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65-14-02: 65-14-02\tBOEING: Amdt. 39-79 Part 39 Federal Register June 12, 1965. Applies to Models 707 and 720 Series Aircraft. \n\n\tCompliance required as indicated. \n\n\tSince the existing bolts attaching each nacelle strut to the wing may be either cadmium plated, electro-nickel-plated, or devoid of plating, and are not adequately protected against corrosion, bolt failures from stress corrosion have occurred. To correct this condition, accomplish the following: \n\n\t(a)\tFor bolts with 10,500 or more hours' time in service on the effective date of this AD, accomplish (c) within 1,500 hours' time in service on the effective date of this AD. \n\n\t(b)\tFor bolts with less than 10,500 hours' time in service on the effective date of this AD, accomplish (c) prior to the accumulation of 12,000 hours' time in service. \n\n\t(c)\tUnless already accomplished, remove the nacelle attachment bolts and install new attachment bolts, Boeing P/N's 65-23413-1 through 65-23413-22, as applicable, or bolts reworked in accordance with Boeing Drawing No. 65-23413, or equivalent approved by the Chief Aircraft Engineering Division, FAA Western Region, on inboard and outboard engine nacelles in accordance with Figure 1 of Boeing Service Bulletins Nos. 1416 and 1416A. \n\n\t(d)\tMaintain a record of hours' time in service for the bolts in order to comply with this AD. If past records of bolt time in service are unavailable, bolt time in service prior to the effective date of this AD shall be considered equal to aircraft time in service.\n \n\t(Boeing Service Bulletins Nos. 1416 and 1416A cover this same subject.) \n\n\tThis directive effective July 12, 1965.
2013-01-04: We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron, Inc. (Bell), Model 412 and 412EP helicopters. This AD requires creating a component history card or equivalent record and begin counting and recording the number of accumulated landings for each high aft crosstube assembly (crosstube). Also, this AD requires installing ``caution'' decals regarding towing of a helicopter at or above 8,900 pounds. This AD also requires confirming the crosstube is within the horizontal deflection limits and replacing it if it is not. This AD also requires a recurring fluorescent penetrant inspection (FPI) of each crosstube and upper center support for a crack, any corrosion, nick, scratch, dent, or any other damage. This AD requires repairing damaged crosstubes and upper center supports that are within acceptable limits, reworking crosstubes by bonding on abrasion strips, and replacing each unairworthy crosstube with an airworthy crosstube. This AD was prompted by analysis of the crosstubes conducted as a result of recent field failures and corrosion problems of the affected crosstubes. The actions are intended to prevent failure of a crosstube, collapse of the landing gear, and subsequent loss of control of the helicopter.
2025-08-04: The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS332L helicopters. This AD was prompted by a determination that new or more restrictive airworthiness limitations are necessary. This AD requires revising the airworthiness limitations section (ALS) of the existing maintenance manual (MM) or instructions for continued airworthiness (ICAs) and the existing approved maintenance or inspection program, as applicable, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
72-23-01: 72-23-01 HANDLEY PAGE (JETSTREAM AIRCRAFT LTD): Amendment 39-1548 as amended by Amendment 39-1585 and 39-1605 is further amended by Amendment 39-2197. Applies to Handley Page HP-137 Mark I airplanes. Compliance is required on or before March 24, 1973, unless already accomplished, except that the airplane may be flown in accordance with FAR Section 21.197 and 21.199 to a base where the alteration can be performed. To prevent fires, which could result from engine rotor failures and combustion chamber burn through torching flames, in the areas of the nacelle forward of the existing vertical firewall from entering the area aft of the vertical firewall and damaging wing structure or burning into the wing fuel tank in this area, install additional fire shielding to the lower nacelle area down from and aft of the existing vertical firewall in accordance with the following: (a) Using fireproof materials which comply with FAR 23.1191, extend the existing vertical firewall andprovide fireproof shielding for the area aft of the extended vertical firewall in accordance with Jetstream Aircraft Limited Modification No. 5001, Part 1, Issue 1, dated September, 1971, and Part 2, Issue 2, dated December, 1971, or other equivalent modification approved by the Chief, Engineering and Manufacturing Branch of an FAA Region (or, in the case of the Western Region, the Aircraft Engineering Division). NOTE: Copies of Jetstream Aircraft Limited Modification No. 5001 may be obtained from the FAA, Engineering and Manufacturing Branch in the FAA Regions (or in the case of the Western Region, the Aircraft Engineering Division). Amendment 39-1548 became effective October 31, 1972. Amendment 39-1585 was effective upon publication in the Federal Register as to all persons except those persons to whom it was made immediately effective by the telegram, dated December 2, 1972, which contained this amendment. Amendment 39-1605 was effective upon publication in theFederal Register as to all persons except those persons to whom it was made immediately effective by the telegram, dated January 23, 1973, which contained this amendment. This amendment 39-2197 becomes effective May 5, 1975.
