# AD 94-11-03: Fan Casing Clearance - Type: Airworthiness directive - Status: Historical - Products: Raytheon BAe.125 Series (all), BH.125 Series (all), DH.125 Series (all), Hawker 1000, Hawker 800, Hawker 800 (U-125A), Hawker 800XP and HS.125 Series (all) - Effective: June 10, 1994 - Published: May 26, 1994 - Superseded by: [AD 2006-01-04](https://openairdocs.org/ad/2006-01-04) - Product type: Aircraft, Large airplane - Amendment: 39-8919 - Docket: 94-NM-69-AD - Registered aircraft: 293 may be affected, by airframe or engine model (OpenAirDocs) - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/B0BE269B8D58071686256A09005E4B32.0001 - DRS record last changed: August 7, 2025 - Page: https://openairdocs.org/ad/94-11-03 ## Summary This amendment adopts a new airworthiness directive (AD) that is applicable to certain Raytheon Corporate Jets Model DH/BH/HS BAe 125 and Hawker 800 and 1000 series airplanes. This action requires a visual inspection to determine whether adequate clearance exists between the fan venturi motor casing and the adjacent equipment, and adjustments, if necessary; and a visual inspection to detect signs of overheating, degradation of insulating materials, and ingestion of debris into the motor, and replacement of discrepant parts with serviceable parts. This amendment is prompted by reports of smoke emanating from the lavatory due to overheating of the fan venturi motor. The actions specified in this AD are intended to prevent smoke or fire in the cabin while the airplane is in flight. Comments for inclusion in the Rules Docket must be received on or before July 5, 1994. ## The airworthiness directive 94-11-03 RAYTHEON CORPORATE JETS, INC.: Amendment 39-8919. Docket 94-NM-69-AD. Applicability: Model DH/BH/HS/BAe 125 and Hawker 800 and 1000 series airplanes on which Modification 253514A has not been installed, certificated in any category. Compliance: Required as indicated, unless accomplished previously. To prevent smoke or fire in the cabin while the airplane is in flight, accomplish the following: (a) Within 30 days after the effective date of this AD, perform a visual inspection to determine whether clearance between the fan venturi motor casing and the adjacent equipment (including insulating materials, ducting, and wire looms) is within the limits specified in Raytheon Corporate Alert Jets Service Bulletin SB 21-A150, dated February 22, 1994, and to detect signs of overheating, degradation of insulating materials in the vicinity of the fan venturi, and ingestion of debris into the motor; in accordance with that alert service bulletin. (1) If clearance is less than the limits specified in the alert service bulletin, prior to further flight, adjust insulating materials, ducting, and/or looms to ensure that contact with other equipment is avoided; in accordance with the alert service bulletin. (2) If any sign of overheating or ingestion of debris into the motor is detected, prior to further flight, replace the fan venturi, and any adjacent equipment (including cables) that shows signs of overheating, with serviceable parts; in accordance with the alert service bulletin. (3) If any sign of degradation of insulation materials is detected, prior to further flight, replace the insulating material with serviceable parts in accordance with the service bulletin. (b) 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, Standardization Branch, ANM-113, FAA, Transport Airplane Directorate. Operators shall submit theirrequests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Standardization Branch, ANM-113. NOTE: Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Standardization Branch, ANM-113. (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) The inspections, adjustments, and replacements shall be done in accordance with Raytheon Corporate Jets Alert Service Bulletin SB 21-A150, dated February 22, 1994. 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 Raytheon Corporate Jets, Inc., 3 Bishops Square, St. Albans Road West, Hatfield, Hertfordshire, AL109NE, United Kingdom. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC. (e) This amendment becomes effective on June 10, 1994. ## Rule preamble ### Supplementary information The Civil Aviation Authority (CAA), which is the airworthiness authority for the United Kingdom, recently notified the FAA that an unsafe condition may exist on certain Raytheon Corporate Jets Model DH/BH/HS/BAe 125 and Hawker 800 and 1000 series airplanes. The CAA advises it has received reports of smoke emanating from the lavatory in the rear of the cabin while several airplanes were being prepared for departure. Investigation revealed that the venturi fan motor overheated due to insufficient clearance between the motor and the adjacent sound insulation