Results
2005-19-25: The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series airplanes. This AD requires repetitive eddy current inspections for cracks of the countersunk rivet holes in the lower lobe, adjacent to the radio altimeter cutouts; additional inspections, for certain airplanes, for cracks and/or corrosion; and further investigative and corrective action if any crack is found. This AD also provides an optional terminating action for the repetitive inspections. This AD results from reports of cracks in the fuselage skin of the lower lobe. We are issuing this AD to detect and correct fatigue cracks of the countersunk rivet holes, which could result in cracks of the fuselage skin of the lower lobe, and consequent rapid depressurization of the cabin.
47-51-07: 47-51-07 CURTISS-WRIGHT Applies to all C-46 Series aircraft. Compliance required not later than March 1, 1948, and each 1,000 hours of operation thereafter. Inspect the landing gear drag strut support structure inside nacelle to determine if landing gear drag strut No. 20-720-1018 attaching bolts at the 70 percent spar have loosened and if angle assembly 20-720-1024-1 and bulkhead assemblies 20-720-1021-1 and 20-720-1023-6 are loose. All defective parts, loose or sheared attachment rivets should be replaced and loose bolts tightened. To accomplish the above, it is necessary to remove one outer panel or provide an access door in order to gain access to the interior of the center panel. (Curtiss-Wright Service Information Letter No. 735 dated August 20, 1947, covers an acceptable wing panel door installation.)
48-44-02: 48-44-02 CURTISS-WRIGHT Applies to all C-46 Series aircraft. Compliance required at original certification and at every 7,500 hours of operation thereafter, or at the approved airframe overhaul period for air carriers. Check the center wing-to-fuselage attachment bolts, P/N AN 8-23A, AN 8-25A, and AN 8-31A, to determine that they are properly torqued. The proper torque value for these bolts is between 480 to 690 inch-pounds as per Curtiss-Wright Drawing No. 20-230-1000. For access to the 30 percent spar fitting, a 1 1/2-inch diameter hole can be cut in the wing center section lower skin beneath the fitting, just forward of the beam, and far enough inboard so that the resultant opening will be completely covered upon reinstallation of the wing foot fairing. This supersedes AD 47-51-06.
2005-19-12: The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A330-301, -321, -322, -341, and -342 airplanes; and Model A340-200 and A340-300 series airplanes. This AD requires repetitive inspections for cracks of the inboard lower flange and radius of the left- and right-hand outboard floor beams at frame (FR) 48, and related investigative and corrective actions if necessary. This AD also provides an optional terminating action for the repetitive inspections. This AD results from reports that cracks were found during fatigue tests at the attachment between the canted lower flange of the floor beam and the pressure diaphragm in front of FR48 on both left- and right-hand floor beams; and that an additional crack was found in the flange radius of the floor beam. We are issuing this AD to detect and correct such cracking, which could propagate and result in reduced structural integrity of the fuselage.
49-46-01: 49-46-01 DOUGLAS: Applies to All Models DC-4 and DC-6 Aircraft Equipped With Vacuum systems, Incorporating Oil Separators Other Than the Type Mentioned in Item 2.\n\n\tTo be accomplished not later than April 1, 1950.\n\n\tTo guard against the possibility of excessive air temperatures in the vacuum system discharge line, one of the following modifications must be accomplished to this system:\n\n\t1.\tInstall a fusible plug in the side of the vacuum pump discharger port at the right angles to the axis of the discharge port boss. Some pumps incorporate a plugged hole in the discharge port which may be enlarged to a 3/8-inch pipe tapped hole to accommodate the fusible plug. This plug should employ an AN 840-8D fitting with a binary eutectic mixture of 67.8 percent tim and 32.2 percent cadmium, which has a melting point of 351 degrees F. Figure 2 describes the design of such a plug. The 3/8-inch fusible plug fitting is intended for pumps such as the Model 3P-211 and 3P-485. For smallerpumps such as the 3P-207, and AN 840-6D fitting, incorporating the same modification as shown below, should be used. Incorporation of an overboard drain line clamped to the fusible plug is recommended but is not mandatory.\n\n\n\n\n\tBrass fittings of the same design as the above dural fittings are acceptable. On installations which do not use an overboard discharge line the possibility exists that the plug may damage other nacelle components if it can hit them upon being out of the adapter as high velocity. Therefore, if no overboard discharge line is provided, the installation must be made in such a manner that the plug will not be directed toward any vulnerable components when it issues from the adapter.\n\n\t2.\tReplace the present oil separator with a new oil separator, Genisco No. 40081 or equivalent. The new separator incorporates a pressure relief valve and can be disassembled for cleaning.\n\n\t(Douglas Service Letter A-129-T-1271/WB-11-Q-4, dated April 1, 1949, covers this same modification.)
