Results
2016-03-04: We are adopting a new airworthiness directive (AD) for all Rolls-Royce plc (RR) RB211-535E4-37, RB211-535E4-B-37, and RB211-535E4- C-37 turbofan engines. This AD requires recalculating the cyclic life for certain engine life-limited rotating parts and removing those parts that have exceeded their cyclic life limit within specified compliance times. This AD was prompted by a review of operational data that determined certain RR RB211-535E4-37 engines have been operated to a more severe flight profile than is consistent with the flight profile used to establish the cyclic life limits for the rotating parts. We are issuing this AD to prevent failure of life-limited rotating parts, uncontained parts release, damage to the engine, and damage to the airplane.
2000-23-18: This amendment adopts a new airworthiness directive (AD), applicable to certain Learjet Model 60 airplanes, that requires inspecting the routing of oxygen tubing to ensure that there is adequate clamping of the tubing and adequate clearance between the tubing and electrical wiring or electrical contacts, and taking corrective action, if necessary. The actions specified by this AD are intended to prevent electrical arcing between the oxygen tubing and an electrical source, which could result in an oxygen fire.
48-02-01: 48-02-01 BELL: Applies to All 47B Series, Through Serial Number 78. Compliance required before next 25 hours of operation. Reinforce the tail rotor drive shaft bearing hangers by riveting reinforcement plates, Bell P/N 47-267-001-152, -153, -154, -155, -156, and -157, to the appropriate hangers with AN 470- AD3-4 rivets. (Bell Service Bulletin 47C56 dated September 10, 1947, also covers this subject.)
2016-03-05: We are superseding airworthiness directive (AD) 2014-13-01 for Airbus Helicopters Deutschland GmbH (Airbus Helicopters) Model MBB-BK 117 C-2 helicopters with a certain Goodrich rescue hoist damper unit (damper unit) installed. AD 2014-13-01 required repairing or replacing the damper unit or deactivating the rescue hoist. AD 2014-13-01 was prompted by a report of an uncommanded detachment of a damper unit from the cable. This new AD retains the optional requirement of deactivating the rescue hoist, expands the applicability, and requires either replacing or modifying the damper unit with a newly developed single- piece retainer. These actions are intended to prevent the hoist damper unit detaching from the cable resulting in loss of an external load or person from the helicopter hoist and injury to persons being lifted by the hoist.
81-13-04: 81-13-04 ROCKWELL INTERNATIONAL: Amendment 39-4167. Applies to Models NA-265-60 (S/N 306-5, -6, -12, -16, -24, -47, -50, -71, -73, -81, -109, -116, -119, and -122); NA- 265-70 (S/N 370-1 through -9); and NA-265-80 (S/N 380-1 through -72) airplanes certificated in any category. COMPLIANCE: Required as indicated unless already accomplished. Reflect this AD compliance by an appropriate entry in the aircraft maintenance records. A) Prior to next flight, clean interior of (MLG) shock strut trunnion and measure inside diameter of trunnion from aft side of gear using an internal micrometer. (Ref. Fig. 1 Sabreliner Service Bulletin 81-4, dated June 11, 1981.) 1. If measurement is 2.948 inches or less, return the airplane to service with an appropriate entry in the aircraft maintenance record. 2. If the measurement exceeds 2.948 inches, either replace the outer cylinder with an airworthy part (P/N 1127L001-3, -4, -5, or -6) and return the aircraft to service with an appropriate entry in the aircraft maintenance record, or remove the airplane from service and contact the FAA Aircraft Certification Program Office at telephone (316) 942-4219. B) A special flight permit, in accordance with Federal Aviation Regulation (FAR) 21.197 for a flight by the most direct route to a base where maintenance can be performed, is authorized provided a dye penetrant check of the shaded area of the main landing gear shock strut outer cylinder as shown on Figure 1 of Sabreliner Service Bulletin No. 81-4, dated June 11, 1981, is conducted and no cracks are found. If cracks are found, a ferry flight will not be authorized unless the defective outer cylinder is replaced with an airworthy part (P/N 1127L001-3, -4, -5, or -6). The airplane shall be limited to a maximum gross weight of 20,500 pounds and a landing weight of 17,500 pounds for this special flight. C) The owner/operator shall report defects found to the Chief, Aircraft Certification Program at the address shown in Paragraph D) below, within 48 hours of the inspection. (Reporting approved by the Office of Management and Budget under OMB No. 04-R0174.) D) Any equivalent method of compliance with this AD must be approved by the Chief, Aircraft Certification Program, Federal Aviation Administration, Room 238, Terminal Building 2299, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 942-4285. Saberliner Service Bulletin No. 81-4, dated June 11, 1981, pertains to the subject matter of this AD. This amendment becomes effective on July 30, 1981, to all persons except those to whom it has already been made effective by an airmail letter from the FAA dated June 16, 1981, and is identified as AD 81-13-04.
