PIA ATR Flight PK-661 Crashes Near Havelian

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Abbas Ali
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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

That document about engine failure was also shown on news channels on January 11, 2019.
Abbas Ali wrote: Fri Jan 11, 2019 12:46 pm Image

Part of a document shown on a news channel:

Immediate Safety Recommendation

Accident of PIA Flight PK-661 ATR 42-500 AP-BHO Near Havelian on 7th December, 2016


1. On December 7, 2016, a PIA ATR 42-500 (AP-BHO) flying from Chitral to Islamabad crashed near Havelian killing all 47 souls on-board. Safety Investigation Board (SIB) of Pakistan was mandated by the Federal Government to carry out detailed investigation into this unfortunate air crash.

The investigation is towards a concluding stage, however, some important findings of technical nature require immediate attention/intervention.

These are as follows:

(a) Sequence of events was initiated with dislodging of one blade of power turbine Stage-1 (PT-1), inside engine number one (left-side engine) due to fatigue.

(b) This dislodging of one blade resulted in in-flight engine shut down and it contributed towards erratic/abnormal behavior of engine number one propeller.

(c) According to Service Bulletin these turbine blades were to be changed after completion of 10,000 hours on immediate next maintenance opportunity. The said engine was under maintenance on November 11, 2016, at that time those blades had completed 10004.1 hour (due for change). This activity should have been undertaken at that time but it was missed out by the concerned.

(d) Aircraft flew approximately ninety-three hours after the said maintenance activity, before it crashed on December 7, 2016.

(e) Missing out of such an activity highlights a lapse on the part of PIA (maintenance and quality assurance) as well as a possible in-adequacy/lack of oversight by Pakistan CAA.

2. In light of the above, following is recommended please:-

(a) PIA is to ensure immediate implementation of said Service Bulletin in letter and spirit on the entire fleet of ATR aircraft, undertake an audit of the related areas of maintenance practices, ascertain root cause(s) for the said lapse, and adopt appropriate corrective measures to avoid recurrence.

(b) Pakistan CAA is to evaluate its oversight mechanism for its adequacy to discover lapses and intervene in a proactive manner, ascertain shortfall(s) and undertake necessary improvements.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

According to Aviation Division, on October 27, 2020, representative of Aviation Division and President Aircraft Accident Investigation Board (AAIB) appeared before Sindh High Court with an overview of the present status of the investigation into crash of PIA flight PK661. The overview did not include any conclusions of the investigation but included a request about the tentative timeline due to completion of an important international obligation, to which the honorable court graciously agreed.



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arshad.altaf
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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by arshad.altaf »

So what now? As is the norm here, nothing will happen. Who will be held responsible? So many changes may have already occurred since the crash. Is it safe to assume that the blades of the currently in-service ATRs are regularly examined. Hard to tell with PIAC.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

Probably December 7, 2016, PIA ATR 42-500 (AP-BHO) Chitral to Islamabad flight PK661 final investigation report to be submitted at Sindh High Court on November 19.



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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

Aircraft Accident Investigation Board (AAIB) of Pakistan final investigation report on December 7, 2016, PIA ATR 42-500 (AP-BHO) Chitral to Islamabad flight PK661 available for download on following link:

https://www.bea.aero/fileadmin/user_upload/AAIB-386.pdf

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Information on The Aviation Herald on following link:

http://avherald.com/h?article=4a1c2ee4/0000

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by ammad »

This line caught my attention.

Owing to an un-precedent combination of technical malfunctions, this
accident proved to be a unique case of its kind in the entire operational life of ATR
aircraft flying all around the world since 1984

page: XXI
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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

Aircraft Accident Investigation Board (AAIB) of Pakistan final investigation report on December 7, 2016, PIA ATR 42-500 (AP-BHO) Chitral to Islamabad flight PK661 now also available for download on Pakistan CAA website:

https://www.caapakistan.com.pk/Upload/S ... IB-386.pdf

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

Aircraft Accident Investigation Board (AAIB) of Pakistan final investigation report on December 7, 2016, PIA ATR 42-500 (AP-BHO) Chitral to Islamabad flight PK661 presented in Sindh High Court today.

The aircraft crashed due to technical problem/poor maintenance by PIA.

The court has summoned PIA Director Safety Management to appear in next hearing.