2005-18-10: The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 777-200 and -300 series airplanes. This AD requires modification of the splice plate assemblies installed under the floor panels at the forward and aft edges of the cabin aisle. This AD results from reports of cracking of the aluminum splice plates under the floor panels in the cabin aisle. We are issuing this AD to prevent loss of the capability of the cabin floor and seat track structure to support the airplane interior inertia loads under emergency landing conditions. Loss of this support could lead to galley or seat separation from attached restraints, which could result in blocking of the emergency exits and consequent injury to passengers and crew.
49-15-01: 49-15-01 AERONCA: Applies to All Models 11AC, S11AC and 11BC Aircraft. To be accomplished not later than July 1, 1949. In order to prevent the seat belt anchorage from failing during crash landings, it has been found necessary to modify the seat installation as follows: 1. If there is no need for an adjustable seat, the rear sliding lugs on each side of the seat should be bolted to the slide tube using 3/16- or 1/4-inch diameter AN bolts. 2. If the seat is to remain adjustable, two 1/8 7 x 19 steel snare cables looped around each end of the seat frame cross tube and the lower end of the vertical slide fuselage tube located aft of the seat should be installed so that they will be taut with the seat in the most forward position. Any approved type cable clamp may be used for joining the ends of the cable. (Aeronca Helps and Hints No. 42 covers this same subject.) This supersedes AD 49-13-01.
92-15-07: 92-15-07 TEXTRON LYCOMING: Amendment 39-8301. Docket No. 91-ANE-40. Supersedes AD 87-11- 09, Amendment 39-5902. Applicability: Textron Lycoming LTS101 series turboshaft and LTP101 series turboprop engines installed on but not limited to Aerospatiale AS350, Bell 222, and MBB BK117 helicopters; and Piaggio P166-DL3, Airtractor AT302, and Cessna 421 airplanes. Compliance: Required as indicated, unless accomplished previously. To prevent fracture of the integrally cast power turbine (PT) rotor blade, which can result in engine power loss and uncontained engine failure, accomplish the following: (a) Perform a Type I, Method C fluorescent penetrant inspection of Part Number (P/N) 4-141-070-XX and P/N 4-143-010-XX PT rotors installed in engines, in accordance with the procedures in Textron Lycoming Service Bulletin (SB) Number LT 101-72-00-0093, Revision 5, dated January 15, 1990, as follows: (1) Inspect for PT rotor blade cracks within 50 hours time in service (TIS) or 300 PT cycles in service (CIS), whichever occurs first, since accomplishing the last inspection performed in accordance with AD 87-11-09. (2) Thereafter, reinspect for PT rotor blade cracks at intervals not to exceed 50 hours TIS or 300 PT CIS, whichever occurs first, since the last Type I, Method C fluorescent penetrant inspection performed in accordance with paragraph (a) of this AD. (3) Remove from service prior to further flight, cracked PT rotors found during the inspections required by paragraphs (a)(1) and (a)(2) of this AD. Prior to returning to service, replace with a serviceable