PK661: These Are the Reasons Behind the Crash [Analysis]

[New World]

i heard that, this aircraft was on his third journey to isb in last 24-30 hours

 

[Musafir117]

Most likely some engine parts hit the tail or other parts after its damage/broke which unable the system to control it there are no other reasons of a free fall but total fail up of entire system.

 

[raihans]

Let’s have a look at flight data of PK661:

Via (FlightRadar24)

Yesterday, i checked flightradar24 and the logged flights of AP-BHO, did not found Chitral - Islamabad PK661 flight log so how come the graph refers to flightradar24 is made available for this analysis?

The last recorded flight of Hotel Oscar is Lahore - Islamabad as PK654 dated 6th Dec'16 https://www.flightradar24.com/reg/ap-bho

so what one can assume about this analysis and how far assured for authentication of this data?

before concluding to ANY result, i am stating from the beginning on all platforms that we no need to jump on speculations and let the investigation find out the cause of crash

 

[SherDil]

Yesterday, i checked flightradar24 and the logged flights of AP-BHO, did not found Chitral - Islamabad PK661 flight log so how come the graph refers to flightradar24 is made available for this analysis?

From Mars.
http://blog.flightradar24.com/blog/data-regarding-crash-of-pk661/

 

[Djinn]

Here's one reason when your time comes it comes there is no stopping it. While the intent of the thread may be to discuss technical aspects but i am quite aware of how such discussions generate post an incident like this and how every one hopes that things could have been avoided. But fact is this is nature taking it's course, yeah even if it's a product of science. The notion that death could have been averted by being cautious is only a delusion and hurtful at best, if it wasn't the engine failure could have been something else. If any of the passengers were to survive irrespective of how plane went down they would have. A very recent example is that of the plane crash in Columbia in which Seventy-one people were killed and six survived.
http://edition.cnn.com/2016/11/29/americas/colombia-plane-accident/

 

[raihans]

From Mars.
http://blog.flightradar24.com/blog/data-regarding-crash-of-pk661/

thank you, i wish i could be lucky like you to fetch data from Mars

 

[war&peace]

Bird strike and FOD, at 13,000ft highly unlikely.

Most likely some part malfunctioned.

Engine malfunctioning should not result in explosion rather a flame out which provides the A/C the possibility to glide especially when one engine is working and altitude is 13000 ft AMSL and weather conditions are normal.
I guess there was some leak of fuel from any of the conduits / pipes that caught fire. The pilot detected that and immediately start the descent to reach the safe altitude and speed to switch off, however the fire climbed up to the fuel reservoir in the wing and that's where it exploded and damaged the wing and thus asymmetric free fall and failure of controls. Thus there was a lapse in the inspection.

 

[ACE OF THE AIR]

Engine malfunctioning should not result in explosion rather a flame out which provides the A/C the possibility to glide especially when one engine is working and altitude is 13000 ft AMSL and weather conditions are normal.
I guess there was some leak of fuel from any of the conduits / pipes that caught fire. The pilot detected that and immediately start the descent to reach the safe altitude and speed to switch off, however the fire climbed up to the fuel reservoir in the wing and that's where it exploded and damaged the wing and thus asymmetric free fall and failure of controls. Thus there was a lapse in the inspection.

Engine Malfunction can be caused by explosion.

ATR is a Turbo-Prop.

The is the PW 100

 

[The Diplomat]

According to PIA; An A-Check was conducted on the aircraft just over a month ago.
Is ATR adapted to their flight routes within Pakistan? Because I understand that ATR have to fly at half-compacity in the summer time in Baluchistan due to the engines not being able to cope with the temperatures.
But then again this was a cold environment and ATR is French made and adapted to France's weather which wasn't that different..

i heard that, this aircraft was on his third journey to isb in last 24-30 hours

Thats not bad considering the ATR usually flys for 30 minutes each time

 

[Morse_Code]

Dear Sister..... We are living in LaLa land... i m not blaming my country... but the system is crap....
What happened to the crash investigation of COAS Mushaf Ali Mir??? What we know about Air Crash of Gen. Zia ul Haq?? What about Bhoja Air Crash?? What revealed about Air Blue Crash in Islamabad??? and the Foker F-27 in Northern Areas 1989??? Sorry to say but we have the answer NONE for all these air crashes. And believe me after some times this case will also be the same and "Dakhil-e-Daftar".