69-12-07: 69-12-07 BELL: Amdt. 39-781. Applies to Bell Model 206A helicopters, Serial Nos. 4 through 153, equipped with the magnesium tail boom assembly, Part No. 206-031-004-1 or -3. Compliance required as indicated. To prevent failure of the magnesium tail boom due to fatigue cracks, accomplish the following: (a) Before the first flight of each day after the effective date of this AD: (1) Remove the tail rotor drive shaft cover. (2) Inspect the skin adjacent to the rivet holes for cracks in the following areas, using a three-power or higher magnifying glass: (i) The tab attachment of the drive shaft cover to the tail boom. (ii) The area adjacent to the rivnut attachment of the tail rotor gear box fairing to the tail boom. (iii) The horizontal stabilizer attachment fittings. (3) Repair tail booms with only one skin crack less than one inch in length if the crack is located in an area described in (a)(2)(ii) or (iii) above, by stop drilling and deburring the holes. (4) Remove and replace tail booms with any other skin crack, in accordance with Paragraphs 8-37 through 8-47 of the Model 206A Maintenance and Overhaul Instructions. (b) Within 25 hours' time in service after the effective date of this AD and thereafter at intervals not to exceed 25 hours' time in service from the last inspection: (1) Remove the tail rotor drive shaft cover and the gear box fairing. (2) Inspect the skin adjacent to the rivet holes for cracks in the following areas, using a three-power or higher magnifying glass: (i) The tab attachment of the drive shaft cover to the tail boom. (ii) The rivnut attachments of the tail rotor gear box fairing to the tail boom. (iii) The horizontal stabilizer attachment fittings. (3) Repair tail booms with only one skin crack less than one inch in length if the crack is located in an area described in (b)(2)(ii) or (iii) above, by stop drilling and deburring theholes. (4) Remove and replace tail booms with any other skin crack, in accordance with Paragraphs 8-37 through 8-47 of the Model 206A Maintenance and Overhaul Instructions, before further flight. (5) Inspect tail rotor balance and balance, if necessary, in accordance with Paragraph 2A on Page 2 of Bell Service Bulletin No. 206A-7 dated August 22, 1968, or later FAA-approved revision or in accordance with an equivalent procedure approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration. (c) Remove and replace magnesium tail booms with 400 or more hours' time in service on the effective date of this AD within 100 hours' time in service therefrom. (d) Remove and replace magnesium tail booms with less than 400 hours' time in service on the effective date of this AD, prior to accumulating 500 hours' time in service. (e) Remove and replace all subsequent replacement magnesium tail booms prior to accumulating 500 hours' time in service. (Bell Helicopter Company Service Bulletin No. 206A-7 dated August 22, 1968, pertains to this subject). This amendment becomes effective July 21, 1969.
2013-02-12: We are adopting a new airworthiness directive (AD) for all EADS CASA (Type Certificate previously held by Construcciones Aeron[aacute]uticas, S.A.) Model CN-235, CN-235-100, CN-235-200, and CN-235-300 airplanes. This AD was prompted by reports of incorrect electrical polarity connections on engine fire extinguishing discharge cartridges. This AD requires a one-time inspection to identify the correct polarity for each pair of electrical connectors on each engine fire extinguisher cartridge, and repair if necessary. We are issuing this AD to detect and correct incorrect polarity connections, which could prevent the actuation of the discharge cartridge in case of automatic fire detection or manual initiation during a potential engine fire, and could result in damage to the airplane and injury to passengers.