2009-03-02: The FAA is superseding an existing airworthiness directive (AD), which applies to certain McDonnell Douglas transport category airplanes. That AD currently 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; 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 new AD also requires, for certain airplanes, modifying and rerouting, as applicable, certain components of the wiring of the electric motor for the auxiliary hydraulic pump located in the right wheel well. This AD results from reports of failure of the electric motor for the auxiliary hydraulic pump. We are issuing this AD 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.
2000-23-20: This amendment adopts a new airworthiness directive (AD), applicable to certain Boeing Model 777-200 series airplanes, that requires replacement of certain components. The actions specified by this AD are intended to prevent corrosion of the axle of the main landing gear, which could result in cracking and failure of one or more axles, loss of the wheels on the axle, and loss of controllability of the airplane on the ground. This action is intended to address the identified unsafe condition.
98-09-16 R1: This amendment rescinds an existing Airworthiness Directive (AD), applicable to all Aerospatiale Model ATR-42 and ATR-72 series airplanes. That AD currently requires revising the Airplane Flight Manual to add specific flightcrew instructions to be followed in the event of failure of the first generator, which could lead to the loss of main battery power and result in the loss of all electrical power, except the emergency battery supply, during flight. The requirements of that AD were intended to prevent failure of the second of two direct current generators after the failure of the first generator. Since the issuance of that AD, the FAA has received further information indicating that the incident that prompted that AD was an isolated case.
98-18-10: 98-18-10 GENERAL ELECTRIC COMPANY: Amendment 39-10726. Docket 98-ANE-18-AD. Applicability: General Electric Company (GE) CF6-6 series turbofan engines, installed on but not limited to McDonnell Douglas DC-10-10 series aircraft. Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.Compliance: Required as indicated, unless accomplished previously. To prevent low pressure turbine (LPT) stage 4 disk cracking, which could result in an uncontained engine failure and damage to the aircraft, accomplish the following: (a) Remove from service LPT stage 4 disks, part numbers (P/Ns) 9010M40P01, 9010M40P02, 9010M40P07, 9010M40P09, and 9010M40P12, and replace with serviceable parts, in accordance with the following schedule: (1) For disks with 12,300 or more cycles since new (CSN) but less than 24,000 CSN on the effective date of this AD, remove from service affected disks at the earliest of the following: (i) The next piece-part exposure after the effective date of this AD; or (ii) The next engine shop visit after accumulating 16,500 CSN; or (iii) Within 4,200 cycles in service (CIS) after the effective date of this AD; or (iv) Prior to exceeding 24,000 CSN. (2) For disks with 5,000 or more CSN, but less than 12,300 CSN, on the effective date of this AD, remove from service affected disks at the earlier of the following: (i) Prior to exceeding 16,500 CSN; or (ii) Within 7,300 CIS after the effective date of this AD. (3) For disks with less than 5,000 CSN on the effective date of this AD, remove from service affected disks prior to exceeding 12,300 CSN. (b) This AD establishes a new cyclic retirement life limit for LPT stage 4 disks of 12,300 CSN. Thereafter, except as provided in paragraph (d) of this AD, no alternative cyclic retirement life limits may be approved for LPT stage 4 disks. (c) For the purpose of this AD, the following definitions apply: (1) An engine shop visit is defined as separation of a major, static flange. (2) Piece-part exposure is when the affected part is completely disassembled in accordance with the disassembly instructions in the engine manual or section of the Instructions for Continued Airworthiness. (d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office. (e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished. (f) This amendment becomes effective on September 30, 1998.
