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67-18-02: 67-18-02 BOEING: Amdt. No. 39-424, Part 39, Federal Register May 27, 1967. Applies to Boeing Model 707 and 720 Series airplanes. \n\n\tCompliance required as indicated.\n \n\tTo prevent fires in the water and electrical galley supply boxes due to water seepage, accomplish the following: \n\n\t(a)\tWithin the next 300 hours' time in service after the effective date of this AD and thereafter, within periods not to exceed 300 hours' time in service from the last inspection, visually inspect each water and electrical galley supply box for water entrapment at the electrical connectors located therein.\n \n\t(b)\tIf water is found trapped at an electrical connector, water traps, including but not limited to tubing, clamps, bushings or boots, must be removed or modified in accordance with a method approved by an FAA Air Carrier Maintenance Inspector. \n\n\t(c)\tWithin the next 3,000 hours' time in service after the effective date of this AD unless already accomplished, modify the water and electrical galley supply box in accordance with the "Accomplishment Instructions" of Boeing Service Bulletin 2428 or FAA-approved revision, or in accordance with a method approved by the Chief, Aircraft Engineering Division, FAA, Western Region. \n\n\t(d)\tThe inspections required by paragraph (a) may be discontinued when the modification required by paragraph (c) is accomplished. \n\n\t(e)\tUpon request of the operator, an FAA Air Carrier Maintenance Inspector, subject to prior approval of the Regional Director, FAA, Western 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 for that operator. \n\n\tThis directive effective June 26, 1967.
2004-05-25: This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas airplane models, that requires inspection of the captain's and first officer's seat locking pins for minimum engagement with the detent holes in the seat tracks; inspection of the seat lockpins for excessive wear; and corrective actions, if necessary. This action is necessary to prevent uncommanded seat movement during takeoff and/or landing, which could result in interference with the operation of the airplane and consequent temporary loss of control of the airplane. This action is intended to address the identified unsafe condition.
2011-07-09: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Service experience has shown that a case of FADEC channel B manifold air pressure (MAP) sensor hose permeability is not always recognized as fault by the FADEC. The MAP value measured by the sensor may be lower than the actual pressure value in the engine manifold, and limits the amount of fuel injected into the combustion chamber and thus the available power of the engine. A change in FADEC software version 2.91 will change the logic in failure detection and in switching to channel B (no automatic switch to channel B if MAP difference between channel A and B is detected and lower MAP is at channel B). In addition, previous software versions allow--under certain conditions and on DA 42 aircraft only--the initiation of a FADEC self test during flight that causes an engine in-flight shutdown. We are issuing this AD to prevent engine in-flight shutdown or power loss, possibly resulting in reduced control of the airplane.
2021-12-13: The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 737-8 and 737-9 airplanes. This AD was prompted by a report that during refueling of the right main tank, if there is a failure of the automatic shutoff system, the refueling panel does not provide the required indication that the automatic shutoff has failed. This AD requires installing a new fuel quantity processor unit (FQPU) and doing an FQPU software check. The FAA is issuing this AD to address the unsafe condition on these products.