2025-07-10: The FAA is superseding Airworthiness Directive (AD) 2020-20-17 and AD 2021-15-05 for all General Electric Company (GE) Model GE90- 110B1 and GE90-115B engines. AD 2020-20-17 prohibits dispatch of an airplane if certain status messages are displayed on the engine indicating and crew alerting system (EICAS) and if certain conditions are present; and as terminating action, requires revision of the existing FAA-approved minimum equipment list (MEL) by incorporating the dispatch restrictions into the MEL. AD 2021-15-05 requires initial and repetitive replacement of the full authority digital engine control (FADEC) integrated circuit (MN4) microprocessor. Since the FAA issued AD 2020-20-17 and AD 2021-15-05, the manufacturer has developed a software revision for the electronic engine control (EEC) FADEC that further mitigates the unsafe condition. This AD retains all the actions of AD 2020-20-17 and AD 2021-15-05, and also requires upgrading the EEC FADEC software to an EEC FADEC software version eligible for installation as a terminating action. The FAA is issuing this AD to address the unsafe condition on these products.
2013-02-10: We are adopting a new airworthiness directive (AD) for all Airbus Model A330-200 Freighter series airplanes; Model A330-200 and - 300 series airplanes; and Model A340-200 and -300 series airplanes. This AD was prompted by a report of a manufacturing defect in certain rods installed in the belly fairing, which could lead to cracks at the crimped end of the rod. This AD requires an inspection of the rods to determine the manufacturer; and for affected parts, an inspection for any cracking of the rods, and related investigative and corrective actions if necessary. We are issuing this AD to detect and correct cracking of the rods, which could result in rupture of rods that attach the belly fairing to the airframe, leading to separation of the belly fairing from the airframe, and consequent damage to airplane structure and airplane systems.
75-04-04: 75-04-04 CESSNA AIRCRAFT CORPORATION: Amendment 39-2067 as amended by Amendment 39-2203. Applies to Cessna Model 305A series airplanes, modified in accordance with STC SA568SW or SA504SW (oil line rerouting), including airplanes listed in Note 3 of Aircraft Specification 5A5. Compliance required within the next twenty-five hours' time in service after the effective date of this AD, unless already accomplished. To prevent failure of the aluminum elbow fitting, P/N X34352, remove the fitting from the oil cooler and replace with a fitting of the same part number fabricated from brass, or Weatherhead P/N C5405X10X6, or an equivalent part approved by the Chief, Engineering and Manufacturing Branch, Flight Standards Division, Southwest Region, Federal Aviation Administration, Fort Worth, Texas. (NOTE: Advisory Circular AC 43.13-1A, Chapter 10, provides information on the proper flex line installation procedure that should be followed when reconnecting the oil system line.These parts are available from Ector Aircraft Company, 414 East Hillmont, Odessa, Texas 79760.) Amendment 39-2067 became effective March 10, 1975. This amendment 39-2203 becomes effective upon publication in the Federal Register.
2013-02-09: We are adopting a new airworthiness directive (AD) for all BAE SYSTEMS (OPERATIONS) LIMITED Model BAe 146, and Avro 146-RJ series airplanes. This AD was prompted by a report of loss of the end caps on the anti-icing piccolo tube of the wing leading edge. This AD requires a detailed inspection of the end caps on the anti-icing piccolo tube for lost or loose end caps, and replacing or repairing the end caps if necessary. We are issuing this AD to detect and correct lost and loose end caps on the anti-icing piccolo tube, and ice accretion on the wing leading edge or run-back ice, which could lead to a reduction in the stall margin on approach and loss of controllability of the airplane.