91-02-08: 91-02-08 AEROSPACE TECHNOLOGIES OF AUSTRALIA PTY LTD.: Amendment 39-6842. Docket No. 90-CE-15-AD. Applicability: Nomad Models N22B, N22S, and N24A airplanes (all serial numbers), certificated in any category. Compliance: Required within the next 100 hours time-in-service after the effective date of this AD, unless already accomplished. To prevent overheating of the terminal lugs connected to the generator cables at the wing leading edge engine firewall, accomplish the following: (a) Modify the airplane electrical system using Nomad Modification No. N724, in accordance with the instructions in Part 3 of Nomad Alert Service Bulletin ANMD-24-5, Revision 1, dated August 4, 1989. (b) 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. (c) An alternate method of compliance or adjustment to the compliance time that provides an equivalent level of safety may be approved by the Manager, FAA, Northwest Mountain Region, Los Angeles Aircraft Certification Office, 3229 E. Spring Street, Long Beach, California 90806-2425. The request should be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, FAA, Northwest Mountain Region, Los Angeles Aircraft Certification Office. (d) All persons affected by this directive may obtain copies of the document referred to herein upon request to Aerospace Technologies of Australia Pty, Ltd., 226 Lorimer Street, Port Melbourne, Victoria 3207, Australia; Telephone 9-011-61-62-68-4142; or may examine this document at the FAA, Central Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri 64106. This amendment (39-6842, AD 91-02-08) becomes effective on February 7, 1991.
2016-02-06: We are adopting a new airworthiness directive (AD) for Bell Helicopter Textron Canada Limited (Bell) Model 429 helicopters. This AD requires inspecting each tail rotor (T/R) pitch link (link) bearing bore for corrosion and pitting and either replacing the T/R link or applying sealant. This AD also requires a recurring inspection of the sealant and repeating the inspections for corrosion and pitting if any sealant is missing. This AD is prompted by an incident in which a helicopter experienced an in-flight failure of a T/R link. These actions are intended to detect corrosion or pitting and to prevent failure of a T/R link and subsequent loss of control of the helicopter.
2009-03-04: 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: Turbomeca S.A. has informed EASA of a case of a "red disk'' plug that has been actually installed on an engine which has been subsequently released for service operation. This engine experienced an in-service high pressure leak event (at the fuel pump outlet) due to cracking of this "red disk'' plug. This leak could lead to in- flight flame-out and/or possibly a fire. We are issuing this AD to prevent fuel leaks, which could result in a fire and damage to the helicopter.
2009-04-14: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) issued by the aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Field reports have indicated that during take-off with light turbulences or after rapid roll/heading attitude changes soon after take-off, it is possible that both PFDs (Primary Flight Display) indicate a roll attitude offset of up to 10 degrees in the same direction. This condition has been reported to correct itself after several minutes of un-accelerated flight with levelled wings and no sideslip. This situation, if not corrected, could result in an undesired bank angle which constitutes an unsafe condition. This AD requires actions that are intended to address the unsafe condition described in the MCAI.
2016-02-05: We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model BD-100-1A10 (Challenger 300) airplanes. This AD was prompted by multiple reports of a short circuit between the heater element and the metal sheath of the pitot-static probe heater. This AD requires replacement of the left and right pitot-static probes with newly redesigned left and right pitot-static probes. We are issuing this AD to prevent degradation of the heating ability of the pitot- static probe heater, resulting in erroneous airspeed indication during flight in icing conditions and consequent reduced controllability of the airplane.
2016-01-18: We are superseding Airworthiness Directive (AD) 98-20-27 for all Airbus Model A300 B4-600, B4-600R, and F4-600R series airplanes, and Model A300 C4-605R Variant F airplanes (collectively called Model A300-600 series airplanes). AD 98-20-27 required repetitive inspections to detect fatigue cracking of the wing top skin at the front spar joint; and a follow-on eddy current inspection and repair, if necessary. This new AD reduces the inspection compliance time and intervals, and expands the inspection area of the wing top skin at the front spar joint. This AD was prompted by reports of cracking of the wing top skin in an area not required for inspection by AD 98-20-27. We are issuing this AD to detect and correct fatigue cracking of the wing top skin at the front spar joint; such fatigue cracking could result in reduced structural integrity of the airplane.
2000-21-08: This amendment supersedes an existing airworthiness directive (AD), applicable to certain Pratt & Whitney JT8D series turbofan engines, that currently requires revisions to the Time Limits Section (TLS) of the JT8D Turbofan Engine Manual to include required enhanced inspection of selected critical life-limited parts at each piece-part exposure. This action adds additional critical life-limited parts for enhanced inspection. This amendment is prompted by focused inspection procedures that have been developed by the manufacturer for additional critical life-limited parts. The actions specified by this AD are intended to prevent critical life-limited rotating engine part failure, which could result in an uncontained engine failure and damage to the airplane.
