00:00A single engine failure is more or less ruled out.
00:04If you come to dual engine failure, that is very, very remote.
00:09And so far, we have not come across frequently that dual engine failure.
00:15Only in case of any bird hit, we get the dual engine failure.
00:20It cannot be due to bird strike.
00:23Because if it is due to bird strike,
00:25then you will get some sort of arcing, sparking and smoke.
00:31At the same time, both the engines will not encounter the bird strike at the same time.
00:37One of the reasons which can cause that sort of thrust loss, power loss,
00:45which prevented the aircraft from climbing,
00:49what I can think of is fuel contamination.
00:52Sir, what do you think about this Ahmadabad plane crash incident, sir?
00:57From your experience, what do you want to say to the public, sir?
01:00Sir, this Ahmadabad plane crash was one of the most unfortunate incident in Indian recent history.
01:11The previous crash, whatever we had, were different.
01:14This Ahmadabad crash, it is a Boeing Dreamliner.
01:19It is one of the most ultra-modern aircraft with all the safety, precaution, navigation.
01:24And it is almost foolproof.
01:27But still, something went wrong.
01:29And then it crashed.
01:31So, they are in the process of recovering the black box to get the actual information.
01:41It has got the CVR as well as the DFDR.
01:44And both of them are integrated.
01:47And they call it as a single unit in order to synchronize the data of CVR and FDR.
01:55Because it will give a better picture.
01:58Whatever event has occurred, it will reflect in the cockpit as well as in the FDR.
02:05So, we are in the process of getting the data.
02:07And looking at the wreckage, it looks like the aircraft is totally destroyed.
02:13And even the black box will undergo a very high temperature impact, whatever is there.
02:19But it is still shockproof, heatproof, whatever is there.
02:23The data that is in-house in a small container will be intact.
02:30So, the first thing what they have to do is to locate the FDR.
02:34They have to pull out the memory card from the FDR, mount it on a healthy unit, which can be replayed.
02:43And then you download the data to your computer to start your analysis.
02:47So, that is the first point.
02:49And then, similarly, you get the data from the CVR.
02:53And you try to synchronize those two to see what is the conservation which has taken place.
02:58And then you try to correlate the root cause of this crash.
03:05So, what are the major measures?
03:08Okay.
03:08What are the airline companies, sir, on avoiding this kind of incidence?
03:13Normally, when we investigate any accident, we follow a certain procedure.
03:22It is called as process of elimination.
03:27That is, we take a very big blackboard.
03:30And we try to write down all possible causes of the crash without leaving anything.
03:38Even if it is something unimaginable, we still take it.
03:41For example, if you say that there can be an alien abduction for MH370, we take it.
03:47Subsequently, we say that it is very remote, but we take everything.
03:51So, taking all the possible causes which can cause the crash, we write on a blackboard and then we start the process of eliminating one after the other, which are very unlikely.
04:06So, the crash can take place due to several reasons.
04:13It can be due to weather phenomena.
04:16So, you have, you are flying and suddenly you encounter some turbulence or severe thunderstorm or whatever it is.
04:25It can damage the aircraft.
04:27So, that is due to natural phenomena.
04:29Or you can have due to something called as a wind shear.
04:34There is a microburst when the packet of air comes down and hits the ground and it gets dispersed in all the direction.
04:44And particularly if it happens on the runway and at the time when the aircraft is landing,
04:51first the aircraft will encounter a head wind because of the downburst.
04:56And the aircraft will tend to pitch up.
05:00The pilot will try to correct the course of action by bringing it down.
05:04And once it passes through the center of the impact of a downburst, it becomes a tailwind.
05:10Then he is going to suddenly lose the speed and the aircraft will stall and crash.
05:16That is one of the weather-based phenomena.
05:19So, like that you have got other man-made disasters where things can go wrong either from pilot or maintenance engineer or whatever is there.
05:33So, that is man-made.
05:35Similarly, we have got many other reasons for the crash.
05:40So, the last one, what I would like to stress is sabotage.
05:46It is something very, very serious and it is difficult to predict.
05:53So, coming back to this Ahmedabad plane crash,
05:59whatever little bit of information we have seen on the TV, on the media,
06:05let us try to draw some inference before we get the actual data.
06:11The system shows that the aircraft climbed to a height of 625 feet before it started descending.
06:23So, if the aircraft is airborne, it means that things are somewhat okay.
06:34But, when you look at the rudder component of the aircraft, it looks very stable.
06:44When the aircraft reached 625 feet and it started descending,
06:48it looked as though it has lost its thrust or the power.
06:53Now, the power loss can be mainly due to loss of engine.
