Airworthiness Directive · Amendment 39-11216 · MT-Propeller Entwicklung GMBH Models MTV-9-B-C and MTV-3-B-C Propellers
MT-Propeller Entwicklung GMBH Models MTV-9-B-C and MTV-3-B-C Propellers
Superseded. A later AD replaced this one: AD 2002-23-09. Comply with the one in force.
MT-Propeller Entwicklung GMBH Model MTV-9-B-C propellers with serial numbers (S/Ns) starting with 98 or less, equipped with CL250-27 or CL260-27 blades with S/Ns starting with letter "A" through "P", equipped with Torx head blade root lag screws, P/N A-549-85 (3mm thread pitch), or P/N A-550-85 (4mm thread pitch); and Model MTV-3-B-C propellers with S/Ns starting with 98 or less, equipped with L250-21 blades with S/Ns starting with letter "A" through "P", equipped with Torx head blade root lag screws, P/N A-549-85 (3mm thread pitch), or A-550-85 (4mm thread pitch). These propellers are installed on but not limited to Sukhoi SU-26, SU-29, SU-31; Yakovlev YAK-52, YAK-54, YAK-55, and Technoavia SM-92 airplanes.
This amendment adopts a new airworthiness directive (AD) that is applicable to MT-Propeller Entwicklung GMBH Models MTV-9-B-C and MTV-3-B-C propellers. This action requires initial and repetitive inspections of Torx head blade root lag screws for torque values and breakage, and, if any screws are found broken or with insufficient torque, replacement of all screws with new lag screws. In addition, this AD requires replacement of certain model Torx head blade root lag screws with improved, hexagonal head blade root lag screws. This amendment is prompted by reports of broken Torx head blade root lag screws. The actions specified in this AD are intended to prevent blade root lag screw breakage, which could result in propeller blade separation and loss of control of the airplane.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
Propellers