2025-07-06: The FAA is superseding Airworthiness Directive (AD) 2024-26- 01, which applied to all Airbus Helicopters Model H160-B helicopters. AD 2024-26-01 required measuring the axial play of the rotating scissors spherical bearings, and depending on the results, accomplishing corrective action and reporting inspection results. Since the FAA issued AD 2024-26-01, Airbus Helicopters issued revised material to extend the applicability to all rotating scissors spherical bearing serial numbers, change the initial compliance time, establish repetitive inspections, and extend the reporting requirements. This AD was prompted by a determination that the initial compliance time and reporting requirement needed to be modified and repetitive inspections for certain axial play measurements added. This AD retains the actions required in AD 2024-26-01, revises the initial compliance time, extends the definition of an affected part to all serial numbered rotating scissors spherical bearings, extends the reporting requirements, and requires repetitive inspections. This AD also prohibits installing an affected rotating scissors spherical bearing unless certain requirements are met. These actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
2013-02-05: We are adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-600, -700, -700C, -800, -900, and -900ER series airplanes. This AD requires, for certain airplanes, installing two warning level indicator lights on each of the P1-3 and P3-1 instrument panels in the flight compartment. This AD also requires, for certain airplanes, replacing the existing P5-16 and P5-10 panels; and, for certain airplanes, replacing the basic P5-16 panel with a high altitude landing P5-16 panel. Additionally, this AD requires revising the airplane flight manual to remove certain requirements of previous AD actions, and to advise the flightcrew of certain changes. This AD was prompted by a design change in the cabin altitude warning system that would address the identified unsafe condition. We are issuing this AD to prevent failure of the flightcrew to recognize and react to a valid cabin altitude warning horn, which could result in incapacitation of the flightcrew due tohypoxia (a lack of oxygen in the body), and consequent loss of control of the airplane.
69-01-01: 69-01-01 FAIRCHILD-HILLER: Amendment 39-703. Applies to F-27 and FH-227 type airplanes. Compliance required within the next 500 hours time in service after the effective date of this AD, unless already accomplished. To preclude the possibility of rendering an engine fire extinguisher system inoperative by a single shorted cartridge unit modify the engine fire extinguisher systems in accordance with Fairchild Hiller Service Bulletins F27-26-5 or FH227-26-3 both dated May 16, 1968, as applicable, or later FAA approved revision, or an equivalent modification approved by the Chief, Engineering and Manufacturing Branch, FAA, Eastern Region. This amendment is effective February 1, 1969.
2012-17-08: We are superseding four airworthiness directives related to the main rotor yoke (yoke) on the Bell Model 204B, 205A, 205A-1, 205B, and 212 helicopters, to retain certain inspections and certain life limits, to require an increased inspection frequency for certain yokes, and to expand these inspections and retirement lives to other yokes. This airworthiness directive is prompted by past reports of cracks in the yoke, another recent report of a cracked yoke, and the decision that other yokes, approved based on identicality, need to be subject to the same inspection requirements and retirement lives. The actions are intended to detect a crack in a yoke to prevent failure of the yoke, and subsequent loss of control of the helicopter.
2025-07-08: The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Model AS332C, AS332C1, AS332L, and AS332L1 helicopters. This AD results from a report of the loss of the tail rotor pitch control due to a fracture of the tail rotor slide of the tail rotor head (TRH) assembly. This AD requires inspecting the slide of the control plate of the TRH assembly for any score, scratch, crack, or corrosion, removing corrosion and replacing the TRH assembly, slide of the control plate, or pitch control assembly if discrepancies are found, and reporting the results of the inspection. This AD prohibits installing an affected TRH assembly unless the actions of this AD are accomplished. All of these actions are specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
2025-06-51: The FAA is adopting a new airworthiness directive (AD) for certain Bell Textron Canada Limited (Bell) Model 505 helicopters. The FAA previously sent this AD as an emergency AD to all known U.S. owners and operators of these helicopters. This AD was prompted by deformation and/or improper pin engagement in the knuckles of the door hinge on the aft movable ballast box assembly. This AD requires removing all ballast weights from the aft movable ballast box assembly and prohibits the use of ballast weights within the aft movable ballast box assembly, as specified in a Transport Canada emergency AD, which is incorporated by reference. The FAA is issuing this AD to address the unsafe condition on these products.