81-02-04: 81-02-04 COSTRUZIONI AERONAUTICHE GIOVANNI AGUSTA (CAGA): Amendment 39-4014. Applies to Models A109 and A109A series helicopters, certificated in all categories. Compliance required as indicated, unless already accomplished. To prevent loss of the main rotor blade pitch control, accomplish the following: (a) Before further flight, hand correct the CAGA manuals referenced in paragraphs (a)(1) and (a)(2) by changing the torque value from "500 to 560 Kg, 434 to 486 inch/pound" to "311 to 345 Kg, 275 to 300 inch/pound." (1) CAGA A109/A109A overhaul manual (all change dates), Chapter 65-10- 01, page 240, paragraph 8, subparagraph (e); (2) CAGA A109/A109A maintenance manual (all change dates), Chapter 65-10-03, page 201, paragraph 3; and (3) Retain the hand corrected pages in both manuals until revised replacement pages are available from CAGA. (b) Within the next 25 hours time in service after the effective date of this AD - (1) Remove the mainrotor pitch horn trunion assembly; (2) Permanently remove from service, nut P/N MS 17825-7, and replace with a new nut of the same part number; and (3) Using a 5X magnifying glass, visually inspect the threaded area of P/N 109-0101-09-1, for deformation, distortion, or damage. (c) If as a result of the inspection of the trunion assembly required in paragraph (b)(3) of this AD, no deformation, distortion, damage, or defect is found. (1) Reinstall the main rotor pitch horn trunion assembly in accordance with CAGA A109/A109A overhaul manual, chapter 65.10.01, or an FAA-approved equivalent, using the torque values listed in paragraph (a) of this AD; or (2) Reinstall the main rotor pitch horn trunnion assembly in accordance with CAGA A109/A109A maintenance manual, or an FAA-approved equivalent, using the revised torque values listed in paragraph (a) of this AD; (3) During reinstallation of the main rotor pitch horn trunion assembly, check to insure that there is 0.10 to 0.20 millimeter play between the trunion shoulder and the bearing inner race; and (4) Return the serviceable trunion assembly to service. (d) If as a result of the inspection of the trunion assembly required in paragraph (b)(3) of this AD, deformation, distortion, damage, or defect indicating overtorque is found - (1) Remove the trunion assembly from service; (2) Replace with a new or serviceable trunion assembly of the same part number; and (3) Reinstall the main rotor pitch horn trunion assembly and torque in accordance with paragraph (c)(1) or (c)(2) of this AD. (e) Report defects found to the Chief, Aircraft Certification Staff, Europe, Africa and Middle East Office, c/o American Embassy, Brussels, Belgium. (Reporting approved by the Office of Management and Budget under OMB No. 04-R0174.) (f) If an equivalent means of compliance is used in complying with this AD, that equivalent must be approved by the Chief, Aircraft Certification Staff, AEU-100, Europe, Africa, and Middle East Office, FAA, c/o American Embassy, Brussels, Belgium. NOTE: Costruzioni Aeronautiche Giovanni Agusta Service Engineering Department messages LD/7/1815 and LD/7/1845, both dated April 22, 1980, refer to this subject. This amendment becomes effective January 5, 1981, as to all persons except those persons to whom it was made immediately effective by telegraphic AD T80EU-22, issued May 1, 1980, which contained this amendment.
96-07-09: This amendment adopts a new airworthiness directive (AD), applicable to Boeing Model 747-400, 757, and 767 series airplanes, that requires a revision to the Airplane Flight Manual that advises flight crews to monitor the engine indication and crew alerting system (EICAS) for "status" level messages pertaining to impending engine fuel filter bypass. This amendment also requires the installation of upgraded EICAS computers that provide "advisory" level messages to indicate such bypass conditions. This amendment is prompted by a finding that EICAS computers currently installed on these airplanes do not provide an appropriate indication to the flight crew of an impending engine fuel filter bypass condition. The actions specified by this AD are intended to ensure that the flight crew is appropriately aware of conditions involving a severely contaminated airplane fuel system and the associated increased potential for engine power loss.
2004-05-27: This amendment adopts a new airworthiness directive (AD), applicable to all Boeing Model 737-200 series airplanes modified by Supplemental Type Certificate (STC) ST00516AT, that requires removal of the in-flight entertainment (IFE) system installed per that STC. This action is necessary to eliminate the possibility that the airplane crew could be unable to remove power from the IFE system during a non-normal or emergency situation, which could result in the airplane crew's inability to control smoke or fumes in the airplane flight deck or cabin. This action is intended to address the identified unsafe condition.
47-21-16: 47-21-16 REPUBLIC: (Was Mandatory Note 6 of AD-769-2.) Applies to Model RC-3 Aircraft Serial Numbers 5 to 250, Inclusive. To be accomplished not later than the next 25 hours of operation subsequent to July 1, 1947, and in any case not later than September 1, 1947. In order to provide a fuel strainer drain which is leakproof and airtight: 1. Remove the existing drain cock or plug from the fuel strainer located near the right hand wing fairing. 2. Install adapter 17P65058-1 in the strainer and install W7600-1/8 drain cock in the end of adapter. Use seal-lube when installing these parts. (Seabee Service Bulletin No. 7 dated February 5, 1947, covers the same subject.)
