# AD 2005-03-16: Engine compartment firewall

- Type: Airworthiness directive
- Status: Current
- Products: Textron BAe.125 Series 800A, BAe.125 Series 800A (C-29A), BAe.125 Series 800A (U-125), BAe.125 Series 800B, BH.125 Series 400A, BH.125 Series 600A, DH.125 Series 1A, DH.125 Series 1A-522, DH.125 Series 1A/R-522, DH.125 Series 1A/S-522, DH.125 Series 3A, DH.125 Series 3A/R and 31 more
- Effective: March 21, 2005
- Published: February 14, 2005, 70 FR 7389–7390
- Issued: January 31, 2005
- Issued as: Final rule
- Superseded by: Nothing supersedes this AD
- Product type: Aircraft, Large airplane
- Amendment: 39-13972
- Docket: FAA-2004-19561 (https://www.regulations.gov/docket/FAA-2004-19561)
- Project: 2004-NM-50-AD
- Registered aircraft: 395 may be affected, by airframe or engine model (OpenAirDocs)
- Official PDF: https://openairdocs.org/files/sha256/a6/8e/a68eba22e25e0889f988aab425df0f6a4d6bb39941624889deb98632f97a25dd (from https://www.govinfo.gov/content/pkg/FR-2005-02-14/pdf/05-2577.pdf)
- Federal Register: https://www.federalregister.gov/documents/2005/02/14/05-2577/airworthiness-directives-raytheon-model-dh125-hs125-and-bh125-series-airplanes-bae125-series-800a
- FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/28BC8DF05E1BA49186256FA8005B5EC7.0001
- DRS record last changed: January 21, 2026
- Page: https://openairdocs.org/ad/2005-03-16

## Summary

The FAA is adopting a new airworthiness directive (AD) for certain Raytheon Model DH.125, HS.125, and BH.125 series airplanes; BAe.125 series 800A (C-29A and U-125) and 800B airplanes; and Hawker 800 (including variant U-125A) and 800XP airplanes. This AD requires installing insulating blankets on the engine compartment firewall and the wire harness passing through the firewall fairlead. This AD is prompted by a report indicating that insulation on the wire harness passing through the firewall fairlead ignited on the fuselage side of the firewall. We are issuing this AD to prevent a fire in the engine compartment from causing possible ignition of outgassing wire insulation on the fuselage side of the firewall, which could lead to an uncontrollable fire in the fuselage.

## The airworthiness directive

Accordingly, under the authority delegated to me by the Administrator, the FAA amends 14 CFR part 39 as follows:

1. The authority citation for part 39 continues to read as follows:

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

2005-03-16 Raytheon Aircraft Company: Amendment 39-13972. Docket No. FAA-2004-19561; Directorate Identifier 2004-NM-50-AD.

### (a) Effective Date

  (a) This AD becomes effective March 21, 2005.

### (b) Affected ADs

  (b) None.

### (c) Applicability

  (c) This AD applies to Raytheon Model DH.125, HS.125, and BH.125 series airplanes; BAe.125 series 800A (C-29A and U-125) and 800B airplanes; and Hawker 800 (including variant U-125A) and 800XP airplanes; certificated in any category; equipped with TFE731 engines; as identified in Raytheon Service Bulletin SB 26-3496, dated November 2003.

### (d) Unsafe Condition

  (d) This AD was prompted by a report indicating that insulation on the wire harness passing through the firewall fairlead ignited on the fuselage side of the firewall. We are issuing this AD to prevent a fire in the engine compartment from causing possible ignition of outgassing wire insulation on the fuselage side of the firewall, which could lead to an uncontrollable fire in the fuselage.

### (e) Compliance

  (e) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

### (f) Installation of Insulating Blankets

  (f) Within 12 months after the effective date of this AD, install insulating blankets on the engine compartment firewall and the wire harness passing through the firewall fairlead, by doing all the actions in accordance with the Accomplishment Instructions of Raytheon Service Bulletin SB 26-3496, dated November 2003.

### (g) No Reporting Requirement

  (g) The service bulletin describes procedures for reporting accomplishment of the service bulletin to the manufacturer; however, this AD does not require that action.

### (h) Alternative Methods of Compliance (AMOCs)

  (h) The Manager, Wichita Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

### (i) Material Incorporated by Reference

    (i) You must use Raytheon Service Bulletin SB 26-3496, dated November 2003, to perform the actions that are required by this AD, unless the AD specifies otherwise. The Director of the Federal Register approves the incorporation by reference of this document in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. For copies of the service information, contact Raytheon Aircraft Company, Department 62, P.O. Box 85, Wichita, Kansas 67201-0085. For information on the availability of this material at the National Archives and Records Administration (NARA), call (202) 741-6030, or go to http://www.archives.gov/federal_register/ code_of_federal_regulations /ibr_locations.html. You may view the AD docket at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street SW., room PL-401, Nassif Building, Washington, DC.

## Rule preamble

### Dates

This AD becomes effective March 21, 2005.

The incorporation by reference of a certain publication listed in the AD is approved by the Director of the Federal Register as of March 21, 2005.

### Addresses

For service information identified in this AD, contact Raytheon Aircraft Company, Department 62, P.O. Box 85, Wichita, Kansas 67201-0085. You can examine this information at the National Archives and Records Administration (NARA). For information on the availability of this material at NARA, call (202) 741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.

Docket: The AD docket contains the proposed AD, comments, and any final disposition. You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone (800) 647-5227) is located on the plaza level of the Nassif Building at the U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, Washington, DC. This docket number is FAA-2004-19561; the directorate identifier for this docket is 2004-NM-50-AD.

