Airworthiness Directive · Amendment 39-17623 · Turbine section
Eurocopter Deutschland GmbH (ECD) Helicopters
This AD applies to ECD Model BO105C (C-2 and CB-2 Variants) and BO105S (CS-2 and CBS-2 Variants) helicopters with a third stage turbine wheel, part number 23065833, installed, certificated in any category.
We are adopting a new airworthiness directive (AD) for ECD Model BO105C (C-2 and CB-2 Variants) and BO105S (CS-2 and CBS-2 Variants) helicopters with a certain third stage turbine wheel installed. This AD requires installing a placard on the instrument panel and revising the limitations section of the rotorcraft flight manual (RFM). This AD is prompted by several incidents of third stage engine turbine wheel failures, which were caused by excessive vibrations at certain engine speeds during steady-state operations. These actions are intended to alert pilots to avoid certain engine speeds during steady-state operations, prevent failure of the third stage engine turbine, engine power loss, and subsequent loss of control of the helicopter.
You are responsible for performing each action required by this AD within the specified compliance time unless it has already been accomplished prior to that time.
Within 30 days:
(1) For BO105C-2 and BO105CS-2 Variant helicopters, revise the Rotorcraft Flight Manual (RFM), Section 2, Limitations Section, by inserting page 2-25 of ECD Flight Manual BO 105 C/CS, revision 5, dated March 12, 2010.
(2) For BO105CB-2 and BO105CBS-2 Variant helicopters, revise the RFM, Section 2, Limitations Section, by inserting pages 2-8 and 2-27 of ECD Flight Manual BO 105 CB/CBS, revision 8, dated March 12, 2010.
(3) Install a placard on the instrument panel next to the triple RPM indicator that states: MIN. CONTINUOUS 98% N 2 —MIN. TRANSIENT 95% N 2.
