Results
2011-21-18: This amendment adopts a new airworthiness directive (AD) for the Eurocopter France Model EC 120B helicopters. This AD requires modifying the pilot cyclic control friction device by replacing a certain thrust washer with two thrust washers. This AD is prompted by an incident in which the pilot encountered a sudden restriction of the cyclic control movement during flight. The actions specified by this AD are intended to prevent jamming of a pilot cyclic control stick and subsequent loss of control of the helicopter.
53-23-02: 53-23-02 de HAVILLAND: Applies to Model DHC-2 (Beaver) Aircraft, Serial Numbers 164 to 407 Inclusive. Compliance required not later than December 15, 1953. When filling the fuel tanks, it is possible for spilled fuel to seep down between the fuel tank filler neck recess box and the aircraft's outer skin. This permits gasoline fumes to accumulate in the tank bays beneath the floor and can create a fire hazard. The aircraft should be inspected to ascertain if a satisfactory seal exists between the filler neck recess box (C2-FS-1005ND) and the outer skin (C2-S-829ND). If seal is unsatisfactory, fill gap with either "Goodyear Plyabond" or "Minneapolis Mining EC776" metal sealing compounds or equivalent. In the interim, until resealing is accomplished, a "No Smoking" placard should be installed in the cabin. The FAA concurs in this mandatory action by the Canadian Department of Transport. (de Havilland Technical News Sheet No. 68, Series B, dated September 15, 1953,covers this same subject and provides resealing instructions.)
2011-24-12: We are superseding an existing airworthiness directive (AD) for certain Model 737-300, -400, and -500 series airplanes. That AD currently requires repetitive external non-destructive inspections to detect cracks in the fuselage skin along the chem-mill step at stringers S-1 and S-2 right, between station (STA) 827 and STA 847, and repair if necessary. This new AD adds inspections for cracking in additional fuselage crown skin locations, and repair if necessary. This new AD also reduces the inspection thresholds for certain airplanes, extends certain repetitive inspection intervals, and adds airplanes to the applicability of the existing AD. This AD was prompted by reports of additional crack findings of the fuselage crown skin at the chem- milled steps. We are issuing this AD to detect and correct fatigue cracking of the fuselage skin panels at the chem-milled steps, which could result in sudden fracture and failure of the fuselage skin panels, and consequent rapid decompression of the airplane.
2011-24-11: We are adopting a new airworthiness directive (AD) for certain Honeywell International Inc. ALF502L-2C, ALF502R-3, ALF502R-3A, ALF502R-5, LF507-1F, and LF507-IH turbofan engines. This AD requires removing from service certain second stage high pressure compressor (HPC2) discs. This AD was prompted by a report of cracks found in an HPC2 disc during routine inspection. We are issuing this AD to prevent the affected discs from fracturing before reaching the currently published life limit. A disc fracture could result in an uncontained failure of the disc and damage to the airplane.
55-22-04: 55-22-04 VICKERS-ARMSTRONG: Applies to All Viscount Model 745D Aircraft. Compliance required as indicated. Cracks have been found in the tailplane center section main spar extending along the lines of rivets attaching the web plate. Accordingly, Vickers-Armstrong (Aircraft) Ltd. issued Preliminary Technical Leaflet No. 52 dated August 19, 1955, covering this subject. The British Air Registration Board considers Modification D.1384, the initial and repetitive inspections recommended therein mandatory in which the FAA concurs. Aircraft complying with the limitations specified in PTL No. 52 will be considered serviceable.
58-09-01: 58-09-01 BELL: Applies to Model 47J Helicopters. Compliance required prior to next flight. 1. All 47-110-401-13 main rotor blades known to have hit an object, or to have contacted the universal joint cover on the tail boom causing an indentation over 1/4-inch deep in the universal joint cover, must be removed from service for further detail inspection, and repair if necessary. Such internal inspections and repairs are to be made by the blade manufacturer. 2. Visually inspect the stainless steel leading edge of the -13 blades for cracks and remove cracked blades. No field repairs are authorized. Cracked blades are to be returned to the blade manufacturer for detail inspection and repair. 3. Remove all 47-110-401-9 main rotor blades. These blades must be reworked to the -13 configuration prior to return to service. CAA telegraphic instructions of April 28, 1958, covered this subject.