Next hearing of the case at Sindh High Court will take place on December 1, 2020.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Flyer1015 »

Abbas Ali wrote: Thu Nov 19, 2020 11:15 am
The aircraft crashed due to technical problem/poor maintenance by PIA.
That's only part of the equation. The technical problem was a horrible failure, the propeller didn't feather properly, and actually oversped and resulted in tremendous drag on the left side. They countered with right rudder and power on right engine, but ultimately made the critical mistake of trying to maintain altitude. That resulted in airspeed depletion which eventually led to a stall and spin. It looks like their only option would have been a continued descent and attempt at an off-airport landing. Sounds like they were in a very unfortunate position.


Here are some tidbits:

(vi) The event was unexpected and the cockpit crew was not trained for this specific sequence of event. This event highlights importance of adhering to the cardinal principle of Fly, Navigate, and Communicate, especially in an unusual emergency situation. The crew actions indicated several events of incorrect prioritization. Top priority must always be accorded to the control of the aircraft first and then consume the remaining effort in effective management of cockpit resources for mitigation of hazards, and subsequent safe recovery of the aircraft.



Training problems/failures of both pilots:


2.2.1.3Recurrent Trainings: Captain‟s all annual proficiency trainings and checks were studied. Observations about his performance were generally diverse in nature, however few recurring observations were about not been assertive, adherence to SOPs / procedures, speed control during drift down / emergency descend, situational awareness etc. The last simulator training records and route checkout reflected grey areas in his performance about adherence to the SOPs / procedures, and decision making etc. However, the same records indicated that he had passed / cleared the required checks(including proficiency check and line check). The possible attribution of any of these aspects with the crash has been discussed in later parts of analysis.



2.2.2.1The First Officer (A) started career in PIA in 2005. He initially flew Twin Otter and Fokker F-27 aircrafts as a First Officer. He converted on ATR42-500aircraft in 2007. At the age of 40 years he had accumulated1416:00 hrs on ATR aircraft and a total of 1742:30 hrs of flying experience, with a meager career progression. His training records reflect frequent observations related to poor / slow progress, and unacceptable performance, however, he remained on the job and after necessary review he was being considered acceptable as per the minimum acceptable standards of PIA and CAAPakistan. He held a valid Commercial Pilot License(CPL-2398 date of issuance 21 May 1998). He had valid medical fitness.


2.2.2.2 Up gradation Training: He joined up gradation training on Airbus 310 as a First Officer, however he was unable to cope with the requirements and was sent back on ATR aircraft (and was restricted to remain a First Officer).





iv ) Reduction of PLA by FO (A) was incorrect action and it subsequently resulted in a decrease of IAS from 186 knots to 146 knots.



(v)IAS progressively decreased. Reducing PLA of good engine was an incorrect action. Np-1 at 102% instead of being at feathering position had an additional drag.Slight increase of PLA-2 was not sufficient to maintain IAS (especially with such high drag). This action indicated that the cockpit crew had the understanding about which engine had the problem, however, had a low understanding about Energy State Management.



(vii) Since PLA-2 was out of notch, selection of MCT was not effective and this action reflected low knowledge about the aircraft systems.



(xiii)The power modulation of No 2 Engine by the Captain (ie first retarding the power from 66.8º to 41.1º and advancing to 71.2º, and then after a while retarding again to 32.7º and then abruptly advancing again to 54.0º) to cater for the asymmetric conditions,was an incorrect action and contributed in rapid depletion of speed.





(xiv)Power modulation to cater for the asymmetric condition and flying at speed range around the white bug on the IAS indicator (later experienced by the cockpit crewto be just above the stall), resultantly caused an improper Energy State Management.(xv)The cockpit crew did not try to trade-off altitude with speed.



(ix)The cockpit crew breathing was abnormal (hyperventilating) and their voices were trembling. (x)The cockpit crew attempted to recover out of this situation;however their actions were not precise during the recovery. (xi)Possible cross-controlling of the elevator control resulted in pitch disconnect, which may have further added up towards existing aerodynamic degradation. (xii)The cockpit crew voices and breathing indicated that they were extremely nervous and traumatized during this part of flight.


(xiv)The blade pitch angle had most probably decreased further beyond the earlier fine pitch value (at which the Np-1 was in the range of 120%to 125%). This new pitch angle was possibly beyond the low pitch in flight(from fine towards reverse angle). At this position the generated drag value was around 2,000 lbf. This drag was about seven times more than the drag a propeller can usually produce (once in feather state) during a single engine flight envelope. (xv)In this aerodynamically degraded state the aircraft was unable to fly a level flight. It could only fly in a gradual descend profile (eg an IAS of 150 to 160 knots and a continuous descend of around 800 to 1,000 fpm).

