Unforgotable Fault recently happened in qatar

That's "came off" in the sense that nobody quite knows how. All happened a few days ago to a Gulf Helicopters machine at Doha, Qatar. Most importantly the tailboom departed during the taxi for take-off, which is obviously very odd but infinitely better than it happening half an hour later. The AW139 tailboom has history which may or may not turn out to be relevant. AgustaWestland on the case but apparently not clear themselves what caused this. And much Pprune discussion here.

Full-size picture, airworthiness directive, and AgustaWestland note to operators below.
The aircraft

Airworthiness directive key text:

Some operators of AB/AW139 helicopters have reported finding debonding of
fuselage tail boom panels. This condition, if not detected and corrected, could
lead to the structural collapse of the tail boom installation, resulting in loss of
control of the helicopter.
For the reason described above, this AD requires repetitive inspections of the
tail boom assembly and, in case signs of debonding are detected, the reporting
of findings to the design approval (type certificate) holder of the helicopter, and
the accomplishment of corrective actions.

AgustaWestland letter text:

Somma Lombardo, Italy
August 26th, 2009

AgustaWestland Statement

To: All Customers and Operators of AW139 Helicopter Model

All AgustaWestland Authorized Service Centres for the AW139
Helicopter Model

Subject: AW139 Tailboom Damage Occurrence

Dear Customer,

The purpose of this Letter is to inform You that on August 25th, 2009 an AW139
aircraft had an occurrence resulting in major damage to the aircraft tail boom while ground
taxiing.
There were no injuries to the crew or passengers.
AgustaWestland has immediately dispatched a technical team to inspect the aircraft and
assist the event investigation.
No similar occurrence has taken place with any other AW139.
AgustaWestland has been notified by the Customer that the rest of its fleet is continuing
operations.
AgustaWestland wish to remind You the importance of strictly applying the inspection
procedures for the tail boom area prescribed in the applicable AW139 Maintenance
publication.
AgustaWestland will keep all AW139 Customers and Operators informed of any follow‐on
information that may emerge.