68-07-05: 68-07-05 MCDONNELL DOUGLAS: Amendment 39-577. Applies to all DC-3 Series and C-47 Series Airplanes having an Elevator P/N 5115210 incorporating Elevator Ribs P/N 5115210-5 or -9 and Trim Tab Hinge P/N 1141847 (hereinafter referred to as the Elevator Installation). \n\n\tThere have been several reports of cracking of the elevator ribs at the inboard and outboard ends of the trim tab cut-outs referred to above. To preclude failure of the elevator installation due to cracking of the elevator ribs, accomplish the following: \n\n\t(a)\tFor airplanes having The Elevator Installation wherein the elevator rib referred to above has not been reinforced by the addition of a .040 inch thick doubler, visually inspect each elevator rib for cracks within 250 hours' time in service after the effective date of this AD and thereafter at intervals not to exceed 250 hours' time in service. \n\n\t(b)\tFor airplanes having the Elevator Installation wherein the elevator rib referred to above has been reinforced by the addition of a .040 inch thick doubler, visually inspect each elevator rib for cracks within 2,500 hours' time in service after the effective date of this AD, and thereafter at intervals not to exceed 2,500 hours' time in service. \n\n\t(c)\tIf cracks are found in the affected elevator ribs, before further flight (except that the airplane may be flown in accordance with FAR 21.197 to a base where the alteration or maintenance can be accomplished), \n\n\t\t(1)\tFor elevator ribs that are part of The Elevator Installation described in Paragraph (a) of this AD; \n\n\t\t(i)\tReinforce by the addition of a .040 inch thick doubler and rebalance the affected elevator rib in accordance with McDonnell Douglas Service Bulletin No. 244, Section I dated September 23, 1946 or later FAA approved revision. Thereafter inspect in accordance with Paragraph (b) of this AD; \n\n\t\t(ii)\tReplace the affected elevator rib with an elevator rib made of .040 inch thick material; or \n\n\t\t(iii)\tModify the affected elevator rib and reinspect in accordance with a method approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\t\t(2)\tFor elevator ribs that are part of the Elevator Installation described in Paragraph (b) of this AD, \n\n\t\t(i)\tReplace the affected elevator rib with an elevator rib made of .040 inch thick material; or \n\n\t\t(ii)\tModify the affected elevator rib and reinspect in accordance with a method approved by the Chief, Aircraft Engineering Division, FAA Western Region. \n\n\tNOTE: Repetitive inspections of elevator ribs made of .040 inch thick material are not required by this AD but should nonetheless be performed in accordance with good maintenance practice. \n\n\tThis supersedes AD 47-02-10 (21 F.R. 9456). \n\n\tThis amendment becomes effective on May 9, 1968.
2021-12-12: The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 717-200 airplanes. This AD was prompted by a report of discrepant spoiler assemblies, which have the wrong splice bar installed and lack reinforcing doublers, and by reports that some splice bars were shipped for installation on Model 717-200 airplanes, although they were not eligible for installation on Model 717-200 airplanes and were identified incorrectly with the Model 717-200 splice bar part number. This AD requires a one-time inspection of the left- and right-wing inboard and outboard spoiler assemblies, for the correct configuration of the splice bar and doublers, and repair or replacement if necessary. The FAA is issuing this AD to address the unsafe condition on these products.
2004-05-20: This amendment adopts a new airworthiness directive (AD), applicable to certain McDonnell Douglas transport category airplanes, that requires modification of the installation wiring for the electric motor operated auxiliary hydraulic pumps in the right wheel well area of the main landing gear, and repetitive inspections of the numbers 1 and 2 electric motors of the auxiliary hydraulic pumps for electrical resistance, continuity, mechanical rotation, and associated airplane wiring resistance/voltage; and corrective actions if necessary. This action is necessary to prevent failure of the electric motors of the hydraulic pump and associated wiring, which could result in fire at the auxiliary hydraulic pump and consequent damage to the adjacent electrical equipment and/or structure. This action is intended to address the identified unsafe condition.