2011-24-03: We are adopting a new airworthiness directive (AD) for certain Bombardier, Inc. Model DHC-8-400 series airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated 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: There has been one reported incident where the main landing gear (MLG) failed to extend during testing of the MLG alternate release system. Investigation revealed that the door release lever bushing was worn, causing an increase in the lateral movement of the release cable system. An increase in free-play within the release cable system would cause additional wear to the door release lever bushing and may lead to the turnbuckle fouling against the nacelle frame. The bushing wear at the door release lever and turnbuckle fouling could cause a failure in the alternate release system, preventing the landing gear from extending in the case of a failure of the normal MLG extension/retraction system. * * * * * The unsafe condition is loss of control during landing. We are issuing this AD to require actions to correct the unsafe condition on these products.
2011-24-08: 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: A helicopter experienced an inadvertent activation of the 65% N1 (gas generator speed) back up control mode. The subsequent technical investigations carried by Turbomeca revealed that an N2 (power turbine speed) sensor harness wire crimping discrepancy was at the origin of this event. Further quality investigations performed with the supplier led to the conclusion that N2 sensor Part Number (P/N) 0 301 52 001 0 whose Serial Numbers (S/N) are between S/N 242 and S/N 339 inclusive are potentially concerned by the same manufacturing discrepancy. This condition, if not corrected, could lead to the inadvertent activation of the 65% N1 back up mode and consequently to significant power loss on one or more or both engines installed on the same helicopter, potentially resulting in an emergency landing of the helicopter. We are issuing this AD to prevent inadvertent activation of the backup control mode, which could result in engine power loss and emergency landing of the helicopter.
52-28-01: 52-28-01 AERONCA: Applies to All Model 11AC and S11AC Aircraft Equipped With the Auxiliary Fuel Tank Installation. Compliance required not later than January 31, 1953. Accidents have occurred in the above model aircraft due to misuse of the fuel transfer system. These accidents have been caused by pilots attempting to transfer fuel while taking off or in a climb attitude. To preclude the possibility of pilot error with regard to the foregoing, the following placard, or its equivalent, shall be displayed near the fuel transfer system shutoff valve and in view of the pilot: "Transfer fuel in level flight or glide only and when main tank is half full or less. Valve is to be closed except while transferring fuel."
2011-23-08: We are superseding an existing airworthiness directive (AD) that applies to certain Bombardier, Inc. Model CL-600-2B19 (Regional Jet Series 100 & 440) airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated 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: Seven cases of on-ground hydraulic accumulator screw cap/end cap failure have been experienced on CL-600-2B19 aeroplanes, resulting in the loss of the associated hydraulic system and high-energy impact damage to adjacent systems and structure. * * * * * * * * A detailed analysis of the calculated line of trajectory of a failed screw cap/end cap for each of the accumulators has been conducted, resulting in the identification of several areas where systems and/or structural components could potentially be damaged. Although all of the failures to date have occurred on the ground, an in-flight failure affecting such components could potentially have an adverse effect on the controllability of the aeroplane. * * * * * We are issuing this AD to require actions to correct the unsafe condition on these products.