2003-09-08: This amendment supersedes an existing airworthiness directive (AD), applicable to all Boeing Model 767 series airplanes, that currently requires an inspection to ensure that all bolts of the support beam of the hinge fitting assembly on both the left- and right- hand outboard trailing edge flaps are the correct length and type, and correction of any discrepancy found. This amendment reduces the applicability of the existing AD, adds inspections, and mandates terminating action. The actions specified by this AD are intended to prevent failure of the bolts that attach the outboard trailing edge flap to the support beam, which could result in loss of the flap and consequent reduced controllability of the airplane. This action is intended to address the identified unsafe condition.
47-51-08: 47-51-08 REPUBLIC: Applies to All Model RC-3 Airplanes with Steerable Tailwheels. Compliance required not later than the next 25-hour inspection. To preclude the possibility of the steerable tailwheel control cable fouling on the tailwheel quadrant arms, install horns 3 9/16 inches long, fabricated from 0.091 aluminum plate, pointing rearward to arms of quadrant assembly No. 17F42093-1. Drill out stop rivet and attach using AN 441-4-5 rivets. Then attach cable clips over horn and arm with AN 24-11 bolts. (Republic Service Bulletin No. 17, Supplement No. 2, dated October 16, 1947, also covers this same subject.)
2013-01-02: We are superseding an existing airworthiness directive (AD) for certain The Boeing Company Model 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747-400D, 747-400F, 747SR, and 747SP series airplanes; and certain Model 757-200, -200PF, and -300 series airplanes. That AD currently requires replacing the control switches of the forward, aft, and nose cargo doors of Model 747 airplanes; and requires replacing the control switches of cargo doors 1 and 2 of Model 757 series airplanes. This new AD adds airplanes to the applicability and revises the initial compliance times for those airplanes. This AD was prompted by reports of problems associated with the uncommanded operation of cargo doors. We are issuing this AD to prevent injuries to persons and damage to the airplane and equipment.
2012-24-09: We are adopting a new airworthiness directive (AD) for Lycoming Engines TIO-540-AK1A, and Continental Motors, Inc. TSIO-360- MB, TSIO-360-SB, and TSIO-360-RB reciprocating engines, with certain Hartzell Engine Technologies (HET) turbochargers, model TA0411, part number (P/N) 466642-0001; 466642-0002; 466642-0006; 466642-9001; 466642-9002; or 466642-9006, or with certain HET model TA0411 turbochargers overhauled or repaired since August 29, 2012. This AD requires removing the affected turbochargers from service before further flight. This AD was prompted by a report of a turbocharger turbine wheel that failed a static strength test at its manufacturing facility. We are issuing this AD to prevent turbocharger turbine wheel failure, reduction or complete loss of engine power, loss of engine oil, oil fire, and damage to the airplane.
73-12-12: 73-12-12 BRITISH AIRCRAFT CORPORATION: Amdt. 39-1661. Applies to Viscount Series 810 airplanes. Compliance is required as indicated. To prevent a possible restriction in a power plant fire extinguisher pipe accomplish the following: Within the next 500 hours' time in service after the effective date of this AD, unless already accomplished within 5 years prior to the effective date of this AD, and thereafter at intervals not to exceed 5 years from the last replacement, replace the rubber seal sleeves P/N FRS.-F-Series 1, installed in the power plant fire extinguisher system in the pipe connector assembly located at the engine fire-proof bulkhead, with seal sleeves of the same part number. (BAC Alert Preliminary Technical Leaflet No. 149, Issue 1, dated July 30, 1971, covers this same subject). This Amendment becomes effective July 6, 1973.