2011-06-12: We are adopting a new airworthiness directive (AD) for the products listed above. This AD requires repetitive inspections for cracking of the left and right upper center skin panels of the horizontal stabilizer, and corrective action if necessary. This AD was prompted by a report of a crack found in the upper skin panel at the aft inboard corner of a right horizontal stabilizer. We are issuing this AD to detect and correct cracks in the upper center skin panels of the horizontal stabilizer. Uncorrected cracks might ultimately lead to the loss of overall structural integrity of the horizontal stabilizer.
2011-06-11: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: An uncontained engine failure has recently occurred on a Rolls- Royce RB211 Trent 900 involving release of high energy debris and resulting in damage to the aeroplane. Analysis of the available elements from the incident investigation shows that an oil fire in the High Pressure/Intermediate Pressure (HP/IP) structure cavity may have initiated a sequence of events leading to rupture of the drive arm of the IP Turbine (IPT) disc and subsequent overspeed and burst of that same disc. We are issuing this AD to prevent overspeed of the intermediate pressure turbine, which could result in loss of disc integrity, an uncontained failure of the engine, and damage to the airplane.
90-02-13: 90-02-13 CESSNA: Amendment 39-6445. Applicability: The following models and serial numbered airplanes certificated in any category: MODEL SERIAL NUMBERS 310 310L0001 through 310R1690 320 320E0001 through 320F0045 340 340-0001 through 340A0801 401 401-0001 through 401B0221 402 402-0001 through 402C0125 411 411-0001 through 411A0300 414 414-0001 through 414A0340 421 421-0001 through 421C0715 Compliance: Required as indicated after the effective date of this AD, unless already accomplished. To assure structural integrity of the main gear barrel inner bearing and prevent jamming of the inner and outer barrels of the main landing gears, accomplish the following: (a) Upon the accumulation of 1,300 hours time-in-service (TIS), or within the next 300 hours TIS after the effective date of this AD, whichever occurs later, and thereafter at intervals not to exceed 1,000 hours TIS, inspect the left and right main gear strut barrel inner bearings, Part Numbers 5041108-1 and 5041108-2, in accordance with the following procedures: (1) Using the appropriate Aircraft Service Manual or Maintenance Manual, refer to the Landing Gear section and use it as a guide to remove the lower barrel and axle assemblies from the upper barrel assemblies. (2) Remove all oil and grease from the external lock rings, inner ring bearings, and extended stop spacers. (3) Visually inspect the external lock rings, inner bearings, and extended stop spacers for cracks. (4) If any cracks are found in the external lock rings or the extended stop spacers, prior to further flight replace the cracked part with a serviceable part. (5) If any cracks are found in the inner bearings, prior to further flight replace the cracked part with a Part Number (P/N) 5141109-1 bearing. (6) If no cracks are found, magnetic particle inspect the inner bearings using the procedures specified in Part B, "MAGNETIC PARTICLE NONDESTRUCTIVE INSPECTION PROCEDURES" of Cessna Service Bulletin MEB88-7, dated December 2, 1988. If any cracks are found, prior to further flight replace the cracked part with a P/N 5141109-1 bearing. (b) The 1,000 hour repetitive inspections specified in paragraph (a) of this AD are no longer required when the P/N 5141109-1 bearing is installed in each gear. (c) Airplanes may be flown in accordance with FAR 21.197 to a location where this AD may be accomplished. (d) An alternate method of compliance or adjustment of the initial or repetitive compliance times which provides an equivalent level of safety may be approved by the Manager, Wichita Aircraft Certification Office, FAA, 1801 Airport Road, Room 100, Mid-Continent Airport, Wichita, Kansas 67209. NOTE: The request should be forwarded through an FAA Maintenance Inspector, who may add comments and send it to the Manager, Wichita Aircraft Certification Office. All persons affected by this directive may obtain copies of the document referred to herein upon request to the Cessna Aircraft Company, P.O. Box 7704, Wichita, Kansas 67277; or may examine this document at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106. This amendment (39-6445, AD 90-02-13) becomes effective on February 5, 1990.
2021-12-09: The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 D-2 helicopters. This AD was prompted by a short circuit in a yaw trim actuator connector that occurred during production electrical tests. This AD requires replacing certain wire harness trim connector backshells (backshells), 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.
