2012-08-05: We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model CL-600-2C10 (Regional Jet Series 700, 701, & 702), CL-600-2D15 (Regional Jet Series 705), CL-600-2D24 (Regional Jet Series 900), and CL-600-2E25 (Regional Jet Series 1000) airplanes. This AD was prompted by reports of the air driven generator (ADG) failing to power essential buses during functional tests, due to the low threshold setting of the circuit protection on the ADG's generator control unit (GCU) preventing the ADG from supplying power to the essential buses. This AD requires installing a new
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or serviceable ADG GCU. We are issuing this AD to prevent loss of power from the ADG to the essential buses which, in the event of an emergency, could prevent continued safe flight.
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2011-18-52: We are publishing a new airworthiness directive (AD) for certain Agusta S.p.A. (Agusta) Model AB139 and AW139 helicopters that requires establishing a revised life limit for each tail rotor (T/R) blade and updating the helicopter's historical records, repetitively inspecting T/R blades for a crack, and replacing certain T/R blades. This AD is prompted by a fatal accident involving an Agusta Model AW139 helicopter, which may have been caused by cracks in a T/R blade. These actions are intended to detect and prevent a crack in a T/R blade, which could lead to failure of a T/R blade and subsequent loss of control of the helicopter.
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98-21-26: This amendment adopts a new airworthiness directive (AD) that applies to certain Mooney Aircraft Corporation (Mooney) Models M20J, M20K, M20M, and M20R airplanes. This AD requires grinding the surface of the main landing gear (MLG) leg bracket, inspecting this area for cracks, and replacing any cracked MLG leg bracket. This AD is the result of the manufacturing of several of the MLG leg brackets using laser pattern cutting. The brackets, when manufactured using this process, develop minor cracks at the bends, which could propagate over time. The actions specified by this AD are intended to prevent failure of the MLG side brace bolt caused by cracking of the MLG leg bracket, which could result in MLG collapse with consequent loss of control of the airplane during taxi, takeoff, or landing operations.
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2012-03-04: We are superseding an existing airworthiness directive (AD) for certain Airbus Model A310 series airplanes. That AD currently requires, for certain airplanes, modifying the wire routing and installing additional protective sleeves. This new AD adds, for certain airplanes, modifying wire routings and installing a modified bracket. This AD was prompted by analyses of the wire routing showing that the route of the fuel electrical circuit in the right-hand wing must be modified in order to ensure better segregation between fuel quantity indication wires and the 115-volt alternating current wires. We are issuing this AD to prevent short circuits leading to arcing, and possible fuel tank explosion.
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54-12-02: 54-12-02 MCCAULEY: Applies to All McCauley Propellers Having 41D5926 Hub With SS-135-6 Blades and D-1093 Hub With SS-135-6M or SS-138-6 Blades.
Compliance required as indicated.
On the basis of satisfactory vibration stress surveys conducted on the 102-inch diameter configuration, these propellers were approved vibration wise for installation on the Continental W-670-6A and W-670-6N and Lycoming R680 engines. When installed on the Continental engine, the propeller must be indexed in the 0 degree position (blades in line with the crankthrow) and operation is to be restricted between 1,500 and 1,650 r.p.m.
Additional approval were given for the installation of propellers in reduced diameters at a time when the effects on the vibratory stresses resulting from such a reduction were not generally appreciated. Accordingly, some installations were made where the propeller diameter was reduced, as in the Fairchild M-62C. Service experience with this installation and a more thorough knowledge of the vibration problems indicate that diameters below the normal 2 percent reduction that is usually permissible on the basis of a stress survey have resulted in serious failures. Accordingly, to preclude additional propeller failures, the following should be performed. Compliance required prior to July 1, 1954.
(a) To preclude failures due to vibratory conditions, remove from service all of these propellers in diameters outside the 102- to 100-inch limits.
(b) To preclude fatigue failures due to corrosion or galling in the blade shank region and/or hub, disassemble propellers maintained in service (diameters 102 to 100 inches) and magnetically inspect hub and blades at intervals not exceeding 100 hours. The propeller blade and hub surface must be kept free from corrosion at all times.
If 100 hours operating time has not been accumulated since an inspection was conducted on the propeller as provided in AD 47-43-09, it will be satisfactory to operate until 100 hours have been accumulated.
This supersedes AD 47-43-09.
