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99-07-18: This document publishes in the Federal Register an amendment adopting Airworthiness Directive (AD) 99-07-18 which was sent previously to all known U.S. owners and operators of Robinson Helicopter Company (RHC) Model R44 helicopters by individual letters. This AD requires, before further flight, inserting a Special Pilot Caution into the Normal Procedures section of the Rotorcraft Flight Manual (RFM). This amendment is prompted by several reports of sprag clutch assemblies with cracked or fractured sprag ends. The sprag clutch failures, determined to be due to a change in the manufacturing process, could result in loss of main rotor revolutions-per-minute (RPM) during autorotations. The intent of this AD is to alert pilots of the potential for the sprag clutch failing to overrun during autorotation, loss of main rotor RPM, and subsequent loss of control of the helicopter.
2013-19-22: We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 717-200 airplanes. This AD was prompted by multiple reports of cracks of overwing frames. This AD requires repetitive inspections for cracking of the overwing frames, and corrective actions if necessary. We are issuing this AD to detect and correct such cracking that could sever a frame, which may increase the loading of adjacent frames, and result in damage to the adjacent structure and consequent loss of structural integrity of the airplane.
56-21-02: 56-21-02 CESSNA: Applies to All Model T-50 (AT-17 Series and UC-78 Series) Aircraft. Compliance required on or before the next periodic inspection but not later than January 1, 1957, and at each periodic inspection thereafter. Receipt of reports of spar deterioration subsequent to the corrective measures of AD 49- 20-01 necessitates repetitive and detailed inspections. It is therefore requested that the rear spar just outboard of the fuselage fittings in the area of the inside corner of the fuel tank compartment be inspected annually for indications of wood deterioration of the spar. To accomplish the inspection, remove a section of plywood wing covering 6 inches x 4 inches adjacent to and outboard of the rear spar fuselage fittings and/or remove the fuel tank. If the inspection reveals any evidence of deterioration or separation of glue lines, removal of the lower cap strip between ribs in the affected area for detail inspection is required. To facilitate periodic inspection a permanent inspection opening may be incorporated provided it is reinforced to maintain strength equivalent to the original panel. If spar deterioration does not exceed 1 inch of spar depth the spar may be repaired by the following method: Remove the damaged wood of the spar and fit with a matched inlay by gluing to the spar with the ends of the inlay tapered in a ratio of no less than 15 to 1. A bottom reinforcing strip or plate of an approximate thickness of 0.4 of the depth of thickness of the inlay with a maximum of 0.4-inch thickness is to be matched and glued to the bottom surface of the spar. This bottom reinforcing strip should extend approximately 3 inches beyond the end of the glue line of the inlay strip. The installation of this reinforcement plate may require a rework of the spacer block at the attachment fitting and a rework of the fore and aft stringers where they attach to the bottom surface of the spar. The following contingencies apply in the repair of the spar: (1) In the "5,700 pound" wing spar, the material for the inlay lamination and bottom reinforcement strip or plate should be fabricated from birch, maple or its equivalent. (2) In the "5,100 pound" wing spar, the material for the inlay lamination and bottom reinforcement strip or plate may be fabricated from spruce. Workmanship, gluing process, quality of materials and other limitations and repair requirements of CAM 18 apply except where otherwise noted. After completion of the spar repair and repair or replacement of deteriorated gussets, stringers, etc., as necessary, drain holes should be incorporated in wings if not already installed. If the drain holes are installed it should be ascertained that they are open. The felt padding under fuel tanks should be inspected for evidence of absorption of moisture, and the padding replaced, if necessary, with neoprene coated felt or equivalent nonabsorbing material. This supersedes AD 49-20-01.
99-08-19: This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 747 series airplanes. This action requires replacement of the auxiliary power unit (APU) fuel boost pump with a serviceable pump. This amendment is prompted by findings from a design review and analysis, conducted as part of an accident investigation, of APU fuel boost pumps installed on certain Boeing Model 747 series airplanes. The actions specified in this AD are intended to prevent potential failures within the electrical motor assembly of the APU fuel boost pump (which could result in leakage of fuel from the electrical connector) or electrical arcing across the connector pins of the pump, and consequent fuel fire.
62-06-02: 62-06-02 EDO: Amdt. 406 Part 507 Federal Register March 10, 1962. Applies to All Aircraft Equipped With Models 345 and 345A Airborne Loran A Receivers. Compliance required within 1200 hours' time in service after the effective date of this AD. In order to reduce the spurious radiation which can adversely effect other navigational and communication equipment, modify Models 345 and 345A receivers in accordance with Edo Field Change Bulletin No. 27, dated August 28, 1961, so that the maximum radiation is 400 micromicrowatts. This directive effective April 10, 1962.
