Calls For Inspection / Modification / Replacement Of Emergency Accumulator For Landing Gear Extension

EASA and CASA have noted an issue with the landing gear on Tecnam's P2006T significant enough to warrant the issuance of an Emergency AD. The directive, initially issued by EASA September 9, revises EASA AD 2011-0153-E dated 25 August 2011.

Tecnam P2006T

During a pre-flight inspection of a P2006T airplane, damaged was found on the lower skin of the fuselage aft tail cone. This damage was caused by the lower lid of the landing gear (LG) emergency accumulator, which had detached from the LG emergency accumulator, violently hitting the lower skin of the fuselage aft tail cone and damaging the accumulator cylinder. This condition, if not detected and corrected, could impair the airplane structural integrity and jeopardize the LG emergency extension in case of system failure in normal mode.

To address this unsafe condition, EASA issued Emergency AD 2011-0063-E to require a one-time inspection of the LG emergency accumulator cylinder for cracks, deformation or oil leakage and, depending on findings, the accomplishment of the applicable corrective actions. After that AD was issued, TECNAM developed a modification (MOD 2006- 108) and published Service Bulletin (SB) SB-048–CS Revision 1, dated 06 July 2011, that contained the instructions for that modification. Prompted by this development, EASA issued Proposed AD (PAD) 11-070 for consultation until 16 August 2011, proposing to require incorporation of this modification on all affected airplanes, and to require certain post-modification repetitive inspections.

During the consultation period of PAD 11-070, an operator who had applied TECNAM SB-048–CS on his airplane, reported finding abnormal deformation of the emergency accumulator, to such an extent that it would jeopardize the LG emergency extension in case of system failure in normal mode. To address this additional safety concern, TECNAM issued SB-068– CS which contains instructions to inspect post-modification airplanes.

For the reasons described above, this AD retains the requirements of EASA AD 2011-0063-E, which is superseded, and requires modification of the landing gear emergency accumulator by installation of safety rings and repetitive inspections after modification. In addition, prompted by the recent post-modification findings, this AD reduces the compliance time for the modification as originally proposed and requires additional first-flight-of-the-day repetitive inspections of the LG emergency accumulator cylinder and replacement of the LG emergency accumulator if cracks, deformation, or oil leakage is detected.

Because of the recent findings, it has been decided that further consultation, prior to Final AD issuance, on the changed requirements compared to those specified in PAD 11-070, is not conducive to safety and not in the public interest. This AD is considered to be an interim measure and further AD action may follow. This AD Revision is issued in order to allow Pilot-Owner to accomplish the daily pre-flight inspection of the modified LG emergency accumulator.

FMI: www.easa.europa.eu, www.casa.gov.au