Remember the mystery - rather a frightening mystery actually - of the AgustaWestland AW139 tailboom that suddenly collapsed during taxi last week? Well it's still a mystery and EASA has put out an emergency airworthiness directive based on an earlier AgustaWestland service bulletin.It requires "detailed" inspections of the "tail panels" within 25 flight hours or 30 days and then repetitive inspections every 50 flight hours.
But on seven aircraft identified by serial number (31006, 31020, 31022, 31042, 31136, 31157 and 31248) the initial inspection has to be done within five hours. I don't immediately know what the significance of those seven aircraft is or what the common factor is. Update: it's suggested to me that all of them have previously suffered tailstrikes.
From Flight's rather neat Helicas database
it seems the gang of seven are currently being operated all over the
place: one in Abu Dhabi, two in the Gulf of Mexico, one in Scotland,
one in Norway, one in Japan, and one with the Pakistan Army. And they
were built anything from five years to five months ago. Anyone know the
connection?
EASA says the reason for all this is as follows: "During the taxiing phase the tailboom of an AW139 helicopter bent and collapsed. The root cause of this accident is still unknown and under investigation.
"Evidence of debonding had been previously reported on some tailboom panels of AB/AW139 helicopters. therefore EASA AD 2008-0157 required repetitive inspections of the tailboom assembly and, in case of debonding detection, the accomplishment of corrective actions."
So this year that's the Sikorsky S-92, Eurocopter EC225 Super Puma, and AW139 that have suffered sudden and catastrophic mechanical failures. Welcome to the ever-interesting world of rotary flight.
EASA says the reason for all this is as follows: "During the taxiing phase the tailboom of an AW139 helicopter bent and collapsed. The root cause of this accident is still unknown and under investigation.
"Evidence of debonding had been previously reported on some tailboom panels of AB/AW139 helicopters. therefore EASA AD 2008-0157 required repetitive inspections of the tailboom assembly and, in case of debonding detection, the accomplishment of corrective actions."
So this year that's the Sikorsky S-92, Eurocopter EC225 Super Puma, and AW139 that have suffered sudden and catastrophic mechanical failures. Welcome to the ever-interesting world of rotary flight.
on September 16, 2009 2:29 PM | Reply
According to the two Agusta Westland "Bollettino Tecnico" referenced in the AD (available on Agusta's website, http://www.agustawestland.com/system/files/139-193.pdf and http://www.agustawestland.com/system/files/139-194.pdf) the one bulletin (139-193) affects only aircraft that have been involved in tailstrikes, tail bumps, or tail scrapes. However, the other bulletin (139-194) affects many many more serial numbers (probably the remainder of the civil fleet).
on January 22, 2010 6:40 PM | Reply
All AW139 helicopter are affecting by EASA EMERGENCY AIRWORTHINESS DIRECTIVE AD No.: 2009-0234-E R1 in Europe.
on July 16, 2010 9:11 AM | Reply
This is unbelievable, lucky it didn't happen during flight!