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98-08-25 R1: This amendment revises Airworthiness Directive (AD) 98-08-25, which currently requires replacing the nose landing gear (NLG) drag link bolt with an approved heat-treated bolt that has the manufacturer's serial number, manufacture date, and the last three digits of the drawing number (055) on the bolt head on certain Twin Commander Aircraft Corporation (Twin Commander) 500, 680, 690, and 695 series airplanes; and changing the bolt part number (P/N) to be installed on Models 690D and 695A from P/N ED10055 to P/N 750076-1. The FAA inadvertently transposed the serial numbers of the 4 affected Model 695A airplanes. This AD retains the same actions of AD 98-08-25, and corrects the serial numbers of these 4 airplanes. Three of the four airplanes are not on the U.S. Register and the other one is already in compliance with the actions of AD 98-08-25. The actions specified in this AD are intended to continue to prevent the NLG from collapsing due to failure of a drag link bolt, which could result in loss of control of the airplane during landing operations.
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2012-07-05: We are adopting a new airworthiness directive (AD) for certain Fokker Services B.V. Model F.27 Mark 050 airplanes. This proposed AD would require performing a low frequency eddy current inspection for cracks of the lap joint of the rear fuselage, and repair if necessary. This AD was prompted by reports of cracking in the fuselage lap joint. We are issuing this AD to detect and correct exponential crack growth, which could lead to failure of the lap joint over a certain length and consequent in-flight decompression of the airplane.
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98-21-05: This amendment adopts a new airworthiness directive (AD), applicable to all SD3-30, SD3-60, SD3-60 SHERPA, and SD3 SHERPA series airplanes, that requires repetitive visual inspections of the flap levers and bracket assembly of the inner flap sub-assembly of the left and right wings to detect certain discrepancies; and corrective actions, if necessary. This amendment is prompted by mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to detect and correct failure of the levers and bracket assembly, which could result in uncommanded retraction of the inner flap assembly and consequent reduced controllability of the airplane.
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2012-06-09: We are adopting a new airworthiness directive (AD) for all Lockheed Martin Corporation/Lockheed Martin Aeronautics Company Model 382, 382B, 382E, 382F, and 382G airplanes. This AD was prompted by a report of incidents involving fatigue cracking and corrosion in transport category airplanes that are approaching or have exceeded their design service objective. This AD requires revising the maintenance inspection program to include inspections that will give no less than the required damage tolerance analysis for each principal structural element (PSE), doing repetitive inspections to detect cracks of all PSEs, and repairing cracked structure. We are issuing this AD to maintain the continued structural integrity of the fleet.
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74-09-03: 74-09-03 AVCO LYCOMING: Amendment 39-1823. Applies to all Avco Lycoming T5309C, T5311A and T5311B turboshaft engines.
Compliance required, unless already accomplished, prior to the accumulation of 100 hours in service after the effective date of this AD.
To prevent possible compressor disc or impeller assembly failures leading to partial or complete loss of engine power, remove and replace the second, third, fourth, and fifth stage compressor rotor discs and centrifugal impeller assemblies in accordance with the table below.
COMPONENT - 2nd Stage Compressor Rotor Disc; REMOVE P/N - 1-100-239-01; INSTALL P/N - 1- 100-239-04 or later FAA approved P/N
COMPONENT - 3rd Stage Compressor Rotor Disc; REMOVE P/N - 1-100-242-01 or 1-100-242-06; INSTALL P/N - 1-100-242-09 or later FAA approved P/N
COMPONENT- 4th Stage Compressor Rotor Disc; REMOVE P/N - 1-100-244-01 or 1-100-244-02; or 1-100-244-04 or 1-100-244-06; INSTALL P/N - 1-100-244-08 or later FAA approved P/N
COMPONENT- 5th Stage Compressor Rotor Disc; REMOVE P/N - 1-100-417-01 or 1-100-417-02; INSTALL P/N - 1-100-417-05 or later FAA approved P/N
COMPONENT - Centrifugal Impeller Assembly; REMOVE P/N - 1-100-440-04 or 1-100-440-07; INSTALL P/N - 1-100-440-07; Rev. B or later FAA approved P/N
Upon submission of substantiating data through an FAA Maintenance Inspector, the Chief, Engineering and Manufacturing Branch, FAA, New England Region, may adjust the compliance time.
NOTE: (Avco Lycoming Service Bulletin Number 0033 pertains to this subject.)
This amendment becomes effective May 2, 1974.
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