70-03-02: 70-03-02 BRITISH AIRCRAFT CORPORATION: Amdt. 39-929. Applies to Viscount Models 744, 745D, and 810 series airplanes. Compliance is required as indicated. To prevent possible failure of the fuselage pressure shell in the area under the dorsal fin structure, accomplish the following: (a) Within the next 90 days after the effective date of this airworthiness directive or within eight years after the date of manufacture, whichever occurs later, and thereafter at intervals not to exceed 12 months from the last inspection, visually inspect the fuselage skin under the dorsal fin for corrosion and breakdown of the protective paint. These inspections may be accomplished through the leading edge access panel for the anti-icing duct connection at the base of the fin and through new inspection holes installed in the dorsal fin in accordance with Figures 2 and 3 of the British Aircraft Corporation Preliminary Technical Leaflet No. 278, Issue 1, for Model 744 and 745D airplanes; orPreliminary Technical Leaflet No. 143, Issue 1 for Model 810 airplanes; or an FAA-approved equivalent. (b) If skin corrosion is found during the inspections required by paragraph (a), before further flight: (1) Repair the corroded area in accordance with the Viscount Repair Manual, or 2) Remove the complete dorsal fin (segments or all at once), repair the corroded skin, and reseal, and repaint the fuselage skin under the dorsal fin in accordance with the Airframe Corrosion Section of Viscount Overhaul Manual, for Model 744 airplanes; the Instruction Manual, for Model 745D airplanes; the Aircraft Manual, for Model 810 airplanes; or an FAA-approved equivalent. (c) The repetitive inspections required by paragraph (a) may be discontinued when all segments of the dorsal fin have been removed and the corrective action required by paragraph (b)(2) has been accomplished. This amendment becomes effective February 22, 1970.
2003-04-08: This amendment adopts a new airworthiness directive (AD) that applies to certain Piaggio Aero Industries S.p.A. (Piaggio) Model P-180 airplanes. This AD requires you to install a placard on the inside of the lavatory door that prohibits occupying the lavatory seat during takeoff and landing. This AD also requires you to incorporate a temporary revision into the Limitations Section of the pilot operating handbook/airplane flight manual (POH/AFM). This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for Italy. The actions specified by this AD are intended to prevent passengers from occupying the lavatory seat during takeoff and landing. The lavatory/cabin partition could fail and lead to passenger injury in an emergency situation.
98-04-28: This amendment adopts a new airworthiness directive (AD) that applies to Cessna Aircraft Company Models T303, 310R, T310R, 335, 340A, 402B, 402C, 404, F406, 414, 414A, 421B, 421C, 425, and 441 airplanes. This action requires revising the FAA-approved Airplane Flight Manual (AFM) to specify procedures that would prohibit flight in severe icing conditions (as determined by certain visual cues), limit or prohibit the use of various flight control devices while in severe icing conditions, and provide the flight crew with recognition cues for, and procedures for exiting from, severe icing conditions. The proposed AD is prompted by the results of a review of the requirements for certification of these airplanes in icing conditions, new information on the icing environment, and icing data provided currently to the flight crew. The actions specified by this AD are intended to minimize the potential hazards associated with operating these airplanes in severe icing conditions by providing more clearly defined procedures and limitations associated with such conditions.
2003-04-03: This amendment adopts a new airworthiness directive (AD) that applies to all SOCATA--Groupe AEROSPATIALE (Socata) Models TB 9, TB 10, TB 20, TB 21, and TB 200 airplanes. This AD requires you to repetitively inspect the aileron control gimbal joint for correct alignment and correct operation, and replace any misaligned or defective gimbal joint. This AD is the result of mandatory continuing airworthiness information (MCAI) issued by the airworthiness authority for France. The actions specified by this AD are intended to prevent failure of the aileron control gimbal joint. Such failure could lead to loss of control of the airplane.
2003-04-05: This amendment adopts a new airworthiness directive (AD) for Robinson Helicopter Company (RHC) Model R44 helicopters that requires inspecting the tail rotor pitch control assembly for roughness or binding of the pitch control bearings (bearings) by hand-rotating the pitch control bearing housing (housing). If the housing does not rotate freely, the AD requires replacing the unairworthy pitch control assembly with an airworthy unit. This amendment is prompted by reports of failure of the tail rotor pitch control assembly due to improperly lubricated bearings on the RHC Model R22 helicopters. Although there have been no reported failures on the RHC Model R44 helicopters, the design of the tail rotor pitch control assembly makes it susceptible to the same failures as have occurred on the Model R22 helicopters. The actions specified by this AD are intended to detect corrosion of the bearings and to prevent bearing failure and subsequent loss of directional control of the helicopter.