PT rotor. NOTE: For information on PT rotor cycle and counting methodology consult the latest revision to Textron Lycoming SB No. LT 101-71-00-0002. (b) Perform a Type I, Method D fluorescent penetrant inspection of P/N 4-141-070-XX and P/N 4-143- 010-XX PT rotors prior to installation into a PT module or prior to returning to service, in accordance with Textron Lycoming SB No. LT 101-72-00-0093, Revision 5, dated January 15, 1990. Cracked PT rotors found during this fluorescent penetrant inspection shall not be returned to service and must be replaced with a serviceable PT rotor. (c) For PT rotors P/N 4-141-070-XX and P/N 4-143-010-XX installed in LTS101-650C-3, LTS101- 650C-3A, and LTS101-750C-1 series engines, avoid continuous operation at certain PT operating speeds in accordance with Textron Lycoming SB Number LTS 101C-72-00-0131, dated September 17, 1990, Bell Helicopter Textron Alert SB 222U-90-30, dated December 21, 1990, and Alert SB 22-90-57, dated December 21, 1990, within 20 hours time in service, after effective date of this AD, as follows: (1) Avoid continuous engine operation at 97% to 98.5% power turbine (Np) speed, including autorotation and single engine operation. Operation in this speed range is only permitted for topping checks and when operations in this range are necessary to maintain safe flight. (2) Install a cockpit tachometer decal and add the temporary rotorcraft flight manual supplement in accordance with applicable Bell Helicopter Textron ASB No. 222U-90-30 or Bell Helicopter Textron ASB No. 222-90-57, as applicable. (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, FAA, Engine and Propeller Directorate. The request should be forwarded through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office. NOTE: 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 FAR 21.197 and 21.199 to operate the airplane to a location where the requirements of this AD can be accomplished. (f) The PT rotor inspection and removal criteria, the establishment of the PT rotor speed operation avoidance ranges, rotorcraft modification, and rotorcraft flight manual revisions shall be accomplished in accordance with the following service bulletins: DOCUMENT NO. PAGES ISSUE/REVISION DATE Textron Lycoming SB LT 101-72-00-0093 1-4 Revision 5 1-15-90 including Commercial Service Letter CSL 063 R-1 1-2 Revision 1 5-31-91 Textron Lycoming SB LTS 101C-72-00-0131 1-2 Original 9-17-90 Bell Helicopter Textron Alert SB 222-90-57 1-4 Original 12-21-90 Bell Helicopter Textron Alert SB 222U-90-30 1-4 Original 12-21-90 This incorporation by reference was approved by the Director of the Federal Register in accordance with 5. U.S.C. 552(a) and 1 CFR Part 51. Copies may be obtained from Textron Lycoming, Technical Publications, Department 30V, 550 South Main Street, Stratford, Connecticut 06497, and Bell Helicopter Textron, P.O. Box 482, Fort Worth, Texas 76101. Copies may beinspected at the FAA, New England Region, Office of the Assistant Chief Counsel, Room 311, 12 New England Executive Park, Burlington, Massachusetts; or at the Office of the Federal Register, 1100 L Street NW., Room 8401, Washington, D.C. (g) This amendment becomes effective on September 2, 1992.
