PPRuNeUser0198
20th Jan 2011, 10:01
VIRGIN Blue was aware of a 737 fault a month before a plane's landing gear broke touching down at Melbourne Airport, a final report by the
Australian Transport Safety Bureau has revealed (ATSB).
When flight DJ208 from Adelaide touched down on October 20, 2009 the crew noticed that the plane was pulling to the right, requiring excessive thrust from the engine.
An examination found that a landing gear wheel was positioned at an unusual angle.
Further checks revealed that the inner wheel hub and bearing mount had broken away from the wheel assembly due to fatigue cracking.
The ATSB's final report into the incident has revealed that the airline, as well as the aircraft and wheel manufacturers, were aware the wheel had a design fault.
A service letter had been issued a month before the incident advising the airline that wheel halves “with a history of fatigue cracks in the transition between the bearing bore and thrust shoulder radius” should be inspected.
However at the time there was no requirement for mandatory inspection of the area during a tyre change. The airline also faced logistical issues, so the jet was not checked.
Australian Licensed Aircraft Engineers Association (ALAEA) federal secretary Steve Purvinas said the incident – which came just months after a nosewheel fell off a Virgin plane at Melbourne – posed an unacceptable risk to travellers.
"It's fortunate that (the) incident did not result in any serious injury but it demonstrates the urgent need for safety inspections across all Virgin's planes," Mr Purvinas said.
The wheel manufacturer first became aware of the issue in 2008 when it received reports of hub fractures and cracking on the inboard wheel halves, and was in the process of reviewing and making changes to their own maintenance schedules at the time of the Virgin incident.
Key changes involved the use of ultrasonic testing and a design change to the affected area.
The ATSB has concluded that the decision not to introduce the ultrasonic inspection at the time was “reasonable”.
“The last opportunity to detect the cracking before it resulted in wheel failure was during the 23rd tyre change on 14 September 2009,” the ATSB report said.
“While that occurred some four weeks after receipt of the service letter, the logistics involved in sourcing the necessary test equipment and training operators meant that the technique was not yet brought to an operational status at the time of that last tyre change.”
A fleet-wide inspection was undertaken by Virgin Blue immediately after the occurrence, with ten wheels potentially at risk of a similar failure removed from service.
As a result of the occurrence, the airline also performed a review of its engineering change evaluation procedure which resulted in changes to the process flow chart to include additional steps and a more structured risk assessment.
It has altered its wheel inspection procedure to include ultrasonic inspections.
Virgin Blue has been contacted for comment. However, at the time an airline spokesman said that they were advised by the wheel manufacturer that the issue was a "rare occurrence".news.com.au (http://www.news.com.au/travel/news/virgin-blue-plane-fell-through-the-cracks/story-e6frfq80-1225991746435)
Australian Transport Safety Bureau has revealed (ATSB).
When flight DJ208 from Adelaide touched down on October 20, 2009 the crew noticed that the plane was pulling to the right, requiring excessive thrust from the engine.
An examination found that a landing gear wheel was positioned at an unusual angle.
Further checks revealed that the inner wheel hub and bearing mount had broken away from the wheel assembly due to fatigue cracking.
The ATSB's final report into the incident has revealed that the airline, as well as the aircraft and wheel manufacturers, were aware the wheel had a design fault.
A service letter had been issued a month before the incident advising the airline that wheel halves “with a history of fatigue cracks in the transition between the bearing bore and thrust shoulder radius” should be inspected.
However at the time there was no requirement for mandatory inspection of the area during a tyre change. The airline also faced logistical issues, so the jet was not checked.
Australian Licensed Aircraft Engineers Association (ALAEA) federal secretary Steve Purvinas said the incident – which came just months after a nosewheel fell off a Virgin plane at Melbourne – posed an unacceptable risk to travellers.
"It's fortunate that (the) incident did not result in any serious injury but it demonstrates the urgent need for safety inspections across all Virgin's planes," Mr Purvinas said.
The wheel manufacturer first became aware of the issue in 2008 when it received reports of hub fractures and cracking on the inboard wheel halves, and was in the process of reviewing and making changes to their own maintenance schedules at the time of the Virgin incident.
Key changes involved the use of ultrasonic testing and a design change to the affected area.
The ATSB has concluded that the decision not to introduce the ultrasonic inspection at the time was “reasonable”.
“The last opportunity to detect the cracking before it resulted in wheel failure was during the 23rd tyre change on 14 September 2009,” the ATSB report said.
“While that occurred some four weeks after receipt of the service letter, the logistics involved in sourcing the necessary test equipment and training operators meant that the technique was not yet brought to an operational status at the time of that last tyre change.”
A fleet-wide inspection was undertaken by Virgin Blue immediately after the occurrence, with ten wheels potentially at risk of a similar failure removed from service.
As a result of the occurrence, the airline also performed a review of its engineering change evaluation procedure which resulted in changes to the process flow chart to include additional steps and a more structured risk assessment.
It has altered its wheel inspection procedure to include ultrasonic inspections.
Virgin Blue has been contacted for comment. However, at the time an airline spokesman said that they were advised by the wheel manufacturer that the issue was a "rare occurrence".news.com.au (http://www.news.com.au/travel/news/virgin-blue-plane-fell-through-the-cracks/story-e6frfq80-1225991746435)