52-18-01: 52-18-01 CURTISS-WRIGHT: Applies to all Model C-46 aircraft equipped with Curtiss Drawing P/N S20-480-1101-2 Carburetor Adapter Gasket. Compliance required not later than December 1, 1952. Several instances of splitting and tearing of the neoprene carburetor adapter gasket, P/N S20-480-1101-2, permitting portions of gasket material to block the carburetor air passage has resulted in abrupt engine cutout. To eliminate the occurrence of this hazardous condition, either of the following changes or an approved equivalent shall be accomplished: (a) Install new gasket and clamping assembly per USAF T.O. 01-25LA-79. (b) Install carburetor adapter flange, Slick Airways P/N 00391-2. As a precautionary measure, the subject gaskets shall be inspected for signs of looseness and splitting during each periodic inspection until accomplishment of the above.
98-04-19: This amendment adopts a new airworthiness directive (AD) that applies to certain Harbin Aircraft Manufacturing Corporation (HMAC) Model Y12 IV airplanes. This action requires revising the FAA-approved Airplane Flight Manual (AFM) to specify procedures that would prohibit flight in severe icing conditions (as determined by certain visual cues), limit or prohibit the use of various flight control devices while in severe icing conditions, and provide the flight crew with recognition cues for, and procedures for exiting from, severe icing conditions. This AD is prompted by the results of a review of the requirements for certification of these airplanes in icing conditions, new information on the icing environment, and icing data provided currently to the flight crew. The actions specified by this AD are intended to minimize the potential hazards associated with operating these airplanes in severe icing conditions by providing more clearly defined procedures and limitations associated with such conditions.
2011-24-01: We are adopting a new airworthiness directive (AD) for Piaggio Aero Industries S.p.A. Model P-180 airplanes. 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: Some lock sleeves (part number (P/N) 114146681), which were installed in some Main Landing Gear (MLG) actuators, had been incorrectly manufactured. If left uncorrected, this condition could lead to failure to lock the MLG actuator or to its unlock from the correct position, with subsequent possible damage to the aeroplane and injuries to occupants during landing. We are issuing this AD to require actions to correct the unsafe condition on these products.
58-24-04: 58-24-04 VICKERS: Applies to All Viscount Models 745D and 810 Series Aircraft. Compliance required by May 15, 1959. 1. In order to provide a means of checking the electrical continuity of the stall warning system, install a switch in the cockpit and associated wiring for the nose gear oleo switch and Safe Flight wing detector vane. Revisions to the airplane flight manuals for Models 745D and 810 include instructions to the pilot for making the necessary checks. (Vickers Modification Bulletin No. D.2858 for 745D and FG.1487 for 810 cover the same subject.) 2. Periodic checking to assure proper calibration of the detector vane and correct functioning of the deicing heater are also required. (Technical News Sheet No. 212 for 745D and 69 for 810 cover the same subject.)
98-04-13: This amendment supersedes an existing airworthiness directive (AD), applicable to Rolls-Royce Limited (R-R) Dart series turboprop engines, that currently establishes a life limit for propeller low torque switches. This amendment adds two propeller low torque switch part numbers and two R-R Dart engine models that were omitted from the current AD, and establishes a calendar end-date for removal of propeller low torque switches from service. This amendment is prompted by the need to add omitted part numbers and engine models to the AD. The actions specified by this AD are intended to prevent cracking of the snap diaphragm in the propeller low torque switch, which could delay propeller auto-feathering and thereby adversely affect aircraft controllability. The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of March 24, 1998.