### For further information contact

Jeff Pretz, Aerospace Engineer, Airframe Branch, ACE-118W, FAA, Wichita Aircraft Certification Office, 1801 Airport Road, room 100, Mid-Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4153; fax (316) 946-4407.

### SUPPLEMENTARY INFORMATION

The FAA proposed to amend 14 CFR Part 39 with an AD for certain Raytheon Model DH.125, HS.125, and BH.125 series airplanes; BAe.125 series 800A (C-29A and U-125) and 800B airplanes; and Hawker 800 (including variant U-125A) and 800XP airplanes. That action, published in the Federal Register on November 10, 2004 (69 FR 65103), proposed to require installing insulating blankets on the engine compartment firewall and the wire harness passing through the firewall fairlead.

### Comments

We provided the public the opportunity to participate in the development of this AD. No comments have been submitted on the proposed AD or on the determination of the cost to the public.

### Explanation of Change Made to the Proposal

We inadvertently left the paragraph number off the paragraph headed “No Reporting Requirement” between paragraphs (f) and (g) of the proposed AD. We have identified the specified paragraph as (g) and reidentified the original paragraph (g) to (h) in the final rule.

### Conclusion

We have carefully reviewed the available data and determined that air safety and the public interest require adopting the AD with the change described previously. We have determined that this change will neither increase the economic burden on any operator nor increase the scope of the AD.

### Costs of Compliance

There are about 804 airplanes of the affected design in the worldwide fleet. This AD will affect about 530 airplanes of U.S. registry. The actions will take about 8 work hours per airplane, at an average labor rate of $65 per work hour. Required parts will cost about $1,784 per airplane. Based on these figures, the estimated cost of the AD for U.S. operators is $1,221,120, or $2,304 per airplane.

### Authority for this Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, Section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in Subtitle VII, Part A, Subpart III, Section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

### Regulatory Findings

We have determined that this AD will not have federalism implications under Executive Order 13132. This AD will not have a substantial direct effect 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.

For the reasons discussed above, I certify that this AD:

  (1) Is not a “significant regulatory action” under Executive Order 12866;

  (2) Is not a “significant rule” under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); and

  (3) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this AD. See the ADDRESSES section for a location to examine the regulatory evaluation.

## 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 40 of 50 models: HS.125 Series 3B/RB, HS.125 Series 401B, HS.125 Series 600A, HS.125 Series 600B/2, HS.125 Series 403A(C), HS.125 Series 600B/1, HS.125 Series 700A, DH.125 Series 1A/R-522…

## 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: 395 (395 by airframe model, 0 by engine model)
- Makers: Raytheon 254, British Aerospace 80, Raytheon Corporate Jets 40, Hawker Siddeley 11, Corporate Jets 8, Hawker Beechcraft 2

Models with the most aircraft:

- [Raytheon HAWKER 800XP](https://openairdocs.org/model/raytheon-hawker-800xp): 251 aircraft (airframe model)
- [British Aerospace BAE 125 SERIES 800A](https://openairdocs.org/model/british-aerospace-bae-125-series-800a): 61 aircraft (airframe model)
- [Raytheon Corporate Jets HAWKER 800XP](https://openairdocs.org/model/raytheon-corporate-jets-hawker-800xp): 23 aircraft (airframe model)
- [British Aerospace HS 125-700A](https://openairdocs.org/model/british-aerospace-hs-125-700a): 14 aircraft (airframe model)
- [Raytheon Corporate Jets HAWKER 800](https://openairdocs.org/model/raytheon-corporate-jets-hawker-800): 9 aircraft (airframe model)
- [Corporate Jets BAE 125-800A](https://openairdocs.org/model/corporate-jets-bae-125-800a): 8 aircraft (airframe model)
- [Raytheon Corporate Jets BAE 125-800A](https://openairdocs.org/model/raytheon-corporate-jets-bae-125-800a): 8 aircraft (airframe model)
- [Hawker Siddeley HS.125 SERIES 700A](https://openairdocs.org/model/hawker-siddeley-hs-125-series-700a): 7 aircraft (airframe model)
- [British Aerospace BAE 125-800A](https://openairdocs.org/model/british-aerospace-bae-125-800a): 5 aircraft (airframe model)
- [Hawker Siddeley BH.125-400A](https://openairdocs.org/model/hawker-siddeley-bh-125-400a): 2 aircraft (airframe model)
- [Hawker Siddeley DH.125-3A/RA](https://openairdocs.org/model/hawker-siddeley-dh-125-3a-ra): 2 aircraft (airframe model)
- [Raytheon BAE 125-800A](https://openairdocs.org/model/raytheon-bae-125-800a): 2 aircraft (airframe model)
- [Hawker Beechcraft HAWKER 800XP](https://openairdocs.org/model/hawker-beechcraft-hawker-800xp): 1 aircraft (airframe model)
- [Hawker Beechcraft BAE 125-800B](https://openairdocs.org/model/hawker-beechcraft-bae-125-800b): 1 aircraft (airframe model)
- [Raytheon HS 125-700A](https://openairdocs.org/model/raytheon-hs-125-700a): 1 aircraft (airframe model)

All 16 models: https://openairdocs.org/ad/2005-03-16/models.md
Every aircraft: https://openairdocs.org/ad/2005-03-16/aircraft.md

## Related documents

- [Proposed rule FAA-2004-19561](https://openairdocs.org/proposed/FAA-2004-19561): Notice of proposed rulemaking (NPRM), published Nov 10, 2004

Its text cites no advisory circulars or STCs.

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