I was to write this ...but then I thought it's better to not discuss it...but yeah ... the entire system is corrupt

 

[BRAVO_]

just like past incidents govt will make one committee which mean end of story .. no action ...in few days we will forget this incident too .. what an irony .... and our people will obviously vote the same idiots in next election

 

[marbella]

a migratory goose found in Pakistan can fly very high.

 

[FlyingAce]

ATSB (Australian Transportation Safety Board) did issue a AD "opposite control column inputs caused a “pitch disconnect” on a Virgin Australia ATR 72-600, resulting in overstress damage to the aircraft’s horizontal stabiliser".
Overnight Transit Inspection didn't reveal anything & Aircraft Flew 13 Additional Sectors before a Bird Strike happened & Inspections happened revealing Structural Damage...
Maybe there was a Structural Damage to the Airframe, Since ATR is a Hightail Aircraft & has a good Climb Rate if IFSD is to happen...
AP-BHO did went through Check A, that happen every 500hrs & is not as detailed as Check C or Check D

 

[newb3e]

Democracy is the best revange remeber! Pia bhi revange ki nazar hogaya! 600 to manage 1 plane and yet our national airline is pathetic.Only in Pakistan!

 

[wali87]

Excellent analysis. On a lighter note, u have some serious chances in the field of aircraft investigation bro.

Pakistan International Airline’s flight PK661 operating from Chitral to Islamabad on an ATR 42-500 with 42 passengers and 5 crew members crashed yesterday near Havelian, some 80KM north of Benazir Bhutto International Airport.



No one survived the crash.

While it is too early to list down the exact reasons behind the crash, we will try to analyze available information and try to come up with possible reasons for the crash of flight PK661.

What We Know About PK661 Aircraft?

ATR 42-500 is one of the most recent versions of ATR aircraft. Its first delivery was made in 1995 while the flight in question, PK661 with Registration AP-BHO, was delivered to PIA in May 2007.

ATR 42-500 comes with six-bladed propellers powered by PW127E engines rated at 2,400 shp (1,800 kW) for improved hot and high performance and increased cruise speed.

ATR 42-500 engines are certified to be safe, strong and solid performer in a variety of conditions.

It had flown 18,740 hours before it crashed yesterday.

Crashed aircraft details are as following:

• Aircraft Type: ATR 42-500
• Manufacturer: ATR
• Registration: AP-BHO
• Certificate of Registration Number: 751
• Registration Date: May 18, 2007
• Operator/Owner: Pakistan International Airlines (PIA)
• Construction Number: 663
• Year Built: 2007
• First Flight: May 3, 2007
• Test Flight Registration: F-WWLU
• Delivery Date: May 14, 2007
• Aircraft Name: Hasanabdal

Weather Conditions

Weather conditions at the time of crash in the area were quite normal.

Below are weather values for Havelian at the time of the crash:

• Time of incident: 4:10PM
• Temperature: 23.0 °C
• Dew Point: 10.0 °C
• Humidity: 44%
• Air Pressure: 1016 hPa
• Visibility: 16KM
• Wind Direction: SE
• Wind speed: 7.4 km/h
• Conditions: Haze

Flight Conditions

Azam Saigol, Chairman PIA, confirmed during a press conference that AP-BHO was Class-A checked just one month ago, indicating that the aircraft was in perfect condition.

While there was one instance of engine failure of the same aircraft back in 2014, it was replaced with a new engine and since then AP-BHO had operated smoothly without any issues being reported.

For flight PK661, there were 47 passengers on-board the ATR 42-500, indicating that the plane was pretty much with-in its load capacity.

Chairman PIA confirmed that flight PK661 was piloted by Salehyar Janjua, with flying experience of more than 12,000 hours.

Pilot of ill-fated PK661 had extensive experience of flying in northern areas, which means that he was well versed with the route and conditions where PK661 crashed.

Engine Failure And Ultimately the Crash!