07:00If there is an engine failure, then obviously the thrust what is generated is reduced a lot.
07:07For engine failure, which is quite rare, it is not something common, but it is very, very rare.
07:15If there is an engine failure, then there is a large amount of thrust asymmetry,
07:21which will try to wear off the engine aircraft in the particular direction,
07:25which is compensated with your rudder.
07:28But, here we find that the rudder is almost a standstill.
07:33There is no movement of rudder.
07:34So, a single engine failure is more or less ruled out.
07:40Now, if you come to dual engine failure, that is very, very remote.
07:46And, so far we have not come across frequently that dual engine failure.
07:52Only in case of any bird hit, we get the dual engine failure.
07:57For example, in U.S., the aircraft, the A320, which landed in the river,
08:02it was mainly due to the dual engine failure of the bolt strike.
08:08Now, here let us see what could have happened.
08:11The runway of the Hamburg airport is 11,500 feet, which is really very long for any aircraft to take off.
08:26And, normally, when the aircraft takes off, it will lift off at something like half the runway
08:32or slightly at 60% of the runway length.
08:35If the aircraft had taken off and it was airborne at 7,000 feet,
08:43by the time it covers another 4,000 feet, it would have climbed a lot of distance.
08:49But, here it looks as though when the aircraft was crossing the boundary of the perimeter of the airport,
08:57it was hardly at 620 feet.
09:00It means the aircraft is unable to generate the required lift for climb.
09:08And, then we find that the landing gear is down.
09:12It is not retracted.
09:14The normal practice is the person who is monitoring the aircraft,
09:21he will give the call out.
09:22He will say 100 knots to alert the pilot.
09:25And, then you have got next V1, that is the decision speed.
09:28The pilot has to take the decision whether to continue with the takeoff or to reject before V1.
09:35And, then you have got the next speed as VR.
09:38It is called as a V-rotate.
09:40So, the pilot will rotate the aircraft and the aircraft is airborne.
09:43Subsequently, the first officer will say, positive climb, gear up.
09:49So, the gear is retracted when the aircraft reaches around 30, 35 feet.
09:54And, then you have got a speed called as a V2 speed.
09:57The aircraft should have climbed, should attend a speed of whatever is the V2 speed.
10:03By the time the aircraft climbs 35 feet,
10:05that will ensure that the aircraft is airborne and has got sufficient power and speed to climb
10:11and to continue even in case of an engine failure.
10:14But, here we find that the landing gear is down.
10:18It is not brought up.
10:19So, what could have been the reason for not bringing the landing gear up?
10:27There may be some problem with the thrust because the aircraft was not climbing.
10:33Now, if we look into the possibility of both the engines malfunctioning,
10:41which is very, very remote,
10:43it cannot be due to bird strike.
10:47Because, if it is due to bird strike,
10:49then you will get some sort of arcing, sparking and smoke.
10:54At the same time, both the engines will not encounter the bird strike at the same time.
11:01There will be a small time lag between the first engine failure and second engine failure.
11:07Meanwhile, the aircraft will try to veer off in one direction
11:11and you will find some rudder moment.
11:13But, here there was no rudder moment.
11:15So, it looks as though both the engines were behaving in a very same way,
11:24without any time difference, without any, there was no discrimination.
11:29So, one of the reasons which can cause that sort of a thrust loss, power loss,
11:38which prevented the aircraft from climbing,
11:40what I can think of is fuel contamination.
11:46That is one of my strong points for both the engines,
11:51stalling simultaneously and losing the power.
11:54Because, the same fuel goes to both the engines.
11:57So, if the fuel is contaminated,
11:59both the engines will behave in the same way
12:01and the thrust what is generated is less.
12:04The aircraft could not sustain the climb rate
12:08and then it could not even sustain the level flight.
12:12The aircraft descended and it fell
12:14because it contained more than 35 tons of fuel to reach London.
12:21It was like a fireball.
12:22The moment it crashed, there was a big, huge fireball
12:26and then there was a lot of smoke
12:27and the aircraft fell on a medical system,
12:34hostiles, what they call it as.
12:36And there were a lot of casualties on that.
12:38So, the most probable cause, what I feel,
12:41is due to fuel contamination.
12:45And the other things will be reflected
12:48once we get the data from DFDR
12:50and we get all the parameters
12:52about the thrust-generated RPM, fuel flow,
12:57how much of fuel is carried.
12:58Those parameters will show up,
13:01EGT, all the autopilot engaged,
13:05the command given to retract the,
13:07whatever command is given,
13:09that will reflect and also the CVR will tell
13:11the coordination between the captain and the first officer,
13:15how they acted and how they handled the situation.