89-18-02 R1: 89-18-02 R1 SCHWEIZER (GRUMMAN): Amendment 39-6300 as revised by Amendment 39-6369. Applicability: All G-164 series (all serial numbers) airplanes certificated in any category. Compliance: Required as indicated in the body of the AD, unless previously accomplished. To prevent the failure of the forward and aft elevator control system push-pull rods and end fittings, accomplish the following: (a) Within the next 30 calendar days after the effective date of this AD, and thereafter at intervals not to exceed 12 calendar months, visually inspect the forward and aft elevator push-pull rod assemblies and end fittings for corrosion and cracks in accordance with the Procedure Section in Schweizer Service Bulletin No. 85, dated June 1, 1989. (b) If corrosion or cracks are found, prior to further flight, replace or repair the defective assembly in accordance with the Procedures Section of Schweizer Service Bulletin No. 85, dated June 1, 1989, utilizing the replacement parts specified in Figure 1 or 2 therein, as applicable, and continue the repetitive inspections specified in paragraph (a) of this AD. (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, New York Aircraft Certification Office, FAA, New England Region, 181 South Franklin Avenue, Room 202, Valley Stream, New York 11581. NOTE: The request should be forwarded through an FAA Maintenance Inspector, who may add comments and then send it to the Manager, New York Aircraft Certification Office. All persons affected by this directive, may obtain copies of the documents referred to herein upon request to the Schweizer Aircraft Corporation, P.O. Box 147, Elmira, New York 14902, or may examine these documents at the FAA, Office of the Assistant Chief Counsel, Room 1558, 601 East 12th Street, Kansas City, Missouri 64106. This AD revises AD 89-18-02, Amendment 39-6300, which became effective on September 15, 1989. This amendment (39-6369, AD 89-18-02 R1) becomes effective on November 24, 1989.
2011-23-10: We are adopting a new airworthiness directive (AD) for certain Model ATR42 and ATR72 airplanes. This AD results from mandatory continuing airworthiness information (MCAI) originated 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: One ATR operator has experienced in-flight elevator travel limitations with unusual effort being necessary on pitch axis to control the aeroplane, while the ``pitch mistrim'' message appeared on the ADU [advisory display unit] display. The elevators seemed to be jammed. During the post-flight inspection, it was discovered that the LH [left-hand] elevator lower stop assembly was broken at the level of the angles, which may have prevented the elevator to respond normally to the flight control input. This condition, if not detected and corrected, could lead to reduced control of the aeroplane. * * * * * We are issuing this AD torequire actions to correct the unsafe condition on these products.
2011-23-01: We are superseding an existing airworthiness directive (AD) for Thielert Aircraft Engines GmbH (TAE) Models TAE 125-01 and TAE 125- 02-99 reciprocating engines. That AD currently requires replacement of certain part numbers (P/Ns) and serial numbers (S/Ns) of clutch assemblies due to clutch failure. The failures identified above could lead to engine in-flight shutdown and loss of control of the airplane. This AD requires the same actions, but applies the corrective action to an additional 244 affected clutch assemblies. This AD was prompted by TAE identifying additional clutch assemblies with nonconforming disc springs. We are issuing this AD to correct the unsafe condition on these products.
2003-04-01: This amendment adopts a new airworthiness directive (AD), that is applicable to Hartzell Propeller Inc. HD-E6C-3B/E13890K propellers. This amendment requires the reduction of the original hub certified service (fatigue) life from unlimited hours to 37,400 flight hours. This amendment is prompted by a reevaluation by Hartzell Propeller Inc. of the D-5108-( ) original hub service life certification calculations. The actions specified by this AD are intended to prevent fatigue failure of D-5108-( ) hubs, which may result in loss of airplane control.