47-33-05: 47-33-05 BEECH: (Was Service Note 3 of AD-75777-2 and Service Note 1 of AD-765-1.) Applies to AT-11, C18S and D18S Aircraft. C18S and AT-11 Airplanes: Inspection required prior to certification or, if certificated, on next periodic inspection but not later than November 1, 1947, and each 100 hours of operation thereafter. D18S Airplanes (Serial Numbers prior to A-378): Inspection required each 25 hours of normal operation or each 10 hours where the airplane is flown for pilot's transition or instrument training. Inspect the horizontal stabilizer front spar and subspar for cracks at the points of attachment to the fuselage. At each annual inspection remove stabilizer and the stabilizer lower front skin panel and check for evidence of cracks. If cracks are found the center section of the main spar must be revised or replaced with one having the lower flange-web radius cutout approximately 2 inches from either end. Two 0.064-inch dural channels (404-186053) should be installed between the new attachment fittings (437-186095 and 6) and the main spar web. At the main attachment fittings and 0.032-inch dural doubler (404-186052) should be riveted to the lower skin, the main spar, and the center nose rib flanges. The forward part of the upper flanges of each stabilizer-fuselage attaching angle should be cut off as far back as the sixth screw hole. The corresponding 12 holes in the stabilizer should be plugged. A three-screw outboard section of the gang nut on each side of the stabilizer subspar should be removed and the corresponding holes in the No. 13 bulkhead angle plugged. The revision of the stabilizer attachments eliminates the necessity for further inspection for cracks except as made during the normal periodic inspection. (Beech Service Bulletin No. D-18-48 revised April 1, 1948, covers this same subject.)
2005-18-15: The FAA is adopting a new airworthiness directive (AD) for certain Dassault Model Falcon 2000EX airplanes. This AD requires revising the airplane flight manual (AFM) to extend runway length limits for takeoff and landing. This AD also provides for an optional terminating action for the AFM revision. This AD results from an event in which braking efficiency was temporarily lost during landing, but was recovered after the flightcrew fully released and then reapplied the brakes. We are issuing this AD to prevent a runway overrun in the event of loss of braking function, which could result in injury to passengers or flightcrew and damage to the airplane.
48-25-03: 48-25-03 CESSNA: Applies to All 120 and 140 Aircraft. Inspection required each 100 hours of operation. Inspect wing drag wire system for loose or broken drag wires and inspect ribs for damage. Inspection openings should be installed aft of the rear spar just inboard of Rib 5 and just outboard of Rib 10 if not already installed. Drag wires should be rerigged if loose, or replaced if broken, and drag ribs should be repaired or replaced if buckled. No. 6 drag wires in the outer wing panel found broken are to be replaced with No. 8. Buckling of the intermediate rib flanges at the spar cutouts does not render the wing unairworthy; however, reinforcement with Cessna P/N 10004-58 is recommended. If the flanges are cracked the reinforcement should be installed. (Cessna Service Letters 27 and 39 cover this same subject.)
2005-17-17: The FAA is adopting a new airworthiness directive (AD) for Turbomeca S.A. Arrius 2F turboshaft engines. This AD requires replacing certain O-rings on the check valve piston in the lubrication unit. This AD results from a report of a forced landing of a Eurocopter EC120B helicopter. We are issuing this AD to prevent an uncommanded in-flight shutdown of the engine, which could result in a forced autorotation landing and damage to the helicopter.
98-26-17: This amendment adopts a new airworthiness directive (AD) that applies to all British Aerospace Jetstream Model 3201 airplanes. This AD requires accomplishing both a routine visual inspection and either a detailed visual inspection or x-ray inspection of the main landing gear (MLG) bay auxiliary spar booms for cracks or fuel leaks on both the left and right sides of the airplane. This AD also requires obtaining and incorporating repair procedures for the MLG bay auxiliary spar where fuel leaks or cracks are found. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for the United Kingdom. The actions specified by this AD are intended to prevent wing failure caused by cracks or fuel leaks in the area of the MLG bay auxiliary spar booms, which could result in loss of control of the airplane.