13:17Can you please repeat the question?
13:23The main safety procedure,
13:25what has to be followed,
13:26is assigned to crew member,
13:29to pilot, to passenger.
13:31Everything is different.
13:33And then we cannot have a single guideline
13:36for all the cases.
13:39It is like giving medicine.
13:41So, when you take medicine,
13:43it depends on what is that element you have got.
13:47So, based on the ailment,
13:48you are going to get the medicine.
13:49So, every case is unique
13:53and it has to be looked deep into the process.
13:56We cannot have a general guideline.
14:00We can have certain minimum guidelines,
14:02but we cannot have a magic stick
14:07which will cure everything.
14:09So, it is for the management
14:11and for the other airport authority
14:13to implement whatever the safety regulations
14:16is based on the past experience.
14:19And every case is totally unique,
14:21totally different
14:22and every crash will give you some new lesson
14:26and it will give you something how to overcome.
14:29Just to take a very simple example,
14:33one of the Boeing 777 aircraft
14:36which long back almost 10 years back
14:39which was landing at Heathrow Airport.
14:43He was in the idle descent
14:45and he was the glide path.
14:47The final approach
14:49when he tried to correct his flight path
14:51by giving some power to the aircraft,
14:55the engine did not respond.
14:58Means there was a fuel starvation
15:01of the engine.
15:03Whatever power he is giving,
15:05absolutely it is like pressing a throttle
15:07and your car is not accelerating.
15:12So, that was the situation.
15:15And when they analyzed
15:17and when they decoded,
15:18they found that there was lot of froth formation
15:21in the fuel tube
15:23and when thrust was given
15:26that froth formed a ice layer
15:30in the heat exchanger
15:32and then it prevented the fuel flow
15:35and that resulted into a short landing.
15:41It landed much before the runway.
15:44The aircraft was slightly damaged.
15:46There was no fatality.
15:47But once they realized the problem,
15:50they immediately changed the heat exchanger
15:53of all the aircraft
15:55and they made it in the form of a straw
15:58with a different altitude,
16:00different height
16:01so that even if some of the heat exchanger
16:04hexagon holes are blocked,
16:08still you will have certain other holes
16:11from where the fuel can flow
16:12and it can heat up the engine.
16:15So, like that,
16:15based on the experience,
16:17every experience will give you,
16:20every accident will give you something new
16:22to improvise the system.
16:26So, it is not something unique.
16:28You cannot have a,
16:29if there is a mid-air explosion
16:32due to some electric spark
16:35in the fuel tank.
16:37There was a case
16:38when there was a fuel tank exploded
16:41because of some small transducer,
16:43electric spark.
16:44Then they said that
16:46we have to see to it
16:47that the air
16:50which is super saturated
16:51in the wing
16:52should be removed.
16:56So, what they did was
16:57they filled that one
16:58with nitrogen
16:59because nitrogen is an inert gas.
17:02So, even there is a small spark.
17:03It is not going to ignite
17:04just like your super saturated air.
17:07So, that gave a very good lesson for them.
17:10Similarly,
17:11Bangalore crash also gave
17:12a lot of information to them
17:14how to design the window,
17:18how to design the,
17:20how to keep,
17:20how much to keep the idle,
17:23this power 40% 60%,
17:25whatever,
17:25every accident will come out
17:28with some new ideas
17:30which helps them in
17:32improving the safety.
17:34But, if you are really
17:37very smart,
17:38then you should be able
17:39to predict certain
17:40false,
17:43there is a failure
17:44in advance
17:44and you should try to take
17:45a remedial action
17:46before it culminates
17:48into a crash.
17:49So, the expertise
17:50will tell you
17:51what are the,
17:52it is like
17:53an iceberg
17:55floating in a sea.
17:57What you see
17:57is the tip of the iceberg.
17:59That is the problem.
18:00But, there are
18:01a lot of other problems
18:02which is hidden
18:03inside the water
18:04which is not seen.
18:07So, only when you
18:08expose that
18:09iceberg
18:10by lowering the water,
18:12you will be able to
18:13indicate
18:14what are the problems
18:15and how to overcome.
18:16So, it is just
18:17evolution,
18:19continuously
18:20improvising.
18:22There is no beginning,
18:23there is no end.
18:24You have to continue
18:25to
18:25improvise the system.
18:27So,
18:29that's all.
18:30Every case
18:31is unique
18:31and you have to
18:32see to it
18:32that things are,
18:34the data
18:34of the previous
18:35crash or incident
18:37is made use of
18:38to improvise
18:39that it doesn't
18:40occur again.
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