(xvi)The cockpit crew did not re-engage Auto-Pilot again.

(xvii) The cockpit crew did not consider diversion to nearby airfields.



(xx)Even after several minutes from the uncontrolled flight condition the conversation still reflected that the cockpit crew was under immense physiological stress and trauma, and their voices were trembling and their breathing reflected fear.

(xxi)The cockpit crew tried to overcome this state of physiological stress and trauma, and their breathing normalized, however they remained grossly confused and scared. Their discussions remained unstructured.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by A310 »

Please don’t forget to quote the part where they mentioned that PIA doesn’t really train its pilots to divert to military airfields specially in northern operations.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by A310 »

I believe the fact that this never ever happened in 36 years life of ATR really explains what happened and also tells a lot about the state engineering keeps the aircraft in.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by A310 »

Explicitly written that pilots were NOT trained for this type of (multiple)failure(s). Would be unwise to even question any of their actions.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by A310 »

Flyer1015 wrote: Thu Nov 19, 2020 3:33 pm
Abbas Ali wrote: Thu Nov 19, 2020 11:15 am
The aircraft crashed due to technical problem/poor maintenance by PIA.
They countered with right rudder and power on right engine, but ultimately made the critical mistake of trying to maintain altitude. That resulted in airspeed depletion which eventually led to a stall and spin. It looks like their only option would have been a continued descent and attempt at an off-airport landing. Sounds like they were in a very unfortunate position.

My friend easy to say this in the comfort of your home. Altitude is very very very critical in northern operations.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by Abbas Ali »

Aviation Division Press Release issued on November 19, 2020

The Aircraft Accident Investigation Board (AAIB) has completed the investigation of PIA flight PK661 (AP-BHO) wherein 47 passengers and crew members lost their lives near Havelian, 24 nautical miles north of Benazir Bhutto International Air Port (BBIAP) - Islamabad.

According to the investigation report, the air crash was the result of three latent technical factors including:
  1. Fracture of one of the power turbine blades of engine number 1.
  2. A broken fractured pin inside overspeed governor.
  3. Probable pre-existing contamination inside Propeller Valve Module (PVM).
The air crash investigation spanned over nearly four years due to complexity and unprecedented nature of latent conditions. The detailed investigation required keeping all stakeholders on board through rigorous coordination with the respective states and their aircraft accident investigation bodies. This report is being release with the concurrence of these stakeholders i.e. BEA of France, Transportation Safety Board of Canada (TSB) and National Transportation Safety Board (NTSB) of USA.

It is added here that the aircraft investigations are carried out under the guidelines provided by International Civil Aviation Organization (ICAO) and are aimed at improving safety of air travel and to avoid any recurrence in future.

Minister for Aviation Ghulam Sarwar Khan has expressed his sympathies and condolences with the families who lost their loved ones in the tragic crash.

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Re: PIA ATR Flight PK-661 Crashes Near Havelian

Post by imiakhtar »

Flyer1015 wrote: Thu Nov 19, 2020 3:33 pm
Abbas Ali wrote: Thu Nov 19, 2020 11:15 am
The aircraft crashed due to technical problem/poor maintenance by PIA.
That's only part of the equation. The technical problem was a horrible failure, the propeller didn't feather properly, and actually oversped and resulted in tremendous drag on the left side. They countered with right rudder and power on right engine, but ultimately made the critical mistake of trying to maintain altitude. That resulted in airspeed depletion which eventually led to a stall and spin. It looks like their only option would have been a continued descent and attempt at an off-airport landing. Sounds like they were in a very unfortunate position.


Here are some tidbits:
:check_mark:

Don't bother yourself withg this crowd Flyer, even after the recent A320 crash, you can't criticise those at the top of the hierarchical chain. In Pakistan, that means those of rank, ie Pilots and military officials.

As you note with your excellent excerpts, these pilots "flew" an aircraft whilst being on the back foot all the time. That means when abnormal situations arise, there is no safety margin. Basics like flying aircraft at the optimum cruise speed. Any cadet worth his salt could tell you a 50 knots higher cruise speed would have given them additional time at alt and range and therefore more options. Higher speed equals greater control surface authority too.

And there were many small errors as you show which culminated in the pilots planting this initially controllable aircraft into the ground. The crew put themselves and their passengers into this situation.
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