2000-22-04: This amendment adopts a new airworthiness directive (AD), applicable to certain Learjet Model 45 series airplanes, that requires repetitive application of grease to the rotating disk assembly of the nose landing gear squat switch mechanism. Application of grease to the squat switch assembly is necessary to prevent moisture contamination and subsequent formation of ice. Such ice formation could result in bending or damaging of the nose landing gear squat switch assembly, which could drive the nose wheel to an uncommanded angle against the force of the steering system. This condition, if not corrected, could result in the airplane departing from the runway at high speeds during landing.
2022-22-11: The FAA is superseding Airworthiness Directive (AD) 2021-14- 08, which applied to all Airbus SAS Model A319-151N, A319-153N, A319- 171N, A320-251N, A320-252N, A320-273N, A321-251N, A321-251NX, A321- 252N, A321-252NX, A321-253N, A321-253NX, A321-271N, A321-271NX, A321- 272N, and A321-272NX airplanes. AD 2021-14-08 required revising the existing airplane flight manual (AFM) to include a procedure to reinforce the airspeed check during the take-off phase and provide instructions to abort take-off in certain cases. This AD was prompted by the development of a software update to the elevator aileron computer (ELAC) to address the unsafe condition. This AD continues to require the actions in AD 2021-14-08 and requires replacing each affected ELAC and removing the AFM revision required by AD 2021-14-08, as specified in a European Union Aviation Safety Agency (EASA) AD, which is incorporated by reference. This AD also prohibits the installation of affected parts. The FAA is issuing this AD to address the unsafe condition on these products.
96-07-02: This amendment adopts a new airworthiness directive (AD), applicable to certain Fokker Model F28 Mark 0100 series airplanes, that requires inspections to verify the correct operation of the main landing gear (MLG) downlock actuators, and replacement of any discrepant unit with a serviceable unit. This amendment also will require eventual replacement of the MLG downlock actuators with improved units. This amendment is prompted by reports of improper operation of the MLG downlock actuator due to jamming. The actions specified by this AD are intended to prevent such jamming of the downlock actuator, which could result in failure of the MLG downlock system, and a potential gear-up landing.
2000-22-03: This amendment adopts a new airworthiness directive (AD), applicable to certain Raytheon Model DH.125, Model HS.125, Model BH.125, Model BAe.125 Series 800A, Model Hawker 800, Model Hawker 800XP, and Model Hawker 1000 series airplanes, that requires leak checks and inspections for corrosion of the pitot/static and stall vent drain valves, and replacement of certain components, if necessary. This amendment is prompted by reports of plugged or taped drain valves as well as consequent corrosion of certain drain valves. The actions specified by this AD are intended to prevent erroneous altimeter and airspeed indications due to plugged or taped pitot/static and stall vent drain valves.
2000-22-02: This amendment supersedes an existing airworthiness directive (AD), applicable to all Boeing Model 737 series airplanes, that currently requires revising the FAA-approved Airplane Flight Manual (AFM). This new amendment revises the AFM procedure in the existing AD to simplify the instructions for correcting a jammed or restricted flight control condition. This amendment is prompted by an FAA determination that the procedure currently inserted in the AFM by the existing AD is not defined adequately. The actions specified in this AD are intended to ensure that the flight crew is advised of the procedures necessary to address a condition involving a jammed or restricted rudder.
2016-02-04: We are adopting a new airworthiness directive (AD) for certain CFM International S.A. (CFM) CFM56-5B series turbofan engines. This AD was prompted by a corrected lifing analysis by the engine manufacturer that shows the need to identify an initial and repetitive inspection threshold for certain part number (P/N) turbine rear frames (TRFs). This AD requires initial and repetitive inspections of certain P/N TRFs on the low-pressure turbine (LPT) frame assembly. We are issuing this AD to prevent failure of the TRF on the LPT frame assembly, which could lead to engine separation, damage to the engine, and damage to the airplane.
2010-21-03: The FAA is superseding an existing airworthiness directive (AD) that applies to all of the McDonnell Douglas Corporation airplanes identified above. The existing AD currently requires revising the maintenance program to incorporate new airworthiness limitations for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. This new AD adds requirements to revise the maintenance program to incorporate specific Critical Design Configuration Control Limitations (CDCCL) information and install fuel tank float switch in- line fuses. This new AD also adds two Airworthiness Limitations inspections (ALIs). This AD results from a design review of the fuel tank systems. We are issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.
