Sunday, April 22, 2012

What Happened to Bhoja Air Flight 213?

Friday's air-crash in Hussainabad near the Benazir Bhutto International Airport was the second worst aviation disaster in the history of Pakistan (behind 2010's Airblue crash). 127 lives ended in a matter of second, 127 dreams ended unrealized.

Apart from possible technical and human errors, a few other possible theories can be put forward to account for this terrible air-crash.


Microbursts


A microburst often causes aircraft to crash when they are attempting to land. It is an extremely powerful gust of air that, once hitting the ground, spreads in all directions. As the aircraft is coming in to land, the pilots try to slow the plane to an appropriate speed. When the microburst hits, the pilots will see a large spike in their airspeed, caused by the force of the headwind created by the microburst. A pilot inexperienced with microbursts would try to decrease the speed. The plane would then travel through the microburst, and fly into the tailwind, causing a sudden decrease in the amount of air flowing across the wings. The decrease in airflow over the wings of the aircraft causes a drop in the amount of lift produced. This decrease in lift combined with a strong downward flow of air can cause the thrust required to remain at altitude to exceed what is available.

This might explain the sudden 950 foot drop that the aircraft underwent prior to the incident.


Debilitating Weather Conditions


The weather was ominious that day.
The Pakistan Meteorological Department had issued two separate warnings to the Civil Aviation Authority of Pakistan( CAAP) about possible, hazardous flying conditions. According to Director General Pak Met, Arif Mahmood, the warnings included "wind gusts approaching 100 kph and low visibility due to heavy rain and cloud cover". He further stated that "the aircraft should never have been given the permission to land at the Benazir Bhutto International Airport but instead should have been redirected to Allama Iqbal International Airport in Lahore."

The Civil Aviation Authority of Pakistan's head, Nadeem Yousafzai, downplayed the importance of the met office's warnings and said that they were not enough to close down an entire airport.


Pilot Error


The tires did not burst.
Eyewitnesses state that they saw the aircraft hit an open field, bounce back upwards and then explode in mid-air. The negligible damage to the surrounding homes supports this theory because if the aircraft had landed and then exploded then the damage would have been extreme. The radius through which the debris and the bodies were found was also just a shade over 1 kilometer. Another fact that propagators of this theory use to supports their notion is the relatively pristine state of the tires. Normally, if an aircraft impacts the ground like that, the resulting g-forces destroy the tires. However the point to note here is that the involved aircraft was a Boeing 737 that had a retractable landing gear.
Retractable Landing Gear

What is not accounted for here are the tire marks found in the area. This means that the pilot had attempted to land in the area first. A little distance from the initial landing site are some destroyed trees and an impact crater. Near the impact crater is a roughly formed ramp which the doomed aircraft might have encountered and this might explain the 'bouncing back'.


The tire-tracks mean that the landing gear was opened.
The impact-crater just ahead of the tire-tracks.
Normally, after the pertinent control tower has communicated the required information to the pilot, the final decision about landing is upon his/her own discretion. Being a private airline pilot, Mr. Afridi, might have considered the losses Bhoja Air might have borne if the jet were to be redirected to another airport (parking fees, fuel expenses, passenger services etc) and might have decided against it. The private airline companies in Pakistan, emphasize a lot on profits and thus the degenerating service and passenger safety (This is the second major private airline crash in Pakistan in the last two years, both being the top two worst aviation disasters in the country's history).

The altitude of the aircraft was also reported as exceedingly low and the sound of its engines as a deafening thunder by the local populace. A point to note here is that, all the aircrafts that take-off from or land at the Benazir Bhutto International Airport pass over this locale.


Technical Fault

Some eyewitnesses, especially those that were traveling on the nearby Islamabad Expressway, report a fire blazing in one of the engines that gradually started to envelope the whole plane. The plane was described by some, as a blazing ball of fire. This might explain the badly charred pieces of the airplane. However, it is premature to say what exactly caused this fire, if it ever existed that is.

The co-pilot of the doomed flight was the last person to communicate with the ATC Tower. Three minutes before the crash he exclaimed: "I have lost control over the airplane!" and after that the communication link was broken

Interestingly, a preliminary investigation by the CAAP yields that the plane exploded in mid-air because it was flying too fast and too low. According to statistics made available the plane was flying at an altitude of 200 feet when it would have been at 1200 feet or more. It was also flying exceedingly fast for a plane that is to land in less than 4 minutes (500 kph).
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Location of the crash, the road that runs through the image is the Islamabad Expressway.