Airworthiness Directive · Amendment 39-14502 · MT-Propeller Entwicklung GmbH Propellers
MT-Propeller Entwicklung GmbH Propellers
Superseded. A later AD replaced this one: AD 2007-26-13. Comply with the one in force.
This AD applies to MT-Propeller Entwicklung GmbH, models MT, MTV-1, MTV-2, MTV-3, MTV-5, MTV-6, MTV-7, MTV-9, MTV-10, MTV-11, MTV-12, MTV-14, MTV-15, MTV-17, MTV-18, MTV-20, MTV-21, MTV-22, MTV-24, and MTV-25 propellers with serial numbers (SNs) below 95000, which have not been overhauled since April 1994. These propellers may be 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.
The FAA is adopting a new airworthiness directive (AD) for certain MT-Propeller Entwicklung GmbH variable pitch and fixed pitch propellers with serial numbers (SNs) below 95000, which have not been overhauled since April 1994. This AD requires overhauling the propeller blades of these propellers within 30 days after the effective date of the AD. This AD also requires performing initial and repetitive visual inspections of affected propeller blades. This AD also requires removing all propeller blades from service with damaged erosion sheath bonding or loose erosion sheaths and installing any missing or damaged polyurethane protective strips. This AD results from reports of stainless steel leading edge erosion sheaths separating from propeller blades and reports of propeller blades with damaged or missing polyurethane protective strips (PU-protection tape) due to insufficient inspection procedures in older MT-Propeller Entwicklung GmbH Operation & Installation Manuals. We are issuing this AD to prevent erosion sheath separation leading to damage of the airplane.
You are responsible for having the actions required by this AD performed within the compliance times specified unless the actions have already been done.
Note 1: Information about inspection procedures and acceptable limits can be found in Table 1 of this AD.
Overhaul all propeller blades of propellers listed in the applicability, within 30 days after the effective date of this AD.
During the next preflight inspection or 100-hour inspection, whichever occurs first, after the effective date of this AD, inspect all MT and MTV propellers by doing the following:
(1) Determine if the erosion sheath of any propeller blade is cracked or loose; and
(2) Determine if any propeller blade has other damage out of acceptable limits.
(3) Before the next flight, remove from service those propeller blades with a cracked or loose erosion sheath, or other damage affecting airworthiness.
| For propeller model... | See operation and installation manual... |
|---|---|
| MT | No. E-112, issued Nov. 1993 or later. |
| MTV-1, MTV-7, MTV-10, MTV-17, MTV-18, MTV-20 | No. E-118, issued March 1994 or later. |
| MTV-5, MTV-6, MTV-9, MTV-11, MTV-12, MTV-14, MTV-15, MTV-21, MTV-22, MTV-25 | No. E-124, issued March 1994 or later. |
| MTV-2, MTV-3 | No. E-148, issued March 1994 or later. |
| MTV-24 | No. E-309, issued March 1994 or later. |
During the next pilot's preflight inspection after the effective date of this AD, if the polyurethane protective strip on the leading edge of the inner portion of the blade is found to be damaged or missing, the polyurethane protective strip must be replaced or installed within 10-flight hours. If electrical de-icing boots are installed, no polyurethane protective strips are required.
(i) If after the effective date of this AD, any propeller blade erosion sheath found to be cracked or loose during the pilot's preflight inspection, or 100-hour inspection, or annual inspection, must be repaired, replaced, or overhauled before the next flight.
If after the effective date of this AD, any propeller blade polyurethane protective strip found to be damaged or missing during the pilot's preflight inspection, or 100-hour inspection, or annual inspection, must be replaced or installed within 10-flight hours. If electrical de-icing boots are installed, polyurethane protective strips are not required.
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