73-14-06: 73-14-06 ROCKWELL COMMANDER: Amdt. 39-1670. Applies to Model 112 airplanes Serial Number 3 and up certificated in all categories equipped with Hartzell propeller spinner C-3533 or C-3533P. Compliance is required within the next 10 hours time in service after the effective date of this AD and every 10 hours time in service thereafter. Accomplish the following: (1) Remove the spinner dome. (2) Visually inspect front bulkhead inside spinner dome for cracks or fractures in the flange or in radius between flange and web. (3) Visually inspect rear bulkhead and doublers for cracks in the vicinity of the spinner dome attachments, and attachment of the rear bulkhead to propeller hub. (4) Replace defective, cracked, or broken parts with new or serviceable parts. (5) Reassemble spinner dome to rear bulkhead. Insure that fiber washers are fitted under the attaching screw heads. Torque screws to 20 - 25 in.lbs. (6) Record compliance with this airworthiness directive in Aircraft Log Book. Rockwell International, Albany Aircraft Division, Service Bulletin, SB-112-4 relates to this same subject. This amendment is effective June 26, 1973, and was effective upon receipt for all recipients of the air mail letter dated June 6, 1973, which contained this amendment.
68-08-09: 68-08-09 FAIRCHILD-HILLER: Amdt. 39-588. Applies to FH-1100 type Helicopters. Compliance required as follows: (a) Remove P/N 19E49-3A -3B coupling shaft serial numbers 20, 21, 22, 23, 24, 25, 75, 77, 87, 90, 93, 98, 104 and 106 from service prior to further flight and replace with the same part number but different serial numbers. This amendment effective April 23, 1968.
2021-11-25: The FAA is adopting a new airworthiness directive (AD) for certain Airbus Helicopters (Type Certificate previously held by Eurocopter France) Model AS350B3 and EC130T2 helicopters. This AD was prompted by a report of failure of an engine digital electronic control unit (DECU). This AD requires revising the existing Rotorcraft Flight Manual (RFM) for your helicopter. The FAA is issuing this AD to address the unsafe condition on these products.
65-18-03: 65-18-03 VICKERS: Amdt. 39-114 Part 39 Federal Register August 14, 1965 as amended by Amendment 39-2282. Applies to Viscount Models 744, 745D and 810 Series Airplanes. Compliance required as indicated. Cases of severe corrosion on the bore surfaces of the support tubes of the engine mount assemblies, Drawing Nos. 70037 Sht. 3, 80237 Sht. 3, 80237 Sht. 35 and 81037 Sht. 29 have been reported. To correct this condition accomplish the following: (a) Within the next 4,000 hours' time in service or at next engine overhaul period, whichever is the sooner, after the effective date of this AD, unless already accomplished, conduct an inspection of the support tubes in accordance with British Aircraft Corporation Preliminary Technical Leaflet No. 252, Issue 2, dated May 22, 1971, for the 700 Series (for 744 and 745D aircraft), and No. 117, Issue 2, dated May 22, 1971, for the 800/810 Series (for 810 Series aircraft), to determine if corrosion exists on the surface of the bore and, if corrosion exits, to determine its depth. (1) Accomplish the inspection by radiographic or ultrasonic methods as set forth in the appendices of the applicable Preliminary Technical Leaflet or by FAA-approved equivalent method. (2) If, on inspection, no corrosion exists or the depth of existing corrosion does not exceed 0.030 inch, subject the support tubes to the dewatering and reprotection scheme set forth in paragraphs 5.1 and 5.1.2 of the applicable Preliminary Technical Leaflet. (3) Where the depth of corrosion is in excess of 0.030 inch in any section of a support tube, the tube in question must be replaced before further flight. (b) In addition to the inspection and reprotection requirements in paragraph (a), accomplish the dewatering and reprotection scheme in paragraphs 5.1 and 5.1.2 of the applicable Preliminary Technical Leaflet whenever the engine mount assembly is broken down for any reason. Accomplish the dewatering and reprotection after the end fittings have been assembled. (c) Within seven years from the date of compliance with paragraph (a) or before the accumulation of 500 hours' time in service after the effective date of this amendment, whichever occurs later, repeat the inspection and action specified in paragraph (a). Thereafter, continue to accomplish the inspection and action specified in paragraph (a) at intervals not to exceed seven years from the last inspection. Amendment 39-114 became effective September 13, 1965. This amendment becomes effective August 27, 1975.