47-51-03: 47-51-03 CURTISS-WRIGHT Applies to Model C-46 Series Aircraft Equipped with Aileron Closure Rib Assembly, Curtiss-Wright P/N 20-030-5039. Compliance required within every 100 hours' time in service after the effective date of this amendment until rework is accomplished. The aileron closure rib assembly 20-030-5039 has failed on some aircraft by cracking at the point of attachment to gusset and adjacent to the bolts which secure the aileron hinge assembly. 1. The rib assembly should be inspected and if cracks are found the following rework should be accomplished: (a) Remove the aileron from the airplane. (b) Remove aileron hinge assembly 20-030-5042 from the aileron closure rib 20-030-5039 located at wing station 273.875. (c) Drill out the ten 671D-5AD-5 rivets and two C71D-5AD-8 rivets which secure gusset 20-030-5039-6 to the bottom of ribs 20-030-5039-504 and 20-030-5039-505. (d) Drill out the eight AN 442AD-5 rivets which secure gusset 20-030-5039- 6 to the sides of ribs 20-030-5039-504L and 20-030-5039-505. (e) Open the inspection doors nearest each side of the aileron closure rib assembly. (f) Working through these inspection doors drill out the fourteen AN 442AD4-4 rivets which secure angles 20-030-5039-3 to the sides of the ribs 20-030-5039-504 and 20-030-5039-505. It will not be necessary to remove the twenty-eight 671D-4AD-4 rivets which secure the angles 20-030-5039-3 to the wing trailing edge closure skin. (g) Working through same inspection doors drill out the eighteen AN 442AD4-4 rivets which secure the angles 20-030-5039-506 to ribs 20-030-5039-504 and 20-030- 5039-505. The ribs are now free and can be removed from the airplane. (h) Fabricate new lower ribs 20-030-5037-504 and 20-030-5039-505 using the removed ribs as templates. (i) Fabricate one left-hand and one right-hand angle "A" 7.06 inches long x 0.90-inch leg x 0.70-inch leg, bend radius 0.09, from 0.064-24SO - ALC (AN-A-13Condition A) and heat treat to 56,000 p.s.i. (Spec. AN-QQ-H-186). (j) Fabricate one left-hand and one right-hand angle "B" 9.25 inches long x .90-inch leg x 0.70-inch leg, bend radius 0.09, from 0.064-24SO-ALC (AN-A-13 Condition A) and heat treat to 56,000 p.s.i. (Spec. AN-QQ-H-186). (k) Working through the inspection doors located in the trailing edge closure skin secure the ribs 20-030-5039-504 and 20-030-5039-505 to angles 20-030-5039-506 and 20- 030-5039-3. (l) Install angle "B" with a 0.90-inch leg against ribs 20-030-5039-504 and 20-030-5039-505 in upper inside corners of assembly using six AN 442 AD4-4 rivets for each angle. Rivet the 0.70-inch flange to top gusset using four AN 442 AD6-8 rivets outboard and five LS 1127-6-8 rivets inboard of opening in gusset. Trim angle to match openings in rib and gusset and end curvature of ribs. (m) Install angles "A" with 0.90-inch leg against ribs 20-030-5039-504 and 20-030-5039-505 in lower inside corners of assembly using two AN 442 AD4-4 rivets at inboard end and four AN 442 AD5-6 rivets to pick up leg of gusset 20-030-5039-6L and 6R and 671D- 5AD rivets on bottom. Trim end of angle to curvature of rib. (n) Drill the necessary bolt holes in ribs 20-030-5039-504 and 20-030-5039- 505 for attaching hinge assembly 20-030-5042 and install same using AN 24-8A bolts, AN 960D416 washer and AN 364-428 nuts. (o) Install the aileron. (Curtiss-Wright Service Information Letter SBS:GS:wd-1482 dated January 6, 1947, and its enclosures, also cover this same subject. This letter and its enclosures may be obtained from the Curtiss-Wright Corp., Airplane Division, Columbus, Ohio, upon request.) (p) Upon request of the operator, an FAA maintenance inspector, subject to prior approval of the Chief, Engineering and Manufacturing Branch, FAA Southern Region, may adjust the repetitive inspection intervals specified in this AD to permit compliance at an established inspection period of the operator if the request contains substantiating data to justify the increase. Revised December 28, 1964.
47-32-01: 47-32-01 BELL: (Was Mandatory Note 1 of AD-1H-1.) Applies Only to Model 47B Serial Numbers 2 Through 13. Compliance required at next 100-hour inspection. Rework the stabilizer damper frame clamp with a 1/16-inch saw cut, as shown in Bell Service Bulletin No. 47C7, revised June 12, 1947, in order to permit a clamping action which will prevent the loosening of the subject part of the main rotor mast.