75-17-32: 75-17-32 DETROIT DIESEL ALLISON: Amendment 39-2336. Applies to Detroit Diesel Allison Model 501-D13 series engines which incorporate P/N 6829072 second stage turbine wheels with the following serial numbers: KK14208 KK14421 KK14443 KK14460 KK15456 KK15484 KK14210 KK14422 KK14445 KK14461 KK15457 KK15485 KK14211 KK14423 KK14446 KK14463 KK15471 KK15486 KK14403 KK14424 KK14447 KK14464 KK15472 KK15487 KK14405 KK14427 KK14448 KK14465 KK15473 KK15489 KK14406 KK14428 KK14449 KK14817 KK15474 KK15490 KK14407 KK14430 KK14450 KK14819 KK15475 KK15492 KK14408 KK14431 KK14451 KK14821 KK15476 KK15493 KK14409 KK14432 KK14452 KK14822 KK15477 KK15494 KK14413 KK14434 KK14453 KK14823 KK15478 KK15495 KK14414 KK14435 KK14454 KK14825 KK15479 KK15496 KK14416 KK14436 KK14455 KK15451 KK15480 KK15497 KK14417 KK14437 KK14456 KK15452 KK15481 KK15498 KK14418 KK14440 KK14457 KK15453 KK15483 KK15500KK14420 KK14442 KK14459 KK15454 Note: At time of overhaul, some wheels have R1, R2, R3, R4 or R5 added as a suffix to the wheel serial number. The suffix should be disregarded in determining the applicability of this airworthiness directive. Compliance required as indicated. I. Remove from service wheels which have not been inspected since installation as new wheels, according to the following schedule: (a) Remove from service within 100 cycles from the effective date of this Airworthiness Directive, wheels with more than 6900 cycles. (b) Remove from service prior to exceeding 7000 cycles, wheels with not more than 6900 cycles, on the effective date of this Airworthiness Directive. II. Remove from service wheels which have been inspected by fluorescent penetrant method FP- 30A/ZL-30A at last inspection, according to the following schedule: (a) Remove from service within 100 cycles from the effective date of this Airworthiness Directive, wheels with more than 3900 cycles since last inspection or more than 9400 total cycles, whichever occurs first. (b) Remove from service prior to exceeding 4000 cycles since last inspection or 9500 total cycles, whichever occurs first, wheels with not more than 3900 cycles since last inspection or not more than 9400 total cycles on the effective date of this Airworthiness Directive. Note: If the method of fluorescent penetrant inspection used at last inspection cannot be determined, it must be assumed that FP-30A/ZL-30A was not used. III. Remove from service wheels which have been inspected by a fluorescent penetrant method other than FP-30A/ZL-30A at last inspection, according to the following schedule: (a) Remove from service within 100 cycles from the effective date of this Airworthiness Directive, wheels with more than 2400 cycles since last inspection, or more than 9400 total cycles, whichever occurs first. (b) Remove from service prior to exceeding2500 cycles since last inspection or 9500 total cycles, whichever occurs first, wheels with not more than 2400 cycles since last inspection or not more than 9400 total cycles on the effective date of this Airworthiness Directive. IV. or the purposes of this airworthiness directive, a cycle is defined as one takeoff. V. Detroit Diesel Allison Commercial Service Letter 501D13 CSL-234 pertains to this subject. This amendment is effective August 14, 1975.
2005-17-07: The FAA is adopting a new airworthiness directive (AD) for certain Airbus Model A320-111 airplanes and Model A320-200 series airplanes. This AD requires doing a one-time general visual inspection of the axle nut on each main landing gear (MLG) wheel for the presence of locking bolts and associated hardware; doing any related investigative and corrective actions as applicable; and submitting an inspection report to the manufacturer. This AD results from a report that an axle nut had separated from an axle on a main landing gear (MLG) wheel, due to missing locking bolts. We are issuing this AD to detect and correct missing locking bolts on the axle nuts of the MLG wheels. Absence of the locking bolts could result in separation of a wheel(s) from the axle and consequent reduced controllability of the airplane during takeoff and landing, and possible injury to people on the ground.
