian record is raising questions maybe he wasn't used to the atr 72600
35:05the record soon confirmed that hunch leo chion song had logged relatively few hours in trans asia's newest commuter plane
35:16the captain in the left-hand seat had approximately 5 000 hours total time and he had about 250 hours
35:24on the atr 72-600 wait a second
35:28pronto number one weather shut off the atr 72-600 is known for its advanced technology
35:37investigators now wonder if this aircraft with its computerized glass cockpit was too complicated for
35:44a relatively inexperienced pilot to manage in a crisis we start the engine and we start the engine
35:52they can often be overwhelmed with a huge volume of information
35:54they also have to consider the nature of the automation and the modes that are presented to them
36:00so it's more challenging
36:04i showed up the wrong engine did information overload lead to the deaths of 43 people in one of taiwan's
36:11worst air disasters
36:13investigators need to know if the advanced technology designed to help pilots in the atr 72-600
36:26may instead have contributed to the crash of flight 235 by confusing the trans asia captain
36:32hey ready to fly out of taipei let's do it to try to find out they program a flight simulator using the
36:47flight data from the downed plane we have weather information we have fdr data we have cvr data so we
36:55put those together to duplicate the condition of the accident the data lets investigators fly the exact
37:04same flight the same speeds same climb rate and 37 seconds into the flight the same cockpit alarm
37:13that's the warning engine to flame out the plane's computer instantly identifies which engine has lost thrust
37:20check autopilot
37:20autopilot armed run the checklist
37:23the automated checklist pops up clear concise and easy to follow
37:29up trim on engine one auto feather on number two check
37:36engine two flame mode confirm confirm secure engine number two
37:42the checklist calls for the pilot monitoring to reduce power in the feathered engine to idle
37:48the other pilot guards the working engine then you would bring the condition lever into the fuel shut
37:53off daytime which removes fuel from the engine condition lever to fuel shut off
38:00check and then the engine will be secured and shut down
38:03engine number two secured now powered by just one engine the plane keeps climbing safely on autopilot
38:11the computerized systems have helped the pilots avoid disaster exactly as designed it's quite manageable
38:18the crew can continue the flight climb to a safe altitude reconsider their options now we just have to fly
38:25back to the airport and land i have an idea let's see what happens if we just let the plane fly itself
38:32hmm reset from the start setting when we do the simulator test we try to find out what will happen
38:44if the pilot do nothing
38:49incredibly the simulation shows that even if there had been no pilot input at all the plane would not have
38:56crashed the aircraft will continue climb in the fly with no problem so i think the aircraft was designed
39:04to handle that situation as long as we don't do anything wrong any doubts about the glass cockpit have now
39:12been erased the advanced systems of the atr 72 600 did not lead to the crash of flight 235
39:20there must have been some other factor at play
39:28investigators study reports from previous incidents where similar mistakes were made
39:34they suggest an intriguing possibility interruptions and multitasking
39:43investigators know the captain's workload was high
39:47taking manual control of the plane distracted him from running a cross-check with his first officer
39:53he's multitasking
39:58watch the speed
40:04he could have been suffering from change blindness
40:08change blindness people are focused or fixated on on another item or area of interest and so they miss
40:14what would be considered a very distinguishable change in the environment but they don't perceive it
40:23now we'll pull back engine one throttle
40:27even when all the systems were telling him it was engine two
40:31his perception told him he was doing the right thing
40:36change blindness
40:37the first officer even tried to warn him no wait a second cross check
40:46it seems the captain was blind to the clear warning that his right engine had feathered
40:57investigators finally understand what went wrong aboard transasia flight 235
41:02a microscopic crack in a circuit board disabled an engine sensor that led the system to wrongly
41:10determine that the right engine had failed
41:15but that in itself wouldn't have caused the plane to crash
41:19this was a series of mistakes on the part of the captain
41:23when engine two feathered the captain reacted before he had properly assessed the situation
41:33the captain should have followed a checklist
41:37i have control instead he turned off the autopilot and reduced power in the wrong engine
41:44i will pull back engine one throttle
41:46all we know for sure is he shut down their only working engine by the time he realizes
41:58it's too late
42:01restart the engine i can't restart the engine
42:05well shut off the wrong engine
42:07why did trans asia hired this pilot
42:18investigators dig into trans asia's corporate background
42:23check this out
42:25trying to understand how a pilot with such a poor record ever got through the door and this
42:33this company's been expanding rapidly
42:36what they find paints a picture of a growing company struggling to compete with bigger players in the
42:41competitive asian market
42:44a more regional operator like trans asia airways
42:48appears to have struggled to certainly recruit and retain the sort of expertise that airlines seek
42:57the crash of flight 235 would be the last accident for trans asia airlines
43:03in november 2016 the company ceased operations and went out of business
43:09there's a multitude of reasons that the board decided to shut down the the airline
43:15but there's an inescapable conclusion that the adverse or poor safety performance of the airline
43:23certainly had an economic impact on the airline
43:26even though trans asia airlines no longer flies
43:29air crash investigators hope that the tragedy of flight 235 will serve as an important safety reminder to pilots at other airlines around the world
43:39we all understand that pilot they're human human make mistakes so that's why we design the standard operating procedures
43:50and the basic
43:53important thing is for people just follow the procedure
43:57the