Air Control Tower confirmed that flight PK661 signaled an engine failure at 4:12PM. Till the time the flight PK661 was flying smoothly at 13,375 feet.

However, as soon as the engine failure was reported, aircraft started descending — gradually at first.

Let’s have a look at flight data of PK661:

Via (FlightRadar24)

The initial descent was gradual and seemingly controlled, until the aircraft reached 12,800 feet. This is when aircraft gained altitude of 50 feet and reached 12,850.

However, it started descending again — in a non-symmetrical manner — and reached 12,175 feet.

Flight PK661 must had become imbalanced by then as it lost irregular altitude during next few moments.

• Flight started to bump starting 4:12PM — this is when it approached ATC and reported engine failure
• PK661 kept loosing altitude and lost 2,000 feet (gradually) with-in next 60 seconds
• Then a free fall and another 1,800 feet were lost with-in a millisecond
• PK661 Slightly stabled for few miliseconds and then lost another 2,000 with-in a millisecond
• PK661 fell freely for over 4,000 feet to reach 8,250 feet with-in moments
• PK661 gained some control and glided for few seconds before another free fall at around 4:13PM before disappearing from the radar

Here is what we are sure about:

• One engine had failed
• PK661 fell freely
• PK661 was damaged structurally

Since PK661 fell freely, we can say with certainty that aircraft was not in-tact and it had lost its shape and failed to glide.

It must be noted here that ATRs can glide even if both engines are switched off / malfunctioned. Since PK661 was flying at around 13,000 feet — had it been in-tact — it could glide some 15-25KMs before hitting the ground.

However, an aircraft will fall freely if there’s any structural damage as hampered aerodynamics will not allow the aircraft to glide with a gradual descent.

Since we know that at least one engine had failed, there’s a chance that it splashed and damaged the wing attached to it, affecting the aerodynamics of the aircraft which ultimately brought it down with-in seconds to and resulted in a crash.

It must be noted here that pilots have a way of shutting down the engine. But before that you need to descend and reduce speed to match the aerodynamics of the situation the aircraft is in, which the pilots did — and is seen in the graph above.

You simply do no shut the problematic engine immediately. Instead, you bring the aircraft to a certain altitude and speed to make sure that the remaining engine is able to handle the load and aerodynamics.

And while the pilot was trying to do so, the failed engine probably caught fire or more likely exploded and damaged the wings.

It must be noted that there are steps involved in stopping a mid flight ATR engine and it includes performing certain checks, such as shutting down the fuel supply, shutting down the engine itself and so on.

Here is what seemingly happened:

• Engine failed
• Pilot reduced speed, dropped altitude — clear from above graph
• Free Fall Due to Structural Damage
  • Pilot shut down the engine and
    • Shut down the malfunctioned engine, however, it was too late and it had exploded before that and damaged the wing
    • Stopped the working engine, and throttled the malfunctioned engine that triggered the explosion and damaged the wing

Here’s what seemingly didn’t happen:

• Aircraft was a good height/speed, and chances of stall are unlikely
• Aircraft didn’t run out of fuel, clear from the burns at the crash site

So the information we have so far indicates that the engine exploded and damaged a wing, impacting the aerodynamics and forced the aircraft to fall freely to ground with-in seconds of the incident.

It must be noted that complete details about the PK661 crash, with an authoritative conclusion is only possible after decoding more info from FDR, Cockpit Voice Recorders and other flight data recorders.

Source: https://propakistani.pk/2016/12/08/...alysis/?utm_source=all_users&utm_medium=notif

@Doordie @GreenFalcon @war&peace @Moonlight @Morse_Code

I heard an MNA on a news channel yesterday saying that he had travelled on this very plane a few times before and that this particular aircraft had a fault in one of the engines from the past year. However few moments later an official from PIA clarified that the faulty engine had been replaced a couple of months back.

There's also an outlandish rumour circulating that the Plane actually took off on just one engine. :S highly unlikely though.

The fact that PIA was quick to not only accept the allegation made by that MNA, but also answer it seems to point that something is definitely fishy here. Now, could be that either the faulty engine was not replaced or if it was, perhaps not properly. Just a thought.