47-20-03: 47-20-03 ERCO: (Was Mandatory Note 11 of AD-718-6.) Applies to All 415 Series Aircraft Ercoupes Up to and Including Serial Number 3642 Which Incorporate Fuel Pumps With a Metal Filter Bowl, and Bearing AC P/N 1539076 on the Pump Mounting Flange. Inspection to be accomplished immediately, alteration to be made not later than the next periodic inspection. Inspect immediately and at each 25 hours thereafter until the following alteration is completed, the fuel pump lines near the pump for failure and leakage due to chafing. Alter fuel pump lines not later than next periodic inspection as follows: Remove the fuel pump top and rotate it 120 degrees clockwise (two screwholes from the original position). Replace the pump inlet port fittings with AN 842-4D elbow and the outlet port fittings with (415-48101-40) elbow having 1/16-inch restriction. Drill two 3/4-inch diameter holes in right front engine cooling baffle and install grommets (AN 931-9-13). Route fuel pump hoses through respective holes; shorten outlet hose (415-48101-2) and install fuel pump hose (415-48101-2 and 415-48101-3) onto respective elbows securing them with two hose clamps (AN 746-4). Safety-wire clamps. Close extra unused hole in baffle with button plug (415-40589-1) or equivalent. (Erco Service Department Memorandum No. 42 dated January 9, 1947, covers this same subject.)
2005-13-35: The FAA is superseding an existing airworthiness directive (AD), which applies to all Bombardier Model DHC-8-100, DHC-8-200, and DHC-8-300 series airplanes. That AD currently requires installation of a placard on the instrument panel of the cockpit to advise the flightcrew that positioning of the power levers below the flight idle stop during flight is prohibited. Additionally, the existing AD requires eventual installation of an FAA-approved system that would prevent such positioning of the power levers during flight. Installation of that system terminates the requirement for installation of a placard. This new AD requires operators who have incorporated a certain Bombardier service bulletin to perform repetitive operational checks of the beta lockout system and to revise the Airworthiness Limitations document. This AD is prompted by in-service issues reported by operators who incorporated Bombardier Service Bulletin 8-76-24 as an alternative method of compliance to the existing AD. We are issuing this AD to prevent the inadvertent activation of ground beta mode during flight, which could lead to engine overspeed, engine damage or failure, and consequent reduced controllability of the airplane.
48-39-01: 48-39-01 AERONCA: Applies to All Model 7 Series Aircraft. To be accomplished as soon as possible but not later than November 1, 1948. Inspect front and rear control stick socket castings, P/N 2-705, for cracks at the ears to which the push-pull tube attaches. If found cracked, the castings should be replaced. To prevent future failures the bolt, nut and washer now installed are to be replaced with a clevis bolt, AN 24- 16 (11/16 grip) and an AN 320-4 shear nut so that excessive loads cannot be placed on the socket ears.
47-49-07: 47-49-07 LOCKHEED: (Was Mandatory Note 40 of AD-763-3.) Applies to All Model 49 Serials Up to and Including 2088, Unless Equipped With MLG Drag Strut Dampers. Compliance required prior to February 1, 1948. (a) Replace the NAS 58A65 bolt used to connect the two halves of each MLG upper drag link assembly, LAC P/N 283418 and 288983, with a 5/8-inch diameter high strength bolt, LAC P/N 297902. (LAC Service Bulletin 49/SB-368 covers installation of MLG shock strut dampers.) (b) Reduce MLG shock strut inflation pressures to provide a static extension of 2 inches at maximum landing weight.
48-05-01: 48-05-01 DOUGLAS: Applies to All DC3 Aircraft Equipped With Pacific Aviation Oil Shutoff Valves. \n\n\tCompliance required at first engine change after March 1, 1948, but not later than May 1, 1948. \n\n\tReplace the present "O" rings in the oil shutoff valves with rings of H222-90 high temperature material or AMS-3228B material. There has been reported leakage attributed to the fact that the material in the "O" rings is not capable of withstanding the operating temperature of the oil. \n\n\t(Douglas Service Bulletin DC3 No. 256 covers this same subject.)
