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FAA orders · airworthiness directive · historical

98-24-35: Outboard Spherical Bearing Ball

FAA order 98-24-35 is an airworthiness directive in force since December 17, 1998. The FAA's subject line: Outboard Spherical Bearing Ball. It names Aerospatiale AS-355, Airbus Helicopters AS350 AStar (Écureuil), now H125, Airbus Helicopters AS355 TwinStar: about 920 aircraft on the U.S. register today across them, though an order usually covers particular versions or serial numbers rather than every one. System: rotorcraft systems.

What it applies to as the FAA lists it

Kind of product
Aircraft
Makes
Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France; Eurocopter France
Models
AS-350B, AS-350B1, AS-350B2, AS-350BA, AS-350C, AS-350D, AS-350D1, AS355E, AS355F, AS355F1, AS355F2, AS355N
On this site
Aerospatiale AS-355 23 registered
Airbus Helicopters AS350 AStar (Écureuil), now H125 891 registered
Airbus Helicopters AS355 TwinStar 6 registered

Dates and paperwork

In force since
December 17, 1998
Published
December 2, 1998
Docket
98-SW-41-AD
Replaced by
2003-22-06
Status
Historical
The FAA's document
Read the order on the FAA's site

The FAA's summary their words, unchanged

This amendment adopts a new airworthiness directive (AD) that is applicable to Eurocopter France Model AS-350B, B1, B2, BA, C, D, D1, and AS 355E, F, F1, F2, and N helicopters. This action requires measuring the tail rotor pitch change control rod (control rod) outboard spherical bearing for radial and axial play. If the play exceeds 0.008-inch, replacing the control rod with an airworthy control rod is required. This amendment is prompted by one accident and one incident. Investigations revealed a broken control rod on the helicopter involved in the accident and a severely worn control rod on the helicopter involved in the incident. This condition, if not corrected, could result in separation of the outboard spherical bearing ball from its outer race, rubbing of the body of the control rod against the tail rotor blade pitch horn clevis, failure of the control rod, and loss of control of the helicopter.

The order itself the regulatory text, as published

Show the full text (2,762 characters)
98-24-35 EUROCOPTER FRANCE: Amendment 39-10921. Docket No. 98-SW-41-AD. Applicability: Eurocopter France Model AS-350B, B1, B2, BA, C, D, D1, and AS 355E, F, F1, F2, and N helicopters, with tail rotor pitch change control rod (control rod), part number (P/N) 350A33-2145-01, installed, certificated in any category. NOTE 1: This AD applies to each helicopter 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 helicopters that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must use the authority provided in paragraph (b) to request approval from the FAA. This approval may address either no action, if the current configuration eliminates the unsafe condition, or different actions necessary to address the unsafe condition described in this AD. Such a request should includean assessment of the effect of the changed configuration on the unsafe condition addressed by this AD. In no case does the presence of any modification, alteration, or repair remove any helicopter from the applicability of this AD. Compliance: Required within 50 hours time-in-service (TIS) after the effective date of this AD, unless accomplished previously, and thereafter at intervals not to exceed 50 hours TIS. To prevent separation of the outboard spherical bearing ball from its outer race, rubbing of the body of the control rod against the tail rotor blade pitch horn clevis, failure of the control rod, and loss of control of the helicopter, accomplish the following: (a) Using a dial indicator, measure the axial and radial play of the outboard spherical bearing on the control rod. If the play exceeds 0.008-inch, replace the control rod with an airworthy control rod. (b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used when approved by the Manager, Rotorcraft Standards Staff, Rotorcraft Directorate, FAA. Operators shall submit their requests through an FAA Principal Maintenance Inspector, who may concur or comment and then send it to the Manager, Rotorcraft Standards Staff. NOTE 2: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Rotorcraft Standards Staff. (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 helicopter to a location where the requirements of this AD can be accomplished. (d) This amendment becomes effective on December 17, 1998.

Related safety bulletins advice on the same designs, not orders

2021-08-13AIR-21-13 · ENGINE EMERGENCY SHUTDOWN SYSTEM
2019-07-15SW-17-23R2 · Fuel System
2018-03-02SW-17-23R1 · Fuel System
2017-08-24SW-17-23 · Fuel System
2015-08-13SW-15-20 · Air Conditioning System Wiring

Source: FAA Dynamic Regulatory System, airworthiness directives. The FAA's document is the authority; the register counts are this site's, from the FAA register of October 7, 2026. Connections as data: /graph/directive/98-24-35.json · aircraft systems.