and wiring. This condition, if not corrected, could result in smoke or fire in the cabin while the airplane is in flight. Raytheon Corporate Jets, Inc., has issued Alert Service Bulletin SB 21-A150, dated February 22, 1994, that describes procedures for a one-time visual inspection to determine whether adequate clearance exists between the fan venturi motor casing and the adjacent equipment (including insulating materials, ducting, and wire looms) and adjustment of the insulating materials, ducting, and/or looms, if necessary. This alert service bulletin also describes procedures for a one-time visual inspection to detect signs of overheating, degradation of insulating materials, and ingestion of debris into the motor, and replacement of discrepant parts with serviceable parts. The CAA classified this alert service bulletin as mandatory and issued a British airworthiness directive in order to assure the continued airworthiness of these airplanes in the United Kingdom. These airplane models are manufactured in the United Kingdom and are type certificated for operation in the United States under the provisions of section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and the applicable bilateral airworthiness agreement. Pursuant to this bilateral airworthiness agreement, the CAA has kept the FAA informed of the situation described above. The FAA has examined thefindings of the CAA, reviewed all available information, and determined that AD action is necessary for products of this type design that are certificated for operation in the United States. Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design registered in the United States, this AD is being issued to prevent smoke or fire in the cabin while the airplane is in flight. This AD requires a one-time visual inspection to determine whether adequate clearance exists between the fan venturi motor casing and the adjacent equipment (including insulating materials, ducting, and wire looms) and adjustment of the insulating materials, ducting, and/or looms, if necessary. This AD also requires a one-time visual inspection to detect signs of overheating, degradation of insulating materials, and ingestion of debris into the motor, and replacement of discrepant parts with serviceable parts. The actions are required to be accomplished in accordance with the alert service bulletin described previously. Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days. Comments Invited Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed. Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 94-NM-69-AD." The postcard will be date stamped and returned to the commenter. The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment. The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed inthe Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety. Adoption of the Amendment Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 106(g); and 14 CFR 11.89. 39.13 - [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: ## Affected data sheets (1) (OpenAirDocs) The type certificate data sheets whose models the AD names. - [TCDS A3EU](https://openairdocs.org/tcds/A3EU): Textron Aviation Inc.; names 3 of 50 models: Hawker 1000, Hawker 800 (U-125A), Hawker 800XP ## Registered aircraft it may apply to (OpenAirDocs) Matched by airframe and engine model; the AD's applicability may narrow it by serial number, part number or equipment. - Aircraft: 293 (293 by airframe model, 0 by engine model) - Makers: Raytheon 252, Raytheon Corporate Jets 40, Hawker Beechcraft 1 Models with the most aircraft: - [Raytheon HAWKER 800XP](https://openairdocs.org/model/raytheon-hawker-800xp): 251 aircraft (airframe model) - [Raytheon Corporate Jets HAWKER 800XP](https://openairdocs.org/model/raytheon-corporate-jets-hawker-800xp): 23 aircraft (airframe model) - [Raytheon Corporate Jets HAWKER 800](https://openairdocs.org/model/raytheon-corporate-jets-hawker-800): 9 aircraft (airframe model) - [Raytheon Corporate Jets HAWKER 1000](https://openairdocs.org/model/raytheon-corporate-jets-hawker-1000): 8 aircraft (airframe model) - [Raytheon HAWKER 1000](https://openairdocs.org/model/raytheon-hawker-1000): 1 aircraft (airframe model) - [Hawker Beechcraft HAWKER 800XP](https://openairdocs.org/model/hawker-beechcraft-hawker-800xp): 1 aircraft (airframe model) All 6 models: https://openairdocs.org/ad/94-11-03/models.md Every aircraft: https://openairdocs.org/ad/94-11-03/aircraft.md ## Related documents - [AD 2006-01-04](https://openairdocs.org/ad/2006-01-04): Fan venturi motor casing ยท Textron BAe.125 Series 1000A, BAe.125 Series 1000B, BAe.125 Series 800A and 42 more. Effective Feb 22, 2006. Supersedes this AD Its text cites no advisory circulars or STCs. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.