84-23-06 R1: 84-23-06 R1 PILATUS BRITTEN-NORMAN LTD.: Amendment 39-10172; Docket No. 84-CE-18-AD; Revises AD 84-23-06, Amendment 39-4942 which superseded AD 83-07-18, Amendment 39-4620. Applicability: BN-2A MK. 111 Series Airplanes (all serial numbers), certificated in any category. NOTE 1: This AD applies to each airplane 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 airplanes 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. NOTE 2: The paragraph structure of this AD is as follows: Level 1: (a), (b), (c), etc. Level 2: (1), (2), (3), etc. Level 3: (i), (ii), (iii), etc. Level 2 and Level 3 structures are designations of the Level 1 paragraph they immediately follow. Compliance: Required initially upon the accumulation of 500 hours time-in-service (TIS) or within the next 50 hours TIS after the effective date of this AD, whichever occurs later, unless already accomplished (compliance with AD 84-23-06), and thereafter at intervals not to exceed 500 hours TIS. To prevent failure of the upper mounting brackets on both wing mounted engines, which could possibly cause structural failure of the airplane, accomplish the following: (a) Visually inspect the following areas in accordance with paragraphs 1 through 6 of the "Inspection" section of the Pilatus Britten-Norman (Pilatus) Service Bulletin (SB) No. BN- 2/SB.61, Issue 5, dated December 9, 1981:(1) The upper engine to wing mounting brackets for: (i) Minimum lug bolt hole-to-edge distance, elongation of the bolt holes, distortion, delamination, cracks, flaking, and corrosion; (ii) The bolts for correct bearing length; and (iii) Loose and fretted bushings. (2) Prior to further flight, correct defects in accordance with the following: (i) If the lug bolt hole-to-edge distance is less than the specified minimum (0.2625-inches), correct in accordance with paragraph 3 of the "Rectification/Modification" section of Pilatus SB No. BN-2/SB.61, Issue 5, dated December 9, 1981; (ii) If the bolt holes are elongated, or if any bushings are loose or fretted, modify and correct in accordance with paragraph 4 of the "Rectification/Modification" section of Pilatus SB No. BN-2/SB.61, Issue 5, dated December 9, 1981; (iii) If any mounting bracket is cracked, modify both brackets on the same engine installation (left side engine or right side engine) concurrently (even if only one bracket is defective) in accordance with paragraph 1 of the "Rectification/Modification" section of Pilatus SB No. BN-2/SB.61, Issue 5, dated December 9, 1981; (iv) If any lug is distorted or delaminated, replace the deficient part in accordance with paragraphs 1 and 2 of the "Rectification/Modification" section of Pilatus SB No. BN-2/SB.61, Issue 5, dated December 9, 1981; (v) If any inspected part is corroded or flaking, replace the part in accordance paragraph 1 with the "Rectification/Modification" section of Pilatus SB No. BN-2/SB.61, Issue 5, dated December 9, 1981; and (vi) If any of the bolts are of incorrect length or damaged, replace with new units of the correct length in accordance with paragraphs 1 and 2 of the "Rectification/Modification" section of Pilatus SB No. BN-2/SB.61, Issue 5, dated December 9, 1981. (b) The intervals between the repetitive inspections required by this AD may be adjusted up to 10 percent of the specified interval to allow for accomplishing these inspections concurrent with the other scheduled maintenance of the airplane. (c) 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 airplane to a location where the requirements of this AD can be accomplished. (d) An alternative method of compliance or adjustment of the initial or repetitive compliance times that provides an equivalent level of safety may be approved by the Manager, Small Airplane Directorate, Aircraft Certification Service, FAA, 1201 Walnut, suite 900, Kansas City, Missouri 64106. The request shall be forwarded through an appropriate FAA Maintenance Inspector, who may add comments and then send it to the Manager, Small Airplane Directorate. NOTE 3: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the SmallAirplane Directorate. (e) The inspections, modifications, and replacements, required by this AD shall be done in accordance with Pilatus Britten-Norman Service Bulletin No. BN-2/SB.61, Issue: 5, Date: December 9, 1981. 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 Pilatus Britten-Norman Limited, Bembridge, Isle of Wight, United Kingdom PO35 5PR. Copies may be inspected at the FAA, Central Region, Office of the Regional Counsel, Room 1558, 601 E. 12th Street, Kansas City, Missouri, or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (f) This amendment becomes effective on November 24, 1997.