2004-05-22: The FAA is adopting a new airworthiness directive (AD) for certain RRD TAY 611-8, TAY 620-15, TAY 650-15, and TAY 651-54 series turbofan engines with ice-impact panels installed in the low pressure (LP) compressor case. This AD requires inspecting all ice-impact panels and fillers in the LP compressor case for certain conditions, and if necessary, replacing any ice-impact panels and fillers that have those conditions. This AD results from two reports of ice-impact panels that released during flight, one of which resulted in reduction of power in both engines. We are issuing this AD to prevent release of ice-impact panels due to improper bonding that can result in loss of thrust in both engines.
2021-12-08: The FAA is adopting a new airworthiness directive (AD) for all Airbus Helicopters Deutschland GmbH (AHD) Model MBB-BK 117 D-2 helicopters. This AD was prompted by reports of chafing marks on the wiring harness behind the middle side panels in the area of the front passenger (PAX) panels. This AD requires inspecting, modifying, and rerouting the wiring harness, 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.
2021-13-15: The FAA is adopting a new airworthiness directive (AD) for Bell Textron Canada Limited (type certificate previously held by Bell Helicopter Textron Canada Limited) (Bell) Model 429 helicopters. This AD was prompted by the identification of certain parts needing life limits and certification maintenance requirement (CMR) tasks. This AD requires establishing life limits and CMR tasks for various parts. Depending on the results of the CMR tasks, this AD requires corrective action. The FAA is issuing this AD to address the unsafe condition on these products.
47-50-08: 47-50-08 SIKORSKY: Applies to Model S-51 Helicopters. Compliance required at each 200-hour inspection period. Disassembly and inspection of the vertical hinge pins and bearings is a mandatory procedure and should be accomplished at each 200-hour inspection period. The helicopters which utilize Torrington No. 4479 bearings at the vertical hinge pins are subject to replacement of these bearings at each 200-hour inspection period. The procedure followed is explained on page 4 of Sikorsky Service Bulletin No. 7 dated August 4, 1947. Helicopters which utilize Smith 14TR-X1 bearings at the vertical hinge pins are subject to inspection at each 200-hour interval and replacement of the bearings is not required unless the installation shows sign of serious wear or damage. Helicopters which utilize Torrington No. 4479 bearings at the vertical hinge pins can be reworked to incorporate Smith 14TR-X1 bearings at the vertical hinge pins if desired by the owner. (The procedure to follow for this exchange of bearings is as explained on page 2 of Sikorsky Service Bulletin No. 7 dated August 4, 1947.)
2004-05-13: This amendment adopts a new airworthiness directive (AD) that is applicable to certain Bombardier Model DHC-8-401 and -402 airplanes. This action requires a records review to determine the repair/modification status of the airplane, and follow-on and corrective actions as necessary. This action is necessary to prevent cracks in the lower fuselage skin due to fatigue damage in the vicinity of the Number 2 VHF antenna, which could result in rapid decompression of the airplane. This action is intended to address the identified unsafe condition.
2011-05-11: We are superseding an existing airworthiness directive (AD) for the products listed above. That AD currently requires repetitive inspections and torque checks of the hanger fittings and strut forward bulkhead of the forward engine mount and adjacent support structure, and visual inspections of the internal angle and external bulkhead chord and detailed inspection of internal angles, and corrective actions if necessary. The existing AD also provides for an optional inspection. This new AD requires additional inspections of airplanes that have hi-lok bolts and collars at all of the Group B fastener locations, except fastener 13, and related investigative and corrective actions. This AD also requires repetitive inspections of the internal angle, and corrective actions if necessary. This AD also requires, for certain airplanes, replacing the fasteners, which terminates certain repetitive inspections. This AD was prompted by reports of undertorqued or loose fasteners, a cracked bulkhead chord, and a fractured back-up angle. We are issuing this AD to detect and correct loose fasteners and/or damaged or cracked hanger fittings, back-up angles, and bulkhead of the forward engine mount, which could lead to failure of the hanger fitting and bulkhead and consequent separation of the engine from the airplane.