2012-26-14: We are adopting a new airworthiness directive (AD) for all Rolls-Royce Deutschland Ltd & Co KG BR700-715A1-30, BR700-715B1-30, and BR700-715C1-30 turbofan engines. This AD requires a one-time removal from service of the high-pressure (HP) compressor stages 1 to 6 rotor disc assembly before exceeding certain thresholds. This AD was prompted by a report of silver chloride-induced stress corrosion cracking of the HP compressor stages 1 to 6 rotor disc assembly, identified during overhaul. We are issuing this AD to prevent failure of the HP compressor stages 1 to 6 rotor disc assembly, which could result in uncontained failure of the engine and damage to the airplane.
73-15-03: 73-15-03 AVIONS MARCEL DASSAULT: Amendment 39-1688. Applies to Fan Jet Falcon airplanes, Serial Numbers 1 thru 111, which have aluminum alloy air conditioning pipes, P/N's MY20-721-28-1 and MY20-721-61-1, installed. Compliance is required as indicated. To prevent leakage of very hot air into the rear compartment, accomplish the following, unless already accomplished: (a) Within the next 100 hours' time in service after the effective date of this AD, comply with subparagraphs (1) and (2), and thereafter comply with subparagraph (1) at intervals not to exceed 200 hours' time in service from the last inspection. (1) Visually inspect the studs which retain the SEMCA coupling on pipe, P/N MY20-721-28-1, for scoring or bending, and inspect the holes receiving those studs for stretching or elongation, in accordance with Dassault Service Bulletin No. 430 (21-30) dated February 16, 1972, or an FAA-approved equivalent. (2) Inspect the weld beads and adjoining areas at the junction of the pipes, P/N's MY20-721-28-1 and MY20-721-61-1, for cracks using a magnifying glass of 5 power or greater and a dye penetrant, in accordance with Dassault Service Bulletin No. 430 (21-30) dated February 16, 1972, or an FAA-approved equivalent. (b) Within the next 100 hours' time in service after the effective date of this AD or before the accumulation of 600 hours' time in service on an aluminum alloy air conditioning pipe, P/N MY 20-721-28-1 or MY20-721-61-1, whichever occurs later (1) Replace the pipes, P/N's MY20-721-28-1 and MY20-721-61-1, with pipes of the same part number and thereafter continue to replace aluminum alloy pipes before the accumulation of 600 hours' time in service thereon and comply with paragraph (d); or (2) Replace the pipes, P/N's MY 20-721-28-1 and MY20-721-61-1, with stainless steel pipes, P/N's MY20-721-28-2 and MY20-721-61-2, in accordance with Dassault Service Bulletin No. 442 (21-31) dated February 16, 1972, oran FAA-approved equivalent. (c) If scoring or bending of the studs or stretching or elongation of the holes are found during an inspection specified in paragraph (a)(1) or cracks are found during an inspection specified in paragraph (a)(2) before further flight comply with subparagraph (1) or (2) of paragraph (b). (d) For aluminum alloy pipes installed as replacement in accordance with subparagraph (1) of paragraph (b) (1) Before the accumulation of 200 hours' time in service thereon, inspect in accordance with subparagraph (1) of paragraph (a); and (2) Thereafter, inspect in accordance with subparagraph (1) of paragraph (a) at intervals not to exceed 200 hours' time in service from the last inspection. (e) Operators who have not kept records of hours' time in service on pipes, P/N's MY20-721-28-1 and MY20-721-61-1, shall substitute airplane hours' time in service in lieu thereof. (f) The inspections required by paragraphs (a) and (d) and the replacements specified in subparagraph (1) of paragraph (b) may be discontinued when the aluminum alloy air conditioning pipes, P/N's MY20-721-28-1 and MY20-721-61-1, are replaced with stainless steel pipes, P/N's MY20-721-28-2 and MY20-721-61-2, in accordance with Dassault Service Bulletin No. 442 (21-31), dated February 16, 1972, or an FAA-approved equivalent. This amendment becomes effective August 15, 1973.