91-04-03: 91-04-03 BRITISH AEROSPACE: Amendment 39-6890. Docket No. 90-NM-234-AD. Applicability: All Model BAe 125-800A series airplanes, certificated in any category. Compliance: Required within 60 days after the effective date of this AD, unless previously accomplished. To detect damage to main landing gear (MLG) components and to prevent reduced structural integrity of the MLG, accomplish the following: A. Perform a visual inspection of the left and right MLG side stay to wing pick-up fitting for adequate clearance, in accordance with British Aerospace Service Bulletin 32-224, Revision 1, dated August 30, 1990. 1. If clearance is less than 0.025 inch, prior to further flight, perform a dye penetrant inspection and repair, in accordance with British Aerospace Service Bulletin 57-72, dated January 28, 1990, and then proceed to paragraph B. of this AD. 2. If there is a minimum clearance of 0.025 inch around the full circumference, prior to further flight,proceed to paragraph B. of this AD. B. Disassemble, clean, lubricate, and reassemble and recheck clearance in accordance with British Aerospace Service Bulletin 32-224, Revision 1, dated August 30, 1990. 1. If a minimum clearance of 0.025 inch does not exist, prior to further flight, repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. 2. If there is a minimum clearance of 0.025 inch, proceed to paragraph C. of this AD. C. Unless accomplished in accordance with paragraph A.1. of this AD, perform a dye penetrant inspection of the left and right MLG side stay attachment lugs, in accordance with British Aerospace Service Bulletin 57-72, dated January 28, 1990. 1. If a crack is found, prior to further flight, repair in accordance with paragraph 2.A.(5) of the service bulletin, and repeat dye penetrant inspection to ensure all cracks have been removed. 2. If cracks are still evident, prior to further flight, repair in a manner approved by the Manager, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. 3. If no cracks are found, prior to further flight, thoroughly degrease the blended area, restore protective treatment and surface finish, reinstall side stay assembly, and torque tighten upper side stay locating pin retaining nut to 500 inch-pounds +/- 50 inch-pounds in accordance with paragraphs 2.A.(9) and (10) of the service bulletin. D. Perform a visual inspection of the left and right MLG side stay center pivot for distortion, in accordance with British Aerospace Service Bulletin 32-225, dated May 30, 1990. 1. If distortion is less than 0.002 inch, prior to further flight, reinstall nut to side stay center pivot, in accordance with paragraph 2.A.(3) of the service bulletin. 2. If distortion is greater than 0.002 inch, prior to further flight, discard nut and replace with new nut, in accordance with paragraphs 2.A.(4) through 2.A.(9)of the service bulletin. 3. If a side stay center pivot nut was found to be distorted and was replaced, prior to further flight, remove the affected side stay from the airplane, disassemble, and perform the following, in accordance with British Aerospace Service Bulletin 32-227, dated August 30, 1990; or Revision 1, dated October 12, 1990: a. Conduct a visual inspection for cracks using an 8X magnifying glass. b. Conduct an eddy current inspection of the upper side stay assembly. c. Conduct a magnetic particle inspection of the lower side stay assembly. 4. If cracked parts are found, prior to further flight, replace with new parts having the same part numbers, and accomplish the following: a. Restore protective treatment, bond any detached washers, replace any worn or damaged items, and reassemble side stay upper arm to lower arm, and reinstall side stay on airplane in accordance with the service bulletin. b. Perform adjustment/test procedures in accordance with the service bulletin. E. 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. F. 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 (39-6890, AD 91-04-03) becomes effective on March 18, 1991.
2015-25-08: We are adopting a new airworthiness directive (AD) for all The Boeing Company Model 777 airplanes. This AD was prompted by an evaluation by the design approval holder (DAH) indicating that the lap splices of the aft pressure bulkhead webs are subject to widespread fatigue damage (WFD) on aging Model 777 airplanes that have accumulated at least 38,000 total flight cycles. This AD requires repetitive inspections for any crack in the aft webs of the radial lap splices of the aft pressure bulkhead, and, if necessary, corrective actions. We are issuing this AD to detect and correct fatigue cracking in the aft webs of the radial lap splices of the aft pressure bulkhead; such cracking could result in reduced structural integrity of the airplane, decompression of the cabin, and collapse of the floor structure.