PIA Flight 688

Pakistan International Airlines Flight 688

Pakistan International Fokker F27 similar to the one that crashed
Accident summary
Date	10 July 2006 (2006-07-10)
Summary	Engine failure which led to pilot error
Passengers	41
Crew	4
Injuries (non-fatal)	0
Fatalities	45 (all)
Survivors	0
Aircraft type	Fokker F27
Operator	Pakistan International Airlines
Registration	AP-BAL
Flight origin	Multan International Airport, Multan
Destination	Allama Iqbal International Airport, Lahore

Pakistan International Airlines (PIA) Flight 688 (PK688, PIA688) was a Fokker F27, operated by Pakistan's flag carrier Pakistan International Airlines scheduled to operate as a domestic passenger flight from Multan to Lahore and Islamabad. At 12:05 pm on 10 July 2006. It crashed into a field after one of its two engines failed shortly before takeoff from Multan International Airport. All 41 passengers and four crewmembers on board were killed.

PK688 remains as the deadliest plane crash in Pakistan until it was surpassed in 2010, 4 years later when an Airbus A321 flew into Margalla Hills in Islamabad while on approach to Benazir Bhutto International Airport which later become the deadliest in Pakistan to date. As of December 2015, PK688 remains as the fifth deadliest aviation disaster in Pakistan, just behind an Afghan Air Force crash in 1998, Pakistan International Airlines Flight 404, Bhoja Air Flight 213 and Airblue Flight 202.

Final report published by Pakistan's Civil Aviation Authority revealed that the Fokker F27 engines, one of its 40 years old engines, encountered problem shortly after take-off. Flight crews should be able to fly just with one engine and made a safe emergency landing. However, the pilots got confused. The Fokker later spiraled down and crashed.

Accident

The plane accelerated at Runway 36 when one of its engines, the right propeller, began to spool down. However, instead of aborting the take-off, the plane continued its take off. The plane then veered to the right. Realizing that an engine failure had occurred, the crews then flew at low altitude. The plane then stalled, clipped trees, and impacted the ground in an inverted attitude. In then exploded and burst into flames. The plane lost contact with Multan International Airport control tower two minutes after takeoff. The aircraft hit an electric power line before crashing into a wheat field. Everyone on board dies instantly. The post impact fire was so intense that even if there had been survivors of the initial impact no-one on board could have survived the fire.

Aircraft

The aircraft was a Fokker F-27 registered as AP-BAL. The aircraft was manufactured in February 1964 and had a total flying hours of 73.591. The engines, produced by Rolls Royce, were manufactured in 1958. The Inspection Form from Engine Log Book containing all relevant run-up data was despatched to Rolls Royce, Germany. It was determined that all the parameters were in required range.

Passengers and Crews

The victims included Asmatullah Khan (Manager Legal Services) of Pakistan International Airlines, Justice Muhammad Nawaz Bhatti and Justice Nazir Ahmed Siddiqui, who served on the Lahore High Court. Three military personnel, Vice-Chancellor of Bahauddin Zakariya University, Prof. Dr. Muhammad Naseer Khan, Prof. Dr. Abdul Rauf Sheikh, Professor department of Urdu at Bahauddin Zakariya University, internationally renowned Pakistani Neurosurgeon Prof. Iftikhar Ali Raja and eight women, including two flight attendants and three doctors, were also among those killed. One of the flight attendants was pulled out alive, but later died. According to the Daily Jang Lahore newspaper, no one was pulled alive from the plane.

The Captain was a 53 year old Captain Hamid Qureshi. He has a total flying experience of 9.320 hours and joined Pakistan International Airlines in December 1989. The First Officer was a 28 year old First Officer Abrar Chughtai with a total flying experience of 520 hours, of which 303 of them were on the Fokker F-27.

Investigation

A special investigation team has been assembled by PIA that announced they will compile a report about the crash within a week of the accident. At the same time, the Air League of PIA Employees Union has charged the PIA administration with responsibility for the crash. They argue that the airline operated flights with too few crew members, promoted incompetent officials, and carried out substandard overhaul work on aircraft, among other flaws.

Following this incident, all PIA Fokker aircraft were withdrawn from service and replaced with ATR aircraft. Mr. Muhammad Umer Draz Awan, the district manager of Faisalabad immediately visited the site and took control of the area until the managing director of PIA reached the site.

The investigation commission reported that following the accident a runway inspection revealed metal debris on the right side of the runway, between 4000 and 6800 feet down the runway, which was identified to originate from turbine blades of the right hand engine. The tracks on the ground suggested the aircraft veered to the right about 4000 feet down the runway and subsequently paralleled the runway center line to the right of it.

The investigation highlighted that although the aircraft had been certified as airworthy, the "procedure for issue of certificate of airworthiness is inadequate and weak to ensure that aircraft is maintained in accordance with Technical Literature" effectively putting into doubt that the aircraft was airworthy. The investigation added, that the last review of the aircraft for renewing certificate of airworthiness was done by an engineer with avionics background only. The investigation commission added pressure stating: "It is the opinion of the inquiry committee that present procedure of C of A cannot ensure that aircraft is maintained in accordance with Technical Literature and there is no Service Bulletin or Mandatory Airworthiness Directive (AD) outstanding. The inspection by Airworthiness for renewal of C of A is also a weak area." The investigation highlighted that for example the right engine's feathering motor was found in a poor condition of maintenance with wrongly fitted bearing and worn out armature, PIA's engineering did not possess diagrams of the CVR and DFDR for maintenance, the engine oil condition had not been monitored by any Spectrometric Oil Analysis Program and the oil was extremely dirty.

A tear down examination of the right hand engine revealed that the "thrust bearing of right engine was improperly assembled during last overhaul at DART Engine Shop PIAC in September 2005." The thrust bearing assembly had been turning eccentric while being assembled and thus was orbiting instead of an ideal rotation. The resulting imbalance caused reverse bending loads on the bold heads of the bearing assembly resulting in the failure of one bolt head, which created even more stresses and caused the bearing housing to open after the next 5 bolts had failed. The rotor assembly of the turbine increased its radii of orbit and caused the turbine rotor to free itsself and move forward resulting in the turbine discs and blades to experience heavy rubbing, the turbine blades failed due to resulting thermal stresses and broke away. The investigation determined "PIAC Engineering, Quality Control, failed to detect improper assembly of thrust bearing during last overhaul." They stated that following the engine failure, which was first observed at about 90 KIAS, the crew made following omissions in handling the emergency contrary to standard operating procedures:

• the crew did not rejected takeoff despite clear indications of an engine anomaly below V1
• did not declare emergency (internally and externally)
• did not retract the landing gear
• started the engine feathering drill below 400 feet AGL instead of taking positive control of the aircraft
• did not maintain runway direction, the resulting turn added to the speed reduction
• "The actions of aircrew lacked professionalism, a poor display of airmanship and an extremely poor emergency handling."

The investigation released 11 safety recommendations focussing mainly on maintenance procedures, maintenance quality assurance and regulatory oversight monitoring maintenance.

The pilots' failure to handle the emergency, specifically failing to raise the gear, caused the accident mostly due to inadequacies of PIA pilot training.

References

(Archive)

External links

• Accident description at the Aviation Safety Network