91-06-13: 91-06-13 BRITISH AEROSPACE: Amendment 39-6930. Docket No. 90-NM-258-AD. Applicability: Model ATP series airplanes equipped with main wheel assemblies, Part Number AHA1538 and AHA1663, certificated in any category. Compliance: Required as indicated, unless previously accomplished. To prevent seizure of the main landing gear (MLG) wheel and subsequent damage to the tire, accomplish the following: A. Within 30 days after the effective date of this AD, and thereafter at each wheel removal, on each wheel of the left and right main landing gear, perform a visual inspection of the wheel hub halves and wheel bearing grease retainer seals, in accordance with British Aerospace Service Bulletin ATP-32-13, Revision 1, dated February 28, 1990. NOTE: The British Aerospace service bulletin references Dunlop Limited Service Bulletin 32-1032, Revision 1, dated February 13, 1990, for additional instructions. 1. Measure the diameter of the grease retainer seal locating groove for wear on the brake side half hub. a. If the diameter of the groove exceeds 4.540 inches, prior to further flight, replace with a serviceable part, in accordance with Dunlop Limited Service Bulletin 32-1032, Revision 1, dated February 13, 1990. b. If the diameter of the groove does not exceed 4.540 inches, prior to further flight, protect the bore of the hub half with an application of Alocrom, in accordance with the Dunlop Limited service bulletin. 2. Verify that the brake side grease retainer seal, Part Number AH089109, has the cross-section shown in Figure 2 of Dunlop Limited Service Bulletin 32-1032, Revision 1, dated February 13, 1990. If this part's configuration is different (has not been chamfered), prior to further flight, replace it with a modified Part Number AH089109, in accordance with the Dunlop Limited service bulletin. 3. Visually inspect the inner bore and outer circumference of brake side grease retainer seal, Part Number AH089109. If the external circumference and the internal bore of the grease retainer seal, Part Number AHO89109, is scored or chipped, prior to further flight, replace it with a serviceable part in accordance with the Dunlop Limited service bulletin. 4. Verify that the valve side grease retainer seal is marked as Part Number AHO89720. Prior to further flight, replace any grease retainer seals not marked Part Number AHO89720 with one so marked. 5. Visually inspect the valve side grease retainer seal, Part Number AH089720. If the internal bore and the wheel bearing face of the grease retainer seal show signs of wear, prior to further flight, replace all defective grease retainer seals in accordance with the Dunlop Limited service bulletin. B. Accomplishment of Dunlop Modification C2614, which consists of installing improved grease retainer seals on both the brake side and the valve side half hubs, in accordance with Dunlop Limited Service Bulletin AHA1538/AHA1663-32-1042, dated April 10, 1990, constitutes terminating action for the repetitive inspections required by paragraph A. of this AD. C. An alternate means of compliance or adjustment of the compliance time, which provides an acceptable level of safety, may be used when approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. NOTE: The request should be submitted directly to the Manager, Standardization Branch, ANM-113, and a copy sent to the cognizant FAA Principal Inspector (PI). The PI will then forward comments or concurrence to the Manager, Standardization Branch, ANM-113. D. Special flight permits may be issued in accordance with FAR 21.197 and 21.199 to operate airplanes to a base in order to comply with the requirements of this AD. All persons affected by this directive who have not already received the appropriate service documents from the manufacturer may obtain copies upon request to British Aerospace, PLC, Librarian for Service Bulletins, P.O. Box 17414, Dulles International Airport, Washington, D.C. 20041-0414. These documents may be examined at the FAA, Northwest Mountain Region, Transport Airplane Directorate, 1601 Lind Avenue S.W., Renton, Washington. This amendment (39-6930, AD 91-06-13) becomes effective on April 15, 1991.
99-07-19: This amendment adopts a new airworthiness directive (AD) that is applicable to AlliedSignal Inc. TFE731-40R-200G turbofan engines. This action requires inspection of the fuel flow meter tube assembly part number (P/N) 3061157-2, which connects the fuel control to the fuel flow meter, and eventual replacement of the tube and fuel flow meter mounting bracket. This amendment is prompted by two in-flight shutdowns on two recently certified TFE731-40R turbofan engines within the last six months that resulted from fuel flow meter tube assembly failures. The actions specified in this AD are intended to prevent fuel from spraying on and around electrical components due to a cracked fuel line, which can result in an in-flight engine shutdown, and could possibly result in an engine fire.
99-07-20: This amendment adopts a new airworthiness directive (AD) that applies to all Avions Pierre Robin Model R2160 airplanes. This AD requires repetitively inspecting the vertical stabilizer spar in the area of the lower fitting of the rudder for cracks, loose rivets, or spar web distortion; and modifying the vertical stabilizer spar either immediately or at a certain time period depending on whether discrepancies are found during the inspections. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for France. The actions specified by this AD are intended to detect defects (cracks, loose rivets, or spar web distortion) in the vertical stabilizer spar, which could result in structural failure of the vertical stabilizer with possible reduced or loss of control of the airplane.
2013-15-01: We are adopting a new airworthiness directive (AD) for Agusta Model AB139 and AW139 helicopters. This AD requires deactivating the Full Icing Protection System (FIPS) and installing a placard next to the FIPS controller stating that flight into known icing is prohibited. This AD is prompted by a report of a fire in the aft avionics bay and the baggage compartment resulting from an Auto Transformer Rectifier Unit internal circuit overload. These actions are intended to prevent a fire, structural damage, and subsequent loss of control of the helicopter.
99-08-07: This amendment supersedes an existing priority letter airworthiness directive (AD) 98-17-14, applicable to MDHS Model 369E, 369FF, 500N, and 600N helicopters, that currently requires, within the next 14 calendar days, inspecting each relay receptacle contact socket for correct size of the contact socket holes and replacing incorrectly-sized contact sockets with airworthy contact sockets. This amendment requires the same inspections and replacements as the existing priority letter AD, but changes the serial numbers affected for the MDHS Model 500N and 600N helicopters and changes a part number that was incorrectly referenced in the existing AD. This amendment is prompted by three incidences in which a MDHS Model 600 helicopter's Engine Control Unit (ECU) Fail light illuminated, even though the ECU continued to automatically control the engine. The cause of the ECU malfunction indication was determined to be contact sockets that did not properly fit the corresponding pins ofthe affected relay. Improperly sized contact sockets could create multiple unsafe conditions. These conditions, if not corrected, could result in the loss of various engine control or warning systems including the undetected loss of the auto-reignition function after an engine flameout, failure of an engine to reignite, and a subsequent forced landing and the inability to immediately detect an engine-out condition or to properly govern main rotor speed following loss of the Full Authority Digital Engine Control (FADEC), and subsequent loss of control of the helicopter.