2005-16-12: The FAA is adopting a new airworthiness directive (AD) for Rolls-Royce Deutschland Ltd & Co KG (RRD) (formerly Rolls-Royce Deutschland GmbH, formerly BMW Rolls-Royce GmbH) model BR700-715A1-30, BR700-715B1-30, and BR700-715C1-30 turbofan engines. This AD requires a onetime inspection of the Independent Overspeed Protection (IOP) unit, part number (P/N) 112E9321G2, for 19 specific serial numbers (SNs), and removal from service of those units. This AD results from a report that incorrect capacitors were installed in 19 IOP units. The incorrect capacitor in the IOP unit can lead to an inadvertent IOP command resulting in an in-flight engine shutdown. We are issuing this AD to prevent inadvertent dual-engine in-flight shutdown.
46-23-05: 46-23-05 NOORDUYN: (Was Mandatory Note 1 of AD-2-578-1.) Applies to Army UC- 64, -64A, and -64B Aircraft. Required at next periodic inspection. Inspect the trailing edge of the horizontal stabilizer to determine whether or not drain holes are present in the metal trailing edge cover. If the holes are not present, it will be necessary to remove enough fabric to permit inspection of the ribs. Defective or deteriorated wood must be replaced and drain holes, approximately 1/16-inch diameter, spaced to drain all pockets must be drilled.
95-05-01: This amendment adopts a new airworthiness directive (AD), applicable to all British Aerospace Model BAe 146-100A, -200A, and -300A series airplanes, that requires conducting closed loop tests to determine the setting of the underfrequency trip level on suspect generator control units (GCU), and either the correction of discrepancies or replacement of the GCU. This amendment is prompted by several malfunctions of in-service GCU's due to the effects of setting the underfrequency trip level too high. The actions specified by this AD are intended to correct GCU's that may have the underfrequency level set too high, which could result in the unwanted shut down of an electrical generator; this condition may lead to loss of all generated electrical power on the airplane when other generator faults or failures occur.
2005-16-04: This amendment adopts a new airworthiness directive (AD) for Bell Helicopter Textron (Bell) Model 206A and 206B helicopters modified by Aeronautical Accessories, Inc. Supplemental Type Certificate (STC) SH1392SO with certain part-numbered high crosstubes. This amendment requires inspecting at specified time intervals and replacing any cracked crosstubes. This amendment is prompted by the discovery of a cracked high forward crosstube. The actions specified by this AD are intended to detect a crack in the crosstube which could lead to failure of the crosstube, collapse of the landing gear, and subsequent loss of control of the helicopter.
48-01-01: 48-01-01 DOUGLAS: Applies to C-54 and DC-4 Aircraft. \n\nBecause of cracking and failure in the locking groove of Goodyear Model 20DHBM wheels, Assembly No. 530402-M, resulting from the use of the old one-place flange and lock ring, the following must be accomplished: \n\nI.\tNot later than the next scheduled inspection at which necessary facilities are available, and at each succeeding No. 3 inspection until II is accomplished: \n\n\t(1)\tRemove the wheel-retaining flange from all wheels which are used with , or ever have been used with, the one-piece retaining flange P/N 511033 or 530405-M and lock ring P/N 511051-1. \n\n\t(2)\tClean and etch the wheel lock ring groove and carefully inspect to determine if any cracking has started. Remove from service all wheels found to be cracked. \n\n\t(3)\tMeasure the diameter of the lock ring groove at the locking surface. The nominal diameter is 0.440 inch + 0.002 inch. When the groove has worn to more than 0.500-inch diameter and less than 0.563-inch, remove wheel from service until it has been reworked to provide a true radius in the outer side of the groove and the thrust surface is made parallel to the end of the wheel. This radius should be 0.220 inch + 0.001 inch. Wheels reworked in this manner must be inspected at each 500 hours or the closest major inspection period thereto. Remove from service any wheels in which the groove has worn to a diameter equal to or exceeding 0.563-inch. \n\nII.\tTo be accomplished not later than August 1, 1948. \n\nRemove from service all one-piece flanges and lock rings and replace by two-piece flange P/N 530735-M and studs P/N 511284-6. \n\n(Goodyear Service Bulletin No. 1 covers this same subject.)